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Objective The complex pore throat structure of tight sandstone leads to variable distribution of movable fluid, and the micropore structure and distribution characteristics of movable fluid are the focus of the study of tight sandstone reservoirs. Methods Based on the principle of the nuclear magnetic resonance (NMR) movable fluid test, the classification standard of pore structure of the He 8 reservoir in the Shenmu area was established using centrifugal test, high-pressure mercury injection, scanning electron microscope, X-ray diffraction and casting thin section. The pore structure parameters and pore throat types of the three types of rocks are defined, and a new method for measuring the conversion coefficient suitable for tight sandstone reservoirs was proposed. The distribution characteristics of movable fluid of three types of rocks were also quantitatively evaluated. Results The results reveal that the type Ⅰ and Ⅱ rock pores in the target reservoir are mainly residual intergranular pores with pore diameters greater than 10 μm and dissolution pores with pore diameters greater than 1 μm. The throats are mainly reduced and curved flaky throats, with good pore structure parameters, a high development degree of large pore space, good connectivity between pore throats, and a large amount of movable fluid.Most of the movable fluid occurs in the macropores corresponding to the right peak of the T2 spectrum, while the content of the movable fluid in the small pores corresponding to the left peak is low. The pore structure parameters of type Ⅲ rocks are poor, the percentage of movable fluid is low, and the pore throats are mainly intergranular pores and tube bundle throats. The average conversion coefficient of the target reservoir is 0.029 μm/ms, but the conversion coefficients of type Ⅰ and Ⅱ rocks are less than that of type Ⅲ rocks. The right peak of the T2 spectrum of type Ⅰ and Ⅱ rocks after conversion corresponds to the main peak of the mercury porosimetry pore radius distribution, while the left peak of the T2 spectrum of type Ⅲ rocks corresponds to the main peak of the distribution of mercury porosimetry pore radius. The percentage of movable fluid in the pores of type Ⅰ and type Ⅱ rocks with pore diameters greater than 1 μm is high, which is the main direction of exploration and development in the future. Conclusion The results provide a reference for improving the recovery of tight reservoirs.

This is an essay in the field of mineral processing engineering. Fluorite and calcite are calcium-bearing minerals with similar physical and chemical properties. Flotation separation of the two minerals has always been one of the difficult problems in the ore processing field. The effect of Fe3+ on flotation separation of fluorite and calcite in sodium silicate system and its mechanism was studied by flotation test, adsorption amount measurement, Zeta potential measurement and chemical calculation of flotation solution. The flotation test results show that, compared with sodium silicate, the addition of Fe3+ has a stronger inhibition effect on the flotation of calcite, but little effect on the flotation of fluorite, which can achieve the selective separation of the two minerals. The results of adsorption amount measurement, Zeta potential measurement and chemical calculation of flotation solution showed that after introducing Fe3+ into the sodium silicate system, Fe-(OH)X, Fe-sodium silicate polymer and Si(OH)4 were selectively adsorbed on the surface of calcite, which hindered the further adsorption of sodium oleate as collector, thus achieving the separation of fluorite and calcite.

This is an essay in the field of mineral processing engineering. In China, fluorite mainly exists in the form of concomitant deposits. In the flotation process, other useful minerals are usually preferentially floated, and a large amount of fluorite exists in tailings. In this paper, the restrained fluorite and calcite in the floating tungsten tailings are taken as objects, and ultrasonic wave is added to change the floatability of the two, so as to explore a method to optimize the comprehensive utilization level of fluorite in the floating tungsten tailings. After ultrasonic pretreatment of pulp inhibited by sodium humate for 39 min, the flotation recovery of fluorite reached 84.74%, while the flotation recovery of calcite was only 11.47%, with a difference of 73.27%. Exploring the mechanism of ultrasonic pretreatment, it is found that the absorption intensity of sodium humate on the surface of fluorite is lower than that of calcite in the infrared spectrum detection. Ultrasonic pretreatment can desorb the sodium humate on the surface of fluorite, increase the absorption amount of sodium oleate on the surface, and make the zeta potential move forward; In addition, ultrasonic pretreatment mainly affects the content of sodium humate on the mineral surface, but does not affect the content of sodium oleate on the mineral surface. If only sodium humate exists in the slurry system during ultrasonic pretreatment, the sodium humate desorption speed is faster, which is more conducive to adsorbing the sodium oleate added subsequently.

In recent years, drilling in Xinhe area on the southern slope of Kuqa Depression, Tarim Basin revealed that the Cretaceous Yageliemu Formation has active hydrocarbon display and high exploration potential in the field of stratigraphic-lithologic traps, which is an important direction for the next strategic breakthrough. Based on the core, well logs, drill cuttings and 3D seismic data, this paper integrated the analytical methods of core facies, electrofacies, wavelet transform, "impression method" paleogeomorphic restoring, seismic facies, seismic attributes, and coherence cube slicing to study the depositional system of the Cretaceous Yageliemu Formation in Xinhe area under the sequence stratigraphic and paleogeomorphic controls. The study shows that there are two types of paleogeomorphology developed in Xinhe area: (ⅰ) western multi-stage slope breaks, and (ⅱ) eastern thrust cliff paleogeomorphology. The Cretaceous Yageliemu Formation can be classified as a third-order sequence SQ1, which includes the lowstand systems tract (LST), transgressive systems tract (TST) and highstand systems tract (HST), corresponding to the three-phase seismic reflections of this formation overlying the western slope, respectively. The LST slope fans and HST fan deltas of the Yageliemu Formation were deposited above the western multi-stage slope breaks, and TST-HST subaqueous nearshore fans were deposited below the eastern thrust cliff, with erosional valleys on the cliff serving as the feeder channels and providing sources for the subaqueous fans. In situ mature hydrocarbon source rocks of the Triassic Karamay Formation are developed in Xinhe area, which is the migration direction of oil and gas far away from hydrocarbon source, indicating excellent source rocks and reservoir forming conditions. The stratigraphic-lithologic traps of the LST slope fan and TST-HST subaqueous nearshore fan located in the northern part of the thrust cliff are lying on the Triassic source rocks and have great exploration potential, which can serve as the main targets for the next subtle oil and gas exploration in this area.

Lithology recognition through artificial intelligence and big data can provide effective assistance to relevant personnel in field investigations.To better promote the application of lithology recognition in professional fields, the deep learning recognition of big data based on rock images were performed through the steps of rock image acquisition, data preprocessing, migration learning, network building, network training and model testing in the northern mountain area of Chaohu.Based on previous work, a multi-scale lithologic identification method is proposed. A multi-scale model is established and given a certain weight according to the rock meso image.The comprehensive results are obtained by identification with the rock identification model. The local texture, particle size and other mesoscale information were used in the overall identification of rock lithology.The results show that the multi-scale method is helpful to improve the identification results. The accuracy of the model is above 95%, which can well identify the rock lithology.

According to the latest three-dimensional seismic stratification data, the Triassic source rocks are recognized to be deeply buried on the southern slope of Kuqa Depression, Tarim Basin, making it possible to develop local source rocks. Based on geochemical data and basin simulation, the burial history, thermal history and maturity evolution history of Triassic source rocks in this area were simulated and analyzed. By discussing the thermal evolution and maturity process of source rocks, the maturity stage and hydrocarbon generation stage of source rocks were proposed and their reservoir forming significance was further discussed. The source rocks of the Triassic Karamay Formation are distributed on the southern slope of Kuqa Depression. The burial depth in the southern area of Xinhe is generally about 6 700 m, which tends gradually to deepen in the north and reaches themaximum depth over 8 000 m, showing an overall characteristics of "shallowly buried in the south and deeply buried in the north". The southern slope of Kuqa Depression has the same overall subsidence amplitude, which has experienced the tectonic evolution process of stable burial in the early stage, continuous subsidence in the middle stage and rapid burial in the late stage. During the Triassic period, the strata were deposited stably and the burial depth was small. From Cretaceous to Paleogene, continental clastic rocks were mainly deposited, and the strata continued to deposit. From Neogene to present, the southern slope of Kuqa Depression entered the stage of rapid thermal subsidence, and the burial depth reached the largest. The evolution degree of Triassic source rocks on the southern slope of Kuqa Depression is characterized by "high degree in the north and low degree in the south". The northern region matured early, which entered the hydrocarbon generation threshold at the beginning of Paleogene (Ro=0.5%), evolved to mature stage by the end of Paleogene (Ro=0.7%) and to high maturity stage in the middle Neogene (Ro=1.0%) and till now (Ro=1.30%), mainly generating gas. The southern region matured relatively late, which entered the oil window in the early Neogene, reached mature stage in the middle Neogene (Ro=0.7%), and till now (Ro=0.86%), mainly generating oil. There are two oil and gas transportation of far-source and near-source on the southern slope of Kuqa Depression, which provides sufficient sources for oil and gas accumulation. This area has the overall characteristics of dual source hydrocarbon supply.

In order to investigate the pore structures of the tight sandstone reservoirs in the 4+5th and 6th members of the Triassic Yanchang Formation (Chang4+5 and Chang6, respectively), and the 9th and 10th members of the Jurassic Yan'an Formation (Yan9 and Yan10, respectively) in the X block of Wuqi Oil Field, Ordos Basin, 12 samples were collected to analyze reservoir properties with the approaches of scanning electron microscope observation, X-ray diffraction and high pressure mercury intrusion. We also quantitatively characterized the pore parameter and fractal dimension of the tight sandstones by the using of digital image analysis and fractal geometry. In addition, we discussed the relationship between fractal dimension and sample properties (porosity, permeability), pore structure parameter (average pore-throat radius, sorting coefficient), pore geometric parameters (dominant pore size, perimeter over area, and pore body-to-throat ratio). The influence of sedimentary facies and diagenetic environment on pore structures were also quantitatively analyzed. Results show that the pore structure fractal dimension ranges from 2.164 to 2.895, with an average value of 2.395. Fractal dimension is negatively correlated to permeability, porosity and average pore-throat radius, and positively related to sorting coefficient. Tight sandstones in the study area generally show properties of low dominant pore size, high perimeter over area, lower body-to-throat ratio, and high dimensions. The fractal dimension is positively related to body-to-throat and perimeter-to-area ratio, and negatively related to pore size. It is indicated that the pore structure of the samples is relatively complex and has strong heterogeneity. Depositional environment affects the compositional maturity and structural maturity of reservoir.

The traditional reinforcement learning method has the problems of overestimation of value function and partial observability in the field of machine motion planning, especially in the obstacle avoidance problem of UAV, which lead to long training time and difficult convergence in the process of network training. This paper proposes an obstacle avoidance algorithm for UAVs based on a deep recurrent double Q network. By transforming the single-network structure into a dual-network structure, the optimal action selection and action value estimation are decoupled to reduce the overestimation of the value function. The fully connected layer introduces the GRU recurrent neural network module, and uses the GRU to process the time dimension information, enhance the analyzability of the real neural network, and improve the performance of the algorithm in some observable environments. On this basis, combining with the priority experience playback mechanism, the network convergence is accelerated. Finally, the original algorithm and the improved algorithm are tested in the simulation environment. The experimental results show that the algorithm has better performance in terms of training time, obstacle avoidance success rate and robustness.

Aiming at the problem that the traditional UAV obstacle avoidance algorithm needs to build offline three-dimensional maps, discontinuous speed control and limited speed direction selection, we study the end-to-end obstacle avoidance decision method of UAV continuous action output based on DDPG(deep deterministic policy gradient) deep reinforcement learning algorithm. Firstly, an end-to-end decision control model based on DDPG algorithm is established. The model can output continuous control variables, namely UAV obstacle avoidance actions, according to the continuous state information perceived. Secondly, the training verification is carried out on the platform of UE4 + Airsim. The results show that the model can realize the end-to-end UAV obstacle avoidance decision. Finally, the 3DVFH(three dimensional vector field histogram) obstacle avoidance algorithm model with the same data source is compared and analyzed. The experiment shows that DDPG algorithm has better optimization effect on the obstacle avoidance trajectory of UAV.

With the increase of the workload and complexity in the ultrasound department, scheduling is becoming more and more important. In order to improve the efficiency of scheduling, satisfaction of employees, and overall service satisfaction of the department, we developed the software system of integrated intelligent scheduling. Scientific, digital and intelligent scheduling can effectively optimize and integrate the human resources of the department, reduce the cost of staff management, enhance the management of operation, and improve medical practice, teaching, research and management.

Oxidative stress and inflammatory factors are closely related to keratoconus. As an important gene expression regulator, MiRNAs participate in the physiological and pathological process of keratoconus. In this study, in order to investigate whether MiRNAs can regulate the expression of matrix remodeling-related genes in keratoconus fibroblasts by targeting IL-1β, potential MiRNAs(miR-21-5p, miR-24-3p, miR-26b-3p, miR-27b-5p, miR-181d-5p, miR-383-3p, MiR-548d-3p, miR-4700-3p) that may be related to IL-1β targeting were predicated by using bioinformatics methods. Hydrogen peroxide was added to human keratoconic corneal fibroblasts in vitro. quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of MiRNAs and IL-1β mRNA at 0, 6, 12, and 24 h. IL-1β was found to be a target of MiR-548d-3p by using a dual luciferase reporter assay. After transfection of MiR-548d-3p mimics into human keratoconus fibroblasts, it was found that under oxidative stress, MiR-548d-3p mimics significantly down-regulated the gene expression of IL-1β, decreased the expression of MMP-1 and MMP-3, and increased the expression of collagenI-α2. These results indicate that MiR-548d-3p may promote corneal matrix synthesis and attenuate matrix degradation by down-regulating the expression of IL-1β, which retards keratoconus progression under oxidative stress. This might provide a new potential target for keratoconus treatment.

IL-8 is highly expressed in tears of keratoconus patients, but its mechanism is still unclear. Abnormal collagen synthesis and degradation are one of the pathogenesis of keratoconus. In this study, the effect of IL-8 on collagen synthesis in corneal fibroblasts and its molecular mechanism were discussed to provide reference for clarifying the pathogenesis of keratoconus. siRNA interference system was established and the expression of IL-8 in corneal fibroblasts was silenced by siRNA. The expression changes of genes related to collagen synthesis and degradation as well as other pro-inflammatory factors after IL-8 silence were analyzed by real-time fluorescent quantitative PCR. The content of total collagen and the activity of MMP-2 were detected by ELISA and gelatin zymography, respectively. Western blot was used to analyze the expression changes of the key proteins of related signal pathway. The results show that the total collagen content and the expression of collagen synthesis genes (COL1A2, COL3A1, COL5A3 and COL6A1) increased significantly after IL-8 silencing, while the expression and activity of MMP-2 which participated in collagen degradation decreased. In addition, silencing IL-8 reduced the gene expression of IL-6, IL-1β, and VEGFA/VEGFR2, as well as the protein expression of AKT and ERK1/2 in downstream signal pathway. IL-8 regulated the expression of VEGF and other pro-inflammatory factors. It negatively regulated the collagen synthesis and participated in MMP-2 mediated collagen degradation in corneal fibroblasts through PI3K/AKT and ERK signaling pathways.

The lacustrine shale in the lower part of the third member of Shahejie Formation (Es3) in well L69 in the Zhanhua Sag of Bohai Bay Basin was studied. The geochemical characteristics of lacustrine shale in different system tracts were analyzed in a framework of sequence stratigraphy. The evolution process of sedimentary environment and the enrichment mechanism of organic matter were clarified, which provided theoretical support for the identification of favorable targets of unconventional shale oil. The combination of logging and lithology reveals that the sequence of the lower Es3 can be divided into transgression, early highstand and late highstand system tracts from bottom to top. Productivity and preservation conditions are the controlling factors of organic matter enrichment. The higher productivity and better preservation conditions together determine that the early highstand system tract is the most favorable organic matter accumulation interval, which provides a good material basis for a good shale oil development target.

A coordination strategy was proposed to smooth the tie-line power fluctuation of the combined heating and power integrated energy system (CMPIES) by using the virtual energy storage system. The structure and energy coupling mode of the CMPIES were analyzed. The controllable devices in CMPIES include micro-gas turbines, heat pumps, batteries and super capacitors. Virtual energy storage system is a thermal model based on utilizing the heat storage characteristics of building. Considering the controllable devices and the virtual energy storage system state index, weighted moving average filtering algorithm was used to optimize the tie-line reference power. The coordination strategy designs state map table to regulate the filter time constant based on the operation state of the controllable devices. The output of controllable devices is adjusted by the correction factor calculated by the state map table. The proposed strategy was validated by the field data from Green Energy University Laboratory in China. The simulation shows the strategy realizes the coupling and coordination between power and heat, ensures the power fluctuation smoothing effect and enhance the CMPIES control flexibility. At the same time, the comfort of the customers participating in the CMPIES can be maintained. The coordination strategy is able to enhance the penetration and consummation of distribution renewable energies and prolong the controllable devices' life.

In order to analyze the effect of final cooling temperature on the wax deposition laws of the crude oil modified with additives, keep the same temperature difference of oil wall and control different final cooling temperatures, static wax deposition contrast test and dynamic shear contrast test were carried out on Daqing oil with nano pour point depressant, Daqing oil with EVA pour point depressant and Daqing blank oil using the wax deposition device of agitation tank, rheometer, differential scanning calorimeter and other test instruments. Then, based on the mechanisms of molecular diffusion and gelling, the wax deposition laws of Daqing oil modified with additives under different experimental conditions were investigated. It is shown that when the final cooling temperature is lower, the blank oil is low in the total wax deposition but its wax crystal structure is stronger; while the oil with additives is significantly higher than the blank oil in the total wax deposition, but there is more condensate in the total amount of wax deposition and the wax crystal structure is weaker. With the increase of the final cooling temperature, the wax deposition in the oil with additives and that in the blank oil decrease gradually and tend to be consistent. When the final cooling temperature is lower and the shear peel strength is weaker, the addition of pour point depressant can increase the wax deposition of pipeline transportation. And once the shear is high or the final cooling temperature is increased, the wax deposition of the oil with additives will be reduced significantly and the safety of pipeline transportation will be improved.

In order to study internel axiomatic systems and ordered features of Alexandrov spaces, with the help of some existed results in topology and locale theory, by restricting the related structures into Alexandrov setting, some equivalent descriptions are obtained. The results show that Alexandrov spaces are categorically isomorphic to Alexandrov neighborhood systems, Alexandrov closure operators, Alexandrov interior operators and Alexandrov derived operators; T0 Alexandrov spaces are isomorphic to posets and dual to complete-generated lattices. Alexandrov spaces can be completely characterized by neighborhood systems, closure operators, interior operators, derived system, the specialization order and the point-free order.

Based on the topological sum, for X being a discrete topological space, we prove that the product topology generated by some topological spaces is equal to the topology of pointwise convergence related to X. For every topology on a Cartesian product, we find an equivalent condition under which every projection from the product to each component is continuous. We propose the definition of functional product spaces, which can be considered as a common framework of the product spaces, the topological sums and the functional spaces (the topology of pointwise convergence).

Objective To explore the current dietary patterns of different obesity metabolic phenotypes in the middle-aged and elderly population in Sichuan area. Methods From the baseline survey of the Natural Population Health Cohort Study at West China Hospital, Sichuan University from 2019-2021, 15 160 eligible middle-aged and older adults were screened out, and then based on their obesity metabolic phenotypes, they were divided into metabolic healthy non-obesity (MHNO), metabolic unhealthy non-obesity (MUNO), metabolic healthy obesity (MHO) and metabolic unhealthy obesity (MUO) groups. Dietary survey was conducted by food frequency questionnaire. The dietary pattern was extracted by principal component analysis. ANOVA was performed to compare the differences in energy and nutrients among the participants with different dietary patterns. Chi-square test was used to compare the distribution of dietary patterns among people with different obese metabolic phenotypes, and stratified analysis was performed by gender and age groups. Results Among the 15 160 middle-aged and elderly participants in Sichuan area, there were 8 340 (55.0%) in the MHNO group, 4 789 (31.6%) in the MUNO group, 763 (5.0%) in the MHO group, and 1 268 (8.4%) in the MUO group. The dietary patterns of these participants mainly consisted of following 4 types: legumes and fruits (22.5%), rice, flour and pickled products (25.5%), offal and drinks (21.1%) and egg and milk (30.9%). The dietary patterns of the different obesity metabolic phenotypes were distributed as follows: the MHNO, MUNO and MHO groups had a predominantly egg and milk diet, while the MUO group had a predominantly rice, flour and pickled products diet. There were statistical differences in the distributions of dietary patterns among different obesity metabolic phenotypes (P < 0.05): the dietary patterns of rice, flour and pickled products accounted for the following percentages among different obesity metabolic phenotypes: MUO>MUNO>MHNO; the dietary patterns of egg and milk were lower in the MUO group than in the MHNO and MUNO groups. The distribution of dietary patterns for the metabolic phenotypes of obesity was statistically different in all age groups of women(P < 0.05). For the women aged 45- < 60 years, the distribution of dietary patterns of obesity metabolic phenotypes was similar to that found in the total population. For the women aged ≥60 years, the offal and drinks dietary pattern was more common in the MUO group than the MHNO and MUNO groups. Conclusion There are differences in the distribution of dietary patterns among middle-aged and elderly people with different obesity metabolic phenotypes in Sichuan area. It is recommended that the MUO people should reduce the intake of rice, flour and pickled products and increase the intake of eggs and milk in their daily diet. In addition, for the female MUO people ≥60 years of age, the intake of offal and beverages should be reduced appropriately.

Stir-frying with oil is a typical cooking method of Chinses cuisine. Using astir-frying cooking simulation device, the key temperature range for cooking pork liver from raw to cooked was selected. Combined with the kinetic method, the reaction kinetics of the quality factors of cooked pork liver (color and shear force) and overheated pork liver (cooking loss) were determined and analyzed. The results revealed that the changes of color, shear force and cooking loss of pork liver during stir-frying with oil followed first-order kinetics model. Meanwhile, the z-values of brightness (L*), redness (a*) and whiteness (W) were 19.53 °C, 20.61 °C and 20.20 °C, and the corresponding Ea values were 116.67 kJ/mol, 110.40 kJ/mol and 112.75 kJ/mol; the z value of shear force change was 14.16 °C with the Ea value being 160.77 kJ/mol; the z value of the overheating quality factor, cooking loss, was 30.12 °C (which was higher than the z value of cooked liver), with the Ea being 75.63 kJ/mol. These results meet the optimization prerequisites of the cooking sufficiency theory, which proves that there's room for optimization of the cooking process. This study provides the necessary kinetic parameters for research on the stir-frying pork liver with oil and quality optimization. [ABSTRACT FROM AUTHOR]

Maximum Entropy (MaxEnt) model has been widely used in recent years. However, MaxEnt is highly inclined to produce misleading results if it is not well optimized. We summarized the researches about the model optimization for sampling bias correction, model complexity tuning, presence-absence threshold selection, and model evaluation. Spatial filtering performs best for sampling bias correction, while restricted background method shows the lowest efficacy. Model complexity is mainly determined by three factors; The number of environmental variables, model feature types, and regularization multiplier. Variables filtering is needed when sample size is less than the number of environment variables. The criterion of variables selection should focus on their ecological significance rather than the co-linearity between them. The choice of feature types has relatively limited effects on predictive performance of the model, therefore it is advised to choose simpler models. To control overfitting, it is necessary to conduct species-specific tuning on regularization multiplier, which was usually bigger than the default setting. There are three criteria called objectivity, equality and discriminability for selecting threshold to convert continuous predication (e. g. probability of presence) into binary results. Maximizing the sum of sensitivity and specificity is a sound method for threshold selection. Model evaluation methods could be classified into two main types; Threshold independent and threshold-dependent. Among the threshold-independent evaluations, information criteria may offer significant advantages over AUC and COR. True Skill Statistics is a better index for threshold-dependent evaluations, because it takes both omission and commission errors into account, and is robust to pseudo-absence assumption and species prevalence. [ABSTRACT FROM AUTHOR]

High strength and low density are the basic requirements for the materials used in the aeronautical field, the engine materials need high temperatures resistance more severely. High entropy alloys (HEAs) containing refractory metal elements with high melting point show excellent material properties at high temperature. At present, more than 120 kinds of refractory high entropy alloys (RHEAs) have been synthesized, and their physical and mechanical properties, such as density, tensile properties, compression properties, elastic modulus and antioxidant properties have been tested experimentally. In this paper, the performance parameters of refractory high entropy alloys and traditional typical aviation materials are summarized, and the density and yield strength limits of refractory high entropy alloys at high temperature are compared, most refractory high entropy alloys show high mechanical strength and microstructure stability.

Six compounds were made hy chemical synthesis or semi-preparative HPLC separation for azithromycin to promote quality and impurity control. They are erythromycin A 6, 9-imino ether, erythromycin A 9, 11-imino ether, 3 -N-demethyl azithromycin, 3 -N-[[4-(acetylamino) phenyl ] sulphonyl ]-3 -N-demethyl azithromycin, 3-decladinosylazithromycin and 12- dedeoxyazithromycin (azithromycin B) , which were ohtained through chemical synthesis or semipreparative HPLC separation. Their structures are identified hy MS, 'H NMR and "C NMR, The source and control methods of these impurities are also presented to improve azithromycin production process. [ABSTRACT FROM AUTHOR]

An objective method for evaluating the quality of streaming audio called perceptual evaluation of streaming audio quality(PESAQ) was presented. PESAQ firstly removed the jitters in the streaming audio by an alignment algorithm. Secondly, the degradation between reference audio and the aligned streaming audio was measured by perceptual evaluation of audio quality (PEAQ), and the result was called objective difference grade (ODG). Thirdly, the degradation caused by jitters were measured by the dynamic time warping(DTW) minimum distance, and the result was called DTW-ODG. Finally, the quality of the streaming audio was derived by summing ODG and DTW-ODG. The experiment results prove that PESAQ provides closer results to the subjective results than PEAQ for streaming audio quality evaluation. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy and efficiency of predictive modeling of the starch content of Huangshui, a byproduct of Baijiu production by solid-state fermentation, spectral information of Huangshui was collected using a Fourier transform near-infrared (FTIR) spectrometer and preprocessed by first derivative. Based on the preprocessed spectra, a predictive model for the starch content of Huangshui was developed using partial least squares regression (PLSR), and its performance was evaluated by determination coefficient (R2) and root mean square error of prediction (RMSEP). As the original spectra contained a lot of redundant information, in order to effectively improve the detection accuracy and to optimize the modeling efficiency, the advantages of different feature extraction methods were combined. Finally, it was found that the PLSR model established by using the spectral features extracted by competitive adaptive reweighted sampling (CARS) combined with the successive projections algorithm (SPA) was significantly better than the model built without feature extraction or using single feature extraction. The results showed that the R2 and RMSEP of the model established using CARS were 0.965 4 and 0.201 2%, while those obtained using CARS-SPA were 0.973 8 and 0.174 8%, respectively. The spectral dimension reduced from 2 203 to 126 after the combination of CARS with SPA, which improved both the prediction accuracy and the modeling efficiency. The method proposed in this study provides an effective means to optimize near-infrared spectral quantitative modeling of starch in Huangshui.

Digital intraoral scanning is a hot topic in the field of oral digital technology. In recent years, digital intraoral scanning has gradually become the mainstream technology in orthodontics, prosthodontics, and implant dentistry. The precision of digital intraoral scanning and the accuracy and stitching of data collection are the keys to the success of the impression. However, the operators are less familiar with the intraoral scanning characteristics, imaging processing, operator scanning method, oral tissue specificity of the scanned object, and restoration design. Thus far, no unified standard and consensus on digital intraoral scanning technology has been achieved at home or abroad. To deal with the problems encountered in oral scanning and improve the quality of digital scanning, we collected common expert opinions and sought to expound the causes of scanning errors and countermeasures by summarizing the existing evidence. We also describe the scanning strategies under different oral impression requirements. The expert consensus is that due to various factors affecting the accuracy of digital intraoral scanning and the reproducibility of scanned images, adopting the correct scanning trajectory can shorten clinical operation time and improve scanning accuracy. The scanning trajectories mainly include the E-shaped, segmented, and S-shaped methods. When performing fixed denture restoration, it is recommended to first scan the abutment and adjacent teeth. When performing fixed denture restoration, it is recommended to scan the abutment and adjacent teeth first. Then the cavity in the abutment area is excavated. Lastly, the cavity gap was scanned after completing the abutment preparation. This method not only meets clinical needs but also achieves the most reliable accuracy. When performing full denture restoration in edentulous jaws, setting markers on the mucosal tissue at the bottom of the alveolar ridge, simultaneously capturing images of the vestibular area, using different types of scanning paths such as Z-shaped, S-shaped, buccal-palatal and palatal-buccal pathways, segmented scanning of dental arches, and other strategies can reduce scanning errors and improve image stitching and overlap. For implant restoration, when a single crown restoration is supported by implants and a small span upper structure restoration, it is recommended to first pre-scan the required dental arch. Then the cavity in the abutment area is excavated. Lastly, scanning the cavity gap after installing the implant scanning rod. When repairing a bone level implant crown, an improved indirect scanning method can be used. The scanning process includes three steps: First, the temporary restoration, adjacent teeth, and gingival tissue in the mouth are scanned; second, the entire dental arch is scanned after installing a standard scanning rod on the implant; and third, the temporary restoration outside the mouth is scanned to obtain the three-dimensional shape of the gingival contour of the implant neck, thereby increasing the stability of soft tissue scanning around the implant and improving scanning restoration. For dental implant fixed bridge repair with missing teeth, the mobility of the mucosa increases the difficulty of scanning, making it difficult for scanners to distinguish scanning rods of the same shape and size, which can easily cause image stacking errors. Higher accuracy of digital implant impressions can be achieved by changing the geometric shape of the scanning rods to change the optical curvature radius. The consensus confirms that as the range of scanned dental arches and the number of data concatenations increases, the scanning accuracy decreases accordingly, especially when performing full mouth implant restoration impressions. The difficulty of image stitching processing can easily be increased by the presence of unstable and uneven mucosal morphology inside the mouth and the lack of relatively obvious and fixed reference objects, which results in insufficient accuracy. When designing restorations of this type, it is advisable to carefully choose digital intraoral scanning methods to obtain model data. It is not recommended to use digital impressions when there are more than five missing teeth.

In order to develop new barbecued pork products from Mountain Black pigs, this study investigated the effects of low-temperature vacuum tumbling (LVT), ultrasonic (U) curing and their combination (U/LVT) on the properties of myofibrillar proteins (MPs) and the eating quality of barbecued pork from Mountain Black pigs, and it also explored the intrinsic mechanism of the effect of curing method on the eating quality of barbecued pork. The results showed that MPs in the U/LVT group had higher solubility and free sulfhydryl group content, lower surface hydrophobicity and hydrogen bond content, and higher fluorescence intensity than the LVT and U groups. The results of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that MPs in the U/LVT group were decomposed into more small-molecule peptides. The highest marinade uptake and the lowest cooking loss and shear force were observed in the U group, while the U/LVT group had the highest total sensory score with better taste and flavor (P < 0.05). In conclusion, U/LVT marination can significantly affect MPs characteristics and improve the eating quality of barbecued pork from Mountain Black pigs.

Aimed at the impact of extreme weather on the stable operation of microgrid, an optimal configuration strategy of microgrid based on fuzzy scene clustering is proposed. Using historical weather data, a fuzzy scene clustering method is used to deal with the problem of new energy output fluctuations caused by random weather on the source side, and a robust optimization model is established on the load side to deal with load fluctuations within a certain range. Using scenes of 8 760 hours in a year, typical scenes and extreme scenes are obtained by distinguishing the unique membership characteristics of fuzzy scene clusters. Considering the impact of extreme scenarios on the optimal configuration of the microgrid, a two-stage robust model with the smallest comprehensive cost is established, which is decomposed by the column and constraint method, and is finally solved iteratively by Cplex solver. The effectiveness and feasibility of the proposed optimal configuration strategy are verified by simulation analysis.

Research in the field of oil and gas development has focused on the production of unconventional reservoirs all over the world. Unconventional oil and gas reservoirs have poor flow conditions, and the interaction of flow, stress, and temperature fields is very complex. Therefore, multiphysical field coupling is essential. The previous application of multiphysical field coupling theory has defects such as oversimplification and inadequate adaptability. Furthermore, the lack of adaptive production practices and effective development plans limits large-scale and efficient development, and there is an urgent necessity to investigate the adaptive multiphysical field coupling theory. Currently, the core rheology in fluid–solid coupling settings can often be measured by a triaxial test system under high temperature and pressure conditions combined with flow experiments. Moreover, the changes in pores and fractures can be tested by micro-CT and SEM. In addition, adsorption is considered an exothermic process, and desorption is deemed a heat-absorbing process, so the reservoir temperature decreases at the location where desorption occurs. Therefore, the production of unconventional oil and gas triggers a series of interactions. As the fluid flows into the wellbore through the fractures, the pressure drop increases the effective stress, decreasing the average pore radius and altering the inherent permeability. Moreover, the change of pressure causes a variation in the micro-flow effect, significantly impacting the apparent permeability, and the heat variation during desorption and adsorption also changes the flow condition as well as the physical properties of the fluid. As a result, these physical fields are closely related. A series of fully coupled partial differential equations are necessary to define the production process by modeling the dynamic porosity and permeability in various flow sectors to distinguish the interactions between different zones and physical fields. These complex interactions generally need to be solved by numerical methods. Thus, a simulator is needed that satisfies the accuracy requirements to match the actual situation. Moreover, adaptability to the decoupling process and acceptable speed requires research for high-performance computing solutions that can perform distributed or cloud computing for a large-scale unconventional reservoir simulation. Future research is necessary for laboratory measurements under realistic stress and temperature environmental conditions of the formation and hydrocarbon adsorption experiments. There should be further understanding of scientific issues such as the plastic strain of the porous rocks, changing stress environment after refracturing, and mixed hydrocarbon transport models with varying stress and temperature. This article further clarifies the dynamics and determines effective production methods of unconventional reservoirs in China to promote the development of flow mechanics.

The existing theory of multiphase seepage can neither explain the cause of the discontinuous phase near the end of relative permeability nor consider the complex flow of multiphase mixing, interface interaction, and mass transfer between phases. In this paper, all phases in pores were treated as a mixed fluid of one phase to investigate multiphase seepage characteristics. Multiphase fluid transport in porous media was studied, including phase dissolution, phase interface change, phase mass transfer, and mixed phases. The exchange relation and flow mechanism of multiphase fluid in porous media, i.e., the law of multiphase mixed flow, are clarified. On the basis of the first and second laws of thermodynamics, the framework of the thermodynamic equilibrium relations of a multiphase system was constructed considering phase equilibria during the seepage process. Consequently, a theoretical model of multiphase mixed seepage was established by combining the multiphase mass conservation and multiphase equilibrium thermodynamics equations in the seepage period, which leads to the proposed mixed seepage theory that this paper focuses on. Then, the similarities and differences between conventional multiphase seepage theory and mixed seepage theory were discussed and described comparatively. The analysis and results indicate that the overall velocity of a multiphase system is positively correlated with the pressure gradient, as well as an outcome of the seepage mixing degree defined as a function of saturation, interfacial tension, pressure gradient, and porosity. Additionally, the seepage mixing degree is the product of the mixed seepage coefficient, which reflects the interaction between phases, and the mobility. Defining the seepage mixing degree can convert the motion equation of mixed seepage into a form similar to the generalized Darcy's law, reflecting the fundamental distinction between these two theories. A multiphase system is considered to comprise continuous phases in conventional multiphase seepage theory. However, the fluid phase can be discontinuous and dispersed in other phases. Furthermore, the quantitative relation between total pressure and phase pressure cannot be directly determined, so the capillary force is ignored in many cases. The treatment of these problems is where the limitation of conventional multiphase seepage theory and the comparative superiority of mixed seepage theory lie. Subsequently, a classic case of oil–water two-phase seepage was examined to validate the practicability and adaptability of mixed seepage theory. It can be derived that the multiphase permeability item related to saturation is a simplified form of the seepage mixing degree. The results illustrate that mixed seepage theory reflects the intrinsic features of multiphase seepage and reveals the inner rules of the phase mixing flow process. This theoretical work remedies the conventional approach of extending single-phase Darcy's law to multiphase cases and addresses the deficiency in the generalized Darcy's law by introducing the overall effect to accurately explain the migration of coupling phases, which is of substantial theoretical significance and practical implications.

Porous media are widely found in underground rocks, biomimetic, and engineering materials. However, the current flow theory of fluids (liquid and gas, etc.) is incomplete to study flows in small and complex pores, thus a new theory is urgently needed for studying a large number of fluid flows in porous media. The theory of meso-scale flow in porous media is a “mysterious key” to unlock the flow of nano-micron porous media. At present, a large number of fluid flow problems need an immediate solution in porous media such as shale oil and gas development, soil seepage, human capillary network, and carbon nanotube (CNT). With the advancement of world petroleum engineering technology, unconventional oil and gas reservoirs have become the main areas of development in the petroleum industry. There are a large number of nano-scale pores in unconventional oil and gas reservoirs, and the existing macro-statistical methods of Darcy and non-Darcy percolation cannot reveal the nonlinear flow mechanism and effective production mechanism of fluid in mesopores. Thus, it is urgent to carry out theoretical research on meso-flow in porous media to provide a theoretical basis for unconventional oil and gas development. This paper summarizes the research results in this area, including those of the authors. The current research status of fine and meso flow in porous media is summarized from three aspects: (1) theoretical analysis, (2) experimental research, and (3) numerical model, focusing on key issues such as the relationship and characterization of meso-scale fluid flow interface and micro-mechanical properties, meso–macro network simulation, meso-scale fluid (oil/water, gas/water) flow, meso-dynamic mechanism, and mathematical models. On this basis, the importance of the research on the interface effect and meso-mechanical characteristics of fine and micro-scale fluid flow, the nonlinear flow mechanism of the fine and meso-scale fluids, the construction of a mathematical model reflecting the meso-scale flow under the action of micro-forces, and the formation of a network simulation method are introduced. The study provides certain guiding significance for unconventional oil and gas development processes, revealing the meso-causes affecting flow, clarifying the production mechanism under different conditions, and promoting further development of the discipline of seepage mechanics.

The shale gas reservoirs in China are unconventional gas reservoirs that have been developed with volumetric fracturing engineering technologies to achieve effective production. However, shale reservoirs differ from conventional reservoirs in that they have widely distributed nanoscale pores, low porosity and permeability, and widely distributed microfractures. Shale reservoirs have various gas flow mechanisms, including desorption, diffusion, slippage, and seepage, which result in a cross-scale and multifluid coexistence flow through matrix microfractures and artificial fractures. Conventional oil and gas development theories and technologies are not directly applicable to shale gas reservoirs. Therefore, to establish shale development theories and technologies and realize the efficient development of shale gas reservoirs in China, targeted research is required. This article summarized the basic laws of shale gas flow, the multifluid, multiscale, and multifield coupled transport mechanism and porous flow laws of shale gas flow, and the multiscale and nonlinear unified flow equation based on desorption, diffusion, slippage, and porous flow. The full multiscale flow pattern was also provided. The multizone and multifield coupling nonlinear porous flow theories for multistage fractured horizontal shale gas wells were established to detect the production range and development dynamics of flow field zone reserves in shale gas reservoirs. A production decline model for shale gas production was developed based on the characteristics of China's shale gas reservoirs. Based on the abovementioned theory, development design methods and classification and optimization target evaluation methods that are suitable for China's shale gas reservoirs have been proposed. The progress of the adaptability technology for China's shale gas fracturing development process was summarized. The future developmental direction of efficient shale gas development theory was forecasted on this basis to provide guidance for shale gas theory and technology research in China.

Objective To evaluate the use of online self-learning application(APP) for precision teaching in joint diagnostic ultrasound. Methods Twelve sonographers were divided into three groups(4 in each) based on their experience in ultrasound diagnosis. At first, all of them were approached to the training courses in self-learning APP to study “the joint diagnostic ultrasound scoring system”. After that, they were admitted to “the ultrasound images assessment platform” in-APP to perform the ultrasound score on 140 small joints with inflammatory rheumatic diseases. The overall agreement rate(%) and intraclass correlation coefficients(ICC) values were calculated to analyze the assessment results among the three groups(%/ICC). A questionnaire survey was also administered at the end of the study via the APP to determine the ease of use of self-learning APP. Results A good interobserver agreement was reached among the three groups(65.2%～67.7%/0.49～0.97). In detail, the best interobserver results were found for the detection of Power Doppler Ultrasound(PDUS) synovitis(74.40%～81.70%/0.91～0.94) and tenosynovitis/paratenonitis in all joints(87.50%～93.80%/0.97～0.98). Good ICC values was found for the detection of Grayscale Ultrasound(GSUS) synovitis, but the agreement rate in this region was poor(45.10%～47.80%/0.58～0.74). For the presence or absence of erosions, moderate agreement rate was calculated, however, the ICC values among the three groups were poor(66.70%～77.80%/0.44～0.58). Regarding agreements in the finger joint regions, lower agreement results were found in both of MCP3(61.1%～71.3%) and PIP2/3 joints(57.4%～63.9%), and a variable agreement rates were found for wrist joints (64%～80%). The majority of survey respondents indicated favorable receptivity to the online self-learning APP(75%) including finding it helpful to improve the learning efficiency and interests (91.7%). Furthermore, a more accurate definition about the joint ultrasound score, standardization of image acquisition and adequate dynamic ultrasonography were advised to further improve interobserver agreements. Conclusions The online self-learning APP can be used as an effective tool in joint ultrasound training. A detailed analysis of the assessment results based on the feedback information from the trainees can help to further optimize and improve the teaching process to realize the precision teaching in joint diagnostic ultrasound.

Shale gas is a type of unconventional natural gas that can be accumulated in a large area in tight shale and has self-generation and self-storage abilities. The low porosity and low permeability characteristics of shale make its development under natural conditions poor, and large-scale stimulations of its production are needed to achieve economic benefits. Due to the complex geological tectonic conditions in China, three types of organic-rich shale strata, namely, marine facies, marine-continental facies, and continental facies, are developed during the multicycle tectonic evolution. China has made important breakthroughs in the exploration and development of marine shale gas. Considerable effort has also been invested in the exploration of continental shale gas. The exploration and research of marine-continental transitional shale have gradually attracted people’s attention. Marine-continental transitional shales are of importance to the shale gas field. However, research on transitional shale gas exploitation is still in its infancy, and this topic needs to be urgently discussed and solved. Shale gas exploitation seriously restricts the development level of shale gas in China. The shale gas in the Zhongmou Block of the southern North China Basin is a typical representative of marine-continental transitional shale gas, with good gas resources and development prospects. In this study, based on a geologic model, the influences of different reservoir parameters on oil recovery, daily gas production, and cumulative gas production were examined through the integration of theoretical analyses and numerical simulations. The main factors affecting the gas production capacity of shale were determined by an orthogonal design and multi-index analysis. Considering the relationship between main control factors and shale gas production capacity, the cumulative gas production and shale gas recovery equations under the horizontal fracturing condition were established. For the target fracturing zones, the shale gas productions under different fracturing parameters were compared and analyzed, which shows that the horizontal length and producing degree are the main parameters that determine the production capacity. In a certain fracturing condition, the increase in fracture length can effectively communicate natural cracks, thereby increasing production capacity. Taking a net present value greater than 0 and a yield rate ranging from 8% to 12% as the economic evaluation indices, three types of fracturing parameters are optimized for the marine-continental transitional shales.

Proppant injection during hydraulic fracturing is to prevent the closure of hydraulic fractures. As a result, the distribution of proppant in the fracture impact the productivity to a great extent. In order to study the rule of proppant transportation and distribution in complex fracture network, and the influence of uneven proppant distribution on the exploitation dynamic characteristics, a full-coupled 3D finite element method calculation model for tight oil reservoir considering sand injection during hydraulic fracturing was established, based on several mathematical models proposed by the author in the past. In the model, a mixture model was utilized, which had advantages to deal with two-phase flow containing solid particles in dispersed phase, to simulate the proppant transportation process in fracture networks. Then, a tight oil reservoir model was established to evaluate the effect of the proppant distribution on the reservoir performance. The calculation results show that in the fracture network, proppant particles will accumulate at the fracture intersection, and the proppant concentration is higher than other parts of the fracture network. The height of proppant settlement dune in the secondary fracture is 25%–50% lower than that in the main fracture, and the communication of secondary fractures has enhanced the proppant settlement degree. Moreover, factors like injection velocity, proppant materials and proppant size are proved to have a strong relation to the average conductivity of fracture network, which could impact the fracture design considerably. Furthermore, the uneven distribution of proppant in fracture network has a great influence on the simulation results. When the reservoir permeability reaches 0.05 mD, the calculation results show that the height, without considering the uneven distribution, of proppant settlement is 41.7% higher than the actual value. Therefore, the uneven distribution of proppant cannot be ignored in the simulation of low permeability reservoir. However, when the matrix permeability is 5 mD, the difference between the actual and simulated result will be within 5%. Thus, it is reasonable to neglect the uneven distribution of proppant in estimations.

Shale gas reservoirs are extremely tight, their pores are mainly nano-micron size, and their gas flow resistance is greater than that of conventional gases. Thus, the flow with low-velocity non-Darcy seepage characteristics of diffusion, slippage, and desorption needs to be solved. Moreover, the fractured reservoir has a complicated structure of pores and fractures, which causes the problem of multi-scale flow. The pressure disturbance propagates over time and does not instantaneously reach infinity. Another problem is that the moving boundary pressure disturbance of unstable seepage propagates slowly with time. Based on the above issues, in this paper, the permeability model of fractal distribution and Gaussian distribution was obtained to describe the different fracturing characteristics. Using the method of successive replacements of steady states and considering desorption, diffusion, and slippage, the mathematical model of unstable flowing pressure disturbance in a multistage fractured horizontal well was established. The moving characteristics of the different fractured conditions were compared and analyzed. The research shows that the pressure moving boundary increases with time, and the lower the permeability, the slower the pressure boundary moves. In general, the shale gas reservoir pressure propagates slowly, the natural productivity of the gas well is low, and the velocity of the pressure moving boundary of the matrix reservoir is less than the fractal distribution of the fractured reservoir and less than the Gaussian distribution of the fractured reservoir. Thus, it is necessary to carry out the large-scale fracturing treatment and reasonable control of the fracturing degree to improve the permeability as well as the development effect. When the production time is 6000 days, based on the moving boundary of the fractured horizontal well, the horizontal section length was optimized to 90 m. The optimum well distance of the well with fractal distribution permeability was 318 m, while the well with Gaussian distribution permeability was 252 m. Thus, the fracture treatment scale should be reasonably controlled to achieve optimal production and high yield.

With the development of liquid production and molecular synthesis technology, the application of soft particle solutions has become increasingly widespread. Soft particle solutions are also used in oil exploitation technology. The soft particles can be elastically deformed through the pores, and the whole process produces a resistance effect on flow. After breaking through the tunnel, the original shape is restored and continuously moved to the deep part of the oil layer. The soft particles do not only block the porous medium but also increase flow resistance. Moreover, they can generate deformation and break through the pores under a certain pressure to reach the depth of the reservoir. The microscopic forces mainly include Van der Waals force, electrostatic force, spatial configuration force, and surface tension. The effect of the spatial configuration force caused by the deformation of the soft particles affected by the tube wall action is considered to address the problem that micron-sized soft particle solutions in microtube deviate from the Poiseuille law. On the basis of Navier-Stokes theory, the flow velocity distribution and flow expression of the polymer solution in the tube were derived. A particle deformation factor was introduced to characterize the effect of the spatial configuration force. A mathematical model of microtube flow was established by considering the spatial configuration force. From the micro-scale flow characteristics experiment, the microtube flow in micron-sized soft particle solution was obtained. As evidenced by the results, when the tube diameter is smaller than the particle diameter, the flow velocity considering the spatial configuration force is closer to the experimental data than the Poiseuille flow under the same pressure gradient. Through the analysis of influencing factors, the spatial configuration force cannot be neglected in the microtube flow. Compared with the Poiseuille flow, the spatial configuration force increases and affects the microtube flow when the microtube size decreases. When the particles are non-spherical and the minimum projected area is the same, the greater the degree of deviation from the spherical particles and the greater the effect of the spatial configuration force.

The exploration and development of unconventional oil and gas become the hotspot in worldwide petroleum industry at present and in the future time. The unconventional resources are the succession and growth of conventional oil and gas production. Mineral resource investigations reveal that tight oil reservoirs in China contain highly geological and recoverable reserves, effective development of which is of great significance but restricted by poor reservoir physical properties and complex oil-water distribution. After decades of exploration and development, low and ultra-low permeability reservoirs have been successfully developed. However, development patterns and flow mechanisms suitable for tight oil are still insufficient, and the field application is far from mature yet. This study first summarized the resource distribution, geological characteristics, exploration, and development status of tight oil reservoirs in China. Then, development patterns and corresponding fundamental scientific issues of tight oil reservoirs were discussed. Corresponding nonlinear flow laws, mathematical flow models of multi-field and multiscale related to different exploitation patterns and scientific issues were summarized. Related study results of the authors were also introduced. Finally, a future development trend was proposed for each aspect. We hope that this study will provide some guiding to promote the tight oil exploration in China.

A dual-porosity medium with micro-fractured spherical matrix blocks was achieved on the basis of the structure characteristics of nano-micro pores and micro-fractures in shale gas reservoirs. The Laplace space solution of the dimensionless bottom hole pressure of fractured well production was obtained in consideration of the seepage,diffusion and desorption mechanism of shale gas and applying the Laplace transform and the Stehfest numerical inversion. Type curves of dimensionless production were plotted and the influencing factors of the type curves were identified. The results show that the matrix surface improves gas transfer from the matrix medium to the fracture network due to matrix micro fractures. Increasing the permeability and length of micro fractures accelerate the productivity significantly.

Objectives: To observe the effect of heat-reinforcing needling (HRN) on synovial inflammation, hypoxia-inducible factor-1α (HIF-1α) and glycolytic activity in serum and synovial tissue in rabbits with cold syndrome of rheumatoid arthritis (RA), so as to explore its mechanisms underlying improvement of RA., Methods: A total of 32 rabbits were randomly divided into normal, model, inhibitor and HRN groups, with 8 rabbits in each group. The RA with cold syndrome model was induced by injecting ovalbumin dry powder and Freund's complete adjuvant combined with cold freezing. Rabbits in the inhibitor group were intraperitoneally injected with 2-methoxyestradiol (2.5 mg/kg), rabbits in the HRN group were received HRN at bilateral "Zusanli" (ST36) for 30 min. The treatments were conducted once daily for 14 consecutive days. After the interventions, the knee circumference and pain threshold were measured. The contents of nicotinamide adenine dinucleotide phosphoric (NADPH), Hexokinase II (HK2) and 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) in serum of rabbits were detected by ELISA. The pathological morphology of synovial tissue of the knee joints were observed by HE staining. The positive expressions of tumor necrosis factor (TNF-α), interleukin (IL)-1β, IL-6 and IL-17 in synovial tissue of knee joint were detected by immunohistochemistry. The content of lactic acid in synovial tissue of rabbit knee joint was detected by spectrophotometry. The expression levels of HIF-1α, pyruvate kinase 2 (PKM2) and lactate dehydrogenase (LDHA) in synovial tissue of knee joint were detected by Western blot., Results: After intervention, compared with the normal group, the knee circumference was significantly enlarged ( P <0.05), the pain threshold was significantly decreased ( P <0.05)；the synovial tissue of knee joints showed significant cell proliferation and inflammatory infiltration, the pathological score was significantly increased ( P <0.05)；positive expressions of TNF-α, IL-1β, IL-6 and IL-17, the content of lactic acid in synovial tissue, the contents of NADPH, HK2 and PFKFB3 in serum, and the protein expression levels of HIF-1α, PKM2 and LDHA in synovial tissue were increased (all P <0.05) in the model group. Compared with model group, the circumference of knee joint was significantly decreased ( P <0.05), the pain threshold was significantly increased ( P <0.05)；in synovial tissue, the pathological score was decreased ( P <0.05)；the positive expressions of TNF-α, IL-1β, IL-6 and IL-17 in synovial tissue were decreased ( P <0.05), the lactic acid content in synovial tissue was decreased ( P <0.05)；the contents of NADPH, HK2 and PFKFB3 in serum and the protein expression levels of HIF-1α, PKM2 and LDHA in synovial tissue were decreased ( P <0.05) in inhibitor group and HRN group. Compared with the inhibitor group, the synovial pathological score was significantly increased ( P <0.05), positive expressions of TNF-α, IL-1β, IL-6 and IL-17, the content of lactic acid in synovial tissue, the contents of NADPH, HK2 and PFKFB3 in serum, and the protein expression levels of HIF-1α, PKM2 and LDHA in synovial tissue were increased (all P <0.05) in HRN group., Conclusions: HRN can increase the pain threshold, reduce the knee circumference and inhibit the inflammatory response in rabbits with cold syndrome of RA. The possible mechanism is related to the down-regulation of HIF-1α and glycolysis activity.

Objective: To observe the effect of heat-reinforcing needling (HRN) on inflammatory factors and necrotizing apoptosis of synovial cells in synovial tissues of knee joint in rabbits with cold syndrome rheumatoid arthritis (RA), so as to explore its underlying mechanisms in treating RA., Methods: By using the random number table method, 40 New Zealand rabbits were randomly divided into normal, model, antagonist(AG), twist-reinforceing needling (TRN) and HRN groups, with 8 rabbits in each group. The model of cold syndrome RA was established by ovalbumin induction combined with Freund's complete adjuvant injection and cryogenic freezing method. In the AG group, the antagonist TAK-632 (25 mg/kg) was administered intragastrically, once every 2 days, for a total of 7 times. Rabbits of TRN and HRN groups were treated with corresponding acupuncture techniques on bilateral "Zusanli" (ST36) for 30 min, once a day for 14 days. After intervention, the changes of knee skin temperature and circumference were measured. Color Doppler ultrasound was used to observe the joint cavity effusion, synovial thickness and internal blood flow signal. The histomorphological changes of synovial tissues were observed after HE staining. ELISA was used to detect the contents of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in serum. Transmission electron microscope was used to observe the ultrastructure, necrosis and apoptosis of synovial cells. Western blot was used to detect the protein expressions of receptor-interacting protein kinase1 (RIPK1), RIPK3, mixed lineage kinase domain-like protein (MLKL), and phosphorylation （p）-MLKL in synovial tissues., Results: Compared with the normal group, the synovial was diffusely hyperplasia, joint cavity effusion and abnormal blood flow signal were obvious, inflammatory cells were clustered, arranged closely and disordered in the model group. The findings of transmission electron microscopy showed disruption of cell membrane integrity, swollen or ruptured mitochondria, obviously ruptured nucleus, condensed and pyknotic chromatin and nucleolus in the model group. Also, the skin temperature of the knee joint was significantly decreased ( P <0.01), while the circumference of the knee joint, the contents of TNF-α, IL-1β and IL-6 in serum, the protein expressions of RIPK1, RIPK3, p-MLKL and MLKL in synovial tissues were significantly increased ( P <0.01) in the model group. Compared with the model group, synovial tissue hyperplasia, joint cavity effusion, abnormal blood flow signals, synovial cell proliferation, inflammatory cell infiltration, disruption of cell membrane integrity, cell swelling, cell rupture, and nuclear pyknosis were reduced to different degrees in the AG, TRN and HRN groups. Additionally, the skin temperature of the knee joint was increased ( P <0.01, P <0.05), while the circumference of the knee joint, the contents of TNF-α, IL-1β and IL-6 in serum, the expressions of RIPK1, RIPK3, p-MLKL and MLKL in synovial tissues were decreased ( P <0.01, P <0.05) in the AG, TRN and HRN groups. The effects of HRN and AG were notably superior to that of TRN in up-regulating skin temperature of the knee joint, and down-regulating the circumference of the knee joint, the contents of TNF-α, IL-1β and IL-6 in serum, the expressions of RIPK1, RIPK3, p-MLKL and MLKL in synovial tissues ( P <0.01, P <0.05)., Conclusion: HRN can reduce synovial inflammation of knee joint in rabbits with cold syndrome RA, which may be related to its function in inhibiting the necrotizing apoptosis of synovial cells.

Objective: To observe the effects of heat-reinforcing needling on synovial inflammation and microRNA-155 (miR-155)/Toll-like receptor 4 (TLR4)/nuclear transcription factor-κB (NF-κB) signaling axis, so as to investigate its anti-inflammatory mechanism in rabbits with cold syndrome of rheumatoid arthritis (RA)., Methods: A total of 36 rabbits were randomly divided into normal, model, agonist, inhibitor, heat-reinforcing needling (HRN) and agonist+heat-reinforcing needling (A+HRN) groups, with 6 rabbits in each group. The RA with cold syndrome model was induced by injecting ovalbumin dry powder and Freund's complete adjuvant combined with cold freezing. Rabbits in agonist group were intraperitoneally injected with miR-155 agomir 4.5 OD; rabbits in the inhibitor group were intraperitoneally injected with miR-155 antagomir 6.1 OD; rabbits in HRN group received heat-reinforcing needling at bilateral "Zusanli" (ST36) for 30 min；rabbits in A+HRN group received the same treatment as agonist group, and 30 min later, received the same treatment as the HRN group; rabbits in the normal and model groups were grasped and fixed in the same way, all groups received continuous treatment once a day for 7 d. After modeling, the knee joints of rabbits were examined by ultrasound, the pain threshold and the circumference were determined. After the interventions, the pain threshold and knee circumference were measured; the pathological morphology of synovial tissue of the knee joints were observed by HE staining; the mRNA levels of miR-155 and suppressor of cytokine signaling protein 1 (SOCS1), the expression levels of SOCS1, TLR4, NF-κB p65, interleukin (IL)-1β and IL-17A proteins in synovial tissue of knee joints were detected by real-time PCR and Western blot respectively., Results: Compared with the normal group, the pain threshold was significantly decreased ( P <0.05), and the knee circumference was significantly increased ( P <0.05); the synovial tissue of knee joints showed significant hyperplasia, abundant blood flow signal, joint cavity effusion and obvious inflammatory invasion, the pathological score was significantly increased ( P <0.05), the expressions of miR-155 mRNA and IL-1β, IL-17A, TLR4, NF-κB p65 proteins were significantly increased ( P <0.05), the expressions of SOCS1 mRNA and protein were significantly decreased ( P <0.05) in the model group. Compared with model group, the pain threshold was significantly increased ( P <0.05), the circumference of knee joint was significantly decreased ( P <0.05); in synovial tissue, the pathological score was decreased ( P <0.05), the expression levels of miR-155 mRNA and IL-1β, IL-17A, TLR4, NF-κB p65 proteins were significantly decreased ( P <0.05), and the expressions of SOCS1 mRNA and protein were significantly increased ( P <0.05) in inhibitor group and HRN group, while the above changes in agonist group were reversed ( P <0.05). Compared with the agonist group, the pain threshold was significantly increased ( P <0.05), the knee circumference was significantly decreased ( P <0.05), the synovial pathological score was significantly decreased ( P <0.05), the expressions of miR-155 mRNA and IL-1β, IL-17A, TLR4, NF-κB proteins in synovial tissue were significantly decreased ( P <0.05), and the expression levels of SOCS1 mRNA and protein were significantly increased ( P <0.05) in A+HRN group., Conclusion: The heat-reinforcing needling can increase the pain threshold, reduce the knee circumference and inhibit the inflammatory response in rabbits with RA cold syndrome. The possible mechanism is related to the regulation of miR-155/TLR4/NF-κB signaling axis.

Objective: To observe the effects of heat-reinforcing needling on the expression of purinergic ligand-gated ion channel 7 receptor(P2X7R)，Nodlike receptor protein 3(NLRP3) and Caspase-1 in synovium tissues of knee joint of rabbits with cold syndrome rheumatoid arthritis(RA)，so as to explore the anti-inflammatory mechanism of heat reinforcing needling in the treatment of RA., Methods: Thirty male New Zealand white rabbits were randomly divided into normal group, model group, reinforcing-reducing needling group(RRG), heat-reinforcing needling group(HRG), and antagonist group(AG), with 6 rabbits in each group.The model of cold syndrome RA was established by ovalbumin combined with Freund's adjuvant and cryogenic freezing. Rabbits of RRG and HRG were treated with corresponding acupuncture techniques on both sides of "Zusanli"(ST36) for 30 min, once a day for 7 days; Rabbits of the AG was intraperitoneally injected with A438079(2.5 mg/kg), once a day for 7 days. After intervention, color Doppler ultrasound was used to observe the joint cavity effusion, synovial thickness and internal blood flow signal.The histomorphological changes of synovial tissues were observed by HE staining. Quantitative real-time PCR method was used to detect the mRNA expression levels of P2X7R, NLRP3, and Caspase-1 in synovial tissues. Western blot was used to detect the protein expression of interleukin(IL)-1β, IL-6 and tumor necrosis factor(TNF)-α in synovial tissues., Results: Compared with the normal group, the synovial tissues in the model group was thickened, linear and punctate blood flow signals were increased, joint effusion was obvious, synovial coating cells were enlarged, the synovial matrix was severely hyperplasia, inflammatory cells infiltration was obvious.The mRNAs expression levels of P2X7R, NLRP3, Caspase-1 and IL-1β, IL-6, TNF-α proteins in synovial tissues were significantly increased( P <0.01). Compared with model group, abnormal blood flow signals, synovial thickness, joint effusion, proliferation of synovial matrix, inflammatory cell infiltration and synovial coating cells in the RRG, HRG and AG were improved. The mRNAs expression levels of P2X7R, NLRP3, Caspase-1 and IL-1β, IL-6, TNF-α proteins in synovial tissues were decreased in the RRG, HRG and AG ( P <0.05, P <0.01). Compared with the RRG, the above indexes were lower in the HRG and AG ( P <0.05, P <0.01).There was no significant difference in all indexes above between the HRG and AG ( P <0.01, P <0.05)., Conclusion: Heat reinforcing needling can improve synovial inflammation of RA, which may be related to regulating the expressions of P2X7R/NLRP3/Caspase-1 signaling pathway.

Objective: To observe the effect of heat-reinforcing needling on the expression of serum inflammatory factors and autophagy of knee synovial tissue in rheumatoid arthritis (RA) rabbits with cold syndrome, so as to explore its mechanism of anti-inflammatory in the treatment of RA., Methods: Fifty rabbits were randomly divided into normal, model, heat-reinforcing needling, inhibitor and agonist groups ( n =10 rabbits in each group). The model of RA with cold syndrome was established by Freund's adjuvant and ovalbumin mixed solution injection combined with freezing and wind-cold dampness method. Heat-reinforcing needling was applied at "Zusanli" (ST36) for 30 min, once a day for 14 days. Rabbits of the inhibitor and agonist groups were given intraperitoneally injected with autophagy inhibitor 3-methyladenine (3-MA) or autophagy agonist rapamycin, once every 2 days for 7 days. The knee circumference and skin temperature of the rabbits in each group were measured. Color doppler ultrasonography was applied to examine the synovial membrane, joint effusion and blood flow signals in the knee joints of the rabbits in each group. Serum tumor necrosis factor (TNF) -α, interleukin (IL)-1β, IL-6 and C-creactive protein (CRP) were detected by ELISA. Transmission electron microscopy was applied to observe the ultrastructure and autophagosomes of synovial cells. The protein expressions of autophagy-related protein Atg5, serine/threonine protein kinase-dysregulated 51-like kinase 1 (ULK1), microtubule-associated protein light chain 3B (LC3B), and Beclin-1 were detected by Western blot. Fluorescence quantitative PCR was used to detect the mRNA expressions of NOD-like receptor 3 (NLRP3) and nuclear factor-κB (NF-κB)., Results: Compared with the normal group, the circumference of the knee joint was increased ( P <0.01), the skin temperature was decreased ( P <0.01), the knee joint synovium was thickened and the blood flow signal was abundant, the contents of serum TNF-α, IL-1β, IL-6, and CRP were increased ( P <0.01), the protein expressions of Atg5, ULK1, Beclin-1 and LC3BⅡ/LC3BⅠof synovial tissue were significantly decreased ( P <0.01), the mRNA expressions of NLRP3 and NF-κB were increased ( P <0.01) in the model group. In comparison with the model and inhibitor groups, the circumference of the knee joint was decreased ( P <0.01), whlie the skin temperature was increased ( P <0.01), the synovial membrane became thinner and the blood flow signal was wea-kened, the contents of TNF-α, IL-1β, IL-6 and CRP were decreased ( P <0.01), the protein expressions of Atg5, ULK1, Beclin-1 and LC3B Ⅱ/LC3B Ⅰ were increased ( P <0.01), and the mRNA expressions of NLRP3 and NF-κB were decreased ( P <0.01) in the heat-reinforcing needling and agonist groups., Conclusion: Heat-reinforcing needling can alleviate the inflammatory response of the knee joint synovium in RA rabbits with cold syndrome, which may be related to its function in enhancing the autophagy activity of synovial cells and inhibiting the synthesis and release of inflammatory factors TNF-α, IL-1β, IL-6 and CRP.