The ecological series of soil animals under the broad-leaved and pine mix ed forest in Darlidai Mountain was studied.Seven sample plots were selected according to different altitude gradients,which belong to dif feren...The ecological series of soil animals under the broad-leaved and pine mix ed forest in Darlidai Mountain was studied.Seven sample plots were selected according to different altitude gradients,which belong to dif ferent vegeta-tion types.By investigating and analyzing soil animals in every sample p lot it is found that there are 45group s and 1956individuals,which are involved in 3phylums,7classes,16orders,respectively.The altitude is a key factor which af-fects ecological series of soil anim als.Both the groups and individuals of soil animals increase with altitu de increasing under certain conditions,which con trastes with ordinary cases,resulting from special micro-climate in studied area.The groups and individuls of soil animals are the most under the broad-leaved and pine forest on the top of the mount ain,and the least under Picea-Abies forest in the foot of the mountain.展开更多
A dual-frequency(105/140 GHz)MW-level continuous-wave gyrotron was developed for fusion application at Institute of Applied Electronics,China Academy of Engineering Physics.This gyrotron employs a cylindrical cavity w...A dual-frequency(105/140 GHz)MW-level continuous-wave gyrotron was developed for fusion application at Institute of Applied Electronics,China Academy of Engineering Physics.This gyrotron employs a cylindrical cavity working in the TE18,7 mode at 105 GHz and the TE24,9 mode at 140 GHz.A triode magnetron injection gun and a built-in quasi-optical mode converter were designed to operate at these two frequencies.For the proof-test phase,the gyrotron was equipped with a single-disk boron nitride window to achieve radio frequency output with a power of~500 k W for a short-pulse duration.In the preliminary short-pulse proof-test in the first quarter of2021,the dual-frequency gyrotron achieved output powers of 300 k W at 105 GHz and 540 k W at140 GHz,respectively,under 5 Hz 1 ms continuous pulse-burst operations.Power upgrade and pulse-width extension were hampered by the limitation of the high-voltage power supply and output window.This gyrotron design was preliminarily validated.展开更多
This paper discusses and sums up the basic criterions of guaranteeing the labeling quality and abstracts the four basic factors including the conflict for a label with a label, overlay for label with the features, pos...This paper discusses and sums up the basic criterions of guaranteeing the labeling quality and abstracts the four basic factors including the conflict for a label with a label, overlay for label with the features, position’s priority and the association for a label with its feature. By establishing the scoring system, a formalized four-factors quality evaluation model is constructed. Last, this paper introduces the experimental result of the quality evaluation model applied to the automatic map labeling system-MapLabel.展开更多
Bubble evolution behaviors play important roles in bubble emission reactions.Here we fabricated one-dimensional(1D)-aligned MoSx microgrids to investigate the influence of the periodic structure on bubble releasing.It...Bubble evolution behaviors play important roles in bubble emission reactions.Here we fabricated one-dimensional(1D)-aligned MoSx microgrids to investigate the influence of the periodic structure on bubble releasing.It is demonstrated that the utilization of the surface energy released during coalescence of bubbles causes them to jump from the electrode,which can be an effective route to eliminate the bubble shielding effect.Under the optimized architecture with 40-μm-wide grooves,the generated bubbles tend to coalesce and release from the electrode with much smaller size(65%less in volume).By balancing the coalescence efficiency and the adhesive work via the architecture engineering,the electrocatalytic performance can be promoted with the rapid bubble removal and lowered ohmic resistance.The results provide new insights into the rational design of novel catalytic electrode architectures and promote their applications in related fields.展开更多
This paper focuses on the historical transition of human being's activities and the eco-environment in the upper reaches of Minjiang River. The history is divided into 4 periods, each with its own feature. During ...This paper focuses on the historical transition of human being's activities and the eco-environment in the upper reaches of Minjiang River. The history is divided into 4 periods, each with its own feature. During the period of nomad immigration, the top-line of the subalpine forest was forced downward by the expanding subalpine meadow. During the period of farming nationality immigration, the bottom-line of middle mountain forest had moved upward forced by the needs for land or timber of the increasing population in the valley basia During the period of the early exploiting, the focus resource was the timber. The total output was limited, comparing with the later period, because of the bad accessibility. But it was large enough to impact the forest ecosystem of the deforesting area. The recent 50 years is the crucial period of economic development and eco-environment degradation. This paper points out that the impact of human being's activities for environment lies on 3 factors: 1) physical features control the location and tendency eco-environmental change; 2) population and productivity control the scale and speed of eco-environmental change; 3) regional accessibility controls the time and location of eco-environmental change.展开更多
This paper presents a class of non-model-based position controllers for a kind of flexible spacecraft. With the controllers, one can achieve not only the closed-loop stability of the original distributed parameter sys...This paper presents a class of non-model-based position controllers for a kind of flexible spacecraft. With the controllers, one can achieve not only the closed-loop stability of the original distributed parameter system, but also the asymptotic stability of the truncated system, which is obtained through representing the deflection of the appendage by an arbitrary finite number of flexible modes. The system dynamics are not explicitly involved in the controller design and stability proof. Instead, only a very basic system energy relationship of the flexible spacecraft is utilized. The controllers possess several remarkable advantages over the traditional model-based ones. Numerical simulations are carried out on a kind of spacecraft with one flexible appendage and satisfactory results are obtained.展开更多
Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts ...Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts design does.Herein the consumption behavior of an individual oxygen bubble on Pt foils with different wettabilities during ORR was tracked by a real-time approach to reveal whether the surface wettability of electrode can influence the consumption dynamics and determine the reaction reactive zones of oxygen bubble consumption.The oxygen bubble underwent a "constant contact angle"dominant consumption model on aerophobic Pt foil,while an initial "constant radius"and the subsequent"constant contact angle"oxygen consumption models were observed on aero philic Pt foil.Results here demonstrated that the current was proportional to the bottom contact area,rather than the three-phase contact line of the bubbles according to the fitting curves between individual bubble current and the consumption behavior parameters.This study highlights the important role of the gas-solid interface in influencing the efficiency of gas consumption electrochemical reactions,which shall benefit the understanding of reaction kinetics and the rational design of electrocatalysts.展开更多
OBJECTIVE: To give a general introduction of journals on traditional medicine, which have been collected by the Science Citation Index(SCI). METHODS: A keyword search was conducted on the SCIE journals on the Thomson ...OBJECTIVE: To give a general introduction of journals on traditional medicine, which have been collected by the Science Citation Index(SCI). METHODS: A keyword search was conducted on the SCIE journals on the Thomson Reuters website(http://www.thomsonscientific.com.cn) with the search formula "Alternative OR Complementary OR Integrative OR Chinese Medicine OR Medicinal OR Ethnopharmacology OR Manipulative OR Natural Medicine OR Natural Product OR Phytotherapy OR Phytomedicine OR Homeopathy OR Acupuncture OR Planta OR Traditional OR Ayurvedic OR Herb OR Herbal". RESULTS: A total of 32 kinds of traditional medicine journals were collected by SCI, of which 30 are in English and the rest are in German.The subject of traditional medical journals covered by SCI covers traditional medicine, supplementary and alternative therapies, botanicals, and natural medicines. Chinese medicine professionals in China can take these factors into consideration when using literature or choosing the direction of paper submission. CONCLUSION: The IF of traditional medicine related journals are relative low, while those of biology and natural drugs are relative high. IF should not be considered as the only factor to evaluate the impact and academic level of journals.展开更多
In a rational chiral molecular design of chalcogenides,optically active thiepin with C_(2)-symmetric chirality was synthesized from commercially available thiophene.Then enatioselective Chalcogeno-Baylis-Hillman react...In a rational chiral molecular design of chalcogenides,optically active thiepin with C_(2)-symmetric chirality was synthesized from commercially available thiophene.Then enatioselective Chalcogeno-Baylis-Hillman reactions of arylaldehydes with methyl vinyl ketone(MVK)and acrylates were investigated in the presence of thiepin-Lewis acid complex.Finally,up to 64%ee was achieved in the presence of 0.2 equiv.of(S)-thiepin at 20℃.展开更多
This paper studies the problem of principal-agent with moral hazard in continuous time.The firm’s cash flow is described by geometric Brownian motion(hereafter GBM).The agent affects the drift of the firm’s cash flo...This paper studies the problem of principal-agent with moral hazard in continuous time.The firm’s cash flow is described by geometric Brownian motion(hereafter GBM).The agent affects the drift of the firm’s cash flow by her hidden effort.Meanwhile,the firm rewards the agent with corresponding compensation and equity which depend on the output.The model extends dynamic optimal contract theory to an inflation environment.Firstly,the authors obtain the dynamic equation of the firm’s real cash flow under inflation by using the It?formula.Then,the authors use the martingale representation theorem to obtain agent’s continuation value process.Moreover,the authors derive the Hamilton-Jacobi-Bellman(HJB)equation of investor’s value process,from which the authors derive the investors’scaled value function by solving the second-order ordinary differential equation.Comparing with He;,the authors find that inflation risk affects the agent’s optimal compensation depending on the firm’s position in the market.展开更多
This paper presents a method of adding label to the map especially for the point feature. This method overcomes the shortcoming of traditional methods, e.g. Conflict\|Backtracking method. Its kernel algorithm use the ...This paper presents a method of adding label to the map especially for the point feature. This method overcomes the shortcoming of traditional methods, e.g. Conflict\|Backtracking method. Its kernel algorithm use the hopfield neural network to find the best label position for point feature. The experimental results proves that this algorithm has good permanence and high speed.展开更多
文摘The ecological series of soil animals under the broad-leaved and pine mix ed forest in Darlidai Mountain was studied.Seven sample plots were selected according to different altitude gradients,which belong to dif ferent vegeta-tion types.By investigating and analyzing soil animals in every sample p lot it is found that there are 45group s and 1956individuals,which are involved in 3phylums,7classes,16orders,respectively.The altitude is a key factor which af-fects ecological series of soil anim als.Both the groups and individuals of soil animals increase with altitu de increasing under certain conditions,which con trastes with ordinary cases,resulting from special micro-climate in studied area.The groups and individuls of soil animals are the most under the broad-leaved and pine forest on the top of the mount ain,and the least under Picea-Abies forest in the foot of the mountain.
基金supported in part by NSAF(No.U1830201)in part by the State Administration of Science,Technology and Industry for Nation Defense of China,Technology Foundation Project(No.JSJL2019212B006)+1 种基金in part by the Academy Innovation Funder(No.CX2020038)in part by the National Defense Basic Scientific Research Program(No.2018212C015)。
文摘A dual-frequency(105/140 GHz)MW-level continuous-wave gyrotron was developed for fusion application at Institute of Applied Electronics,China Academy of Engineering Physics.This gyrotron employs a cylindrical cavity working in the TE18,7 mode at 105 GHz and the TE24,9 mode at 140 GHz.A triode magnetron injection gun and a built-in quasi-optical mode converter were designed to operate at these two frequencies.For the proof-test phase,the gyrotron was equipped with a single-disk boron nitride window to achieve radio frequency output with a power of~500 k W for a short-pulse duration.In the preliminary short-pulse proof-test in the first quarter of2021,the dual-frequency gyrotron achieved output powers of 300 k W at 105 GHz and 540 k W at140 GHz,respectively,under 5 Hz 1 ms continuous pulse-burst operations.Power upgrade and pulse-width extension were hampered by the limitation of the high-voltage power supply and output window.This gyrotron design was preliminarily validated.
基金Funded by the National Natural Science Foundation of China (N0.40001019).
文摘This paper discusses and sums up the basic criterions of guaranteeing the labeling quality and abstracts the four basic factors including the conflict for a label with a label, overlay for label with the features, position’s priority and the association for a label with its feature. By establishing the scoring system, a formalized four-factors quality evaluation model is constructed. Last, this paper introduces the experimental result of the quality evaluation model applied to the automatic map labeling system-MapLabel.
基金the National Natural Science Foundation of China(21675007,21676015,21520102002,91622116 and 22005022)the National Key Research and Development Project(2018YFB1502401 and 2018YFA0702002)+2 种基金the Royal Society and Newton Fund through Newton Advanced Fellowship award(NAF\R1\191294)the Program for Changjiang Scholars and Innovation Research Team in the University(IRT1205)the Fundamental Research Funds for the Central Universities and the long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of China。
文摘Bubble evolution behaviors play important roles in bubble emission reactions.Here we fabricated one-dimensional(1D)-aligned MoSx microgrids to investigate the influence of the periodic structure on bubble releasing.It is demonstrated that the utilization of the surface energy released during coalescence of bubbles causes them to jump from the electrode,which can be an effective route to eliminate the bubble shielding effect.Under the optimized architecture with 40-μm-wide grooves,the generated bubbles tend to coalesce and release from the electrode with much smaller size(65%less in volume).By balancing the coalescence efficiency and the adhesive work via the architecture engineering,the electrocatalytic performance can be promoted with the rapid bubble removal and lowered ohmic resistance.The results provide new insights into the rational design of novel catalytic electrode architectures and promote their applications in related fields.
基金Supported by the Knowledge Innovative program of Chinese Academy of Sciences(KSCX1-07-03)
文摘This paper focuses on the historical transition of human being's activities and the eco-environment in the upper reaches of Minjiang River. The history is divided into 4 periods, each with its own feature. During the period of nomad immigration, the top-line of the subalpine forest was forced downward by the expanding subalpine meadow. During the period of farming nationality immigration, the bottom-line of middle mountain forest had moved upward forced by the needs for land or timber of the increasing population in the valley basia During the period of the early exploiting, the focus resource was the timber. The total output was limited, comparing with the later period, because of the bad accessibility. But it was large enough to impact the forest ecosystem of the deforesting area. The recent 50 years is the crucial period of economic development and eco-environment degradation. This paper points out that the impact of human being's activities for environment lies on 3 factors: 1) physical features control the location and tendency eco-environmental change; 2) population and productivity control the scale and speed of eco-environmental change; 3) regional accessibility controls the time and location of eco-environmental change.
文摘This paper presents a class of non-model-based position controllers for a kind of flexible spacecraft. With the controllers, one can achieve not only the closed-loop stability of the original distributed parameter system, but also the asymptotic stability of the truncated system, which is obtained through representing the deflection of the appendage by an arbitrary finite number of flexible modes. The system dynamics are not explicitly involved in the controller design and stability proof. Instead, only a very basic system energy relationship of the flexible spacecraft is utilized. The controllers possess several remarkable advantages over the traditional model-based ones. Numerical simulations are carried out on a kind of spacecraft with one flexible appendage and satisfactory results are obtained.
基金the National Natural Science Foundation of China(Nos.21675007,21676015,21520102002,91622116)the National Key Research and Development Project of China(Nos.2018YFB1502401,2018YFA0702002),the Royal Society and the Newton Fund Through the Newton Advanced Fellowship Award(No.NAF/R1/191294)+2 种基金the Program for Changjiang Scholars and Innovation Research Team in the University,China(No.IRT1205)Fundamental Research Funds for the Central Universities of Chinathe Long-term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China。
文摘Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts design does.Herein the consumption behavior of an individual oxygen bubble on Pt foils with different wettabilities during ORR was tracked by a real-time approach to reveal whether the surface wettability of electrode can influence the consumption dynamics and determine the reaction reactive zones of oxygen bubble consumption.The oxygen bubble underwent a "constant contact angle"dominant consumption model on aerophobic Pt foil,while an initial "constant radius"and the subsequent"constant contact angle"oxygen consumption models were observed on aero philic Pt foil.Results here demonstrated that the current was proportional to the bottom contact area,rather than the three-phase contact line of the bubbles according to the fitting curves between individual bubble current and the consumption behavior parameters.This study highlights the important role of the gas-solid interface in influencing the efficiency of gas consumption electrochemical reactions,which shall benefit the understanding of reaction kinetics and the rational design of electrocatalysts.
文摘OBJECTIVE: To give a general introduction of journals on traditional medicine, which have been collected by the Science Citation Index(SCI). METHODS: A keyword search was conducted on the SCIE journals on the Thomson Reuters website(http://www.thomsonscientific.com.cn) with the search formula "Alternative OR Complementary OR Integrative OR Chinese Medicine OR Medicinal OR Ethnopharmacology OR Manipulative OR Natural Medicine OR Natural Product OR Phytotherapy OR Phytomedicine OR Homeopathy OR Acupuncture OR Planta OR Traditional OR Ayurvedic OR Herb OR Herbal". RESULTS: A total of 32 kinds of traditional medicine journals were collected by SCI, of which 30 are in English and the rest are in German.The subject of traditional medical journals covered by SCI covers traditional medicine, supplementary and alternative therapies, botanicals, and natural medicines. Chinese medicine professionals in China can take these factors into consideration when using literature or choosing the direction of paper submission. CONCLUSION: The IF of traditional medicine related journals are relative low, while those of biology and natural drugs are relative high. IF should not be considered as the only factor to evaluate the impact and academic level of journals.
基金The work was partially supported by the Science and Technology Commission of Shanghai Municipality(No.12ZR1431100).Support from Prof.Gang Zhao was also greatly appreciated.
文摘In a rational chiral molecular design of chalcogenides,optically active thiepin with C_(2)-symmetric chirality was synthesized from commercially available thiophene.Then enatioselective Chalcogeno-Baylis-Hillman reactions of arylaldehydes with methyl vinyl ketone(MVK)and acrylates were investigated in the presence of thiepin-Lewis acid complex.Finally,up to 64%ee was achieved in the presence of 0.2 equiv.of(S)-thiepin at 20℃.
基金supported by the National Natural Science Foundation of China under Grant No.71571001。
文摘This paper studies the problem of principal-agent with moral hazard in continuous time.The firm’s cash flow is described by geometric Brownian motion(hereafter GBM).The agent affects the drift of the firm’s cash flow by her hidden effort.Meanwhile,the firm rewards the agent with corresponding compensation and equity which depend on the output.The model extends dynamic optimal contract theory to an inflation environment.Firstly,the authors obtain the dynamic equation of the firm’s real cash flow under inflation by using the It?formula.Then,the authors use the martingale representation theorem to obtain agent’s continuation value process.Moreover,the authors derive the Hamilton-Jacobi-Bellman(HJB)equation of investor’s value process,from which the authors derive the investors’scaled value function by solving the second-order ordinary differential equation.Comparing with He;,the authors find that inflation risk affects the agent’s optimal compensation depending on the firm’s position in the market.
文摘This paper presents a method of adding label to the map especially for the point feature. This method overcomes the shortcoming of traditional methods, e.g. Conflict\|Backtracking method. Its kernel algorithm use the hopfield neural network to find the best label position for point feature. The experimental results proves that this algorithm has good permanence and high speed.
