Search

Objective To investigate the safety of regular plasma donors aged 55 to 60, so as to provide reference for retention and recruitment of elderly plasma donors in China. Methods Plasma donors from 9 blood products manufacturing enterprises from 2018 to 2020 and the local general population were selected as the research objects. The total protein level, albumin and globulin ratio(ALB/GLB, A/G) and adverse reactions of plasma donation of regular plasma donors and local general population were retrospectively analyzed. Results The total protein level (g/L) and A/G of plasma donors aged 56 to 60 and the general population were 61.21±5.62 vs 60.04±6.93 and 1.610±0.299 vs 1.635±0.330, respectively, and the differences were statistically significant. The total protein level of regular plasma donors was higher than that of general population, but A/G was slightly lower than that of general population. From 2018 to 2020, there were a total of 23 056 302 plasma donations in 108 plasma stations, and adverse reactions occurred in 20 932 donations, with a total incidence of 0.09%, with no serious adverse reactions. Conclusion It is safe for regular plasma donors aged 55 to 60 to donate plasma, and the retention of them can alleviate the pressure of plasma supply.

Aiming at the current problem of low grinding efficiency of domestic ball screw grinding, a new type of ball screw grinding device is proposed. On this basis, a four-factor three-level quadrature test is designed for the four main process parameters of grinding torque, grinding speed, grinding time and abrasive particle size in the grinding process of the lead screw; a set of optimal process parameters is obtained by taking the surface roughness of the lead screw as the detection index. Then the friction torque measurement test is carried out on the ball screw before and after grinding. The effect of grinding on friction torque performance of the ball screw is explored.

In order to solve the problems of large quantity of mass satellite production, short cycle, and shortage of personnel, a new type of satellite automatic test system is proposed. The hardware architecture of the system is composed of a comprehensive test server, remote-control telemetry ground inspection equipment, and an automated test terminal. The software architecture is based on the joint development by TestStand and LabVIEW. The code module edited by LabVIEW realizes the function of creating information channels with remote control and telemetering ground inspection equipment, server databases, etc. Following the operation process of the test instructions， TestStand edits the automated test sequence, realizing the highly automated processes such as remote control instruction sending, telemetry data interpretation, process monitoring, test report generation, and multi-satellite parallel testing. The test sequence of this architecture has high flexibility and strong versatility, and can meet the demands of a variety of satellite automated test conditions. It has been successfully applied in the mass production and testing process of Jilin-1 Gaofen 03 series satellites. While greatly improving the test efficiency, it saves a lot of manpower.

Objective: To evaluate the regulating effect of black jerusalem artichoke oligosaccharide on the blood lipid level in hyperlipidemic mice and give a preliminary investigation to the mechanism of lowering blood lipid. Methods: According to the evaluation method of auxiliary hypolipidemic function in the national standard, C57BL/6 mice were fed with high-fat diet to establish a mixed hyperlipidemia animal model. The model animals were randomly divided into MC group (MC), active control group (AC), black jerusalem artichoke oligosaccharide low, medium and high dose groups (OSL, OSM, OSH). At the same time, a blank control group (CK) was set up. There were eight mice in each group, and the dose of gavage was 0.2 mL/d for each mouse. Gavage had lasted for 46 days. CK group and MC group were given normal saline, AC group was given 1.0 mg/(kg·bw) atorvastatin, and black jerusalem artichoke oligosaccharide groups were given 0.25, 1.25, 2.50 g/(kg.bw) black jerusalem artichoke oligosaccharide solution respectively. The blood lipid level and the contents of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in serum were detected. The morphological changes of mouse liver were observed. The expression of sterol regulatory element binding protein-1c (SREBP-1c) and peroxisome proliferator activated receptor-γ (PPAR-γ) in mouse liver were detected. Results: The triglyceride (TG), total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) in the MC group were significantly higher than those in the CK (P

Epoxy resin coatings have been widely researched and applied in the field of corrosion prevention due to their excellent characteristics such as strong adhesion to the substrate， easy application and good corrosion resistance. The modification of epoxy resin with modified nanomaterials can greatly improve the anti-corrosion performance of the epoxy resin coating. Based on the principle for nanomaterials to improve the anti-corrosion performance of epoxy coatings， the research progress on modification mechanisms of several nanomaterials such as graphene oxide， nano-silica， hexagonal boron nitride and molybdenum disulfide as well as the research progress on the modification of epoxy resin coatings were introduced and listed. Finally， the future research and development direction of epoxy coatings were prospected.

Objective To summarize the characteristics of delayed facial paralysis (DFP) after retrosigmoid approach surgery for vestibular schwannoma and screen its related influencing factors. Methods A total of 171 patients with vestibular schwannoma treated in The First Affiliated Hospital of Zhengzhou University from January 2019 to May 2021 were included in the study. All patients underwent retrosigmoid approach surgery under neuroelectrophysiological monitoring. Before and after the surgery, facial paralysis was classified according to House⁃Brackmann (H⁃B) grade of facial nerve function. Univariate and multivariate forward Logistic regression analysis was used to screen related risk factors of DFP after vestibular schwannoma surgery. Results Patients were divided into DFP group (n=19) and non⁃DFP (NDFP) group (n=152) according to whether there was DFP after surgery. The tumor diameter in DFP group was smaller than that in NDFP group (t=6.623, P=0.001), the proportion of small tumors (χ2=18.585, P=0.000) and the proportion of slight adhesion between tumor and facial nerve (χ2=21.442, P=0.000) were higher than those in NDFP group. Logistic regression analysis showed small tumor (OR=15.797, 95%CI: 3.324-75.081; P=0.001) and slight adhesion between tumor and facial nerve (OR=11.690, 95%CI: 3.413-40.042; P=0.000) were risk factors for DFP after vestibular schwannoma surgery. Following up to one year after surgery, the recovery rate of facial nerve function (H⁃B grade Ⅰ-Ⅱ) in DFP group was 17/19. Conclusions The patients with small tumor volume and slight adhesion between tumor and facial nerve are prone to DFP, and the prognosis of facial nerve function in such patients is good.

Conducting the soil environmental condition survey and accessing the distribution and potential sources of heavy metals and arsenic in soils in Xiongan New Area are of great significance for the land resources and environment management of the district. Based on the data of soil survey samples in the Xiongan New Area, spatial distributions of the elements (As, Hg, Cd, Cu, Pb, Zn, Ni and Cr) are analyzed and computed by using geostatistics and ArcGIS techniques. A combination of spatial analysis, multivariate statistical analysis, and positive matrix factorization model is used to assess the sources of these elements. The result show that the soil quality is good and the pollution risk is low. Approximately 4.35% of the soil samples for Cd and Cu have total concentrations higher than the risk screening values for soil contamination of agricultural land, and lower than the risk control values for soil contamination of agricultural land. However, moderate and significant enrichment in Cd, Cu, Pb, Zn and Hg in the surface soils was observed compared with their background values of Hebei province. The contents of As, Cd, Cu, Pb, Zn, Ni and Cr exhibite a gradually increasing trend from north to south. These elements principally concentrate in the southwest of the study area. The distribution of Hg is relatively dispersed, and the high-values are mainly located in the urban and industrial areas. The vertical distributions of heavy metals and arsenic in soils of different landuse types are dominantly controlled by physicochemical factors such as pH, organic carbon, and Fe/Al oxides. Anthropogenic sources contribute 67.12% of the heavy metal concentrations in soils, indicating the great influence on soil heavy metal accumulation. Hg is dominated by atmospheric deposition related to anthropogenic emissions such as coal combustion and smelting activities. As is principally affected by industrial activities. Cd, Cu, Pb and Zn are influenced by anthropogenic activities such as industrial production, sewage irrigation and vehicle emission.

Pancreatic cancer has a low surgical resection rate and a very poor prognosis. In recent years,with the emergence of new drugs, the diversification of treatment methods, the development of multidisciplinarydiagnosis and treatment models, neoadjuvant treatment and translational treatment of pancreatic cancer haveattracted widespread attention. This article systematically sorts out the clinical application of neoadjuvant therapyand translational therapy in pancreatic cancer, as well as the timing of surgery after translational therapy, and proposes to divide resectable pancreatic cancer into low-risk groups and high-risk groups. Patients in the low-riskgroups are recommended to prioritize surgical resection. The high-risk groups and patients with borderlineresectable pancreatic cancer have a lower rate of R0 resection. Neoadjuvant therapy can significantly increase therate of R0 resection. For patients with unresectable pancreatic cancer, a comprehensive assessment should be madeon whether conversion therapy can be performed, and radical surgery is feasible for some effective patients.However, there is no consensus on the selection of neoadjuvant treatment and translational treatment for pancreaticcancer, the treatment cycle, and postoperative adjuvant options. It is believed that with the emergence of highlevel evidence-based medicine, neoadjuvant therapy and conversion therapy will be more widely used in thetreatment of pancreatic cancer.

For infrastructure projects, the traditional strategy is difficult to meet the requirement of operation and maintenance. To solve this problem, an evolutionary game model of operation and maintenance enterprise strategy selection in PPP mode was constructed. In the proposed model, Matlab was used to simulate the stability trend of the evolutionary game. The results show that transformation cost input, additional profit, direct profit coefficient, and synergetic profit coefficient were the key factors affecting the strategic selection of operation and maintenance enterprises. In addition, countermeasures and suggestions were put forward from the aspects of increasing policy support and capital investment for intelligent operation and maintenance, stimulating innovative management power for intelligent operation and maintenance, and constructing collaborative information sharing platforms. [ABSTRACT FROM AUTHOR]

Objective To analyze the changes of lipid profiles and atherogenic index of plasma (AIP) in Human Immunodeficiency Virus (HIV)/Acquired-Immune Deficiency Syndrome (AIDS) patients after 48 and 96 weeks of antiretroviral therapy (ART), to evaluate the risk factors of cardiovascular disease in HIV / AIDS patients after art treatment. Methods Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were assessed, and Non-HDL-C (NHC), Castelli's risk index I and II (CRI-I, CRI-II), insulin resistance surrogate (IRS), AIP were calculated in HIV/AIDS patients. Results The incidence of abnormal TC, TG, HDL-C, LDL-C, NHC and AIP increased, and the difference of TC,TG,LDL-C and NHC was statistically significant (P<0.05); the incidence of HDL-C, CRI- I and CRI- H abnormalities decreased, and there was significant difference in HDL-C (P<0.05) in 384 patients after 48 and 96 weeks of ART. At baseline, 48 weeks and 96 weeks after art, AIP was significantly different in different age groups (P< 0.05), and there was a significant positive correlation with age (r=0.208, 0.183, 0.170, P<0.001). There was significant difference in AIP between normal TG group and abnormal TG group (P<0.05), and there was a significant positive correlation with baseline TG (r=0.841, 0.641, 0.602, P<0.001). AIP had significant difference between normal HDL-C group and abnormal HDL-C group (P<0.05), and had a significant negative correlation with baseline HDL-C (r=-0.608, -0.390, -0.326, P<0.001). It was not related with CD4 counts, HIV-RNA virus load, baseline TC and LDC-C. Logistic regression analysis was carried out determine the risk factors of abnormal AIP value. The results shows that compared with 18-<30 years old, HIV/AIDS patients over 30 years old were the risk factors of abnormal AIP after 48 and 96 weeks of ART (OR=2.02, 95% CI: 1.30-3.13, P<0.01; OR=1.77, 95%CI: 1.13-2.78, P<0.05). Conclusions Dyslipidemia is present in HIV/AIDS patients after ART. Age is a risk factor for plasma atherosclerosis in HIV/AIDS patients. Lipid levels need to be monitored regularly after ART, especially to HIV/ AIDS patients with ≥ 30 years, to reduce the risk of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Because of their excellent lightness and crashworthiness, metal thin-walled structures have been widely used in the collision kinetic energy dissipation system of vehicles such as automobiles, airplanes and trains. In this paper, the deformation mode, energy absorption capacity, specific energy absorption and average compression force of sunflower thin-wall sandwich structure under radial impact load in two directions are studied. The results show that the wall thickness, the number of petals, the loading speed and the loading direction of the thin-wall sandwich structure of sunflower have certain effects on the impact resistance of the structure. Under the condition of constant mass, with the increase of the thickness of the outer shell, the energy absorption efficiency of the thin-walled structure under the tip pressure is reduced. The specific energy absorption under gap side pressure was 44.6% higher than that under tip side pressure. With the change of the number of petals, the energy absorption efficiency of thin-walled metal structure has an optimal value. [ABSTRACT FROM AUTHOR]

The flame-retardant high temperature vulcanized (HTV) silicone rubber was prepared with the addition of Al(OH)3, Mg(OH)2, nitrogen containing flame-retardant filler and phosphorus-nitrogen containing flame-retardant filler, respectively. The effects of the four halogen-free flame retardant fillers on the flame retardancy, mechanical properties, curing characteristics and thermal stability of the rubber were investigated by TGA. The flame retardant mechanism of HTV silicone rubber with the four above-mentioned fillers was also studied. Results show that when the vertical flame retardant properties of all the rubbers meet grade FV-0, the vertical combustion time of the flame-retardant HTV silicone rubber modified by phosphorus-nitrogen containing flame-retardant filler was the shortest, the tensile strength, elongation at break and tear strength were 6. 43 MPa, 408% and 16. 5 kN/m, respectively. The oxygen index of the flame-retardant HTV silicone rubber modified by Al(OH)3 was 45%, higher than the others. Among the four kinds of the flame-retardent HTV silicone rubber, the silicone rubber modified by nitrogen containing flame-retardant filler has the lowest curing speed. TGA results indicate that the flame-retardant HTV silicone rubber modified by Mg (OH)2 has good thermal aging stability. [ABSTRACT FROM AUTHOR]

We aimed to explore changes in basic soil productivity ( BSP) under different fertilization regimes in the Poyang Lake region, Jiangxi Province, China. Soil samples were collected from a long-term fertilization experiment (since 98) that included treatments of no fertilization (CK), chemical fertilization ( NPK), and combined chemical and organic fertilization ( NPKM) . Then, a three-year pot experiment (from 0 to 0) with double rice cropping was conducted with two different fertilization regimes (no fertilization, F0; fertilization, F1) using CK, NPK and NPKM soils. Grain yield and BSP were analyzed among soils with different fertilization regimes to identify the key factors driving changes in BSP. Results showed that grain yields in NPKM soil were higher than in NPK and CK soils regardless of fertilization in the pot experiment. Under the F0 condition, annual grain yields of NPKM soil were 7.7%-.9% and 0.8%-66.7% higher than CK and NPK soils, respectively. The BSP values of CK, NPK and NPKM soils in three years were .8%-5.%, 5.%-6.6% and 59.%-88.%, respectively. NPKM soil had significantly higher BSP than NPK and CK soils. Furthermore, there were significant positive correlations between soil organic matter and BSP as well as between organic carbon balance and BSP. These results suggested that long-term application of chemical and organic fertilizers could improve BSP in the double rice cropping system of the Poyang Lake region. In addition, soil organic matter and organic carbon balance are important factors for improving BSP in this region. [ABSTRACT FROM AUTHOR]

In order to study the pore structure characteristics and pore connectivity of low-permeability coal, low-field nuclear magnetic resonance technology was used to analyze the raw coal sample. The T2 curve of the coal sample under saturated water and residual water conditions was used to obtain the free fluid value, irreducible fluid value, effective porosity, pore size distribution, and permeability etc. A quantitative calculation model of pore connectivity was established on the basis of these works. The results showed that the porosity of the experimental coal sample was changing from 6.30% to 11.02%, and the pore size was distributed in three stages, the pore size was mainly concentrated in the 0 nm to 100 nm segment. The fissures and the pores which including macropore and medium ones were not developed. Adsorption pore was inversely proportional to porosity. Percolation pore was proportional to porosity. The pore connectivity of experimental coal sample was varying between 31.50% and 62.05%. The pore connectivity was affected by the pore size, and the pore connectivity rate of the experimental coal sample with a pore size below 100 nm was up to 58.45%. The connectivity rate of pores with pore size over 100 nm was above 94%. Pore connectivity has a good positive correlation with porosity, effective porosity, and permeability.

The cable recovery operation will cause the cable structural deformation. Due to different recovery methods, there are different deformation states such as coil, reel and bending. Theses states cause differences in cable distribution parameters, which have influences on the main line voltage loss in long-distance power supply. The problems of existing analytical calculation of cable distribution parameters are complicated implementation process, limited extraction accuracy of distribution parameters and not being applicable to large deformation in the cable recovery process. In order to solve the above problems, this paper proposes a method to analyze the changes of cable distribution parameters in the process of cable recovery by using ANSYS and the working principle of monorail crane and cable car. The influence of cable car recovery method and monorail crane recovery method on cable distribution parameters and heat dissipation is analyzed. The influence of the cable recovery method on the long-distance power supply of the fully mechanized working face is analyzed by using ETAP. The analysis results show that the coil, reel, and bending deformation of the cable caused by the recovery operation will cause small changes in the capacitance value, the conductance value and the resistance value, and cause significant reduction of the inductance value. When the monorail recovery method is adopted, the cable deformation is greater and the inductance value per unit length is smaller with a drop of up to 29%. Compared with the cable car recovery method, the monorail crane recovery method has more advantages in terms of automation, cable heat dissipation and main line voltage loss. The changes in cable distribution parameters lead to changes in main line voltage loss. With the increase in cable recovery distance, the total voltage loss of each main line of the long-distance power supply system shows a decreasing trend as a whole. There is an increase in some parts of the main line, which influences the longest power supply distance and equipment carrying capacity.

At present, mine hoist's wired communication system is complicated in wiring and maintenance, however, due to fixed transmission power, frequency and radiation direction of antenna, the mine hoist's wireless communication system has disadvantages of limited wireless communication distance, the signal cannot be flexibly covered according to shape and length of shaft, and communication signal is unstable. In view of the above problems, an adaptive wireless communication system for mine hoist was designed.The data of all equipments in the system is input through Ethernet interface, and wireless communication part adopts the adaptive antenna with automatic sensing of received signal strength, automatic adjustment of working frequency and radiation beam, which can wirelessly interconnect wireless camera,wireless telephone and other mine-used equipments, so as to realize video monitoring, data monitoring and voice communication of main equipments such as hoist, cage ear, oil cylinder, steel wire rope and hoisting sheave. When the hoist is in operating, the system can automatically adjust working parameters of the antenna located at the top of the shaft according to structure, depth and size of vertical shaft, so that the antenna can always be aligned with the moving hoist, communications equipment operating frequency and power is always in the best state, ensuring good coverage of wireless signals.The field application verifies when the hoist is in operating, the ground dispatching personnel can real-timely monitor internal conditions of the hoisting sheave, shaft, cage ears and hoist, and can realize telephone and broadcasting with the relevant personnel in the cage at any time, the image is clear, the voice communication is smooth, and the equipment power consumption is low.

More effective methods are needed to evaluate the water demand to improve water resource management as the population and economy grow leading to water shortage. Time series models are useful tools in the estimation and forecasting of reference evapotranspiration series and their changes. However, due to the dynamic nature of reference evapotranspiration, accurate estimation of variance has been being a challenging task and requires new modelling approaches in application. The Generalized Autoregressive Conditional Heteroscedasticity (GARCH) family models, which provide an appropriate framework for focusing on the conditional variance remaining in the residuals of the time series models, were applied in this study to comply with the estimation. Daily climate data including average air pressure, air temperature, relative humidity, wind speed, and saturation deficit were provided by the Chinese National Climatic Data Center (CDC). The observed meteorology dataset from 1953-2007 in Yichang station in Hubei province in China was chosen as the selected station for its data available. The FAO Penman-Monteith method was applied to obtain the potential reference evaporation series. Then, for deseasonalization of the seasonal variation in the series, a Seasonal Autoregressive Moving Average (SARMA) model was set up to estimate the conditional mean of the potential reference evaporation. Besides, four types of GARCH models (GARCH, Threshold GARCH, Exponential GARCH, and Power GARCH models) were investigated to take the advantages of GARCH family models to simulate the conditional variance of the potential reference evaporation series. Also, six criteria were utilized to compare the model performance. It was shown that the data of potential reference evaporation series in Yichang Station had skewness, and right tail on an annual cycle, indicating the necessary of SARMA model used in this study. The final SARMA model was chosen by the minimum of AIC values. The results of SARMA model showed that it was efficient for modelling the monthly mean total daily reference evaporation series as a small redisudal mean square error (RMSE) between the observed and estimated values (0.089 mm). However, the heteroscedasticity was present in the residuals of SARMA model according to the Engle test, which suggested the necessary of GARCH models used for modeling of reference evaporation series. Results of GARCH models showed its ability to remove the heteroscedasticity from the reference evaporation residuals. The asymmetric effects of solar radiation series were also confirmed by the application of GARCH family models for estimating the residuals of SARMA model. Among the SARMA and GARCH models, the EGARCH model was best to predict the series because the prediction of the EGARCH model had a narrower confidence level. The better interval estimation would provide more useful information for analysis of hydrological processes and was undoubtedly more favorable to further uncertainty analysis in water resource management. The multi-criteria evaluation for model performance also proved that the EGARCH model was best among SARMA and GARCH models, and it was recommended to use the EGARCH model to estimate the potential reference evaporation series in practice. In conclusion, the results indicated that the application of GARCH family models would be a promising alternative over the traditional approaches in the estimation of potential reference evaporation series, and can be a useful tool to existing water resources management. Further studies about the comprehensive application of GARCH models should focus on the model performances with different observed dataset among stations. It also suggests to use more GARCH models to estimate the hydrological series and the results of accuracy estimation should be linked with water risk analysis. [ABSTRACT FROM AUTHOR]

Mammalian oocyte maturation is a complex physiological process regulated by a vast number of factors, which aims to produce a fertilizable oocyte from the oocyte finished already the meiotic division and arrested in the secondary metaphase. The meiotic division arrested in secondary metaphase is mainly dependent on the cytoplasm cAMP at high concentration. Meanwhile, many factors and their signaling pathways, as well as cellular structures, are involved in promoting the meiotic division and oocyte maturation, such as LH, EGF, ERKl/2, p38MAPK, Ca2s and gap junction. Oocyte maturation and its molecular regulation were reviewed, so as to provide useful references for the research and treatment of female infertility and the in vitro maturation. [ABSTRACT FROM AUTHOR]

Aiming to the burst signal detection in high-dynamic environments, an NLFM signal parameter estimation algorithm based on high order items eliminated sequentially was presented, which converting the problem into a relatively simple issue, that is LFM signal parameter estimation. The proposed scheme has the feature of concise principle and low computational complexity, and was easily used for projects. Besides, a burst communication signals detection algorithm named as adaptive FFT PAPR (peak to average ratio) threshold detecting was raised, which could work well even the received signal power varying severely. Simulation results show that both of the two schemes could achieve signal detection and parameter estimation accurately in high-dynamic circumstances while the SNR (signal to noise ratio) is only -27dB. [ABSTRACT FROM AUTHOR]

To solve problems of lack of water resources for agriculture in arid areas, it is necessary to utilize and compare the advantage of water using in different areas that are linked together through the commodity trade. The active regulation of commodity trade and water consumption in production is capable to build rational virtual water use embodied in commodity trade. It will ease the conflict between water supply and demand. This requires the implement of integrated management about real water and virtual water to achieve regional equilibrium of virtual water utilization. Considering the water utilization should fit the scale of water resources endowment and economy, the equilibrium level based on Gini coefficient is used to evaluate the regional equilibrium of virtual water flow against water resources endowment and Gross Domestic Product. To improve the regional equilibrium, a comprehensive regulation model about agricultural water consumption was setup. The decision variables belonged to the aspects of water use efficiency, plant area of grain and yield level per unit area. Through the adjustment of the decision variable, the relevant equilibrium level can be calculated using a sub-model. In the sub-model, based on the equilibrium analysis of grain supply-demand, the grain flow direction and quantity were estimated using the optimization model for minimizing the total transportation costs. Combined with the agricultural water consumption per unit mass evaluation on every district, the amounts of virtual water flow among districts, and the total amounts of virtual water inflow and outflow of every district were setup. Then the equilibrium level about water resources endowment and Gross Domestic Product were calculated and became the output of the sub-model. To minimize the value of equilibrium level, the particle swarm optimization was used to search the non-inferior solutions about the combination of various decision variables. Then the final solution was selected in the non-inferior solutions. To test the performance of the method, a case study was made in Gansu Province in semi-arid Western China. The grain supply and demand, agricultural water consumption and water resources endowment of every county and city in Gausu province were estimated. They were the inputs of the comprehensive regulation model. The decision variables included planted areas, irrigation water amounts per unit area, and the yield per unit areas of wheat and corn in every district. The planted area can increase or reduce within a certain range, the irrigation water amounts per unit area and the yield per unit areas can only have a certain amount of reduction and growth respectively. The objective was that the agricultural water consumption in every district after regulation should not increase. The transportation of corn and wheat were railway and highway, and the specific means of transportation between every two districts was determined by the lowest cost per unit mass. By using the comprehensive regulation model, the non-inferior solutions gave the various combinations about decision variables. The grain areas, grain productions, water consumptions and virtual water flows in different solutions were quite different, but the equilibrium increased significantly comparing to that before regulation. In these solutions, the overall pattern about the virtual water flow in Gansu did not change a lot, and the virtual water import and export districts kept unchanged. The significant change emerged in the grain production and virtual water flows in some districts. The results showed that the agricultural water comprehensive regulation was capable to improve the equilibrium of virtual water matching the water cap, and can be a useful supplement to existing integrated water resources allocation methods. Further studies about the comprehensive regulation need to focus on the introduction about more realistic constraints, finer regulation mechanism and more accurate flow of grain trade. [ABSTRACT FROM AUTHOR]

A combined kinematic/adaptive neural sliding mode control law is proposed for leader follower based formation control of multiple nonholnomic mobile robots. The radial basis function neural network (RBFNN) was introduced to approximate the nonlinear uncertain part of dynamics of the follower and its leader, and the adaptive robust controller compensated modeling errors of uncertainties by neural network. The results show that this approach not only solves parameter and non-parameter uncertainties of mobile robots, but also ensures the desired trajectory tracking of robot formation in the case of maintaining formation. The stability of the control system was proved by using the Lyapunov theory. [ABSTRACT FROM AUTHOR]

To study the impact of information technology application on farmer households' income from agricultural business, this paper collected and surveyed 1 072 valid questionnaires from 6 provinces and cities. By establishing multi-line regression model analysis, the paper found that (1) the agricultural infonnationization level needed to be improved; (2) at present the traditional elements have greater impact on farmer households' income than informationization elements; (3) the income of farmer households who search for agriculture information through varies channels is 45.8% higher than those who never search for information; (4) in western regions more foundational information infrastructure and primary information technology promotion are needed; (5) the effect for households living in central and eastern China to improve conditions of agricultural production by using information technology is better. Based on the above mentioned analysis the paper put forward some policy suggestions. [ABSTRACT FROM AUTHOR]

From June, 2007 to October, 2009, a measurement with static chamber/gas chromatograph techniques was conducted on the soil CH4 flux in a typical secondary hardwood forest in Northeast China under the effects of different harvest disturbances, i. e. , uncut (control), clear cutting (including both farming and reforestation after clear cutting), 50% stand volume removed, and 25% stand volume removed. In all of the four treatments, the soil was the sink of atmospheric CH4, but cutting decreased the soil CH4 uptake flux, with the order of uncut (-85. 03 μg CH4•m-2 •h-1 ) > 50% stand volume removed (-80. 31 μg CH4 •m-2 •h-1 ) > 25% stand volume removed (-70. 97 μg CH4 •m-2h-1) > farming after clear cutting (-65. 57 μg CH4•m-2•h-1) > reforestation after clear cutting (-62. 02 μg CH4•m-2•h-1). During the study period, the seasonal patterns of the soil CH4 uptake flux in all treatments were similar, with a higher value in growth season and a lower one in winter. After the harvest disturbance, the soil temperature, humidity, and NO3 --N, and NH4 +-N contents were all increased, and the soil CH4 flux had a significant quadratic correlation with soil temperature, and a negative linear correlation with soil moisture content. It was suggested that the increase of the soil moisture, NO3 --N, and NH4 +-N contents after the forest harvest was the main cause of the decrease of the soil CH4 uptake flux. [ABSTRACT FROM AUTHOR]

In this paper, the characters of high shrinkage cationic polyester, VILOFT and flat polyester are introduced with the influence of properties on the spinning processes and yarn style analyzed. A detailed exploration process circulation and productive technology measures of wool/high shrinkage cationic polyester/flat cationic polyester/VILOFT/cationic polyester blending yarn which is developed on the cotton spinning equipment were discussed. By strictly controlling each process, the entire production is with low-ratio wool blending yarn price, but has pure wool good qualities. The formed fabrics has a unique style and color with bulkiness, loftiness, rich elasticity, good drapability, soft hand-feel, improved anti-creasing and dyeing properties and high value-added, which will bring a good reference guide for enterprises. [ABSTRACT FROM AUTHOR]

Solidification of microbial oil rich in 46% arachidonic acid at low temperatures ( ≤10°C ) makes it difficult to use. In this paper, the microbial oil was used as the experimental material to optimize the best conditions of surfactant fractionation process. In addition, a number of physiochemical indexes about liquid and solid fat obtained by fractionation process were evaluated, and their compositions of fatty acid and triglycerols were also analyzed by gas chromatography and mass spectrometry. The result shows that the yield of liquid oil was 57.0%, the melting point drops to 9°C, the iodine value increased, the viscosity decreased, the content of arachidonic acid increased and its main type of triglycerols was tri - unsaturated triglycerol. The melting point of solid fat increased to 27°C, the main type of triglycerols was di - unsaturated triglycerol. Other indexes all display opposite trends com-pared to liquid oil. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to investigate the effects of irrigation with treated wastewater on the nutrient distribution in cucumber and tomato plants and their fruit quality. Irrigation with treated wastewater promoted tomato growth significantly, but had definite inhibition effect on cucumber growth. After the irrigation with treated wastewater, the nitrogen in plants had the characteristics of upward translocation, potassium was easily to be accumulated in cucumber leaf but not accumulated in tomato root, and sodium was mostly accumulated in root but less enriched in leaf, not giving damage to the plants. No significant effects were observed on the distribution of calcium, magnesium, and chlorine in plants. Under the irrigation with treated wastewater, the overall quality of cucumber and tomato fruits was less affected. The nitrate concentration in cucumber and tomato fruits was increased by 5.3% and 32.9%,respectively, but still lower than the state food safety standard of China. [ABSTRACT FROM AUTHOR]

To quantitatively analyze the effect of debonding between steel tube and filled concrete on the ultimate bearing capacity of CFST arch bridge, a calculation model was proposed based on reasonable assumptions. The calculation program was written by using finite element method, and used to simulate the process of debonding between steel tube and filled concrete. The program was verified. By taking a single tube CFST arch bridge as a case study, the calculation results show that under uniformly distributed load on full span, the complete debonding makes the ultimate bearing capacity of single tube CFST arch bridge decreased about 10%. [ABSTRACT FROM AUTHOR]

Aiming at the control network of unknown hybrid powertrain, a set of scheme for reverse analysis and test is presented. This paper puts forward a new contrastive regression method and conceives a valid control protocol. Based on the protocol, a rapid prototyping controller is developed utilizing virtual instruments to test the characteristics of system components in bench test experiments. The remnant bus method is also used in the bench test experiments. This scheme has been used to analyze a foreign parallel hybrid powertrain system. The good performance of the rapid prototype controller proves the validity of the protocol and the suitability of the proposed methods~ In addition, the remnant bus method has the advantage of realizing the components test without leaving the system. [ABSTRACT FROM AUTHOR]

Experimental program on cubic concrete specimens was conducted using a servo - hydraulic multi-axial testing machine to investigate the dynamic properties of concrete in biaxial stress states. The data processing method to deal with the obtained data in the experiment was discussed. Considering the limitations of conventional data processing method, the artificial neural network method was adopted to process the multifactor dynamic properties of concrete. By comparing with the conventional data analysis method, it is proved that the artificial neural network method is more simple and effective in dealing with the complex dynamic properties of concrete and can be used widely in engineering practice. [ABSTRACT FROM AUTHOR]

Recent studies have revealed that deep neural networks (DNN) used in artificial intelligence systems are highly vulnerable to adversarial sample-based attacks.To address this issue, a dual adversarial attack method was proposed for license plate recognition (LPR) systems in a DNN-based scenario.It was demonstrated that an adversarial patch added to the pattern location of the license plate can render the target detection subsystem of the LPR system unable to detect the license plate class.Additionally, the natural rust and stains were simulated by adding irregular single-connected area random points to the license plate image, which results in the misrecognition of the license plate number.or the license plate research, different shapes of adversarial patches and different colors of adversarial patches are designed as a way to generate adversarial license plates and migrate them to the physical world.Experimental results show that the designed adversarial samples are undetectable by the human eye and can deceive the license plate recognition system, such as EasyPR.The success rate of the attack in the physical world can reach 99%.The study sheds light on the vulnerability of deep learning and the adversarial attack of LPR, and offers a positive contribution toward improving the robustness of license plate recognition models.

The results of ellipse fitting can be considerably distorted by outliers in the fitted point set.To tackle this problem, three improved ellipse fitting algorithms, one of which is based on least trimmed square, and the other two on dual point removal, are proposed.The least trimmed square algorithm starts from a random sample of the original complete fitted set, and then in each iteration, new fitted set is formed by points with the least residual errors, till the process converges to an ellipse fitting a subset whose members are mostly non-outliers.Dual point removal algorithms, on the other hand, starts from the whole fitted set, removes the two points respectively with the maximal positive and the minimal negative residual errors, and halts when the number of points in the remaining set does not exceeds a user-defined threshold.The two proposed algorithms and existing methods are compared on an image base of actual accessories.Experimental results show that when the number of reserved ellipse points is relatively small, the dual removal-based algorithms present the best fitting accuracies, but are slower than the least trimmed square fitting algorithm.When the best performance with parameter tuning is concerned, however, the least trimmed square algorithm achieves a shape-location matching accuracy of 0.62 pixels and an orientation matching accuracy of 0.6°, at an average execution time of 6.5ms, outperforming other algorithms.Other advantages of the proposed algorithms include the small number of algorithm parameters, the intuitiveness of the parameters, and the insensitivity of the algorithm performance to the parameters.These experimental results provide solid evidences for the effectiveness of the proposed algorithms, especially the least trimmed square algorithm.

Objective To improve the learing outcomes of parasitology by asking undergraduates of nursing school to make a nursing plan for patients with parasitic diseases during the process of teaching human parasitology. Methods Undergraduates of four-year curriculum in School of Nursing, Peking Union Medical College enrolled in 2019 (n=125) and in 2018 (n=150) were selected as objects in experiment group and control group respectively. The education in the experiment group was supplemented by writing a simulating nursing plan while in the control group only implemented the traditional teaching performance. The learning outcome was evaluated in forms of both test of key knowledge points and a questionnaire survey at the end of the last class undertaken by the author in each semester. Results The performance of the students in the experiment group was statistically better than the control group in terms of the test of key knowledge points, as well as the capacity building of self-learning , problem-analyzing and solving, nursing cognition for patients with parasitic diseases,understanding of related theory to practice, communication skill and team spirit, enthusiasm for learning parasitology, and the overall satisfaction to the teaching design and methods (P＜0.05). Conclusions The teaching of parasitology supplemented with creating simulating nursing plans for patients with parasitic diseases is guided by the concept of “workplace-based learning” in the current teaching system, and is proved to be a smart pathway of education in nursing school as a supplement to routine teaching process.

Objective To explore the homogeneity level of four different functional mRNA （PUM2, TAB2, Cx45 and CHRNA1） expressions in rats with skeletal muscle contusion. Methods The relative expressions of PUM2, TAB2, Cx45 and CHRNA1 mRNAs were detected by quantitative real-time reverse transcription-polymerase chain reaction （RT-qPCR）. The coefficient of variation （CV） of the relative expressions for different individuals in each injury group was calculated. The extreme value of CV, cumulative variability, and CVCV were compared. Results A high CV of PUM2 and TAB2 mRNAs appeared on several different time points. However, the CV of Cx45 and CHRNA1 mRNAs was relatively low. The cumulative variability from high to low was PUM2, CHRNA1, TAB2 and Cx45 mRNAs. The relative expression of PUM2 mRNA was significantly higher than that of TAB2, Cx45 and CHRNA1 mRNAs （P0.05） in the CVCV of the relative expression of TAB2, CHRNA1 and Cx45 mRNAs. Conclusion As the mRNAs involving in biological process regulation, PUM2 and CHRNA1 mRNAs show a lowest individual homogeneity of the relative expression followed by TAB2 mRNA. As the mRNAs participating in the composition of cellular structure, Cx45 and CHRNA1 mRNAs show a high individual homogeneity of the relative expressions. The functional classification should be considered for the screening of the mRNA indicators used for wound age estimation.

Aerodynamic characteristics of iced conductors were investigated by the wind tunnel test. Under the homogeneous turbulence of 5% intensity, aerodynamic force coefficients of single and bundle conductors were obtained at angles of attack between 0°~180°. The variation patterns of aerodynamic forces on the iced conductors with respect to wind angels of attack were systematically studied for the ice thickness of 0.25, 0.5, 0.75 and 1 times of the conductor diameter. The differences of aerodynamic force characteristics for single and bundle conductors were identified and discussed. Based on the Den Hartog and Nigol's mechanisms of galloping, the ranges of attack sensitive to galloping were analyzed. The results show that lift and torsion force coefficients reach peak values at angles of attack between 15°~20°. For bundle conductors, lift force curve is agree with the curve of single conductor approximately. Drag force coefficients were smaller than those of single conductor at some wind angles. There are noticeably differences of torsion coefficients existed between bundle conductors and single conductor. According to two classical galloping mechanisms, wind angles of 15°~30° are critical for the galloping of iced conductors with crescent shapes. [ABSTRACT FROM AUTHOR]

To investigate the explosion seismic and vibration isolation in underground protective engineering, a method for an artificial synthesis of blast-induced ground motion by matching the target response spectra is presented. The calculation and processes of the matching target spectrum method are described. In the process of generating non-stationary acceleration time histories in the near or far field, two types of wave functions of blast ground acceleration are adopted to deduce the envelope functions. A procedure for construction of blast-induced ground motion design response spectra is introduced, and a modified function of the design response spectrum is proposed. As an illustration, an induced ground acceleration time history for a shallowly buried engineering is artificially synthesized using the matching-target spectrum method. The example shows that, after iterative calculation, the adjusted response spectrum can be close to the target response spectrum within the given fitting accuracy, the synthetic blast-induced ground motion time history meets the spectrum design requirements and can reflect the spectral characteristics and non-stationary characteristics of blast-induced ground motion. [ABSTRACT FROM AUTHOR]

By the mechanical tests of the coal samples, the physical and mechanical properties of coal and the law of permeability during the complete stress-strain process were studied. It is shown that, compared with the rocks from coal roof and floor, the coal is more prone to plastic deformation with the property of lower mechanical strength, lower elastic modulus and higher Poisson' s ratio. For the coal samples which have obvious strain-softening character during the complete stress-strain process, first, the coal sample volume is compressed and the permeability of coal with stress increases slightly or permeability changes little in the micro-cracks closure and elastic deformation stage. After the stress increases higher than the elastic limit, the coal sample gets into the crack propagation stage. The volume strain of coal changs from compression to expansion. The permeability of coal first slowly and then sharply increases with an increasing of crack extension. During the strain-softening stage, the coal permeability achieves the maximum and follows by a sharp decrease. The coal permeability after the peak strength is generally greater than that before the peak. For coal samples which have little strain-softening character or strain-hardening during the complete stress-strain process, the maximum permeability is mainly achieved in the plastic deformation stage before the peak. During the strain-hardening stage after the peak strength, the permeability decreases with an increasing of stress. Commonly, the coal permeability after the peak strength is generally less than that before the peak. [ABSTRACT FROM AUTHOR]

D-mannitol is a six-carbon sugar alcohol and one of the most abundant polyols in the nature. With antioxidant and osmotic pressure-regulating effects and non-metabolism by the human body, D-mannitol has been widely used in functional food and pharmaceutical industries. At present, a major way for industrial production of D-mannitol is chemical hydrogenation. In addition, D-Mannitol can be produced by microbial metabolism or catalysis. Compared with the chemical hydrogenation, the microbial methods for synthesizing mannitol do not produce sorbitol as a by-product and have the advantages of mild reaction conditions, strong specificity, and high conversion rate. Microbial fermentation is praised for easy access of strains and raw materials and simple separation of the product. Microbial catalysis usually adopts a multi-enzyme coupling strategy, which uses enzymes produced by engineered bacteria for whole-cell catalysis, and the cofactor recycling pathway is introduced to replenish expensive cofactor. This method can achieve high yields with cheap substrates under mild conditions without the formation of by-products. However, the application of microbial methods in the industrial production of D-mannitol is limited by the high costs of fermentation media and substrates and the long reaction time. This article reviews the reported microbial methods for producing D-mannitol, including the use of high-yielding strains and their fermentation processes, the utilization of low-cost substrates, whole-cell catalytic strategies, and the process control for high productivity. The biosynthesis of mannitol is not only of great significance for promoting industrial upgrading and realizing green manufacturing, but also provides strong support for the development of new bio-based products to meet the growing market demand. With the continuous improvement of technological innovation and industrial chain, it is expected to become one of the main ways of mannitol production in the future.

Understanding water absorption mechanisms of sand-fixing plants is important for the rational establishment of plant community structures, thereby providing a scientific basis for desertification control and the efficient utilization of water resources in sandy areas. Based on the hydrogen and oxygen isotopic compositions of precipi-tation, soil water, xylem water, and groundwater, coupled with soil water-heat dynamics, annual water consumption characteristics of vegetation, using the multi-source linear mixing model (IsoSource), we analyzed the differences in water sources between Salix psammophila and Artemisia ordosica , during winter and the growing season. We further examined the effects of groundwater depth (2 m and 10 m), soil freezing-thawing, and drought on their water utilization to elucidate water absorption mechanisms of those species. The results showed that: 1) During soil freezing-thawing period (January to March), S. psammophila mainly utilized soil water in 60-120 cm depths below the frozen layer (69.1%). In the green-up season (April and May), soil water from the 0-60 cm layers could satisfy the water demand of S. psammophila (30.9%-87.6%). During the dry period of the growing season (June), it predominantly utilized soil water at the depth of 120-160 cm (27.4%-40.8%). Over the rainy season (July and September), soil water in 0-60 cm depths provided 59.8%-67.9% of the total water required. A. ordosica , with shallow roots, could not utilize soil water after complete freezing of root zone but could overwinter by storing water in rhizomes during autumn. During the growing season, it primarily relied on 0-40 cm soil layer (23.4%-86.8%). During the dry period, it mainly utilized soil water from 40-80 cm and 80-160 cm soil layers, with utilization rates of 14.6%-74.4% and 21.8%-78.2%, respectively. 2) With decreasing groundwater depth, vegetation shifted its water absorption depth upward, with water source of S. psammophila transitioning from 120-160 cm to 60-160 cm layers, while A. ordosica shifted water absorption depth from 80-160 cm to 0-40 cm. S. psammophila 's utilization of soil water is influenced by transpiration, adopting an "on-demand" approach to achieve a balance between water supply and energy conservation, whereas A. ordosica tends to utilize shallow soil water, exhibiting a higher depen-dence on water sources from a single soil layer.