Through the Latour concept of philosophy of science of laboratory life,the life course of a(geo)ethnographer researcher is analyzed,in order to establish the emotional or more personal dimensions that do not usually a...Through the Latour concept of philosophy of science of laboratory life,the life course of a(geo)ethnographer researcher is analyzed,in order to establish the emotional or more personal dimensions that do not usually appear in research papers,but that have notable relevance in qualitative research.The text is structured in three large parts:A conceptual vision of the new experimental geography;the experimental geo-ethnography in old social,new social and place scenarios;and finally,the most personal and emotional dimension of the research.The first part establishes the geo-ethnographic experimental context and the assumptions in fieldwork,in addition to the geo-ethnographic reconciliation process.In the second part,the main qualitative research problems related to mobility,resistance and dynamics in place are established.Finally,in the third part the research perceptions,the personal experiences,and the emotional dimension of the research in remote rural areas are established.The laboratory life of a researcher,allows one to establish scalar conclusions and rigor in qualitative research.展开更多
In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different para...In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors' research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.展开更多
The absence of effective therapies for castration-resistant prostate cancer(CRPC) establishes the need to develop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. Bu...The absence of effective therapies for castration-resistant prostate cancer(CRPC) establishes the need to develop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. But its application has been limited due to lack of favorable gene vector and the reduction of "bystander effect". Consequently, scientists all over the world focus their main experimental research on the following four aspects: targeted gene, vector, transfer means and comprehensive therapy. In this paper, we reviewed the latest advances of experimental research on targeted gene therapy for prostate cancer.展开更多
Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to reco...Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to recover hemolysin HC50, to increase the weight of the thymus, and increase the alexin of serum C3 and the IgG content of tumor bearing mice. FSP also significantly raised the pha-gocytic activity of macrophages in normal mice. PSP had a significant inhibitory effect on P38S and S180 cells. At the concentration of 1 mg/ml, PSP inhibited the proliferating activity of some human tumor call lines, such as SGC 7901, SPC, SLY and Mei. It had a direct toxic effect on SPC cells. PSP significantly inhibited the synthesis of nucleic acids of Ehrlich ascites carcinoma cells. In addition, PSP was antagonistic to the side effects of chemotherapy and radiotherapy.展开更多
?Fundamental experiments on lower hybrid current drive (LHCD) have been undertaken on HT-7 superconducting tokamak. The experiments on LHCD efficiency reveal its depen- deuce on plasma density and the toroidal magnet...?Fundamental experiments on lower hybrid current drive (LHCD) have been undertaken on HT-7 superconducting tokamak. The experiments on LHCD efficiency reveal its depen- deuce on plasma density and the toroidal magnetic field. Furthermore, the experiments on HT-7 successfully demonstrate the ability for LHCD to sustain long pulse tokamak discharges, such as discharges with full non-inductive current drive for several seconds. The experimental study to improve plasma confinements by LHCD suggests that the improvement should be due to the change o f current profile. It has also been demonstrated by the experiments that the lower hybrid wave may lead to an enhanced ionization of particles in the region where the wave is deposited.展开更多
The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, d...The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency, in order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result, it can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.展开更多
The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-ph...The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15 Ω/. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.展开更多
This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through th...This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through the hydraulic model test, the mechanism of stability of the block has been proved and the relations between stability and wave height, wave period, water depth, slope, laying method, porosity and cushion have been found. The effect of weight on steadiness have also been discovered. Finally, the method of design and some formulas are given.展开更多
To provide hexapod robots with strategies of locomotion planning, observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis. Through digitali...To provide hexapod robots with strategies of locomotion planning, observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis. Through digitalization of original analog video, locomotion characters of ants were obtained, the biomimetic foundation was laid for polynomial trajectory planning of multi-legged robots, which was deduced with mathematics method. In addition, five rules were concluded, which apply to hexapod robots marching locomotion planning. The first one is the fundamental strategy of multi-legged robots＇ leg trajectory planning. The second one helps to enhance the static and dynamic stability of multi-legged robots. The third one can improve the validity and feasibility of legs＇ falling points. The last two give criterions of multi-legged robots＇ toe trajectory figures and practical recommendatory constraints. These five rules give a good method for marching locomotion planning of multi-legged robots, and can be expended to turning planning and any other special locomotion.展开更多
Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Inves...Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.展开更多
Reburning technology is one of the most cost-effective NOx reduction strategies for coal combustion systems. In this paper, a nitric oxide submodel incorporated into a comprehensive coal combustion model was developed...Reburning technology is one of the most cost-effective NOx reduction strategies for coal combustion systems. In this paper, a nitric oxide submodel incorporated into a comprehensive coal combustion model was developed for predicting NOx reduction in a 93 kW laboratory-scale coal combustion furnace by reburning. This NO submodel, including reburning mechanism, requires the solution of only two transport equations to model the behavior of NO reduction in the reburning process. A number of experiments have been performed in the same furnace, and the experimental data obtained from the optimized reburn configuration was used to validate the model. Measurements and predictions both show above 50% reduction of NO emissions for the optimized reburning process. Profile comparisons show that the predicted temperature and oxygen concentration match well with the measurements, and the general trend of predicted NO concentration is very similar to that measured. The results of this study show that the present nitric oxide submodel depicts quite well the observed behaviour of NO annihilation in the reburning process. It is expected that this usable and computationally economic model represents a useful tool to simulate the gaseous fuel reburning process for the researchers concerned with practical combustors.展开更多
in this paper, an experimental research the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The ...in this paper, an experimental research the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The results show that the ablating material with accidented surface and its high temperature have remarkably affected the reflection and the transmission of microwaves. The experiment proves that the system has outstanding precision and reliability.展开更多
Mr.Liu Zhenya,general manager of the State Grid and Mr.Fu Zhifang,executive vice governor of Hebei Province together with their colleagues jointly inspected the development of new energy project in Zhangbei County,Zha...Mr.Liu Zhenya,general manager of the State Grid and Mr.Fu Zhifang,executive vice governor of Hebei Province together with their colleagues jointly inspected the development of new energy project in Zhangbei County,Zhangjiakou City,Hebei Province.展开更多
The sugarcane field excitation,cutting forces and the engine excitation constitute complicated excitations acting on sugarcane harvesters.In this study,the sugarcane cutting mechanism under complicated excitations was...The sugarcane field excitation,cutting forces and the engine excitation constitute complicated excitations acting on sugarcane harvesters.In this study,the sugarcane cutting mechanism under complicated excitations was analyzed.The dynamics and the mathematical models of sugarcane harvesters were established and simulated.Based on theoretical analysis,sugarcane cutting experiments were done on a self-built sugarcane harvester test platform(SHTP),designed as single-factor and the orthogonal experiments.Effects of the sugarcane field excitation characterized by the sugarcane field excitation device(SFED)output frequency,the engine excitation characterized by the actuating engine output frequency,the cutter rotating speed,the sugarcane harvester travelling speed simulated through the sugarcane transporting speed of the SHTP and the cutter inclination angle on the cutting quality of sugarcane harvesters were studied.Effects of the axial cutter vibration on three-directional cutting forces and the sugarcane cutting quality(SCQ)as well as effects of three-directional cutting forces on the SCQ were further studied.It is shown that the sugarcane field excitation,the axial cutter vibration amplitude and frequency as well as the three-directional cutting forces have significantly negative monotonic correlated effects on the SCQ while the cutter rotating speed,the sugarcane harvester travelling speed and the cutter inclination angle have significantly positive monotonic correlated effects on the SCQ.Significance levels of effects on three-directional cutting forces and the SCQ form high to low are as follow,the axial cutter vibration,the sugarcane field excitation,the cutter rotating speed,the engine excitation,the cutter inclination angle,the sugarcane harvester travelling speed.The theoretical analysis results were verified through experiment and an optimal combination was obtained with the cutter rotating speed of 700 r/min,sugarcane harvester travelling speed of 0.6 m/s and cutter inclination angle of 8º.This study can provide a reference for setting cutting parameters of sugarcane harvesters with a good SCQ.展开更多
Prostate cancer remains the second most common malignancy in men worldwide, is a global health issue,and poses a huge health burden. Precision medicine provides more treatment options for prostate cancer patients, but...Prostate cancer remains the second most common malignancy in men worldwide, is a global health issue,and poses a huge health burden. Precision medicine provides more treatment options for prostate cancer patients, but its popularity, drug resistance, and adverse reactions still need to be focused on. Chinese herbal medicines(CHMs) have been widely accepted as an alternative therapy for cancer, with the advantages of multiple targets, multiple pathways, and low toxicity. We searched the experimental research and clinical practice of CHMs for prostate cancer treatment published in Pub Med, Embase, and Web of Science in the last five years. We found five CHM formulas and six single CHM extracts as well as 12 CHM-derived compounds, which showed induction of apoptosis, autophagy, and cell cycle arrest, suppression of angiogenesis, proliferation, and migration of prostate cancer cells, reversal of drug resistance,and enhancement of anti-tumor immunity. The mechanisms of action include the PI3K/Akt/mTOR, AR,EGFR and Wnt/β-catenin signaling pathways, which are commonly implicated in the development of prostate cancer. We also summarized the advantages of CHMs in patients with hormone-sensitive and castration-resistant prostate cancer and provided ideas for their further experimental design and application.展开更多
To examine the environmental characteristics of the microgravity force and the weathered layer on an asteroid surface,a symmetric wheel brush asteroid sampler is proposed for the collection of particles on the asteroi...To examine the environmental characteristics of the microgravity force and the weathered layer on an asteroid surface,a symmetric wheel brush asteroid sampler is proposed for the collection of particles on the asteroid surface.To study the influence of the wheel brush rotation speed on the sampling efficiency and the driving torque required for the wheel brush,the contact dynamics model between particles and sampling wheel brushes is established and a simulation and experimental verification of the sampling process are conducted.The parameter calibration of the sampled particles is studied first,and the calibrated particle parameters are used in the numerical simulation of the sampling process.The sampling results and the particle stream curves are obtained for the working conditions of different rotation speeds,and the effects of different parameter settings on the sampling efficiency are analyzed.In addition,a set of rotating symmetrical sampling wheel brush devices is built for the ground test,and the dynamic torque sensor is used to test the torque change of the wheel brush during the sampling process.The relationship between the speed of the wheel brush and the driving torque of the wheel brush motor is determined by comparing the simulation results with the test results.Results indicate that when the rotating speed of the wheel brush is faster,the sampling efficiency is higher,and the driving torque required for the sampling wheel brush is greater.Moreover,a numerical simulation analysis of the sampling process of the wheel brush sampler in a microgravity environment is conducted to determine the optimal speed condition,and the brushing test of the wheel brush sampler in the microgravity environment is verified with the drop tower method.This research proposes the structural optimization design and motor selection of a wheel brush asteroid sampler,which provides important reference value and engineering significance.展开更多
The inlet swirl distortion and non-uniform tip clearance have great effects on aero-engine performance and stall margin.In this paper,the effects of paired swirl distortion on the aerodynamic stability and stall incep...The inlet swirl distortion and non-uniform tip clearance have great effects on aero-engine performance and stall margin.In this paper,the effects of paired swirl distortion on the aerodynamic stability and stall inception of a single stage axial compressor with non-uniform tip clearance are quantitatively analyzed by using the swirl distortion descriptors.The experimental results show that the paired swirl distortion dominated by co-rotating swirl improves the stability of the axial compressor.For a single-stage axial compressor with eccentricity of 100%,the stall inception starts at the maximum tip clearance with clean inlet.The initial position of the stall inception is determined by the maximum tip clearance when the small intensity paired swirl distortion exists at the compressor inlet.As the swirl intensity increases,it shifts towards the position of the counter rotating swirl vortex core.The inlet swirl will not change the type of stall inception.展开更多
Aircraft engines deteriorate during continuous operation under the action of external factors including fouling, corrosion, and abrasion. The increased surface roughness of compressor passage walls limits airflow and ...Aircraft engines deteriorate during continuous operation under the action of external factors including fouling, corrosion, and abrasion. The increased surface roughness of compressor passage walls limits airflow and leads to flow loss. However, the partial increase of roughness may also restrain flow separation and reduce flow loss. It is necessary to explore methods that will lower compressor deterioration, thereby improving the overall performance. The experimental research on the effects of surface roughness on highly loaded compressor cascade aerodynamics has been conducted in a low-speed linear cascade wind tunnel. The different levels of roughness are arranged on the suction surface and pressure surface, respectively. Ink-trace flow visualization has been used to measure the flow field on the walls of cascades, and a five-hole probe has been traversed across one pitch at the outlet. By comparing the total pressure loss coefficient, the distributions of the secondary-flow speed vector, and flow fields of various cases, the effects of surface roughness on the aerodynamics of a highly loaded compressor cascade are analyzed and discussed. The results show that adding surface roughness on the suction surface and pressure surface make the loss decrease in most cases. Increasing the surface roughness on the suction surface causes reduced flow speed near the blade, which helps to decrease mixing loss at the cascades outlet. Meanwhile, adding surface roughness on the suction surface restrains flow separation, leading to less flow loss. Various levels of surface roughness mostly weaken the flow turning capacity to various degrees, except in specific cases.展开更多
ABSTRACT To give an overview of contemporary experimental research using Chinese medicine （CM） for the treatment of cancer. As an integral part of mainstream medicine in the People＇s Republic of China, CM emphasize...ABSTRACT To give an overview of contemporary experimental research using Chinese medicine （CM） for the treatment of cancer. As an integral part of mainstream medicine in the People＇s Republic of China, CM emphasizes improvements in holistic physical condition instead of merely killing tumor cells, which is consistent with the current medical model that advocates patient-oriented treatment. Great progress has been made in experimental research, and the principle aspects include anti-tumor angiogenesis, inducing apoptosis and differentiation, reversing multi- drug resistance, and improving immune function. As a current hot topic in cancer research, tumor micreenvironment （TME） highlights the mutual and interdependent interaction between tumor cells and their surrounding tissues, and the CM treatment concept bears a striking resemblance to it. To date, primary points of TME include extracellular matrix remodeling, inflammation, hypoxia, and angiogenesis, but trials using CM with a focus on TME are rare. Despite considerable recent development, experimental research on CM for solving cancer issues appears insufficient. Greater efforts in this field are urgently needed.展开更多
Two-dimensional internal waves generated by a moving flat body in a continuous- ly stratified fluid are investigated by using three kinds of flow-visualization methods:electrolytic precipitation,hydrogen bubbles,and d...Two-dimensional internal waves generated by a moving flat body in a continuous- ly stratified fluid are investigated by using three kinds of flow-visualization methods:electrolytic precipitation,hydrogen bubbles,and dye streaks.Attentions are paid mainly to the generation and propagation process in the upstream region under low internal Froude number(1/10π<F_r<1/2π).The features of the upstream disturbances as well as their relationship with stratification number K (K=1/F_r) are illustrated.The corresponding theoretical analysis is briefly presented,and by comparison,the experimental and theoretical results agree well.展开更多
文摘Through the Latour concept of philosophy of science of laboratory life,the life course of a(geo)ethnographer researcher is analyzed,in order to establish the emotional or more personal dimensions that do not usually appear in research papers,but that have notable relevance in qualitative research.The text is structured in three large parts:A conceptual vision of the new experimental geography;the experimental geo-ethnography in old social,new social and place scenarios;and finally,the most personal and emotional dimension of the research.The first part establishes the geo-ethnographic experimental context and the assumptions in fieldwork,in addition to the geo-ethnographic reconciliation process.In the second part,the main qualitative research problems related to mobility,resistance and dynamics in place are established.Finally,in the third part the research perceptions,the personal experiences,and the emotional dimension of the research in remote rural areas are established.The laboratory life of a researcher,allows one to establish scalar conclusions and rigor in qualitative research.
基金supported by the National Natural Science Foundation of China (Grant number 51776015)
文摘In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors' research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.
文摘The absence of effective therapies for castration-resistant prostate cancer(CRPC) establishes the need to develop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. But its application has been limited due to lack of favorable gene vector and the reduction of "bystander effect". Consequently, scientists all over the world focus their main experimental research on the following four aspects: targeted gene, vector, transfer means and comprehensive therapy. In this paper, we reviewed the latest advances of experimental research on targeted gene therapy for prostate cancer.
文摘Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to recover hemolysin HC50, to increase the weight of the thymus, and increase the alexin of serum C3 and the IgG content of tumor bearing mice. FSP also significantly raised the pha-gocytic activity of macrophages in normal mice. PSP had a significant inhibitory effect on P38S and S180 cells. At the concentration of 1 mg/ml, PSP inhibited the proliferating activity of some human tumor call lines, such as SGC 7901, SPC, SLY and Mei. It had a direct toxic effect on SPC cells. PSP significantly inhibited the synthesis of nucleic acids of Ehrlich ascites carcinoma cells. In addition, PSP was antagonistic to the side effects of chemotherapy and radiotherapy.
文摘?Fundamental experiments on lower hybrid current drive (LHCD) have been undertaken on HT-7 superconducting tokamak. The experiments on LHCD efficiency reveal its depen- deuce on plasma density and the toroidal magnetic field. Furthermore, the experiments on HT-7 successfully demonstrate the ability for LHCD to sustain long pulse tokamak discharges, such as discharges with full non-inductive current drive for several seconds. The experimental study to improve plasma confinements by LHCD suggests that the improvement should be due to the change o f current profile. It has also been demonstrated by the experiments that the lower hybrid wave may lead to an enhanced ionization of particles in the region where the wave is deposited.
基金This project is supported by National Key Technologies R&D Programme,China (No.2001BA501A22).
文摘The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency, in order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result, it can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.
基金Supported by the National Natural Science Foundation of China under Grant No 61306076
文摘The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15 Ω/. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.
文摘This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through the hydraulic model test, the mechanism of stability of the block has been proved and the relations between stability and wave height, wave period, water depth, slope, laying method, porosity and cushion have been found. The effect of weight on steadiness have also been discovered. Finally, the method of design and some formulas are given.
基金Sponsored by the Ministerial Level Advanced Research Foundation(65822576)
文摘To provide hexapod robots with strategies of locomotion planning, observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis. Through digitalization of original analog video, locomotion characters of ants were obtained, the biomimetic foundation was laid for polynomial trajectory planning of multi-legged robots, which was deduced with mathematics method. In addition, five rules were concluded, which apply to hexapod robots marching locomotion planning. The first one is the fundamental strategy of multi-legged robots＇ leg trajectory planning. The second one helps to enhance the static and dynamic stability of multi-legged robots. The third one can improve the validity and feasibility of legs＇ falling points. The last two give criterions of multi-legged robots＇ toe trajectory figures and practical recommendatory constraints. These five rules give a good method for marching locomotion planning of multi-legged robots, and can be expended to turning planning and any other special locomotion.
基金Supported by National Natural Science Foundation of China(No.50305020)
文摘Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.
基金Project 2004CB217704-4 supported by the Special Funds for Major State Basic Research Projects of China and 306012 by the Key Grant Project of Chinese Ministry of Education
文摘Reburning technology is one of the most cost-effective NOx reduction strategies for coal combustion systems. In this paper, a nitric oxide submodel incorporated into a comprehensive coal combustion model was developed for predicting NOx reduction in a 93 kW laboratory-scale coal combustion furnace by reburning. This NO submodel, including reburning mechanism, requires the solution of only two transport equations to model the behavior of NO reduction in the reburning process. A number of experiments have been performed in the same furnace, and the experimental data obtained from the optimized reburn configuration was used to validate the model. Measurements and predictions both show above 50% reduction of NO emissions for the optimized reburning process. Profile comparisons show that the predicted temperature and oxygen concentration match well with the measurements, and the general trend of predicted NO concentration is very similar to that measured. The results of this study show that the present nitric oxide submodel depicts quite well the observed behaviour of NO annihilation in the reburning process. It is expected that this usable and computationally economic model represents a useful tool to simulate the gaseous fuel reburning process for the researchers concerned with practical combustors.
文摘in this paper, an experimental research the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The results show that the ablating material with accidented surface and its high temperature have remarkably affected the reflection and the transmission of microwaves. The experiment proves that the system has outstanding precision and reliability.
文摘Mr.Liu Zhenya,general manager of the State Grid and Mr.Fu Zhifang,executive vice governor of Hebei Province together with their colleagues jointly inspected the development of new energy project in Zhangbei County,Zhangjiakou City,Hebei Province.
基金supported by the Middle-aged and Young Teachers'Basic Scientific Research Ability Promotion Project of Guangxi Universities,China(Grant No.2023KY0701)Wuzhou University Research Foundation for Advanced Talents,China(Grant No.WZUQDJJ17195)+13 种基金Key University-level Scientific Research Project of Wuzhou University,China(Grant No.2020B003)Middle-aged and Young Teachers'Basic Scientific Research Ability Promotion Project of Guangxi Universities,China(Grant No.2024KY0697)Wuzhou University Research Foundation for Advanced Talents,China(Grant No.WZUQDJJ17179)Major Special Project of Guangxi Sugarcane Science and Technology in the 14th Five-year Plan,China(Grant No.2022AA01010)the general program of the National Natural Science Foundation Project,China(Grant No.32071916)a horizontal technical service project of the Zhenkang Professor Workstation,Yunnan,Chinathe Double First-class Discipline Construction Project:Mechanized sugarcane harvesting equipment development of Zhenkang,Yunnan,Chinathe first universitydirectlyunder-Education-Ministry-served innovative rural revitalization test project:the China-Agricultural-University-served innovative Bangdong Village revitalization test plan,mechanizedsugarcaneharvesting assistant rural revitalization in hilly areas,Zhenkang,Yunnan,Chinathe Portable Sugarcane Harvester Research and Development,China(Grant No.NK2022160504)the 2115 Talent Development Program of China Agricultural UniversityGuangxi Science and Technology Project,China(Grant No.Guike AA22117007)Guangxi Science and Technology Project,China(Grant No.Guike AA22117005)Guangxi Special Project of Science Technology Bases and Talents,China(Grant No.Guike AD23026033)the Opening Project of Guangxi Key Laboratory of Advanced Microwave Manufacturing Technology,China(Grant No.2024GKLAMMTKFKT001).
文摘The sugarcane field excitation,cutting forces and the engine excitation constitute complicated excitations acting on sugarcane harvesters.In this study,the sugarcane cutting mechanism under complicated excitations was analyzed.The dynamics and the mathematical models of sugarcane harvesters were established and simulated.Based on theoretical analysis,sugarcane cutting experiments were done on a self-built sugarcane harvester test platform(SHTP),designed as single-factor and the orthogonal experiments.Effects of the sugarcane field excitation characterized by the sugarcane field excitation device(SFED)output frequency,the engine excitation characterized by the actuating engine output frequency,the cutter rotating speed,the sugarcane harvester travelling speed simulated through the sugarcane transporting speed of the SHTP and the cutter inclination angle on the cutting quality of sugarcane harvesters were studied.Effects of the axial cutter vibration on three-directional cutting forces and the sugarcane cutting quality(SCQ)as well as effects of three-directional cutting forces on the SCQ were further studied.It is shown that the sugarcane field excitation,the axial cutter vibration amplitude and frequency as well as the three-directional cutting forces have significantly negative monotonic correlated effects on the SCQ while the cutter rotating speed,the sugarcane harvester travelling speed and the cutter inclination angle have significantly positive monotonic correlated effects on the SCQ.Significance levels of effects on three-directional cutting forces and the SCQ form high to low are as follow,the axial cutter vibration,the sugarcane field excitation,the cutter rotating speed,the engine excitation,the cutter inclination angle,the sugarcane harvester travelling speed.The theoretical analysis results were verified through experiment and an optimal combination was obtained with the cutter rotating speed of 700 r/min,sugarcane harvester travelling speed of 0.6 m/s and cutter inclination angle of 8º.This study can provide a reference for setting cutting parameters of sugarcane harvesters with a good SCQ.
基金supported by the National Administration of Traditional Chinese Medicine: 2019 Project of Building Evidencebased Practice Capacity for TCM (No. 2019XZZX-ZL007)National Administration of Traditional Chinese Medicine: Jia Yingjie National Famous Traditional Chinese Medicine Experts Academic Experience Inheritance Project (No. 974022)。
文摘Prostate cancer remains the second most common malignancy in men worldwide, is a global health issue,and poses a huge health burden. Precision medicine provides more treatment options for prostate cancer patients, but its popularity, drug resistance, and adverse reactions still need to be focused on. Chinese herbal medicines(CHMs) have been widely accepted as an alternative therapy for cancer, with the advantages of multiple targets, multiple pathways, and low toxicity. We searched the experimental research and clinical practice of CHMs for prostate cancer treatment published in Pub Med, Embase, and Web of Science in the last five years. We found five CHM formulas and six single CHM extracts as well as 12 CHM-derived compounds, which showed induction of apoptosis, autophagy, and cell cycle arrest, suppression of angiogenesis, proliferation, and migration of prostate cancer cells, reversal of drug resistance,and enhancement of anti-tumor immunity. The mechanisms of action include the PI3K/Akt/mTOR, AR,EGFR and Wnt/β-catenin signaling pathways, which are commonly implicated in the development of prostate cancer. We also summarized the advantages of CHMs in patients with hormone-sensitive and castration-resistant prostate cancer and provided ideas for their further experimental design and application.
基金supported by the National Natural Science Foundation of China(Grant No.51975567)the Strategic Priority Research Program on Space Science,CAS(Grant No.XDA1502030505)+4 种基金the independent project of State Key Laboratory of Robotics,China(Grant Nos.2022-Z01 and 2019-Z06)the Liaoning Revitalization Talents Program,China(Grant No.XLYC1907152)the Youth Innovation Promotion Association,CAS(Grant No.2018237)the Natural Science Foundation of Liaoning Province,China(Grant Nos.2020-MS-029 and 2021-MS-029)the Development Fund of Space Automation Technology Laboratory,SIA,CAS.
文摘To examine the environmental characteristics of the microgravity force and the weathered layer on an asteroid surface,a symmetric wheel brush asteroid sampler is proposed for the collection of particles on the asteroid surface.To study the influence of the wheel brush rotation speed on the sampling efficiency and the driving torque required for the wheel brush,the contact dynamics model between particles and sampling wheel brushes is established and a simulation and experimental verification of the sampling process are conducted.The parameter calibration of the sampled particles is studied first,and the calibrated particle parameters are used in the numerical simulation of the sampling process.The sampling results and the particle stream curves are obtained for the working conditions of different rotation speeds,and the effects of different parameter settings on the sampling efficiency are analyzed.In addition,a set of rotating symmetrical sampling wheel brush devices is built for the ground test,and the dynamic torque sensor is used to test the torque change of the wheel brush during the sampling process.The relationship between the speed of the wheel brush and the driving torque of the wheel brush motor is determined by comparing the simulation results with the test results.Results indicate that when the rotating speed of the wheel brush is faster,the sampling efficiency is higher,and the driving torque required for the sampling wheel brush is greater.Moreover,a numerical simulation analysis of the sampling process of the wheel brush sampler in a microgravity environment is conducted to determine the optimal speed condition,and the brushing test of the wheel brush sampler in the microgravity environment is verified with the drop tower method.This research proposes the structural optimization design and motor selection of a wheel brush asteroid sampler,which provides important reference value and engineering significance.
基金supported by National Science and Technology Major Project(Grant No.2017-II-0004-0017)。
文摘The inlet swirl distortion and non-uniform tip clearance have great effects on aero-engine performance and stall margin.In this paper,the effects of paired swirl distortion on the aerodynamic stability and stall inception of a single stage axial compressor with non-uniform tip clearance are quantitatively analyzed by using the swirl distortion descriptors.The experimental results show that the paired swirl distortion dominated by co-rotating swirl improves the stability of the axial compressor.For a single-stage axial compressor with eccentricity of 100%,the stall inception starts at the maximum tip clearance with clean inlet.The initial position of the stall inception is determined by the maximum tip clearance when the small intensity paired swirl distortion exists at the compressor inlet.As the swirl intensity increases,it shifts towards the position of the counter rotating swirl vortex core.The inlet swirl will not change the type of stall inception.
基金Financially supported from"National Natural Science Foundation of China"(Grant No.51206035)"the Foundation for Innovative Research Groups of the National Natural Science Foundation of China"(Grant No.51121004)
文摘Aircraft engines deteriorate during continuous operation under the action of external factors including fouling, corrosion, and abrasion. The increased surface roughness of compressor passage walls limits airflow and leads to flow loss. However, the partial increase of roughness may also restrain flow separation and reduce flow loss. It is necessary to explore methods that will lower compressor deterioration, thereby improving the overall performance. The experimental research on the effects of surface roughness on highly loaded compressor cascade aerodynamics has been conducted in a low-speed linear cascade wind tunnel. The different levels of roughness are arranged on the suction surface and pressure surface, respectively. Ink-trace flow visualization has been used to measure the flow field on the walls of cascades, and a five-hole probe has been traversed across one pitch at the outlet. By comparing the total pressure loss coefficient, the distributions of the secondary-flow speed vector, and flow fields of various cases, the effects of surface roughness on the aerodynamics of a highly loaded compressor cascade are analyzed and discussed. The results show that adding surface roughness on the suction surface and pressure surface make the loss decrease in most cases. Increasing the surface roughness on the suction surface causes reduced flow speed near the blade, which helps to decrease mixing loss at the cascades outlet. Meanwhile, adding surface roughness on the suction surface restrains flow separation, leading to less flow loss. Various levels of surface roughness mostly weaken the flow turning capacity to various degrees, except in specific cases.
文摘ABSTRACT To give an overview of contemporary experimental research using Chinese medicine （CM） for the treatment of cancer. As an integral part of mainstream medicine in the People＇s Republic of China, CM emphasizes improvements in holistic physical condition instead of merely killing tumor cells, which is consistent with the current medical model that advocates patient-oriented treatment. Great progress has been made in experimental research, and the principle aspects include anti-tumor angiogenesis, inducing apoptosis and differentiation, reversing multi- drug resistance, and improving immune function. As a current hot topic in cancer research, tumor micreenvironment （TME） highlights the mutual and interdependent interaction between tumor cells and their surrounding tissues, and the CM treatment concept bears a striking resemblance to it. To date, primary points of TME include extracellular matrix remodeling, inflammation, hypoxia, and angiogenesis, but trials using CM with a focus on TME are rare. Despite considerable recent development, experimental research on CM for solving cancer issues appears insufficient. Greater efforts in this field are urgently needed.
基金The project supported by National Natural Science Foundation of China.
文摘Two-dimensional internal waves generated by a moving flat body in a continuous- ly stratified fluid are investigated by using three kinds of flow-visualization methods:electrolytic precipitation,hydrogen bubbles,and dye streaks.Attentions are paid mainly to the generation and propagation process in the upstream region under low internal Froude number(1/10π<F_r<1/2π).The features of the upstream disturbances as well as their relationship with stratification number K (K=1/F_r) are illustrated.The corresponding theoretical analysis is briefly presented,and by comparison,the experimental and theoretical results agree well.
