Objective To study how to improve and perfect the information platform and processing mechanism of drug shortages in China.Methods By searching the relevant policies from official websites of FDA,European Medicines Ag...Objective To study how to improve and perfect the information platform and processing mechanism of drug shortages in China.Methods By searching the relevant policies from official websites of FDA,European Medicines Agency(EMA),Health Canada(HC)and National Health Commission,the good experience of the United States,the European Union and Canada in the construction of information platform and processing mechanism of drug shortages was summarized for reference in China.Results and Conclusion China has initially established the processing mechanism of drug shortages,but the platform construction should be improved,and the information disclosure of drug shortages varies from province to province.We should improve the information platform of drug shortages,strengthen the disclosure and communication of information,enrich the processing tools and measures after the drug shortages occurs,and strengthen the cooperation with relevant associations and other non-governmental departments.展开更多
This paper analyzes a problem processing mechanism in a new collaboration system between the main manufacturer and the supplier in the"main manufacturer-supplier"mode,which has been widely applied in the col...This paper analyzes a problem processing mechanism in a new collaboration system between the main manufacturer and the supplier in the"main manufacturer-supplier"mode,which has been widely applied in the collaborative development management of the complex product.This paper adopts the collaboration theory,the evolutionary game theory and numerical simulation to analyze the decision-making mechanism where one upstream supplier and one downstream manufacturer must process an unpredicted problem without any advance contract in common.Results show that both players'decision-makings are in some correlation with the initial state,income impact coefficients,and dealing cost.It is worth noting that only the initial state influences the final decision,while income impact coefficients and dealing cost just influence the decision process.This paper shows reasonable and practical suggestions for the manufacturer and supplier in a new collaboration system for the first time and is dedicated to the managerial implications on reducing risks of processing problems.展开更多
Aiming at solving the problem of low resolu- tion and visual blur in infrared imaging, a super-resolution infrared image reconstruction method using human vision processing mechanism (HVPM) was proposed. This method...Aiming at solving the problem of low resolu- tion and visual blur in infrared imaging, a super-resolution infrared image reconstruction method using human vision processing mechanism (HVPM) was proposed. This method combined a mechanism of vision lateral inhibition with an algorithm projection onto convex sets (POCS) reconstruction, the improved vision lateral inhibition network was utilized to enhance the contrast between object and background of low-resolution image sequences, then POCS algorithm was adopted to reconstruct super- resolution image. Experimental results showed that the proposed method can significantly improve the visual effect of image, whose contrast and information entropy of reconstructed infrared images were improved by approxi- mately 5 times and 1.6 times compared with traditional POCS reconstruction algorithm, respectively.展开更多
This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following s...This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following sentence pattern: "subject (noun) + yi/gang/zheng + predicate (verb)". Event-related potentials on the scalp were recorded using 32-channel electroencephalography. Compared with correct sentences, target words elicited an early left anterior negativity (N400) and a later positivity (P600) over frontal, central and temporal sites in sentences involving semantic violations. In addition, when sentences contained both semantic and syntactic violations, the target words elicited a greater N400 and P600 distributed in posterior brain areas. These results indicate that Chinese sentence comprehension involves covert grammar processes.展开更多
Surface defects introduced by conventional mechanical processing methods can induce irreversible damage and reduce the service life of optics applied in high-power lasers.Compared to mechanical processing,laser polish...Surface defects introduced by conventional mechanical processing methods can induce irreversible damage and reduce the service life of optics applied in high-power lasers.Compared to mechanical processing,laser polishing with moving beam spot is a noncontact processing method,which is able to form a defect-free surface.This work aims to explore the mechanism of forming a smooth,defect-free fused silica surface by high-power density laser polishing with coupled multiple beams.The underlying mechanisms of laser polishing was revealed by numerical simulations and the theoretical results were verified by experiments.The simulated polishing depth and machined surface morphology were in close agreement with the experimental results.To obtain the optimized polishing quality,the effects of laser polishing parameters(e.g.overlap rate,pulse width and polishing times)on the polishing quality were experimentally investigated.It was found that the processing efficiency of fused silica materials by carbon dioxide(CO2)laser polishing could reach 8.68 mm2 s−1,and the surface roughness(Ra)was better than 25 nm.Besides,the cracks on pristine fused silica surfaces introduced by initial grinding process were completely removed by laser polishing to achieve a defect-free surface.The maximum laser polishing rate can reach 3.88μm s−1,much higher than that of the traditional mechanical polishing methods.The rapid CO2 laser polishing can effectively achieve smooth,defect-free surface,which is of great significance to improve the surface quality of fused silica optics applied in high-power laser facilities.展开更多
1 Introduction Physical and numerical models are constructed to investigate the evolution and mechanism of salt migration driven by tectonic processes.In recent years,we have designed and ran series of models to simul...1 Introduction Physical and numerical models are constructed to investigate the evolution and mechanism of salt migration driven by tectonic processes.In recent years,we have designed and ran series of models to simulate salt展开更多
Amounts of lithium-containing salt lake brine resources are widely distributed in the four provinces named Qinghai,Tibet,Inner Mongolia and Xinjiang province,especially the salt lakes in Qinghai-Tibet Plateau are abun...Amounts of lithium-containing salt lake brine resources are widely distributed in the four provinces named Qinghai,Tibet,Inner Mongolia and Xinjiang province,especially the salt lakes in Qinghai-Tibet Plateau are abundant of展开更多
Since the launch of the economic reform and opening to the outside world, China has seen rapid growth in its export of mechanical and electrical products, with its export
A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast China. The main findings are as follows:The changes of ...A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast China. The main findings are as follows:The changes of kinetic energy are mainly attributed to the generation due to non-divergent wind. During the early stage of the typhoon landing, there exits only a small quantity of kinetic energy exchanging with the environment. And after it is transformed into an extratropical cyclone, a large amount of kinetic energy is exported from the system toward the environment.The horizontal and vertical flux-divergence terms of eddy available potenlial energy are the prominent sinks in the budgets of eddy kinetic energy. The generations of eddy kinetic energy due to both the barotropic and baroclinic processes are source terms. The former is remarkable during the initial stage. But after the depression is transformed into an extratropical cyclone, the roles of the generation by the barotropic and baroclinic processes are reversed, 1. e. , the latter has become more significant than the former.Diabatic heating is the most dominant heat source. The terms of vertical heat flux by cumulus and large-scale motion are the major sinks. And the latter is prominent after the system is transformed into an extratropical cycfone.展开更多
Under steady-state conditions, the general currents of EE reactions at disk,hemispherical and spherical microelectrodes are derived.From these equations, some electrode reaction parameters can be very simply obtained.
Background:To promote the quality evaluation,clarify the processing mechanism and distinguish origins of Corni Fructus(cornus)from different regions.Methods:This study developed a high performance liquid chromatograph...Background:To promote the quality evaluation,clarify the processing mechanism and distinguish origins of Corni Fructus(cornus)from different regions.Methods:This study developed a high performance liquid chromatography method for simultaneous determination of 5-hydroxymethylfurfural,2 phenolic acids and 4 iridoid glycosides and the reference fingerprint of cornus from different regions.In addition,the feedforward neural network model provided a pattern classification of sample regions.Results:The content of morroniside and loganin were the highest in all raw cornus samples ranging from 9.45μg/mg to 16.3μg/mg and 6.64μg/mg to 13.7μg/mg,respectively.The level of sweroside in raw cornus from Henan(0.83μg/mg^(-1).39μg/mg)and Zhejiang(0.64μg/mg^(-1).17μg/mg)were greater than other origins.After wine-processing,the glucose or fructose were dehydrated to increase the levels of 5-hydroxymethylfurfural.The C-4 position of-COOCH3 of hot-sensitive iridoid glycosides was hydrolyzed to generate-COOH as stable components.Polyphenol derivatives may be degraded to increase the content of phenolic acid.Subsequently,an excellent feedforward neural network model for identification of raw cornus and wine-prepared cornus was established which could distinguish the sample origins.Conclusion:This work provided a trustworthy method to evaluate the quality and distinguish the sources of cornus.Meanwhile,the clear processing mechanism provided a scientific foundation for controlling the cornus quality during wine-processing.展开更多
Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to b...Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to be elasto-plastic and it obey the Von Mises yield criterion and Prandtl- Reuss rule. Deformation of the workpiece is simulated in a step-by-step manner,updating the coordinates of material points and the property after each step, so that both nonsteady-state and stendy-state deformation can be simulated. The heat transfter between the workpiece, the rolls, and enviroment and the heat generation due to plastic work and friction force, are considered in the analys- is.Predicted the deformation shape of the workpiece, distributions of strains, stresses, strain rates and temperatures, roll-separating force and roll torque are presented.展开更多
The formation mechanisms and processes of geochemical anomalies used as proxies in surface geochemistry exploration (SGE) have not been well understood. Previous studies cannot realize 3D measurement of microseeping...The formation mechanisms and processes of geochemical anomalies used as proxies in surface geochemistry exploration (SGE) have not been well understood. Previous studies cannot realize 3D measurement of microseeping hydrocarbons from reservoirs to the surface, which made it difficult to understand the features and pathways of deep hydrocarbon microseepages. Understanding the processes of hydrocarbon microseepages will contribute to the acceptance and effectiveness of surface geochemistry. Based on a simplified geological model of hydrocarbon microseepages, including hydrocarbon reservoir, direct caprock, overlying strata and Quaternary sediments, this work established a 3D experimental system to simulate the mechanisms and processes of deep hydrocarbon microseepes extending to the surface. The dispersive halos of microseeping hydrocarbons in the subsurface were adequately described by using this 3D experimental system. Results indicate that different migration patterns of hydrocarbons above the point gas source within the simulated caprock and overlying strata can be reflected by the ratio of i-butane to n-butane (i-C4/n-C4), which follow diffusion and infiltration (buoyancy) mechanisms. This is not the case for vertical measurement lines far from the point gas source. A vertical gas flow in the form of a plume was found during hydrocarbon microseepage. For sampling methods, the high-density grid sampling is favorable for delineating prospecting targets. Hydrocarbon infiltration or buoyancy flow occurs in the zones of infiltration clusters, coupling with a diffusion mechanism at the top of the water table and forming surface geochemical anomalies. These results are significant in understanding hydrocarbon microseepage and interpreting SGE data.展开更多
Shortcomings of the Boltzmann physical kinetics and the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics are considered. From the position of nonlocal p...Shortcomings of the Boltzmann physical kinetics and the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics are considered. From the position of nonlocal physics, the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger equation is a local equation;this fact leads to the great shortcomings of the linear Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics. Nonlocal nonlinear quantum mechanics is considered using the wave function terminology.展开更多
In this brief report, we analyzed ecological correlates of risk of extinction for mammals endemic to China using phylogenetic eigenvector methods to control for the effect of phylogenetic inertia. Extinction risks wer...In this brief report, we analyzed ecological correlates of risk of extinction for mammals endemic to China using phylogenetic eigenvector methods to control for the effect of phylogenetic inertia. Extinction risks were based on the International Union for Conservation of Nature (IUCN) Red List and ecological explanatory attributes that include range size and climatic variables. When the effect of phylogenetic inertia were controlled, climate became the best predictor for quantifying and evaluating extinction risks of endemic mammals in China, accounting for 13% of the total variation. Range size seems to play a trivial role, explaining -1% of total variation; however, when non-phylogenetic variation partitioning analysis was done, the role of range size then explained 7.4% of total variation. Consequently, phylogenetic inertia plays a substantial role in increasing the explanatory power of range size on the extinction risks of mammals endemic to China. Limitations of the present study are discussed, with a focus on under-represented sampling of endemic mammalian species.展开更多
The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms. Traditionally,the underlying source parameters responsible fo...The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms. Traditionally,the underlying source parameters responsible for these emission processes,like particle energy density,magnetic field,etc.,are obtained through simple visual reproduction of the observed fluxes. However,this procedure is incapable of providing confidence ranges for the estimated parameters. In this work,we propose an efficient algorithm to perform a statistical fit of the observed broadband spectrum of blazars using different emission models. Moreover,we use the observable quantities as the fit parameters,rather than the direct source parameters which govern the resultant SED. This significantly improves the convergence time and eliminates the uncertainty regarding initial guess parameters. This approach also has an added advantage of identifying the degenerate parameters,which can be removed by including more observable information and/or additional constraints. A computer code developed based on this algorithm is implemented as a user-defined routine in the standard X-ray spectral fitting package,XSPEC. Further,we demonstrate the efficacy of the algorithm by fitting the well sampled SED of blazar 3 C 279 during its gamma ray flare in 2014.展开更多
With the development of society,the virtual reality technology and multimedia technology have been applied to modern large-scale agriculture. The paper describes the design ideas for animation display of mechanized ri...With the development of society,the virtual reality technology and multimedia technology have been applied to modern large-scale agriculture. The paper describes the design ideas for animation display of mechanized rice production in cold region,and elaborates the design of major part of each scene. By animation display,we can know about the whole process of rice production,as well as the benefits of mechanized operation.展开更多
In the first step, the Ehrenfest reasoning concerning the adiabatic invariance of the angular orbital momentum is applied to the electron motion in the hydrogen atom. It is demonstrated that the time of the energy emi...In the first step, the Ehrenfest reasoning concerning the adiabatic invariance of the angular orbital momentum is applied to the electron motion in the hydrogen atom. It is demonstrated that the time of the energy emission from the quantum level n+1 to level n can be deduced from the orbital angular momentum examined in the hydrogen atom. This time is found precisely equal to the time interval dictated by the Joule-Lenz law governing the electron transition between the levels n+1 and n. In the next step, the mechanical parameters entering the quantum systems are applied in calculating the time intervals characteristic for the electron transitions. This concerns the neighbouring energy levels in the hydrogen atom as well as the Landau levels in the electron gas submitted to the action of a constant magnetic field.展开更多
Demand of improving the mechanical properties and productivity of automotive components while minimizing environmental impact makes the development of special steel combined with advance heat treatment and surface mod...Demand of improving the mechanical properties and productivity of automotive components while minimizing environmental impact makes the development of special steel combined with advance heat treatment and surface modification technologies become an important research area. Recently,to reduce CO_2 emissions by saving the manufacturing time,the following new special steel and advance heat treatment methods were developed: (1 ) An anti-coarsening extra-fine case hardening steel for automobile gear was developed,whose carburizing temperature can be improved for conventional 930 - 950℃to 1 050℃without coarsening,and the carburizing time can be reduced by maximum 75%. (2) Various microalloyed steels for fracture splitting connecting rod were developed.By using the above-mentioned steel combined with Thermo Mechanical Control Process(TMCP) method,the manufacturing time can be reduced by 30%-40%. (3) Vacuum carburizing and mild carburizing combined with induction quenching are being developed to replace the traditional gas carburizing,and the CO_2 emissions can be reduced by 20%-40%. (4) Intensive quenching is another new quenching technology which can be defined as cooling usually with pure water quenchant or low concentration water/salt solutions at a rate several times higher than the rate of ' normal' or conventional quenching,and the conventional effective case hardening depth can be reduce greatly and carburizing time can reduced. In addition,the high pressure gas quenching for reducing the quenching distortion and dual shot-peening for improving fatigue strength of gear will also be discussed. In a word,the present paper will focus on how to use the interaction among the development of special steel, advance heat treatment and surface modification to improve the strength of automotive components while reducing the manufacturing cost and impact to environment.展开更多
To evaluate the property of the organic coatings in oil and gas plants, the aging process was studied in high temperature and high CO_2 partial pressure environment. Correlations were developed between the macroscopic...To evaluate the property of the organic coatings in oil and gas plants, the aging process was studied in high temperature and high CO_2 partial pressure environment. Correlations were developed between the macroscopic properties and microstructure of the organic coatings. The surface appearance, mechanical properties, and permeability of the organic coatings were measured. Furthermore, the crystal structure of the organic coatings was investigated through synchrotron radiation grazing incidence X-ray diffraction(GIXRD) on the BL14B1 beam line in Shanghai Synchrotron Radiation Facility. Combined with the Fourier transform infrared spectroscopy, the molecular structure of the organic coatings was investigated. The experimental results indicate that the thickness variation and weight loss of the organic coatings increase with the immersion time, and the penetration resistance of the coating obviously decreases as the temperature rises. Moreover, the degradation of the organic coatings with immersion time in high temperature and high CO_2 partial pressure environment is caused by the amorphization of the organic coatings as the groups and bonds of the organic coatings were not damaged.展开更多
文摘Objective To study how to improve and perfect the information platform and processing mechanism of drug shortages in China.Methods By searching the relevant policies from official websites of FDA,European Medicines Agency(EMA),Health Canada(HC)and National Health Commission,the good experience of the United States,the European Union and Canada in the construction of information platform and processing mechanism of drug shortages was summarized for reference in China.Results and Conclusion China has initially established the processing mechanism of drug shortages,but the platform construction should be improved,and the information disclosure of drug shortages varies from province to province.We should improve the information platform of drug shortages,strengthen the disclosure and communication of information,enrich the processing tools and measures after the drug shortages occurs,and strengthen the cooperation with relevant associations and other non-governmental departments.
基金supported by the National Natural Science Foundation of China(7117111271502073)。
文摘This paper analyzes a problem processing mechanism in a new collaboration system between the main manufacturer and the supplier in the"main manufacturer-supplier"mode,which has been widely applied in the collaborative development management of the complex product.This paper adopts the collaboration theory,the evolutionary game theory and numerical simulation to analyze the decision-making mechanism where one upstream supplier and one downstream manufacturer must process an unpredicted problem without any advance contract in common.Results show that both players'decision-makings are in some correlation with the initial state,income impact coefficients,and dealing cost.It is worth noting that only the initial state influences the final decision,while income impact coefficients and dealing cost just influence the decision process.This paper shows reasonable and practical suggestions for the manufacturer and supplier in a new collaboration system for the first time and is dedicated to the managerial implications on reducing risks of processing problems.
文摘Aiming at solving the problem of low resolu- tion and visual blur in infrared imaging, a super-resolution infrared image reconstruction method using human vision processing mechanism (HVPM) was proposed. This method combined a mechanism of vision lateral inhibition with an algorithm projection onto convex sets (POCS) reconstruction, the improved vision lateral inhibition network was utilized to enhance the contrast between object and background of low-resolution image sequences, then POCS algorithm was adopted to reconstruct super- resolution image. Experimental results showed that the proposed method can significantly improve the visual effect of image, whose contrast and information entropy of reconstructed infrared images were improved by approxi- mately 5 times and 1.6 times compared with traditional POCS reconstruction algorithm, respectively.
基金the Foundation of National Social Sciences hosted by Professor Huanhai Fang, No. 03BYY013
文摘This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following sentence pattern: "subject (noun) + yi/gang/zheng + predicate (verb)". Event-related potentials on the scalp were recorded using 32-channel electroencephalography. Compared with correct sentences, target words elicited an early left anterior negativity (N400) and a later positivity (P600) over frontal, central and temporal sites in sentences involving semantic violations. In addition, when sentences contained both semantic and syntactic violations, the target words elicited a greater N400 and P600 distributed in posterior brain areas. These results indicate that Chinese sentence comprehension involves covert grammar processes.
基金supported by the National Natural Science Foundation of China(Grant Nos.51775147,51705105)Science Challenge Project(Grant No.TZ2016006-0503-01)+3 种基金Young Elite Scientists Sponsorship Program by CAST(Grant No.2018QNRC001)China Postdoctoral Science Foundation funded project(Grant Nos.2018T110288,2017M621260)Self-Planned Task(Grant Nos.SKLRS201718A,SKLRS201803B)of State Key Laboratory of Robotics and System(HIT)Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.2019053).
文摘Surface defects introduced by conventional mechanical processing methods can induce irreversible damage and reduce the service life of optics applied in high-power lasers.Compared to mechanical processing,laser polishing with moving beam spot is a noncontact processing method,which is able to form a defect-free surface.This work aims to explore the mechanism of forming a smooth,defect-free fused silica surface by high-power density laser polishing with coupled multiple beams.The underlying mechanisms of laser polishing was revealed by numerical simulations and the theoretical results were verified by experiments.The simulated polishing depth and machined surface morphology were in close agreement with the experimental results.To obtain the optimized polishing quality,the effects of laser polishing parameters(e.g.overlap rate,pulse width and polishing times)on the polishing quality were experimentally investigated.It was found that the processing efficiency of fused silica materials by carbon dioxide(CO2)laser polishing could reach 8.68 mm2 s−1,and the surface roughness(Ra)was better than 25 nm.Besides,the cracks on pristine fused silica surfaces introduced by initial grinding process were completely removed by laser polishing to achieve a defect-free surface.The maximum laser polishing rate can reach 3.88μm s−1,much higher than that of the traditional mechanical polishing methods.The rapid CO2 laser polishing can effectively achieve smooth,defect-free surface,which is of great significance to improve the surface quality of fused silica optics applied in high-power laser facilities.
基金supported by China Geological Survey Bureau potash resources investigation and evaluation project (1212011085524)NSFC projects (40872134, 41272227 )
文摘1 Introduction Physical and numerical models are constructed to investigate the evolution and mechanism of salt migration driven by tectonic processes.In recent years,we have designed and ran series of models to simulate salt
基金Financial support from the State Surface Project of National Natural Science of China (21276194)the Specialized Research Fund for the Doctoral Program of Chinese Higher Education (20101208110003)the Key Pillar Program of Tianjin Municipal Science and Technology (11ZCKGX02800)
文摘Amounts of lithium-containing salt lake brine resources are widely distributed in the four provinces named Qinghai,Tibet,Inner Mongolia and Xinjiang province,especially the salt lakes in Qinghai-Tibet Plateau are abundant of
文摘Since the launch of the economic reform and opening to the outside world, China has seen rapid growth in its export of mechanical and electrical products, with its export
文摘A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast China. The main findings are as follows:The changes of kinetic energy are mainly attributed to the generation due to non-divergent wind. During the early stage of the typhoon landing, there exits only a small quantity of kinetic energy exchanging with the environment. And after it is transformed into an extratropical cyclone, a large amount of kinetic energy is exported from the system toward the environment.The horizontal and vertical flux-divergence terms of eddy available potenlial energy are the prominent sinks in the budgets of eddy kinetic energy. The generations of eddy kinetic energy due to both the barotropic and baroclinic processes are source terms. The former is remarkable during the initial stage. But after the depression is transformed into an extratropical cyclone, the roles of the generation by the barotropic and baroclinic processes are reversed, 1. e. , the latter has become more significant than the former.Diabatic heating is the most dominant heat source. The terms of vertical heat flux by cumulus and large-scale motion are the major sinks. And the latter is prominent after the system is transformed into an extratropical cycfone.
文摘Under steady-state conditions, the general currents of EE reactions at disk,hemispherical and spherical microelectrodes are derived.From these equations, some electrode reaction parameters can be very simply obtained.
基金supported by the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine.(No.ZYYCXTD-D-202005)the Key Project at Central Government Level(No.2060302)+1 种基金the National Natural Science Foundation of China Grants(No.81872956)Tianjin Science and Technology Planning Project(No.19YFZCSY00170).
文摘Background:To promote the quality evaluation,clarify the processing mechanism and distinguish origins of Corni Fructus(cornus)from different regions.Methods:This study developed a high performance liquid chromatography method for simultaneous determination of 5-hydroxymethylfurfural,2 phenolic acids and 4 iridoid glycosides and the reference fingerprint of cornus from different regions.In addition,the feedforward neural network model provided a pattern classification of sample regions.Results:The content of morroniside and loganin were the highest in all raw cornus samples ranging from 9.45μg/mg to 16.3μg/mg and 6.64μg/mg to 13.7μg/mg,respectively.The level of sweroside in raw cornus from Henan(0.83μg/mg^(-1).39μg/mg)and Zhejiang(0.64μg/mg^(-1).17μg/mg)were greater than other origins.After wine-processing,the glucose or fructose were dehydrated to increase the levels of 5-hydroxymethylfurfural.The C-4 position of-COOCH3 of hot-sensitive iridoid glycosides was hydrolyzed to generate-COOH as stable components.Polyphenol derivatives may be degraded to increase the content of phenolic acid.Subsequently,an excellent feedforward neural network model for identification of raw cornus and wine-prepared cornus was established which could distinguish the sample origins.Conclusion:This work provided a trustworthy method to evaluate the quality and distinguish the sources of cornus.Meanwhile,the clear processing mechanism provided a scientific foundation for controlling the cornus quality during wine-processing.
文摘Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to be elasto-plastic and it obey the Von Mises yield criterion and Prandtl- Reuss rule. Deformation of the workpiece is simulated in a step-by-step manner,updating the coordinates of material points and the property after each step, so that both nonsteady-state and stendy-state deformation can be simulated. The heat transfter between the workpiece, the rolls, and enviroment and the heat generation due to plastic work and friction force, are considered in the analys- is.Predicted the deformation shape of the workpiece, distributions of strains, stresses, strain rates and temperatures, roll-separating force and roll torque are presented.
基金supported by the National Natural Science Foundation of China(grants No.41373121 and 41072099)the scientific and technological project of SINOPEC under Contract No.P05069Support by SINOPEC Key Laboratory of Petroleum Accumulation Mechanisms,China
文摘The formation mechanisms and processes of geochemical anomalies used as proxies in surface geochemistry exploration (SGE) have not been well understood. Previous studies cannot realize 3D measurement of microseeping hydrocarbons from reservoirs to the surface, which made it difficult to understand the features and pathways of deep hydrocarbon microseepages. Understanding the processes of hydrocarbon microseepages will contribute to the acceptance and effectiveness of surface geochemistry. Based on a simplified geological model of hydrocarbon microseepages, including hydrocarbon reservoir, direct caprock, overlying strata and Quaternary sediments, this work established a 3D experimental system to simulate the mechanisms and processes of deep hydrocarbon microseepes extending to the surface. The dispersive halos of microseeping hydrocarbons in the subsurface were adequately described by using this 3D experimental system. Results indicate that different migration patterns of hydrocarbons above the point gas source within the simulated caprock and overlying strata can be reflected by the ratio of i-butane to n-butane (i-C4/n-C4), which follow diffusion and infiltration (buoyancy) mechanisms. This is not the case for vertical measurement lines far from the point gas source. A vertical gas flow in the form of a plume was found during hydrocarbon microseepage. For sampling methods, the high-density grid sampling is favorable for delineating prospecting targets. Hydrocarbon infiltration or buoyancy flow occurs in the zones of infiltration clusters, coupling with a diffusion mechanism at the top of the water table and forming surface geochemical anomalies. These results are significant in understanding hydrocarbon microseepage and interpreting SGE data.
文摘Shortcomings of the Boltzmann physical kinetics and the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics are considered. From the position of nonlocal physics, the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger equation is a local equation;this fact leads to the great shortcomings of the linear Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics. Nonlocal nonlinear quantum mechanics is considered using the wave function terminology.
基金This work was supported by the China Scholarship Council (CSC)(201308180004) Acknowledgements: I would like to thank two anonymous reviewers for constructive comments on this manuscript.
文摘In this brief report, we analyzed ecological correlates of risk of extinction for mammals endemic to China using phylogenetic eigenvector methods to control for the effect of phylogenetic inertia. Extinction risks were based on the International Union for Conservation of Nature (IUCN) Red List and ecological explanatory attributes that include range size and climatic variables. When the effect of phylogenetic inertia were controlled, climate became the best predictor for quantifying and evaluating extinction risks of endemic mammals in China, accounting for 13% of the total variation. Range size seems to play a trivial role, explaining -1% of total variation; however, when non-phylogenetic variation partitioning analysis was done, the role of range size then explained 7.4% of total variation. Consequently, phylogenetic inertia plays a substantial role in increasing the explanatory power of range size on the extinction risks of mammals endemic to China. Limitations of the present study are discussed, with a focus on under-represented sampling of endemic mammalian species.
文摘The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms. Traditionally,the underlying source parameters responsible for these emission processes,like particle energy density,magnetic field,etc.,are obtained through simple visual reproduction of the observed fluxes. However,this procedure is incapable of providing confidence ranges for the estimated parameters. In this work,we propose an efficient algorithm to perform a statistical fit of the observed broadband spectrum of blazars using different emission models. Moreover,we use the observable quantities as the fit parameters,rather than the direct source parameters which govern the resultant SED. This significantly improves the convergence time and eliminates the uncertainty regarding initial guess parameters. This approach also has an added advantage of identifying the degenerate parameters,which can be removed by including more observable information and/or additional constraints. A computer code developed based on this algorithm is implemented as a user-defined routine in the standard X-ray spectral fitting package,XSPEC. Further,we demonstrate the efficacy of the algorithm by fitting the well sampled SED of blazar 3 C 279 during its gamma ray flare in 2014.
基金Supported by Natural Science Foundation of Heilongjiang Province(F201428)Foundation of Heilongjiang Reclamation Area(HNK125B-04-06)
文摘With the development of society,the virtual reality technology and multimedia technology have been applied to modern large-scale agriculture. The paper describes the design ideas for animation display of mechanized rice production in cold region,and elaborates the design of major part of each scene. By animation display,we can know about the whole process of rice production,as well as the benefits of mechanized operation.
文摘In the first step, the Ehrenfest reasoning concerning the adiabatic invariance of the angular orbital momentum is applied to the electron motion in the hydrogen atom. It is demonstrated that the time of the energy emission from the quantum level n+1 to level n can be deduced from the orbital angular momentum examined in the hydrogen atom. This time is found precisely equal to the time interval dictated by the Joule-Lenz law governing the electron transition between the levels n+1 and n. In the next step, the mechanical parameters entering the quantum systems are applied in calculating the time intervals characteristic for the electron transitions. This concerns the neighbouring energy levels in the hydrogen atom as well as the Landau levels in the electron gas submitted to the action of a constant magnetic field.
文摘Demand of improving the mechanical properties and productivity of automotive components while minimizing environmental impact makes the development of special steel combined with advance heat treatment and surface modification technologies become an important research area. Recently,to reduce CO_2 emissions by saving the manufacturing time,the following new special steel and advance heat treatment methods were developed: (1 ) An anti-coarsening extra-fine case hardening steel for automobile gear was developed,whose carburizing temperature can be improved for conventional 930 - 950℃to 1 050℃without coarsening,and the carburizing time can be reduced by maximum 75%. (2) Various microalloyed steels for fracture splitting connecting rod were developed.By using the above-mentioned steel combined with Thermo Mechanical Control Process(TMCP) method,the manufacturing time can be reduced by 30%-40%. (3) Vacuum carburizing and mild carburizing combined with induction quenching are being developed to replace the traditional gas carburizing,and the CO_2 emissions can be reduced by 20%-40%. (4) Intensive quenching is another new quenching technology which can be defined as cooling usually with pure water quenchant or low concentration water/salt solutions at a rate several times higher than the rate of ' normal' or conventional quenching,and the conventional effective case hardening depth can be reduce greatly and carburizing time can reduced. In addition,the high pressure gas quenching for reducing the quenching distortion and dual shot-peening for improving fatigue strength of gear will also be discussed. In a word,the present paper will focus on how to use the interaction among the development of special steel, advance heat treatment and surface modification to improve the strength of automotive components while reducing the manufacturing cost and impact to environment.
基金Funded by the National Science and Technology Major Project(2011ZX05022-013)
文摘To evaluate the property of the organic coatings in oil and gas plants, the aging process was studied in high temperature and high CO_2 partial pressure environment. Correlations were developed between the macroscopic properties and microstructure of the organic coatings. The surface appearance, mechanical properties, and permeability of the organic coatings were measured. Furthermore, the crystal structure of the organic coatings was investigated through synchrotron radiation grazing incidence X-ray diffraction(GIXRD) on the BL14B1 beam line in Shanghai Synchrotron Radiation Facility. Combined with the Fourier transform infrared spectroscopy, the molecular structure of the organic coatings was investigated. The experimental results indicate that the thickness variation and weight loss of the organic coatings increase with the immersion time, and the penetration resistance of the coating obviously decreases as the temperature rises. Moreover, the degradation of the organic coatings with immersion time in high temperature and high CO_2 partial pressure environment is caused by the amorphization of the organic coatings as the groups and bonds of the organic coatings were not damaged.