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In order to reveal the differences in the biosynthesis and metabolism of the major bioactive composition in sea buckthorn berry pulp during ripening, non-targeted metabolomics based on ultra-high performance liquid chromatography coupled to mass spectrometry (UPLC-MS) was used to analyze the metabolites of sea buckthorn berry pulp from two strains at different developmental stages (green and orange pulp). The results showed that the four sample groups had significant metabolic differences. A total of 124 significantly differential metabolites were detected among the four groups based on variable importance in the projection (VIP) > 1 and t-test P < 0.05, including organic acids, carbohydrates, lipids, flavonoids and secondary metabolites. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, 15, 7 and 4 significantly differential metabolites associated with lipid, flavonoid and serotonin metabolism were identified, respectively, and eight significantly differential metabolites involved in anticancer function were selected. The significant up-regulation of phosphatidylcholine (PC) (16:0/16:0) and glycerophosphocholine could be the reason for the high accumulation of lipids in sea buckthorn berry pulp. The significant upregulation of isorhamnetin was key for the high flavonoid content in sea buckthorn berry pulp. Relatively high contents of N-acetylserotonin, capecitabine, γ-aminobutyric acid (GABA) and other bioactive composition involved in anticancer function were shown in sea buckthorn berry pulp during its development. These results provide a scientific basis for revealing the metabolic mechanism of bioactive composition of sea buckthorn berries and developing related functional products.

The differences in quality properties between 40 major oil and feed soybean varieties in four major production areas of China were analyzed. Ten key quality indexes of soybean for each purpose were determined. One-way analysis of variance (ANOVA) and principal component analysis (PCA) were carried out, and a model was proposed using combination weighting method in order to select the quality characteristics of soybeans for different purposes and the superior soybean production areas and varieties. Significant differences in all quality properties except color, odor and carbohydrate content were found among varieties and production areas (P < 0.01 or P < 0.001). In the PCA, crude fat content, vitamin E (VE) content, impurity content, damage ratio, moisture content, and phospholipid content were extracted by factor analysis as key quality characteristics of oil soybean. For feed soybean, seven key quality characteristics including 7S/11S protein, protein dissolution ratio, crude fat content, protein content, impurity content, damage ratio, and soybean isoflavone content were identified. Using the proposed model, top 10 oil and feed soybean varieties with the highest comprehensive score and their major production areas were selected. Using cluster analysis, the oil and feed soybeans were assigned into five and nine groups with similar quality characteristics, respectively. This study provides a theoretical basis for quality evaluation of soybeans from different major production areas in China and specialty soybean variety selection.

Food-derived protein hydrolysates/peptides and saccharides are valuable and exploitable food resources. Covalent complexes formed by the Maillard reaction of food-derived protein hydrolysates/peptides and saccharides are superior in their structure and nutritional functions. Therefore, the Maillard reaction has been widely used to improve the functional characteristics of protein hydrolysates, and has currently become a hot spot in the field of food research. This article reviews the sources of raw materials for and the mechanism of the Maillard reaction between food-derived protein hydrolysates/peptides and saccharides and the preparation methods, structural characteristics, functional properties, nutritional and biological activities of the Maillard reaction products as well as their current applications and future prospects in the fields of food and medicine. This review provides a new idea for the development of functional food products based on the Maillard reaction between food-derived protein hydrolysates/peptides and saccharides, and provides a theoretical basis to explore their health effects in the future.

Named entity recognition (NER), as a core task in natural language processing, finds extensive applications in information extraction, question answering systems, machine translation, and more. Firstly, descriptions and summaries are provided for rule-based, dictionary-based, and statistical machine learning methods. Subsequently, an overview of NER models based on deep learning, including supervised, distant supervision, and Transformer-based approaches, is presented. Particularly, recent advancements in Transformer architecture and its related models in the field of natural language processing are elucidated, such as Transformer-based masked language modeling and autoregressive language modeling, including BERT, T5, and GPT. Furthermore, brief discussions are conducted on data transfer learning and model transfer learning methods applied to NER. Finally, challenges faced by NER tasks and future development trends are summarized. [ABSTRACT FROM AUTHOR]

Aiming at the parameter identification of six-degree-of-freedom tandem robots, a dynamic parameter identification method based on weighted least squares and migrating birds optimization (WLS-MBO) is proposed. Firstly, based on the dynamic's principle of the robot, a linearized dynamic equation considering the Coulomb viscous friction parameters is obtained. The fifth-order Fourier series is used as the identification excitation trajectory, the robot controller drives the joints to track the excitation trajectory and collects the joint position and torque data during the robot movement, and the initial solution of the dynamic parameters is obtained by the weighted least square (WLS) method. Based on the results of the WLS method, the migrating birds optimization (MBO) is used for secondary optimization to improve the identification accuracy of parameters. The analysis of the results shows that the identification method has a good identification effect and can further improve the identification accuracy, and it verifies that the MBO has better global search ability. [ABSTRACT FROM AUTHOR]

[Objective] Rainfall erosivity serves as an indicator to assess the potential impact of rainfall on soil erosion, playing a crucial role in evaluating regional soil erosion risk. Therefore, analyzing the temporal and spatial variations of rainfall erosivity in Beijing from 1981 to 2020 holds significant importance for scientifically assessing and preventing regional soil erosion risks. [Methods] This study employed Kriging interpolation, Mann-Kendall non-parametric test, and wavelet analysis based on daily precipitation data collected from 119 rainfall stations in Beijing and its surrounding areas between 1981 and 2020. These methods were utilized to analyze the spatial distribution, trend changes, and periodic fluctuations of annual rainfall erosivity as well as erosivity associated with moderate rain (10~25 mm), heavy rain (25~50 mm), and extreme rain (≥50 mm) in Beijing. [Results] The annual rainfall erosivity in Beijing ranged from 1 691.51 to 3 914.89 (MJ·mm)/(hm2·h·a) during the period from 1991 to 2020. The spatial distribution characteristics of annual rainfall erosivity exhibited similarities with heavy rain and rainstorm but differed from moderate rain patterns. Overall, there was a decreasing trend observed from northeast regions towards the surrounding areas. Over the past four decades, moderate rainfall erosivity demonstrated a significant increasing trend in Beijing; however, no significant mutations or trends were observed for annual rainfall erosivity, heavy rain events, rainstorms or July-August summer precipitation erosivity. Notably large decreasing trends were identified for annual rainfall erosivity within local areas such as Miyun and Pinggu districts. The main cycle for both annual rainfall erosivity and medium-to-heavy intensity precipitation lasted approximately twenty-five years with two to three alternating “low-high” changes. [Conclusion] The study can offer a scientific foundation for soil and water conservation, agricultural practices, and ecological preservation in Beijing.

Rice (Oryza sativa L.) holds significant importance as a staple food crop, and its continual improvement plays a crucial role in sustainable advancement of agriculture and food security in China. Radiation mutagenesis technology offers an effective approach for breeding high-yield, superior-quality, and stress-resistant rice varieties, thereby contributing positively to the independent innovation of China's seed industry. This study provides a comprehensive review on the progress and notable achievements made in the field of radiation-induced mutation breeding of rice in China over the past two decades. It encompasses various aspects, including the application of various types of radiation sources for radiation mutagenesis in rice, establishment of reliable screening methods, progress in understanding the molecular mechanisms underlying radiation-induced mutation, particularly through genomic variation studies. Additionally, the study highlights the development of a rice mutant bank comprising diverse phenotypes such as yield, resistance, and quality, along with the identification of related gene mutations. Furthermore, it discusses the creation of new varieties through radiation mutagenesis. Looking ahead, this technology will further contribute to the cultivation of higher yielding rice varieties adaptable to different environments and possess superior quality, while also creating new germplasms for gene function research in China.

Brassica oleracea is one of the important vegetable crops in China. Its seeds are primarily imported. Hence, developing innovative varieties belonging to China is an urgent requirement. Since broccoli is a cross-pollinated crop systematic selection and cross-breeding are challenging, and the application of radiation mutagenesis breeding in broccoli has not been reported. In this study, the seeds of Brassica oleracea were irradiated using carbon ion beams to investigate the biological effects of these beams on broccoli. The growth indices, antioxidant enzyme activity, photosynthetic indices, and chlorophyll fluorescence were detected at the seedling stage. The results revealed that irradiation with 100–500 Gy exhibited no significant effect on the germination of Brassica oleracea, while the germination of seeds was significantly inhibited at 600 Gy. After irradiation with 100–600 Gy, the root length, shoot length, seedling height, and leaf area decreased with the increase in irradiation dose. The Median lethal dose (LD50) of Brassica oleracea irradiated using a carbon ion beam was 415.89 Gy, and the dose that halved the root length was 495.12 Gy. After irradiation, the activities of superoxide dismutase (SOD) and peroxidase (POD) were higher than that of the control plants, while the activity of catalase (CAT) was lower than that of the control plants. The content of malondialdehyde (MDA) increased significantly at a dose of 400 Gy. The photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids) showed an increasing trend initially, and then a decreasing trend with an increasing irradiation dose, and the highest value was detected at a dose of 300 Gy. Net photosynthesis, transpiration rate, and stomatal conductance exhibited a negative correlation with irradiation dose, while the non-photosynthetic quenching coefficient exhibited a significant increase after irradiation. The findings indicated that heavy ion beam radiation inhibited the growth of broccoli plants and affected the activity of antioxidant enzymes and photosynthesis. The study provided basic data for the radiation mutation breeding of Brassica oleracea.

The spraying construction robot is unable to include information about ground leveling in the map when it is created, and when the robot operates according to the built map, the spraying clamping fixture at the working end of the spraying construction robot can not be parallel to the wall due to the lack of ground information. In order to compensate the posture error of the spraying fixture relative to the wall, a multi-sensor fusion method is proposed based on the unscented Kalman filter to compensate the posture of the spraying fixture.The state equation of the fixture posture is constructed from the data measured by the displacement measurement sensor， the equation of fixture posture measurement is constructed from the data measured by the gyroscope, and the optimal estimation of the fixture posture is obtained by using the unscented Kalman filter algorithm and transferring them to the robot, so as to achieve the purpose of compensating the posture error of the spraying fixture. Finally, the experimental platform is built to verify the feasibility of the error compensation system. The experimental results show that the positional error between the spraying fixture and the wall after error compensation is reduced to 0.005°.

【Objective】To study the physiological response of different bitter gourd materials at seedling stages to high temperature stress, preliminarily evaluate the heat resistance of this materials, and provide theoretical basis for the subsequent breeding of heat-resistant varieties of bitter gourd.【Method】This study used 10 high-generation inbred lines (KG1-KG10) and 6 hybrid varieties (KG11-KG16) of bitter gourd as test materials. Different bitter gourd materials were subjected to high temperature cycling at 40 ℃ /12h during the day and 25 ℃ /12h at night for 3 days. The relative electrical conductivity (REC), malondialdehyde (MDA) content, proline (Pro) content, and antioxidant enzyme activity of seedling bitter gourd leaves were measured. And the heat resistance of these 16 bitter gourd materials was preliminarily evaluated using the membership function method.【Result】The relative electrical conductivity (REC) of the leaves of 16 bitter gourd materials increased during the seedling stage under high temperature compared with normal temperature conditions. Among them, the bitter gourd materials with significant differences in increase were KG1, KG2, KG9, KG10, KG11, KG13, KG14, KG15, and KG16. Except for KG1 and KG2, the content of malondialdehyde (MDA) in the other 14 bitter gourd materials decreased. Among them, the bitter gourd materials with significant differences in decrease amplitude were KG3, KG4, KG5, KG6, KG8, KG10, KG11, KG12, KG13, KG14, KG15, and KG16. The content of proline (Pro) also increased and decreased, with 6 bitter gourd materials showing an increase in Pro content in their leaves. The bitter gourd materials with significant differences in increase were KG1, KG2, KG3, KG4, and KG10; However, 10 bitter gourd materials showed a decrease in Pro content in their leaves, KG6, KG7, KG8, KG9, KG11, KG14, KG15, and KG16 showed significant decrease. Among the antioxidant enzyme activities, the peroxidase (POD) activity of leaves of 16 bitter gourd materials increased significantly, while the activities of superoxide dismutase (SOD) and catalase (CAT) increased and decreased. The SOD activity of bitter gourd materials KG5 and KG14 decreased, while the SOD activity of the other 14 bitter gourd materials increased to varying degrees. The bitter gourd materials with significant differences in increase were KG1, KG2, KG3, KG4, KG6, KG7, KG8, KG9, KG10, KG11, KG12, KG15, and KG16; The CAT activity of bitter gourd materials KG8, KG10, KG12, and KG16 significantly increased, while the CAT activity of the other 12 bitter gourd materials decreased to varying degrees. The bitter gourd materials with significant differences in decline were KG1, KG2, KG3, KG4, KG5, KG7, KG9, KG11, KG13, and KG14. Through comprehensive evaluation using the membership function method, it was preliminarily determined that the heat resistance of these 16 bitter gourd materials is in the following order: KG1 > KG2 > KG16 > KG11 > KG10 > KG3 > KG9 > KG12 > KG15 > KG4 > KG13 > KG8 > KG6 > KG5 > KG7 > KG14.【Conclusion】Different bitter gourd materials have undergone different changes in six physiological indicators under high temperature stress, further indicating that these six physiological indexes have varying degrees of correlation with the heat resistance of bitter gourd. Preliminary evaluation showed that the KG1, KG2, KG16, KG11, and KG10 bitter gourd materials with better heat resistance have potential application value and can be utilized in subsequent bitter gourd heat resistance breeding.

ObjectiveTo analyze the effect of O3 pollution on outpatient visits for respiratory diseases in a district of Shanghai.MethodsWe collected the respiratory disease outpatient data， and atmospheric and meteorological data of from a suburban general hospital in Shanghai from 2015 to 2017. A time-series analysis by generalized additive model was conducted to examine the relationship between O3 pollution and daily outpatient visits.ResultsThe daily outpatient volume for respiratory diseases was 831. The daily 8 h median concentration of O3 was 101.04 μg·m-3. The excess relative risk was 0.461% （95%CI： 0.240%‒0.682%） at lag3. Stratified by gender and age， females， child and the aged had higher risk of respiratory diseases. In the double-pollutant model， PM2.5 and PM10 increased health effects， while CO reduced health effects.ConclusionThe increase of O3 concentration can increase the daily outpatient volume of respiratory diseases.

Tire stiffness is one of the important parameters of tire dynamics model. The influence law of tire stiffness on the shimmy of large civil aircraft nose landing gear can provide reference for the anti-shimmy design of large civil aircraft nose landing gear. The nonlinear mathematical model of the nose landing gear shimmy is established, and the shimmy region diagram of different tire torsional stiffness and tire side bending stiffness is calculated by using Matlab/Matcont software. The influence law of tire torsional stiffness and tire side bending stiffness on the shimmy of the nose landing gear is studied, and the sensitivity of the two on the shimmy of the nose landing gear is compared. The results show that the sensitivity of tire torsional stiffness to the impact of nose landing gear shimmy is greater than that of tire lateral bending stiffness. When the positive torque coefficient is decreased by 1%, the maximum critical damping of torsional shimmy is decreased by 0.88%, and the minimum critical damping of lateral shimmy is increased by 33.87%. Reducing the torsional stiffness of tire and increasing the lateral stiffness of tire are beneficial to restrain the yaw of large civil aircraft nose landing gear.

Objective A recent randomized controlled trial suggested that aggressive medical management was superior to angioplasty for symptomatic intracranial artery stenosis. But it still had its flaws. This study investigated the perioperative safety of balloon angioplasty for symptomatic intracranial artery stenosis. Methods Twenty-eight patients with severe symptomatic intracranial artery stenosis were treated by balloon dilatation alone from May 2016 to May 2019. The success rate, complications, modified Rankin scale (mRS) and follow-up data were evaluated. Results Twenty-six of 28 patients underwent balloon angioplasty successfully with a success rate of 92.86%. Immediate distal stenosis perfusion was more than Modified Thrombdysis in Cerebral Infarction (mTICI) grade 2b. Stent-assisted angioplasty was used in the other 2 cases. No complications related to worsening clinical symptoms occurred in 28 patients after operation and 30 d of follow-up. There were 10 patients whose modified Rankin Scale (mRS) score was 1 on the 30th day after operation, and the other 18 patients' mRS score was 0. Conclusions Balloon angioplasty is relatively safe in the perioperative period of symptomatic intracranial artery stenosis. Stent-assisted angioplasty is a technique used when balloon angioplasty is ineffective. [ABSTRACT FROM AUTHOR]

As one of the main factors affecting the shimmy stability of aircraft in high speed rolling,the structural clearance of landing gear determines the safety and comfort of aircraft rolling.In this paper,the existing form of landing gear structural clearance is summarized,and the formation reasons of landing gear structural clearance on shimmy are analyzed.The existing landing gear shimmy clearance analysis models are described in detail,and the limitations of the models and future modeling direction are pointed out.Furthermore,the solving methods of the shimmy model with clearance are summarized through literature analysis,and the applicability of different methods is illustrated.The future research direction is prospected.

The gas extraction effect during the initial pressure on the working face by using conventional high-level directional long drilling is poor. In order to solve the above problem, taking the project background of 12309 fully mechanized caving face of Wangjialing Mine of China Coal Huajin Group Co., Ltd. as an example, the paper analyzes the overburden rock structure and fracture development law of the coal seam roof in the fully mechanized caving face during the initial mining period by physical similar simulation and numerical calculation. During the initial mining period, the height of fractures is low and the number of fractures is small in the coal seam roof. With the advancement of working face, the roof fractures gradually develop, the height and range of fractures increase with the increase of advancement distance. The maximum height of the fractures is about 28 m, and the pressure step distance of the working face is about 50 m. During the initial mining period, the gas concentration and emission volume of the working face are relatively large. Along the working face tendency, the gas concentration gradually increases from 20 to 150 supports. Along the working face direction, the gas concentration gradually increases from 300 mm of the coal wall to the rear scraper conveyor. The gas emission volume of the goaf mining area accounts for more than 50% of the gas emission volume of the working face, and the gas emission volume as a whole is on an upward trend with obvious phase characteristics. According to the actual situation of the site and the gas emission characteristics, overburden rock structure and fracture evolution law of the fully mechanized caving face during the initial mining period, the trajectory of the conventional high-level directional drilling during the initial mining period is optimized, and the parabolic high-level directional drilling gas extraction method during the initial mining period is proposed. The final hole of the borehole is designed in the coal seam, which is directly connected with the goaf mining area and used for low level gas extraction in the mining area during the initial mining period of the working face. It solves the problem of high level of conventional high-level long borehole during the initial mining period. The field application results show that compared with the conventional high-level directional drilling, the use of parabolic high-level directional drilling can extract the low level gas in the goaf mining area effectively before the initial pressure of the basic roof of the working face. The average pure volume of gas extraction increases by about 37%, and the maximum gas volume fraction in the upper corner and return air flow is less than 0.80%. The result has achieved the expected effect of gas extraction.

Alzheimer's disease (AD) is one of most common neurodegenerative diseases, which gradually begins and develops after 65 years old, presenting as progressive and irreversible memory loss and other cognitive decline, and finally causes dementia and disability. Therefore, early diagnosis, timely treatment and effective prevention of AD have been become important clinical and scientific problems. During the period of Twelfth Five-Year Plan for National Economic and Social Development, our team have engaged in AD diagnosis and treatment for a long time and carried out studies in the field of pathogenesis, epidemiology, screening of risk factors, neuropsychological tests, imaging, biomarkers and early intervention of AD. This paper has summarized these research achievements. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Because of its high prevalence, severe disability and chronic course of disease, it has become one of the most important research focuses in modern medicine ranging from early diagnosis and treatment to prevention. During the period of Twelfth Five-Year Plan for National Economic and Social Development, our team made use of previously established PD Clinical Databse and applying basic research platform, focused on clinical and basic development of PD, and further extended our investigation into the field of pathogenesis, diagnosis and treatment in PD with characteristics of translational medicine. Several progresses have been made in a multiple of aspects: 1) a novel cellular mechanism of mitochondrial fission with the involvement of VPS35 gene, dysregulation of which might be involved in the pathogenesis of familial and sporadic PD. 2) The predictive value of autonomic dysfunction and dopamine transporter (DAT) PET in identifying patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) with a high risk of progressing into neurodegenerative synucleinopathy diseases could form a basis for future disease - prevention trials. Additionally, we initiated the research on PD mortality rate and analyzed the common reasons of death, which added to the evidence of clinical prognosis and progression. 3) We issued the first, second and third versions of "Chinese guidelines for treatment of Parkinson's disease", as well as the "Diagnostic criteria of Parkinson's disease in China (2016 edition)", which could help improve the diagnostic ability and optimize the clinical treatment of PD in China. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of location of intracranial arterial stenosis on the safety of intracranial stenting. Methods A total of 73 patients with symptomatic intracranial atherosclerotic stenosis (ICAS) were divided into intracranial internal carotid artery (IICA, N = 18), middle cerebral artery (MCA)-M1 segment (MCA-M1, N = 11), intracranial vertebral artery (IVA, N = 27) and basilar artery (BA, N = 17). All of them underwent intracranial stenting. The improvement of intracranial arterial stenosis, cerebrovascular complications including perforating events, artery dissection, in - stent thrombosis, distal stent arterial embolism and cerebral hyperperfusion, and neurological complications including transient ischemic attack (TIA), ischemic stroke and intracranial hemorrhage were recorded. Modified Rankin Scale (mRS) was used to evaluate the prognosis 30 d after operation. Results A total of 73 stents were implanted in 73 patients (35 Apollo balloon - expandable stents and 38 Wingspan self - expandable stents). Among them, 10 cases (10/18) were treated with Apollo stents and 8 cases (8/18) with Wingspan stents in IICA group, 5 cases (5/11) were treated with Apollo stents and 6 cases (6/11) with Wingspan stents in MCA-M1 group, 16 cases (59.26%, 16/27) were treated with Apollo stents and 11 cases (40.74%, 11/27) with Wingspan stents in IVA group, and 4 cases (4/17) were treated with Apollo stents and 13 cases (13/17) with Wingspan stents in BA group. No significant difference was seen in stent type among 4 groups (χ² = 7.422, P = 0.201). The stenosis rate of IICA group after treatment [(10.94 ± 1.99)%] was significantly improved than before treatment [(90.89 ± 7.71)%; t = 69.545, P = 0.000]. The stenosis rate of MCA - M1 group after treatment [(10.37 ± 2.14)%] was significantly improved than before treatment [(87.64 ± 9.46)%; t = 26.000, P = 0.000]. The stenosis rate of IVA group after treatment [(11.02 ± 1.99)% ] was significantly improved than before treatment [(89.11 ± 7.97)%; t = 50.726, P = 0.000]. The stenosis rate of BA group after treatment [(10.99 ± 3.39)%] was significantly improved than before treatment [(91.35 ± 5.62)%; t = 69.545, P = 0.000]. In 73 patients, cerebrovascular complications occurred in 11 cases (15.07%), including 4 cases of perforating events, 4 cases of artery dissection, one case of in-stent thrombosis and 2 cases of distal stent arterial embolism. There were 3 cases (3/18) in IICA group, including 2 cases of artery dissection and one case of distal stent arterial embolism, and 8 cases (8/17) in BA group, including 4 cases of perforating events, 2 cases of artery dissection, one case of in - stent thrombosis and one case of distal stent arterial embolism. No cerebrovascular complications occurred in MCA-M1 group and IVA group. The difference among 4 groups was statistically significant (H = 63.134, P = 0.000). Neurological complications occurred in 6 cases (8.22%), including 4 cases of TIA and 2 cases of ischemic stroke. There was one case (1/18) of ischemic stroke in IICA group, and 5 cases (5/17) in BA group, including 4 cases of TIA and one case of ischemic stroke. No neurological complications occurred in MCA-M1 group and IVA group. The difference among 4 groups was statistically significant (H = 65.698, P = 0.003). At 30 d after operation, there was one case with mRS 1 score in IICA group and one in BA group. The total rate of good prognosis 30 d after operation was 97.26% (71/73). Conclusions The location of intracranial arterial stenosis have a great influence on the risk of perioperative cerebrovascular and neurological complications in the intracranial stenting, and the overall prognosis is good. [ABSTRACT FROM AUTHOR]

In consideration of the difficulties of sulfur release and deposition prediction in wellbores with high content of sulfur, a mathematical model was built for multi-phase fluid flow and heat transfer in gas wells with high content of sulfur, and a discrimination rule and computing method were given for multi-field coupling sulfur release in wellbore and sulfur deposition. The computing results show that the sulfur solubility from hole bottom to wellhead in gas well with high sulfur content decreases gradually, showing non-linear variation; sulfur release occurs in the wellbore, and the precipitation location and amount are mainly affected by temperature gradient, pressure gradient and H2S mass concentration; and sulfur deposition in wellbore is mainly affected by gas carrying capacity and local flow field disturbance. The greater the temperature and pressure decrease, the earlier the sulfur precipitates; under the same flow pressure, the higher the gas production is, the earlier the sulfur precipitates and the greater the precipitation is. This study simulates the production performance of gas wells and gives the distribution law of sulfur release, sulfur deposition, pressure and temperature in gas wells with high sulfur content; the calculation results may be used to provide guidance for field adjustment of development scheme and optimization of production parameters and provide basis for formulating a scheme to prevent sulfur deposition. [ABSTRACT FROM AUTHOR]

Soil salinization is one of the most important eco-environment problems in arid area, which can not only induce land degradation, inhibit vegetation growth, but also impede regional agricultural production. To accurately and quickly obtain the information of regional saline soils by using remote sensing data is critical to monitor soil salinization and prevent its further development. Taking the Weigan-Kuqa River Delta Oasis in the northern Tarim River Basin of Xinjiang as test object, and based on the remote sensing data from Landsat-TM images of April 15, 2011 and September 22, 2011, in combining with the measured data from field survey, this paper extracted the characteristic variables modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), and the third principal component from K-L transformation (K-L- 3). The decision tree method was adopted to establish the extraction models of soil salinization in the two key seasons (dry and wet seasons) of the study area, and the classification maps of soil salinization in the two seasons were drawn. The results showed that the decision tree method had a higher discrimination precision, being 87. 2% in dry season and 85. 3% in wet season, which was able to be used for effectively monitoring the dynamics of soil salinization and its spatial distribution, and to provide scientific basis for the comprehensive management of saline soils in arid area and the rational utilization of oasis land resources. [ABSTRACT FROM AUTHOR]

Objectives When an offshore nuclear power platform operates in the Bohai Sea area, it faces a threat from floating ice in winter. Therefore, for the sake of safety, it is necessary to analyze the collision process between the floating ice and the platform.Methods The finite element numerical simulation method is used to simulate the collision process between floating ice and a marine nuclear power platform. Comparing the resistance-displacement curve of the numerical simulation process with the data of the ice cone compression experiment, the feasibility of the numerical simulation method is verified. Based on the ice conditions in the Bohai sea, a typical floating ice model is established, and structural response is analyzed by the impact process between the floating ice and the platform. The bearing capacity of the platform for floating ice is then analyzed by changing the size of the floating ice with fixed ice thickness and fixed ice speed respectively.Results The results show that during collision, the strength of the aggregate has a great influence on the bearing capacity of the platform, and the impact force increases with the continuous extrusion of the floating ice until the floating ice rebounds. With the increase of the size and thickness of the floating ice, the size of the floating ice that the platform can withstand a collision with reduces accordingly.Conclusions Studies have shown that the strength of the aggregate at the collision site between the platform and the floating ice directly affects its own carrying capacity. This analysis finds that the speed of the floating ice has a greater impact on the bearing capacity of a platform than its thickness.

Aiming at the problem that the numerical atlas method can’t be used to synthesize the finitely separated positions design requirements for the planar four-bar mechanism,based on the complex function least square method,a method for realizing the feature extraction of finitely separated positions discrete points is proposed by using the Fourier series approximation fitting finitely separated position. The relationship of feature parameters between the finitely separated positions and their transformations,including translation,rotation,and scaling is found. Combining with numerical atlas method,the finitely separated positions design requirements path generation of the planar four-bar mechanism is realized. Examples are presented to illustrate the applicability and effectiveness of the proposed method.

For evaluating elastogram objectively, image processing and pattern recogniton techniques are proposed. First the real elasticity information encoded in color was extracted by transform the image from RGB color space to HSV space. Then the statistical features and texture features were extracted from region of interest on the elastogram. The important and reliable features were selected by using Minimum-Redundancy-Maximum-Relevance (mRMR) algorithm. Finally the selected features were input to the SVM classifier to classify the thyroid nodules into benign and malignant. The experiment results confirmed the method had higher accuracy (92%). It is helpful to improve the clinical accuracy by using CAD techniques. [ABSTRACT FROM AUTHOR]

Panel acoustic power contribution analysis is put forward according to panel acoustic contribution analysis methodology investigation. According to gearbox noise radiation, finite element method and boundary element method are used to construct gearbox calculation model. According to the partition regions of gearbox, panel acoustic power contribution can be obtained by every panel calculation. Then, main contribution regions of the power and peak frequency are found according to calculation results. Improvement design and analysis are carried Out based on acoustic power analysis for gearbox. It can be concluded that this method is helpful for gearbox noise control investigation and realization. [ABSTRACT FROM AUTHOR]

Based on the existing study results of the development potential of tourism industry both at home and abroad, the paper sums up the connotation and features of development potential and establishes evaluation index system containing self-growth potential and external-supported potential. The paper then makes spatial-temporal analysis of tourism development potential in China' s 31 provinces and municipalities by using weighted principal components TOPSIS valuation function model. The study indicates that development potential of China's regional tourism industry is on the rise. In terms of space distribution, there appears non-balanced situation, with eastern region displaying stronger, followed by middle region and north-eastern region, while western region is weaker and tourism development potential in quite a lot of provinces has not been brought into full play. Finally, the paper summarizes two suggestions on how to speed up the development of China's tourism industry. [ABSTRACT FROM AUTHOR]

To overcome the shortcoming of temperature-sensing valve of radiator used in individual household metering heating systems, a new regulating valve actuator based on reversible step-by-step unit is developed. In this actuator, the reversible differential pressure produced in two airtight containers for semiconductor refrigerator is used as driving force. Then the reversible step-by-step revolution is realized by cooperating two clutches with a clockwise step-by-step unit and a counter clockwise step-by-step unit,which have the same structure. The drive mechanism of each step-by-step unit turns vertical push to horizontal couple of forces with inclination connecting rods in order to revolve a globe valve. The operating principle of actuator is introduced, and the experimental data of the model machine are analysed. Results indicate that the developed actuator exhibits better energy saving than temperature-sensing valve of radiator. [ABSTRACT FROM AUTHOR]

With the establishment and implement of national and regional land use programming, to approach the technology and methodology of environmental assessment appropriate for the overall land use programming is of great significance. By using the theories of strategic environmental assessment and taking ecosystem services value as an evaluation index, a comprehensive assessment on the potential eco-environmental effects of 1996(KG-*2)-(KG-*7)2010 land use programming of Shaya County in Xinjiang Uygur Automous Region was made. The results showed that from 1996 to 2010, the total ecosystem services value of the County increased from 6933×108 Yuan to 7081×108 Yuan, with an annual increment of 015%, which suggested that this programming was basically reasonable. However, the common land expansion should be controlled strictly. The increase rate of eco-value was higher than that of GDP, indicating that Shaya County was of eco-value gaining. There were still some shortages in the programming, e. g., the area ratio of unutilized land (desert) would be 8395% in 2010, and thus, the programming should be emended to increase the eco-benefit of land use. Keywords: 28-Evaluation of economic forest ecosystem services in China. [ABSTRACT FROM AUTHOR]

The surface of HT-200 grey cast iron was alloyed with B, Si slagging elements and Cr, Ni alloying powder (Cr : Ni=20 : 80) by light beam. The results show that the formation of alloying layer depends on the protecting effect of B, Si slagging elements on melting metal; on the other hand, the alloying degree and microstructure uniformity depend on the influence of B, Si slagging elements on alloying process. When the dosage of B, Si slagging elements is too little (<5 mg), the formation of alloying layer is poor. While the dosage of B,Si slagging elements is too much (>20mg), the uniformity of composition and microstructure decreases. The top of the alloying layer is composed of γ (Fe, Ni) and (Fe, Cr)3 C and α, while the bottom consists of blocky (Cr, Fe)7C3 on hypoeutectic structure matrix composed of γ (Fe, Ni) and ledeburite. When the dosage of B, Si slagging elements is between the two points, the good formation and micmstructure uniformity of alloying layer can be acquired. The alloying zone is hypoeutectic structure composed of γ (Fe, Ni) and ledeburite. [ABSTRACT FROM AUTHOR]

Aiming at the adverse influence of penalty parameter and mode number on the VMD（ variational mode decomposition）,a newly MVMD（ modification variational mode decomposition） was proposed through the information entropy difference. The change of the amount of information in each mode extraction characteristic of information entropy difference was analyzed. The information entropy difference under the condition of different penalty parameters was got through making full use of the analysis result of extraction characteristic. The excellent penalty parameter was determined in the position of jumpy information entropy difference. The Fourier spectrum of MVMD was used to detect the unbalance of Cardan shaft in high-speed train. The method and model was verified through the unbalance experiment data. The experiment results show that this method could effectively seize the basic frequency,multi-frequency fault features. With comparison to VMD,the problem of Parameter selection has been solved. With comparison to the classic ensemble empirical model decomposition,the fault detection ability has been significantly improved.

Aiming at the impact feature in fault signals of the rolling bearings,The improved algorithm diagnosis method EEMD-RA-KU was proposed to capture the impact feature. Firstly,Fault signals were decomposed into a series of intrinsic mode functions（ IMFs） with ensemble empirical mode decomposition（ EEMD）. Secondly,The IMFs were selected to reconstruct signals based on relative analysis（ RA） and kurtosis（ KU）. Thirdly,The reconstructed signals were filtered by the filter that the parameters were determined with the spectral kurtosis. Finally,The fault can be diagnosed by comparing the frequency of the envelope spectrum with the fault characteristic frequency of the bearing. The result shows that the fault feature information of the signal can be extracted accurately when there was a lot of background noise.

The pendulum conveyor chain and its driving device are the core part of the pendulum conveyor,the reliability and the stability of the driving device directly affect the normal production and the coating quality of the product. The main technical parameters and the design key points of the pendulum conveyor chain and the structural characteristics of the pendulum conveyor chain and the driving device are described. The multipoint automatic lubricating is adopted to avoid increasing the running resistance of the system due to poor lubrication in the course of operation,leading to the drive device capacity becomes insufficient,thus appear chain crawling and influence on the quality of coating.

The vibration failure issue of the motor control unit during the vibration test was studied,and the reasons of the failure were analyzed by applying spectrum analysis method,the results showed that the coupled vibration is the main reason of the vibration failure. The optimization schemes against this problem were designed,the octave criterion was applied to design the component for avoiding coupled vibration,and the damping was increased to decrease the peak of the vibration response. The optimization schemes were verified by simulation and experiment,the results showed the vibration acceleration decreased by 23% ～ 31% using octave criterion design,and decreased by 25% ～ 34% through increasing damping. The conclusion can be drawn that two optimization ways can decrease vibration acceleration level obviously,and the fatigue durability of the product was improved.

Objective: To analyze the correlation between hip joint musculoskeletal ultrasound score and ankylosing spondylitis (AS) disease activity, as well as to investigate the value of high frequency ultrasound in the assessment of hip joint involvement in AS., Methods: The clinical data of 244 patients with AS who were treated in the rheumatology department of from March 2019 to March 2022 were retrospectively analyzed. Among them, there 174 males and 70 females, aged from 19 to 58 years old with an average of (34.22±9.49) years old;the disease duration of AS patients ranged from 8 months to 26 years, with an average of (13.68±4.04) years.The 244 patients were divided into disease group (83 cases) and control group (161 cases) based in the presence of hip joint involuement. According to the the disease activity, patients in the disease group were further categorezed into active phase (45 cases) and stable phase (38 cases). The ultrasound scores of patients in the active and stable phases of the disease group and the control group were compared. Relevant factors of hip joint involvement in AS patients were analyzed, and analyze the correlation between ultrasound score and Bath ankylosing spondylitis disease activity score index(BASDAI), Bath ankylosing spondylitis functional index(BASFI), visual analogue score of pain (VAS), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and the correlation between hip joint capsule score and tendon attachment end score and BASDAI, BASFI, VAS, CRP and ESR., Results: The hip joint capsule score(3.06±1.12), femoral head score(1.45±0.43), tendon attachment end score(3.28±1.30) and total ultrasound score(6.65±2.31) of the disease group were higher than those of the control group(1.51±0.48)、(0.66±0.27)、(1.61±0.53)、(3.81±1.44)scores ( P <0.05). Multifactor Logstic regression analysis showed that the course of disease, hip joint capsule score and total ultrasound score were independent risk factors for hip involvement in AS patients.The hip capsule score (3.65±1.22)and total ultrasound score(8.28±2.33) in the active phase of the disease group were higher than those in the stable phase (2.48±1.04)、( 6.82±1.96)scores( P <0.05). The hip joint capsule score and total ultrasonic score of AS patients were positively correlated with BASDAI, BASFI, VAS, CRP, and ESR ( P <0.05, P <0.01).The score of tendon attachment end was positively correlated with CRP ( P <0.05). The score of joint capsule effusion in AS patients was positively correlated with BASDAI, BASFI and VAS ( P <0.05, P <0.01). The synovial blood flow score was positively correlated with BASDAI, VAS, CRP and ESR ( P <0.05, P <0.01). The synovial thickening score was positively correlated with BASDAI, BASFI, VAS, CRP and ESR ( P <0.05, P <0.01). There was no correlation between the score of tendon attachment end and BASDAI, BASFI, VAS, CRP and ESR., Conclusion: There is a correlation between hip joint ultrasonic score of hip joint and clinical indexes in AS patients.Hip joint capsule score and total ultrasonic score were independent risk factors for hip involvement in AS patients. High frequency ultrasound exhibits clinical value in the diagnosis of hip joint involvement in AS patients.

Objective: To analyze the risk factors that affect the prognosis of patients with hypopharyngeal squamous cell carcinoma（HPSCC） and to compare the efficacy of surgical resection followed by adjuvant radiotherapy（SR） with that of neoadjuvant therapy consisting of platinum-based chemotherapy and fluorouracil combined with either cetuximab or nimotuzumab, followed by SR. The study also aimed to evaluate the overall survival（OS） of patients, their postoperative eating function, tracheostomy decannulation rate, and tumor response to the two neoadjuvant chemotherapies. Methods: A retrospective analysis was performed on the medical records of HPSCC patients who received SR or neoadjuvant therapy followed by SR treatment at the Shanghai General Hospital from 2012 to 2019 and had not undergone any prior treatment. The prognostic factors were analyzed, and the survival analysis of patients who underwent SR treatment with two neoadjuvant chemotherapy regimens was performed. Results: A total of 108 patients were included in the study. The results of the univariate analysis showed that gender（ P =0.850） had no significant correlation with the survival rate of HPSCC patients who underwent SR. However, age, smoking history, alcohol consumption history, platelet-to-lymphocyte ratio（PLR）, neutrophil-to-lymphocyte ratio（NLR）, T stage, N stage, neoadjuvant therapy with either cetuximab or nimotuzumab combined with platinum-based chemotherapy and fluorouracil, and histological grade were significantly associated with prognosis（ P <0.05）. The multivariate analysis revealed that smoking history, histological grade, and neoadjuvant therapy with either cetuximab or nimotuzumab combined with platinum-based chemotherapy and fluorouracil were independent risk factors affecting the prognosis of HPSCC（ P <0.05）. Patients who received neoadjuvant therapy had longer OS than those who underwent SR only（ P <0.001）. There was no significant difference in tumor response to the two neoadjuvant therapies and in OS（ P >0.05）, and there was no significant difference in the rate of oral feeding and tracheostomy decannulation among the three treatment groups（ P >0.05）. Conclusion: Univariate analysis showed that age at tumor onset, smoking history, alcohol consumption history, NLR, PLR, T stage, N stage, whether receiving neoadjuvant chemotherapy, and pathological grade were associated with the prognosis of HPSCC patients receiving SR treatment. Multivariate analysis showed that smoking history, pathological grade, and neoadjuvant chemotherapy were independent risk factors affecting the prognosis. Neoadjuvant chemotherapy with cetuximab or nimotuzumab can prolong the OS of patients, providing a certain basis and reference for the treatment of HPSCC., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: To investigate the application value of apparent diffusion coefficient (ADC) and signal intensity ratio (SIR) of MR diffusion-weighted imaging (DWI) in quantitative evaluation of lumbar spine osteoporosis., Methods: A total of 175 patients with lumbar spine diseases who received dualenergy X-ray absorption (DXA) bone mineral density (BMD), routine MRI and DWI of the lumbar spine from May 2017 to October 2019 were selected. According to the T-value of DXA, the patients were divided into osteoporosis group (64 cases), osteopenia group (53 cases) and normal bone mass group (58 cases). The ADC and SIR values of L 2 -L 4 were measured and compared among the three groups and the correlation between ADC, SIR and BMD was analyzed. The ROC curve was used to evaluate the differential diagnosis value of ADC and SIR for osteoporosis, osteopenia and normal bone mass., Results: There were statistically significant differences in ADC and SIR values among three groups ( F =41.386, 37.114, all P =0.000). The ADC value of the osteoporosis group was lower than that of the osteopenia group and the normal bone mass group, and the difference was statistically significant ( t =3.540, 9.069, P =0.001, 0.000);the SIR value of the osteoporosis group was higher than that of the osteopenia group and the normal bone mass group, and the difference was statistically significant ( t =5.083, 8.523, all P =0.000). Spearman correlation analysis showed that ADC value was positively correlated with BMD ( r =0.313, P =0.004);SIR value was negatively correlated with BMD ( r =- 0.589, P =0.000). Receiver operator characteristic (ROC) curve analysis showed that the area under curve (AUC), sensitivity andspecificity of ADC and SIR in the diagnosis of lumbar osteoporosis and osteopenia were 0.742, 89.1% , 52.8% and 0.729, 89.1%, 50.9% respectively ( P =0.000);the AUC, sensitivity and specificity of ADC and SIR in the diagnosis of lumbar osteoporosis and normal bone mass were 0.815, 100.0%, 50.0% and 0.856, 65.6%, 93.1%, respectively ( P =0.000);the AUC, sensitivity and specificity of ADC and SIR in the diagnosis of lumbar osteoporosis were 0.78, 89.1%, 51.4% and 0.795, 50.0% and 94.6% respectively ( P =0.000);All have a certain diagnostic value., Conclusion: ADC and SIR can better reflect the BMD of patients with lumbar diseases, and can quantitatively evaluate the vertebral body of osteoporosis, which play an important role in the diagnosis of lumbar osteoporosis.

The chemical components of Lycii Fructus were analyzed by liquid chromatography( LC) and mass spectrometry( MS for the establishment of spectrum-activity relationship,on the basis of which its antioxidant active ingredients were determined. In this experiment,Lycii Fructus was extracted with different solvents and then separated into 80 samples by macroporous adsorption resin and reversed-phase chromatography,respectively. The antioxidant components were enriched into 11 samples and their scavenging abilities against DPPH free radical and ferric ion reducing antioxidant power( FRAP) were significantly stronger than those before the treatment( P&lt;0. 05). The spectrum-activity relationship regarding the antioxidant activity in vitro of Lycii Fructus was established by Pearson correlation analysis,orthogonal partial least squares( OPLS) and elastic net regression. Six chromatographic peaks greatly contributing to the antioxidant activity in vitro of Lycii Fructus were identified as rutin( P6),quercetin( P35),scopoletin( P14),N-cis-feruloyl-4-O-β-D-glucopyranosyl-tyramine or N-( 4-O-β-D-glucopyranosyl-trans-feruloyl)-tyramine( P8), ferulic acid( P13) and1,3,5-dihydroxy-2-isoprenyl-3-xanthone( P23). The active components associated with free radical scavenging were rutin and quercetin both belonging to flavonoids. The reduction of Fe3+was based on phenylpropanoids such as ferulic acid,scopoletin,xanthone and phenolic amides. These results indicated that the antioxidant activity of Lycii Fructus was ascribed to the synergistic action of different products through different ways. Besides,the data analysis model should be chosen carefully for the establishment of spectrum-activity relationship,thus ensuring the reliability of results.

In order to explore the temporal and spatial distribution characteristics of atmospheric aerosol optical depth (AOD) in the urban agglomeration on the northern slope of the Tianshan Mountains, the temporal and spatial distribution characteristics and trends of changes in the AOD in the study area from 2000 to 2019 were analyzed by MODIS aerosol products(MCD19-A2). For 2016-2019, when the AOD was relatively stable, the parameters such as the AOD and Ångström wavelength index ( α ) were analyzed using multi-band sun photometer ground-based remote sensing technology. The results showed that ① the spatial distribution of AOD in the study area was consistent with the topography, and high values were mainly distributed in the low altitude area. The spatial distribution of AOD in the four seasons showed a strong seasonal change from spring (0.15±0.03) > autumn (0.14±0.03) > summer (0.14±0.02). ② In terms of time, the annual average AOD value of the study area was 0.12 from 2000 to 2019 with an annual growth rate of 1.03%, thereby showing an overall increasing trend. The annual variation in the monthly mean value of AOD was bimodal; the first and second peaks were in May and November. The main reason for the increase in AOD was the release and transmission of dust from natural sources and heating. ③ Under the influence of dust weather, the AOD changed sharply in spring, and the size and change range of aerosol particles were larger than those in summer. The high value of AOD in the study area was mainly affected by coarse mode particles. The moisture absorption growth of fine mode particles caused a fluctuation in the AOD, but it was not the cause of the high value of AOD.

Objective To analyze the CT characteristics of consolidation type of pulmonary cryptococcosis in immunocompetent patients,and thus improve the diagnosis of this disease. Methods A total of 20 cases with consolidation-type pulmonary cryptococcosis confirmed by pathological examinations were studied.Each patient underwent breath-hold multislice spiral CT,and 10 patients underwent contrast enhanced CT.The data including lesion number,lesion distribution,lesion density,performance of enhanced CT scan,accompanying signs,and prognosis were analyzed. Results The occurrence rates of single and multiple lesions were 80.0%(n=16)and 20.0%(n=4),respectively.In all the 16 multiple-lesion patients,the occurrence rate of unilateral lobar distribution was 56.0%(n=9).The 76 measurable lesions mainly presented subpleural distribution(71.1%,n=54)and lower pulmonary distribution(75.0%,n=57).A total of 39 lesions were detected in the 10 patients received contrast enhanced CT,in which 31 lesions(79.5%)showed homogeneous enhancement,34 lesions(87.2%)showed moderate enhancement,and all the lesions manifested angiogram sign.Consolidation lesions were accompanied by many CT signs,of which air bronchogram sign had the occurrence rate of 63.2%(n=48),including types Ⅲ(n =37)and Ⅳ(n=11).Other signs included halo signs(43/76,56.6%),vacuoles or cavities(9/76,11.8%),pleural thickening(14/20,70.0%),and pleural effusion(2/20,10.0%).After treatment,the lesions of 7 patients were basically absorbed and eventually existed in the form of fibrosis. Conclusions The lesions in the immunocompetent patients with consolidation type of pulmonary cryptococcosis usually occur in the lower lobe and close to the pleura,mainly presenting unilateral distribution.The CT angiogram signs,proximal air bronchogram signs,and halo signs are the main features of this disease,which contribute to the diagnosis.