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Aim of the study To evaluate the efficacy and preliminary outcomes of using a postauricular-groove approach without endoscopic assistance for the excision of parotid tumors. Case series Patients who underwent parotidectomy using a postauricular-groove incision were selected for this study. For patients in which parotidectomy was difficult, namely, for tumors located in the deep lobe area, the parotid gland sternocleidomastoid space was fully utilized, and the tumor was resected from the posterior plane. A total of fifty-eight patients with parotid tumor were enrolled and divided into superior lobe group (n=46) and deep lobe group (n=12). The difference in operation time (94 vs 119 min) and postoperative drainage (20.18 vs 45.33 mL) was statistically significant between the tumors in the superficial and deep lobes. However, postoperative cosmetic VAS score was 10 (extremely satisfied) for all patients. The incidence of transient facial nerve paralysis was comparable (8.7% vs 16.7%), and all of them resolved spontaneously within 3 months. No recurrence of tumors was found in either group in the median follow-up interval of 26.45 months (range 22.2-35.3 months), which was comparable to the result using the conventional “S” approach. Conclusion After making full use of the parotid gland sternocleidomastoid space, the postauricular-groove approach demonstrated satisfactory facial nerve protection, as well as easy maneuverability without the risk of surgical complications for tumors located in the deep lobe area. Importantly, the postauricular-groove approach showed excellent cosmetic outcomes for all patients and should be considered an alternative approach for parotidectomy of selected cases.

Image analysis of power equipment has important practical significance for power-line inspection and maintenance. This paper proposes an image recognition method for power equipment based on multitask sparse representation. In the feature extraction stage, based on the two-dimensional (2D) random projection algorithm, multiple projection matrices are constructed to obtain the multilevel features of the image. In the classification process, considering that the image acquisition process will inevitably be affected by factors such as light conditions and noise interference, the proposed method uses the multitask compressive sensing algorithm (MtCS) to jointly represent multiple feature vectors to improve the accuracy and robustness of reconstruction. In the experiment, the images of three types of typical power equipment of insulators, transformers, and circuit breakers are classified. The correct recognition rate of the proposed method reaches 94.32%. In addition, the proposed method can maintain strong robustness under the conditions of noise interference and partial occlusion, which further verifies its effectiveness.

Coal and gas outburst seriously threatens the safety of underground coal mining. After the outburst, it will not only cause harm in the near-field outburst roadway but may also have a strong impact on the far-field ventilation network connected to the outburst roadway, expanding the impact of the disaster. In order to define the propagation law of shock wave and airflow induced by the outburst and its influence on the far-field ventilation network, the coal and gas outburst experimental system was used to carry out an experimental study under different air current and local resistance conditions in this paper. The results show that, under different air current states, the first overpressure peak increases with an increase of outburst pressure and decreases with an increase of propagation distance. Compared with the propagation characteristics in a windless roadway, the first overpressure peak and attenuation coefficient of shock wave propagating downwind are smaller, whereas opposite in upwind state. The local resistance enhances the impact and disturbance ahead of it and weakens that after it. When shock airflow propagates downwind, the increase of shock airflow velocity is approximately equal to the original airflow velocity in the roadway, whereas the airflow direction may reverse when the shock airflow propagates upwind. This paper provides some references to prevent the impact expansion of coal and gas outburst, which are of great significance for the optimization of ventilation network and emergency management.

Cancer is the second leading cause of mortality worldwide. Conventional therapies, including surgery, radiation, and chemotherapy, have limited success because of secondary resistance. Therefore, safe, non-resistant, less toxic, and convenient drugs are urgently required. Natural products (NPs), primarily sourced from medicinal plants, are ideal for cancer treatment because of their low toxicity and high success. NPs cure cancer by regulating different pathways, such as PI3K/AKT/mTOR, ER stress, JNK, Wnt, STAT3, MAPKs, NF-kB, MEK-ERK, inflammation, oxidative stress, apoptosis, autophagy, mitophagy, and necroptosis. Among the NPs, steroid saponins, including polyphyllins (I, II, D, VI, and VII), have potent pharmacological, analgesic, and anticancer activities for the induction of cytotoxicity. Recent research has demonstrated that polyphyllins (PPs) possess potent effects against different cancers through apoptosis, autophagy, inflammation, and necroptosis. This review summarizes the available studies on PPs against cancer to provide a basis for future research.

The scraper conveyor is the key coal transportation equipment on the coal mining face. The conveyor often encounters the influence of abnormal working conditions, such as stuck chains, broken chains, and impact loads, which have a great effect on the smooth operation of the scraper chain and seriously affect the safety of coal production. If the chain breaks during the test, the broken link may fly out and hurt the tester. The test risk of the scraper conveyor under abnormal working conditions is relatively large; hence, the test research is impossible to carry out. The combination of experiment and simulation is used to carry out the research. The dynamic characteristic test bed of the chain drive system is created to collect the speed of the sprocket and the acceleration of the scraper. The two groups of data are obtained by simulation, and the accuracy of the simulation is verified by comparing the test data with the simulation data. The dynamic characteristics of the chain drive system under abnormal working conditions are analyzed by simulation. Results show that the longitudinal velocity of the link dramatically changes, the contact force increases by 5.4 times, and the link vibrates under impact loads. When the chain is stuck, the speed of the running direction suddenly changes, and the chainring vibrates. The contact force between the chainrings increases by 7.2 times compared with the smooth operation. When the chain is broken, the acceleration in the running direction of the link dramatically changes. This study provides a basis and reference for the further optimization design of the chain drive system and detection of the abnormal working conditions.

An obstacle perception system for intelligent vehicle is proposed. The proposed system combines the stereo version technique and the deep learning network model, and is applied to obstacle perception tasks in complex environment. In this paper, we provide a complete system design project, which includes the hardware parameters, software framework, algorithm principle, and optimization method. In addition, special experiments are designed to demonstrate that the performance of the proposed system meets the requirements of actual application. The experiment results show that the proposed system is valid to both standard obstacles and non-standard obstacles, and suitable for different weather and lighting conditions in complex environment. It announces that the proposed system is flexible and robust to the intelligent vehicle.

Ischemic stroke (IS) caused by cerebral arterial occlusion is the leading cause of global morbidity and mortality. Cellular oxidative stress and inflammation play a vital role in the pathological process of neural damage in IS. It is necessary to develop functional food or drugs, which target neuroinflammation and oxidation mechanisms against IS. The molecule compound aloe-emodin (AE) is derived from aloe and rhubarb. However, the exact mechanism of the pharmacological action of AE on IS remains unclear. Here, for aiming to demonstrate the mechanism of AE, our study explored the middle cerebral occlusion reperfusion (MCAO/R) rats in vivo, oxygen and glucose deprivation reperfusion (OGD/R), and lipopolysaccharide (LPS)-stimulated cells in vitro. We found that AE significantly improved the infarct size and behavioral score of MCAO/R rats, decreased the expression of TNF-α, MDA, LDH, Caspase 3, and increased the expression of SOD, Bcl-2/Bax. Liquid chromatography-mass spectrometry (LC/MS) results showed that AE could penetrate the blood-brain barrier in the sham group and MCAO/R group. In vitro, AE significantly protected SH-SY5Y cells from the insult of OGD/R and reduced the production of inflammatory cytokines in BV2 cells stimulated by LPS. In vivo and in vitro, western blot analysis results showed that AE significantly increased the expression of PI3K, AKT and mTOR proteins. In addition, AE significantly decreased NF-κB protein expression in BV2 cells. The use of AKT-specific inhibitor MK-2206 2HCL to inhibit AKT expression can block the protective effect of AE on SH-SY5Y cells subjected to OGD/R insults. Overall, our study suggests that AE protected against cerebral ischemia-reperfusion injury probably via the PI3K/AKT/mTOR and NF-κB signaling pathways. Thus, these results indicated that AE could be a promising first-line therapy for preventing and treating ischemic stroke and can be used as functional food.

An ultra-wideband metamaterial (MM) filter with steep cut-off is proposed at terahertz (THz) region. The filter is based on the flexible hybrid structure of copper (Cu)–polyimide (PI)–polymethacryl...

In order to explain the influence of the coal ash on the combustion characteristics of coal, the physical and chemical structures of pulverized coal with different ash contents were compared and analyzed, and the combustion characteristics and kinetics of pulverized coal were systematically studied by non-isothermal thermogravimetric analysis. The results show that the physical and chemical structure of the deashed coal is not significantly changed compared with the raw coal. The combustion process of the deashed coal gradually moves to the high temperature zone, and the combustion performance is obviously weakened. The comprehensive combustion characteristic parameters of the three samples can be arranged as: raw coal > primary deashed coal > secondary deashed coal. In this study, the RNGM model was used to analyze the combustion kinetics of pulverized coal, and the fitting effect is good. And there is a significant kinetic compensation effect in the combustion process. After calculation, the activation energy value of the samples is between 16.15~29.51 kJ/mol. The RNGM model can effectively characterize the various stages of the combustion reaction and validate the experimental results.

Non-isothermal thermogravimetric analysis was employed to study the combustion reaction behavior of three different hydrochars and one anthracite in the paper. The particle size distribution analysis, scanning electron microscopy, specific surface area and Raman spectroscopy were also used to observe and characterize physiochemical properties. The Coats-Redfern kinetic model method was used to calculate the activation energy of different combustion reactions. The results showed that the combustion of fiber reject had a more effective combustion property than the other two hydrochars. The main reason was that fiber reject had higher specific surface area and lower carbon microcrystalline structure. Meanwhile, the co-combustion of different hydrochars with coal had similar combustion trends, and with the increase of hydrochar proportion, the combustion rate was higher. The results of the kinetic calculation correspond to this conclusion. It can be found that as the proportion of the three hydrochar increased, the activation energy of two stages gradually decreased.

Objective To evaluate the differences between two types of decompression for treating large mandibular odontogenic cysts. Materials and methods This retrospective, cohort study included patients who were diagnosed for large mandibular odontogenic cysts from January 2015 to April 2018 and underwent two different types of decompression based on removal or retention of the cyst wall. The primary outcome was the percentage of the residual cyst area within 1 year after surgery. We used the propensity score matching (PSM) to balance the covariates of the two groups, and the primary outcome was analyzed by the non-inferiority test. Results A total of 93 cases were included in our study. After 1 year, the wall removal group was non-inferior to the wall retaining group in terms of cyst area, cyst volume, and the difference between the HU values of the original cyst region and the normal mandible. In subgroup analysis, we found there were no differences between two groups in the percentage of patients in whom the cystic area was reduced by 90% after 1 year. Conclusion Our findings suggest that the wall removal group showed better results than the cyst wall retaining group in large mandibular odontogenic cysts.

Here we propose an inverted evanescently-coupled waveguide modified uni-traveling-carrier photodiode (IECWG MUTC-PD) and verify the character numerically. In this photodiode, the epitaxial structure is inverted from p-i-n to n-i-p, and a diluted waveguide is applied. The material of capacitance control layer is optimized to realize energy band compensation and capacitance control. Such structure possesses a large electric field in the whole depletion region and has a uniform light absorption, which improves the space charge effect. As a result, the PD achieves a 3-dB bandwidth of 71.9 GHz with a 35 µ m 2 active area at − 5 V bias voltage and an internal responsivity of 0.59 A/W in 7-µm long short PD with a 200-nm-thick absorption layer.

To effectively solve the problem of environmental pollution, the Chinese government has implemented an environmental supervision system since 2002. The environmental supervision system mainly uses the four functions of supervision, investigation, coordination, and emergency response to strengthen environmental protection supervision and law enforcement, respond to environmental emergencies, and coordinate cross-regional pollution disputes. As an important system design for China to control environmental pollution and promote the ecological transformation of economic development, the policy effect of the environmental supervision system deserves attention. This paper uses the difference-in-differences method to investigate the impact of the top-down environmental supervision system on air quality based on the 2000–2016 data for 285 prefecture-level cities in China. The results indicate that the annual average concentration of PM2.5 decreased significantly after the implementation of the environmental supervision system. The dynamic analysis shows that PM2.5 decreased most markedly in the first year after the implementation of the policy, and then the effect gradually weakened. Mechanism analysis suggests that the environmental supervision system can break the collusion between government and enterprise, encourage enterprises to carry out technological innovation, change pollutant discharge behavior and push local governments to adjust the industrial structure, enhance environmental protection awareness to reduce the PM2.5 concentration, and improve air quality. Comparing different regions, the PM2.5 in East China, North China and Northeast China are relatively high, and the pressure for air pollution control is great. Meanwhile, we find that the environmental supervision system has a significant station effect. Compared with other cities, the cities where the environmental supervision centers are located are more deterred by the environmental supervision, and their air quality has improved to a significantly greater degree. In the future, we should further strengthen the environmental supervision of high-pollution areas and non-station cities, and pay more attention to improving the long-term effect of the environmental supervision system.

Addressing the phenomenon of data sparsity in hostile working conditions, which leads to performance degradation in traditional machine learning based fault diagnosis methods, a novel Wasserstein distance based Asymmetric Adversarial Domain Adaptation (WAADA) is proposed for unsupervised domain adaptation in bearing fault diagnosis. A GAN-based loss and asymmetric mapping are integrated to alleviate the difficulty of the training process in adversarial transfer learning, especially when the domain shift is serious. Moreover, simplified lightweight architecture is introduced to enhance the generalization and representation capability and reduce the computational cost. The experiment results show that our method not only achieves outstanding performance with sufficient data but also outperforms these prominent adversarial methods with limited data (both source and target domain), which provides a promising approach to the real industrial bearing fault diagnosis.

In order to expand the range of bituminous coal injected into blast furnace, the ash melting behavior and regulation mechanism of bituminous with high calcium and low ash fusion temperature (AFT) were investigated by coal blending. And the mineral transformation behavior in the blended ashes was investigated by X-ray powder diffractometry with normalized reference intensity ratio software and FactSage software. The experimental results manifest that the softening temperature (ST) of coal D is 8 degrees C lower than that of the hot blast temperature. By adequately mixing coal B and coal D, it is easy to meet the requirements of pulverized coal injection. And coal D has become a standard bituminous for blast furnace injection. However, the high content of CaO in the coal S ash makes the AFT much lower than the hot blast temperature, which leads to the reluctance of the steel industry to inject coal S. With the increase of coal B mass ratio, the content of high-melting eutectic matters (3Al(2)O(3)center dot 2SiO(2) and tridymite) increases at high temperature, while the content of low-melting anorthite, andradite, gehlenite, and grossularite decreases, which leads to the increase of AFTs. The variation in the liquid phase under certain conditions reflects the change in AFT. In summary, by blending with coal B, the ST of blended coals S/B is higher than the hot blast temperature (1250 degrees C), so that coal S can be applied to blast furnace injection. And the injection ratio of coal S in blended coals can reach about 50%.

Four bituminous coals and one anthracite were used in this study. On the basis of the similar volatile matter contents of the four bituminous coals, the effects of ash in coal on the microstructure, carbonaceous structure, and chemical composition of pulverized coal were studied. Thermogravimetric analysis was used to study the effect of the addition of anthracite on the combustibility of four different bituminous coals. The results showed that with the increase of ash content in pulverized coal, the microstructure of carbon particles in coal was not much different. However, the analysis results of Raman spectroscopy and X-ray diffraction pattern showed that as the ash content increased, the degree of graphitization of coal carbonaceous structure gradually decreased. The combustibility of the four bituminous coals were better than that of the anthracite. When bituminous coal and anthracite were mixed and burned, the combustibility of the mixed sample decreased as the ash content increased.

Programmed death ligand-1 (PD-L1) expression is a key biomarker to screen patients for PD-1/PD-L1-targeted immunotherapy. However, a subjective assessment guide on PD-L1 expression of tumor-infiltrating immune cells (IC) scoring is currently adopted in clinical practice with low concordance. Therefore, a repeatable and quantifiable PD-L1 IC scoring method of breast cancer is desirable. In this study, we propose a deep learning-based artificial intelligence-assisted (AI-assisted) model for PD-L1 IC scoring. Three rounds of ring studies (RSs) involving 31 pathologists from 10 hospitals were carried out, using the current guideline in the first two rounds (RS1, RS2) and our AI scoring model in the last round (RS3). A total of 109 PD-L1 (Ventana SP142) immunohistochemistry (IHC) stained images were assessed and the role of the AI-assisted model was evaluated. With the assistance of AI, the scoring concordance across pathologists was boosted to excellent in RS3 (0.950, 95% confidence interval (CI): 0.936–0.962) from moderate in RS1 (0.674, 95% CI: 0.614–0.735) and RS2 (0.736, 95% CI: 0.683–0.789). The 2- and 4-category scoring accuracy were improved by 4.2% (0.959, 95% CI: 0.953–0.964) and 13% (0.815, 95% CI: 0.803–0.827) (p

BACKGROUND To describe the indications, technique, and preliminary experience in the application of the superior thyroid artery perforator flap (STAPF) for the reconstruction of various medium-sized intraoral defects. METHODS From September 2018 to September 2019, 12 consecutive cases of oral squamous cell carcinoma underwent reconstruction with a STAPF. Clinical details were collected, and postoperative function was analyzed. RESULTS The venous drainage of the STAPF is variable with drainage into the internal jugular vein in six cases, into both the internal and external jugular veins in four cases, and into the external jugular vein in two cases. Ten cases were harvested as pedicled flaps, while two cases required a venous anastomosis due to inadequate length of the venous pedicle. Ten flaps survived completely, whereas two flaps had partial necrosis that ultimately resolved with secondary healing. CONCLUSIONS STAPF is a reliable method for the reconstruction of medium-sized intraoral defects.

The Tibetans’ better aerobic exercise capacity at altitude remains ill-understood. We tested the hypothesis that Tibetans display better muscle and brain tissue oxygenation during exercise in hypoxia. Using near-infrared spectrometry (NIRS) to provide indices of tissue oxygenation, we measured oxy- and deoxy-hemoglobin ([O2Hb] and [HHb], respectively) responses of the vastus lateralis muscle and the right prefrontal cortex in ten Han Chinese and ten Tibetans during incremental cycling to exhaustion in a pressure-regulated chamber at simulated sea-level (air at 1 atm: normobaric normoxia) and 5,000 m (air at 0.5 atm: hypobaric hypoxia). Hypoxia reduced aerobic capacity by ∼22% in both groups (d= 0.8,p< 0.001 vs. normoxia), while Tibetans consistently outperformed their Han Chinese counterpart by ∼32% in normoxia and hypoxia (d= 1.0,p= 0.008). We found cerebral [O2Hb] was higher in Tibetans at normoxic maximal effort compared Han (p= 0.001), while muscle [O2Hb] was not different (p= 0.240). Hypoxic exercise lowered muscle [O2Hb] in Tibetans by a greater extent than in Han (interaction effect:p< 0.001 vs. normoxic exercise). Muscle [O2Hb] was lower in Tibetans when compared to Han during hypoxic exercise (d= 0.9,p= 0.003), but not during normoxic exercise (d= 0.4,p= 0.240). Muscle [HHb] was not different between the two groups during normoxic and hypoxic exercise (p= 0.778). Compared to Han, our findings revealed a higher brain tissue oxygenation in Tibetans during maximal exercise in normoxia, but lower muscle tissue oxygenation during exercise in hypoxia. This would suggest that the Tibetans privileged oxygenation of the brain at the expense of that of the muscle.

In response to targeted poverty alleviation, traffic + tourism and other national strategies, exploring the integration development direction of High-speed Railway and tourism in Sichuan Province, this article combed the railway tourism basic conditions of Sichuan Province, used mathematical statistics and kernel density estimation to study the spatial distribution of tourist resources and High-speed Railway. Based on urban nodes, the minimum travel time between nodes, the urban power, tourism resources and other elements, constructed travel accessibility time measurement model and attractive model, and used ArcGIS to compute the accessibility value of High-speed Railway and the coefficient of tourist attraction. Finally, for the regions with different tourism resource quality and the accessibility of High-speed Rail in Sichuan, based on the calculation results, the problem of rail tourism and the national policy, the High-speed Railway tourism plans and development strategies are proposed respectively.

Innovation acts as a crucial role in urban economy development. As the technology and education center in China, Beijing has developed diverse types of innovation districts in the past few years, which have supported all kinds of innovation activities giving new impetus into urban growth. We reviewed the forming process of innovation districts in Beijing to reveal the development characteristics of four stages. We also show the distribution of innovation districts in Beijing recently, including six main types varied from science and technology park, university park, science city, entrepreneurship community, characteristic town to science and technology building. The newly developed entrepreneurship community has several new features. Based on the generalization for development mechanisms of innovation districts, planning policies for all kinds of innovation districts have been discussed. In general, the innovation districts in Beijing are experiencing the transformation from traditional science and technology parks to innovation districts with enterprises as its core, from government leading to enterprise and community leading, from spatial agglomeration to spatial decentralization.

As a carbon–neutral fuel, biomass plays a prominent role in replacing fossil fuels. The objective of this research is to uncover the influence of pyrolysis temperature on the metallurgical properties of biochar, as well as to provide a theoretical reference for the preparation of biochar suitable for blast furnace injection. The metallurgical properties of biochar have been systematically studied through the comparative analysis of the physical and chemical properties of biochar. The results show that pyrolysis technology can effectively improve the fuel performance of biomass. As the pyrolysis temperature increases, the fuel performance of biochar increases, the carbonization degree gradually increases, and the combustion performance and reactivity gradually weaken, approaching carbonaceous materials. The Coats-Redfern kinetic equation is used for the kinetic fitting of the combustion process of biochar, and has achieved good results. This clarifies the speed control link in the combustion process of biochar.

As the voltage level of IGBT devices continues to increase, the insulation design of press-pack IGBT devices will be widely concerned as a key issue. First of all, this paper compares three typical insulation methods of gas insulation, silicon gel insulation and solid insulation under press-pack structure, and analyzes its advantages and disadvantages in detail. Secondly, based on the packaging structure of the press-pack IGBT devices, the electric field calculation method commonly used is introduced, and the limitations of this calculation method are demonstrated from both theoretical and experimental aspects. Thirdly, the electric field calculation method based on semiconductor simulation software is introduced, and the distribution of electric field on the chip surface under the common influence of chip terminal structure, package structure and material characteristics is analyzed.

A broadband circularly polarized antenna array is presented in this paper. An open-loop antenna revolving laid in the array is chosen as the radiating elements to achieve a better wide-angle axial ratio and suit the distribution of CMOS chips and circuit in T/R modules built in tile. The proposed array achieves 12.5% bandwidth and radiation efficiency greater than 90% across the entire band-width. A 6*4 prototype was fabricated and tested to validate the design.

In order to reduce industrial pollution, various policies have been issued in many countries and regions encouraging businesses to install pollution control equipment (PCE). However, some businesses do not use PCE as required, which is currently a blind spot for the regulatory authorities. Advanced metering infrastructure (AMI) provides large amount of electrical data which can well characterize the operating states of PCE. To this end, the anomaly detection of pollution control equipment (ADPCE) based on AMI data analytics is proposed in this paper. Clustering and Gaussian models (CGM) are used as the basic tools to identify the abnormal conditions of PCE, and convolutional neural network (CNN) is further introduced to detect the anomalies when the PCE is suspected to be replaced by a similar process equipment. The case study using realistic and simulated data demonstrates the validity of the proposed methods. The achievements made in this paper can effectively help the government supervise the implementation of pollution control by relevant businesses.

Background: To explore the risk factors of prognosis in elderly patients with acute respiratory failure (ARF), and to develop a nomogram model to predict the short-term mortality risk of ARF.Methods: A total of 1432 patients were included in this study from MIMIC-III database. 759 patients were categorized into the training set and 673 patients were categorized into the validation set. Demographical, laboratory variables, SOFA score and APS-III score were collected within the first 24 h after the ICU admission. The univariate and multivariate logistic regression were used to identify risk factors from the training data set. A nomogram model was developed to predict the mortality risk of ARF patients within 30 days according to the risk factors.Results: Multivariate logistic regression analysis showed that the heart rate, respiratory rate, systolic pressure, SPO2, albumin and 24 h urine output were independent prognostic factors for 30-day mortality in ARF patients. A nomogram was established based on above independent prognostic factors. This nomogram had C-index of 0.741 (95% CI: 0.7058–0.7766), and the C-index was 0.687 (95%CI: 0.6458-0.7272) in the validation set. The calibration curves both in training and validation set were close to the ideal model. The SOFA had a C-index of 0.653 and the APS-III had a C-index of 0.707 in predicting 30-day mortality. The predictive performance of our nomogram is better than the SOFA score and APS-III score. Conclusions: Our nomogram performed better than APS-III and SOFA scores and should be useful as decision support on the prediction of mortality risk in elderly patients with ARF.

In a distributed OFDMA network, wireless channel is divided into multiple time-frequency resource block for transmission. Because there is no information interaction between nodes in a distributed network, and independent resource allocation of each nodes will result in collisions. Reasonable allocation resources can effectively reduce the collision ratio and improve system throughput. For the distributed network, we propose a time-frequency resource allocation method based on deep reinforcement learning (DRL), with definition of the state space, action space, and rewards. Each node uses this algorithm to realize time-frequency resource allocation. The nodes in the network use this algorithm without information interaction between the other nodes. Different nodes have a preference for the occupation of resource blocks, which reduces the probability of collisions in resource allocation. When the traffic intensity fluctuates, we introduce the concept of virtual traffic, which improves the continuity of the node’s selection of resource blocks. This continuity reduces the impact of traffic fluctuations on the node’s decisions. Compared with the random access slotted-aloha protocol, simulation results show the network throughput has been significantly improved. When the traffic intensity remains constant or fluctuates, the throughput can approximate that of the centralized network.

Based on the panel data of 134 counties (cities and districts) from 1998 to 2017, the temporal-spatial variation characteristics and influencing factors of agricultural eco-efficiency in Shandong Province were analyzed by using various methods, such as the super-efficiency SBM (slacks-based measure) model considering undesired output and the STIRPAT (stochastic impacts by regression on population, affluence, and technology) model, which helps clarify the improvements needed for agricultural eco-efficiency and provides a basis for the development of ecological agriculture in Shandong Province. Results showed the following: (1) During 1998-2017, the agricultural eco-efficiency of Shandong Province showed a fluctuating increasing tendency, but the overall efficiency value wasrelatively low. (2) The agricultural eco-efficiency of Shandong Province had a significant regional disparity, and its spatial agglomeration gradually weakened. The spatial distribution had a sporadic distribution of high value areas at first and then gradually formed the “low-high-low-high” zonal distribution from west to east. (3) The net income per capita of farmers and the added value of the primary industry had a significantly positive correlation with the agricultural eco-efficiency of Shandong Province, while the mechanization level, the planting area per capita, the level of financial support to agriculture and the planting structure exhibited a mainly negative correlation with the agricultural eco-efficiency of Shandong Province. Moreover, the added value of the primary industry and the financial support to agriculture in the 0.75 quantile had no significant influence on the agricultural eco-efficiency of Shandong Province, and the planting structure in the 0.25 and 0.75 quantiles also had no significant influence. RESUMO: Com base nos dados do painel de 134 municípios (cidades, distritos) na província de Shandong de 1998 a 2017, as características de variação espacial e temporal da ecoeficiência agrícola na província de Shandong foram analisadas usando vários métodos, como o modelo SBM (Medida baseada EM estacas) supereficiente. Considerando indesejados produção e modelo STIRPAT (Impactos estocásticos da regressão da população, da afluência e da tecnologia), ajudará a esclarecer a direção da melhoria da eco eficiência agrícola na província de Shandong e fornecerá uma base para o desenvolvimento da agricultura ecológica. Os resultados mostraram que (1) em 1998-2017, a ecoeficiência agrícola da província de Shandong mostrou uma tendência ascendente na flutuação, mas o valor geral da eficiência foi baixo. (2) A distribuição espacial da distribuição esporádica inicial da área de alto valor se formou gradualmente de oeste para leste, distribuição zonal “ “baixo-alto-baixo-alto”” (3) O lucro líquido per capita dos agricultores e o valor acrescentado da indústria primária foram significativamente correlacionados positivamente com a ecoeficiência agrícola da província de Shandong. O nível de mecanização, a área de plantio per capita, o apoio financeiro ao nível agrícola e a estrutura de plantio, entre eles, o valor acrescentado da indústria primária e o apoio financeiro à agricultura em 0,75 quantil, a estrutura de plantio em 0,25 e 0,75 quantil na ecoeficiência agrícola da província de Shandong não é significativa.

The development of "intelligent manufacturing" has promoted the intelligent upgrade of China's manufacturing industry, which has caused the emergence and increase of China's emerging professional positions, and most enterprises have faced a situation of lack of emerging professional talents. In order to create 2025 more synthetic technical talents for China, higher vocational colleges should change the traditional way of thinking, reform in the aspects of education and teaching mode, talent training standards and school-enterprise cooperation, so as to cultivate all-round and comprehensive talents that meet the needs of the market.

Based on SURF feature detection operator, image feature points are extracted, matched and mosaic Wavelet transform is used to fuse the registered images and eliminate the edges between stitched images. Overall, the splicing effect is well.

Purpose The aims of this study are to review our surgical experience in maxillary and midface reconstruction using free vascularized tissue and to compare the postoperative outcomes based on superficial temporal versus cervical recipient vessels. Materials and Methods We performed a retrospective review of patients who underwent maxillary and midface reconstruction with free vascularized tissue from March 2001 to July 2014. Two groups were analyzed: those in whom superficial temporal vessels were used as the recipient vessels and those in whom cervical vessels were used as the recipient vessels. Patient gender and age, cause and classification of the defect, flap choice for reconstruction, recipient vessels, postoperative course, and complications also were recorded and analyzed. A 2-tailed Fisher exact test was used to compare outcomes between the 2 groups. Results On the basis of the different recipient vessels, 94 patients were divided into 2 groups: those with superficial temporal recipient vessels (n = 44) and those with cervical recipient vessels (n = 50). The overall flap survival rate was 99.0%. The overall complication rate for vascular anastomoses was 5.3%. The complication rate in patients with cervical recipient vessels was higher than the complication rate in those with superficial temporal recipient vessels (8.0% vs 2.27%, P = .37). In addition, in patients in the group with superficial temporal recipient vessels, the postoperative scar in the pre-tragal region was rated as more satisfactory than the postsurgical scar in those in the cervical recipient vessel group. Conclusions We recommend that the superficial temporal vessels be the first option for recipient vessels in free vascularized tissue maxillary and midface reconstruction because of proximity, superficial positioning, and suitability for anastomosis and monitoring and because these vessels are rarely compromised by prior operations or radiotherapy.

Background This study investigated the effect of flight transport stress on beagles' routine blood indexes and biochemical parameters and evaluated the anti‐stress effect of dangshen (Codonopsis pilosula). Methods We selected 12 beagles and divided them into two groups. One group was treated with dangshen decoction two hours before the flight, and the other group was untreated. Their routine blood indexes and clinical biochemical parameters were tested and analyzed before transport, after unloading and after adaptation for 1, 2, 3, 4, 5, and 6 days after administering dangshen. Results We found that flight transportation stress adversely influenced many of the beagles' routine blood indexes. These recovered during adaptation, with dangshen administration assisting recovery of most indexes. Flight transport stress also adversely influenced biochemical indexes in the beagles. Again these recovered during adaptation, and dangshen aided in the recovery. Conclusion Thus, we found that flight transport adversely affected the beagles' blood indexes, and dangshen reversed the damage from transport stress.

According to the requirements of tractor automatic steering hydraulic system, a proportional integrated control valve was designed. Based on the non-linearity of the hydraulic system, the state equation of the integrated proportional control valve that works in the open-center hydraulic steering systems was established. With the establishment of the MATLAB/Simulink models, the static and dynamic performance of the integrated proportional control valve were simulated. Furthermore, the indoor test platform was built on the basis of the proposed test scheme, on which the properties of steady flow, load flow and pressure loss of the integrated proportional control valve were analyzed. The simulation and experimental results show that the valve flow can be better to follow the drive voltage; when the spool opening unchanged, load step change, the simulation and test results of the flow is about 10L/min. The differential pressure relief valve pressure compensation performance is better. Finally, the actual test of the proportional integrated control valve is carried out. The experimental results show that the average deviation of the target tracking is less than 2.192° and the maximum deviation is less than 2.44°. The valve proposed in this study performed well referring to the tracing and quick response characteristics, which meets the requirements of tractor navigation control.