Recent advances in dynamical climate prediction at the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP/CAS) during the last five years have been briefly described in this paper. Firstly, the second ...Recent advances in dynamical climate prediction at the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP/CAS) during the last five years have been briefly described in this paper. Firstly, the second generation of the IAP dynamical climate prediction system (IAP DCP-Ⅱ) has been described, and two sets of hindcast experiments of the summer rainfall anomalies over China for the periods of 1980-1994 with different versions of the IAP AGCM have been conducted. The comparison results show that the predictive skill of summer rainfall anomalies over China is improved with the improved IAP AGCM in which the surface albedo parameterization is modified. Furthermore, IAP DCP-II has been applied to the real-time prediction of summer rainfall anomalies over China since 1998, and the verification results show that IAP DCP-II can quite well capture the large scale patterns of the summer flood/drought situations over China during the last five years (1998-2002). Meanwhile, an investigation has demonstrated the importance of the atmospheric initial conditions on the seasonal climate prediction, along with studies on the influences from surface boundary conditions (e.g., land surface characteristics, sea surface temperature). Certain conclusions have been reached, such as, the initial atmospheric anomalies in spring may play an important role in the summer climate anomalies, and soil moisture anomalies in spring can also have a significant impact on the summer climate anomalies over East Asia. Finally, several practical techniques (e.g., ensemble technique, correction method, etc.), which lead to the increase of the prediction skill for summer rainfall anomalies over China, have also been illustrated. The paper concludes with a list of critical requirements needed for the further improvement of dynamical seasonal climate prediction.展开更多
In a wavelength routing optical network (WRON), the optimal allocation of wavelength converters (WCs) is very important to minimize the number of WCs, enhance the fiber utilization, reduce the blocking probability, et...In a wavelength routing optical network (WRON), the optimal allocation of wavelength converters (WCs) is very important to minimize the number of WCs, enhance the fiber utilization, reduce the blocking probability, etc.. In this paper, a novel simplified network model with shared WCs has been proposed. An effective algorithm for optimal allocation of shared WCs has been presented by using a revised Dijkstra algorithm and genetic algorithm (GA). The effectiveness of the revised algorithm was verified through the simulation on Nature and Science Foundation (NSF) net of USA. This revised algorithm can achieve blocking probability 36% less than the algorithm in previous work, and the calculating time of the minimum blocking probability can be reduced dramatically.展开更多
This paper introduces the new electronic business mode of ASP （Application Server Provider） and points out that employing ASP is the certain way to informationize the enterprises, especially the medium and small-sca...This paper introduces the new electronic business mode of ASP （Application Server Provider） and points out that employing ASP is the certain way to informationize the enterprises, especially the medium and small-scale enterprises. Base on the analysis about the feature of current ASP provider and market, this paper forecasts the development trends of ASP in China.展开更多
Major earth-changing events took place in the first decade of the 21st century. First,the 9/11 terrorist attacks created shockwaves in the realm of international security. But the global financial crisis had even grea...Major earth-changing events took place in the first decade of the 21st century. First,the 9/11 terrorist attacks created shockwaves in the realm of international security. But the global financial crisis had even greater repercussions than 9/11. Policy makers and strategists should closely follow the developments and ramifications of this crisis.展开更多
This paper reports the evolution of textile structure and mechanical properties of vascular prosthesis in the level of the whole prosthesis and the constituent filaments with respect to the manufacturing process. The ...This paper reports the evolution of textile structure and mechanical properties of vascular prosthesis in the level of the whole prosthesis and the constituent filaments with respect to the manufacturing process. The tubular wall of the prosthesis is divided circumferentially into three zones; basic line (BL), remeshing line ( RL) and guide line ( GL). Some heterogeneity has been observed on the tubular wall in terms of stitch structure of the prosthesis and linear density of the constituent filaments. The breaking position of the prosthesis under circumferential tensile localizes preferentially in remeshing line that is the weakest zone by warp knitting with double needle bed. Furthermore, the statistical differences of the mechanical properties of the filaments of zone RL, GL and BL have been confirmed too. It is predictable that the deterioration of prosthesis, under physiological loads (periodical pulse blood pressure etc.), could happen firstly in the weaker zone in vivo.展开更多
In this paper, the characteristics of eastern Asian dust storm are examined with emphasis on the satellite measurements of aerosol optical thickness. The reflectivity of solar radiation from the earth's atmosphere...In this paper, the characteristics of eastern Asian dust storm are examined with emphasis on the satellite measurements of aerosol optical thickness. The reflectivity of solar radiation from the earth's atmosphere depends on the optical thickness. The satellite measurement of radiance of sunlight, scattered by the earth and its atmosphere, is used to derive the properties of aerosol on oceanic surfaces. This paper involves the following: (1) investigation of the measurement of dust storm over the oceanic surface by GMS satellite; (2) investigation of the measurement of dust storm over the land surface by ground-based instruments such as actinometer, lidar, etc.; (3) for comparison, deriving an atmospheric aerosol size distribution over the oceanic surface of calm weather through measurements of NOAA satellite; and (4) the weather process and its mass load of eastern Asian dust storm.展开更多
Invariance principle and strong approximation for error variance estimates in Linear regression model has been discussed. In this article, we consider the rate of error variance estimates by a Wiener process, when the...Invariance principle and strong approximation for error variance estimates in Linear regression model has been discussed. In this article, we consider the rate of error variance estimates by a Wiener process, when the sample is a strongly stationary, φ-mixing sequence. From this we can deduce immediately the weak invariance principle, law of the iterated logarithm, etc.展开更多
Phycobiliproteins, the photosynthetic antenna pigments, occur in red algae (Rhodophyta), blue green algae (Cyanophyta) and cryptomonad algae (Cryptophyta). Phycobiliprotein is the collective name of phycoerythrin, phy...Phycobiliproteins, the photosynthetic antenna pigments, occur in red algae (Rhodophyta), blue green algae (Cyanophyta) and cryptomonad algae (Cryptophyta). Phycobiliprotein is the collective name of phycoerythrin, phycocyanin and allo-phycocyanin, etc. The chromophores are open tetrapyrroles, covalently attached to apoproteins. The phycoerythrins have been further divided into R-, B-and C-phycoerythrins according to the absorption spectra characteristics.展开更多
Based on the study on the city transport systems of some typical cities worldwide,this paper put forward that each city transport system has its own development mode,which is influenced by the city development plan,ec...Based on the study on the city transport systems of some typical cities worldwide,this paper put forward that each city transport system has its own development mode,which is influenced by the city development plan,economic development level,traveling vehicle composition etc..When some problems occur,such as the congestions caused by contradiction between the road capacity and vehicle composition,the city transport system may come into temporary maturity period.If the improvement for road system is limited meanwhile,optimized structure of vehicle composition should be an effective solution in this case.With the development of economy-internationalization,the development speed of city transport modernization is rapid.When traveling easiness is conflicting with efficiency,the advantages of public transport system become more obvious.Correspondingly,the superiority of two-wheel vehicles will reappear.Though the important function of two-wheel vehicles for alleviating city traffic problems is obvious,however,their development strategy must be reasonably proposed,and operation regulations must be performed accordingly.展开更多
The gait of the biped robot is described using six parameters such as stature,velocity,length of the step,etc.The algorithm of the Newton-Euler is actualized by object-oriented idea,and then the zero moment point (ZMP...The gait of the biped robot is described using six parameters such as stature,velocity,length of the step,etc.The algorithm of the Newton-Euler is actualized by object-oriented idea,and then the zero moment point (ZMP) of the dynamically walking biped is calculated.Finally,the gait of biped is optimized using gene algorithm,and the optimized result prove the correctness of the algorithm.展开更多
The proposed algorithm for reflectance measured with optical glass has been verified with materials of various forms. The reflectances measured with optical glass ( raw), without glass (true) and corrected by the algo...The proposed algorithm for reflectance measured with optical glass has been verified with materials of various forms. The reflectances measured with optical glass ( raw), without glass (true) and corrected by the algorithm are compared. The results show that the corrected reflectance agrees very well with true one and their color differences fall below the acceptable limit, which indicates the validity of the correction algorithm. The algorithm could be used not only for fiber-forming materials, but also for powder-forming, granulate-forming, etc.展开更多
Many properties of polyester filaments such as heat shrinkage, tenacity, elongation at break and etc. are greatly influenced by drawing, so post-drawing is important in downstream processing. As more and more profile ...Many properties of polyester filaments such as heat shrinkage, tenacity, elongation at break and etc. are greatly influenced by drawing, so post-drawing is important in downstream processing. As more and more profile fibers and multi-variance fibers used in textile industry, the properties of above two kinds of differential polyester filaments after drawing in different heat conditions were studied. Finally following conclusions were obtained: Firstly, the tenacity and elongation at break decreases with the rise of Tp. Secondly, the tenacity rises but the elongation at break decreases with the increase of Tb. Then, when the Tb is low, both the shrinkage in boiling water and hi hot air decreases with the rise of Tp, while, when the Tb is high, both the shrinkage rises with the rise of Tp. The last, both the shrinkage decreases with the rise of Tb.展开更多
The nature of ESR signals derived from bilirubin-Ⅸα has been studied by focusing onthe samples treated with free radical generating and inhibiting systems, i.e. X-XOD, Fe/EDTA, SOD, mannitol/ascorbate, CO, KCN, etc....The nature of ESR signals derived from bilirubin-Ⅸα has been studied by focusing onthe samples treated with free radical generating and inhibiting systems, i.e. X-XOD, Fe/EDTA, SOD, mannitol/ascorbate, CO, KCN, etc. In all the cases, the stable signals comprisethose originated from semiquinone radical (g = 2.0012) and superoxide free radical (g_∥=2.041, g_⊥= 2.0040). The superoxide is shown binding with certain metal ions chelated bybilirubin. The free radical scavengers are able to destroy these radicals. The kinetic curveof the regeneration of bilirubin radicals has been determined and the reaction follows azero order mechanism. It is likely that both the physiological and toxic actions of bilirubinare related to the characters of its free radicals. Bilirubin is discussed as "active oxygensink" in mammalians.展开更多
Hypothyroidism is not uncommon in dogs,but it is actually very often diagnosed in elderly dogs.When and how does the disease start?What are the first recognizable signs?The first symptoms are usually changes in the be...Hypothyroidism is not uncommon in dogs,but it is actually very often diagnosed in elderly dogs.When and how does the disease start?What are the first recognizable signs?The first symptoms are usually changes in the behavior.First,these changes are quite subtle,but as the illness progresses,they can get very grave.We do often hear from the worried owners,that their report of a behavioral change to their vet is often ignored,not taken seriously or simply interpreted as unsteady or insufficient dog training/education.This not taking seriously of the first signs is very concerning and a big problem in many ways.It is delaying the finding of the right diagnosis and treatment,which leads to suffering of the animal and the owner.In some cases,it leads to giving the dog up as an unbearable danger to the family.So the dog,who is only ill and could be back to normal with the right medical treatment,finally ends up in a dog shelter or a new family.The common understanding is,that hypothyreoidism is an illness solely occurring in the elderly dog.In contrast to this,the authors found out,that thyroidal problems occur already at relatively young ages.This is a very important finding,considering that many clinically practising veterinarians expect hypothyreoidism only in the aged or elderly dog and will not run any diagnostics in relatively young or middle-aged animals.The authors also found significant differences in the personality traits of emotional stability and extraversion.Therefore,we would like to expand the existing studies,so that this widely underestimated topic finally comes to the fore and hopefully,in the future the right diagnostcal steps can be taken at an early stage of the disease.展开更多
Chemical reactions (such as hydrogenation, hydroformylation, alkylation, esterification, etc.) at supercritical conditions afford opportunities to manipulate the solubility of reactants and products, to eliminate inte...Chemical reactions (such as hydrogenation, hydroformylation, alkylation, esterification, etc.) at supercritical conditions afford opportunities to manipulate the solubility of reactants and products, to eliminate interphase transport limitations in the reaction systems, and to be beneficial to the environment. This review concentrates on the most recent developments after 2001 with only a brief summary of pioneering research work before 2001.展开更多
Loess is widely distributed on the Miao Islands, covering mainly the foot of mountains, valleys, cleuches and individual mountain tops. Its thickness, with a tendency of gradual downward-increase, is generally from 3 ...Loess is widely distributed on the Miao Islands, covering mainly the foot of mountains, valleys, cleuches and individual mountain tops. Its thickness, with a tendency of gradual downward-increase, is generally from 3 to 6 m, but up to 15—20 m on the Tuoji Island, the Daheishan Island, the Bozicun of Penglai County on the Miao Island, etc.,展开更多
The Ⅲ-Ⅴ compound semiconductor devices such as FET, laser, solar cell, etc. were developed recently. These devices require materials of multiple heterojunction and p-n junction structures. But it is impossible to de...The Ⅲ-Ⅴ compound semiconductor devices such as FET, laser, solar cell, etc. were developed recently. These devices require materials of multiple heterojunction and p-n junction structures. But it is impossible to determine their carrier concentration, layer thickness and the position of p-n junction simultaneously by general C-V method and the Hall measurement. In this aspect some progress has been made by electrochemical methods, nevertheless, the measurement of carrier concentration profile and the position of p-n junction of heterostructure materials have not yet been reported.展开更多
Controversy exists on the magnitude and variability of farm nutrient balances and quality of arable land in sub-Saharan Africa with Kenya among those affected negatively. This study investigates quality of arable land...Controversy exists on the magnitude and variability of farm nutrient balances and quality of arable land in sub-Saharan Africa with Kenya among those affected negatively. This study investigates quality of arable land by fitting multivariate multilevel model to farm nutrient balance data collected from five agro-climatic zones of Kenya (arable lands). Objectives of the study were to investigate the magnitude and variability of Nitrogen, Phosphorus and Potassium (NPK) farm nutrient balances in arable lands of Kenya, study effects of agro-climatic zones on nutrient balances and to determine effects of household resource endowments on NPK nutrient balances. The study concludes that agro-climatic zones differ with respect to farm nutrient balances;that livestock resource endowments and hired labour have positive effects on the magnitude and direction of farm nutrient balances;and that household ownership of large capital resources do not guarantee a positive effect on farm nutrient balances. The study recommends integration of sound livestock practices and application of agro-climatic zone differentiated interventions in future strategies for addressing farm nutrient balances and arable land quality, and the use of large sample sizes and relevant factors/covariates in future analysis to shed additional insights on farm nutrient balances and on how arable land quality can be improved.展开更多
There are different views in the academic circle on the correlation between lunar phases and great earthquakes. Analyses show that such a correlation is not evident when a global inspection is taken, but regional stat...There are different views in the academic circle on the correlation between lunar phases and great earthquakes. Analyses show that such a correlation is not evident when a global inspection is taken, but regional statistics indicate that the earthquakes of different sliding modes or occurring in different geological tectonics are generally corresponding to different lunar phases (the new moon, full moon, first quarter, last quarter, maximum latitude of moon, etc.). In this article discussions on the syzygyearthquakes (M.≥6) in Hebei Province (including Beijing and Tianjin) ave given.展开更多
基金supported by the Key P roject of the National N atural Science Foundation of China(Grant Nos:40233027 and 40221503)the Key Project of the Chinese Academy of Sciences(KZCX2-203)the IAP/CAS Knowledge Innovation Project.
文摘Recent advances in dynamical climate prediction at the Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP/CAS) during the last five years have been briefly described in this paper. Firstly, the second generation of the IAP dynamical climate prediction system (IAP DCP-Ⅱ) has been described, and two sets of hindcast experiments of the summer rainfall anomalies over China for the periods of 1980-1994 with different versions of the IAP AGCM have been conducted. The comparison results show that the predictive skill of summer rainfall anomalies over China is improved with the improved IAP AGCM in which the surface albedo parameterization is modified. Furthermore, IAP DCP-II has been applied to the real-time prediction of summer rainfall anomalies over China since 1998, and the verification results show that IAP DCP-II can quite well capture the large scale patterns of the summer flood/drought situations over China during the last five years (1998-2002). Meanwhile, an investigation has demonstrated the importance of the atmospheric initial conditions on the seasonal climate prediction, along with studies on the influences from surface boundary conditions (e.g., land surface characteristics, sea surface temperature). Certain conclusions have been reached, such as, the initial atmospheric anomalies in spring may play an important role in the summer climate anomalies, and soil moisture anomalies in spring can also have a significant impact on the summer climate anomalies over East Asia. Finally, several practical techniques (e.g., ensemble technique, correction method, etc.), which lead to the increase of the prediction skill for summer rainfall anomalies over China, have also been illustrated. The paper concludes with a list of critical requirements needed for the further improvement of dynamical seasonal climate prediction.
基金This work was supported by Wuhan Science & Technol- ogy Great Foundation under Grant No. 2002100513004.
文摘In a wavelength routing optical network (WRON), the optimal allocation of wavelength converters (WCs) is very important to minimize the number of WCs, enhance the fiber utilization, reduce the blocking probability, etc.. In this paper, a novel simplified network model with shared WCs has been proposed. An effective algorithm for optimal allocation of shared WCs has been presented by using a revised Dijkstra algorithm and genetic algorithm (GA). The effectiveness of the revised algorithm was verified through the simulation on Nature and Science Foundation (NSF) net of USA. This revised algorithm can achieve blocking probability 36% less than the algorithm in previous work, and the calculating time of the minimum blocking probability can be reduced dramatically.
文摘This paper introduces the new electronic business mode of ASP （Application Server Provider） and points out that employing ASP is the certain way to informationize the enterprises, especially the medium and small-scale enterprises. Base on the analysis about the feature of current ASP provider and market, this paper forecasts the development trends of ASP in China.
文摘Major earth-changing events took place in the first decade of the 21st century. First,the 9/11 terrorist attacks created shockwaves in the realm of international security. But the global financial crisis had even greater repercussions than 9/11. Policy makers and strategists should closely follow the developments and ramifications of this crisis.
基金Funded by the Shanghai Post Doctoral Foundation Overseas Returned Scholars' Foundation of Education Ministry the Shanghai Key Discipline Project
文摘This paper reports the evolution of textile structure and mechanical properties of vascular prosthesis in the level of the whole prosthesis and the constituent filaments with respect to the manufacturing process. The tubular wall of the prosthesis is divided circumferentially into three zones; basic line (BL), remeshing line ( RL) and guide line ( GL). Some heterogeneity has been observed on the tubular wall in terms of stitch structure of the prosthesis and linear density of the constituent filaments. The breaking position of the prosthesis under circumferential tensile localizes preferentially in remeshing line that is the weakest zone by warp knitting with double needle bed. Furthermore, the statistical differences of the mechanical properties of the filaments of zone RL, GL and BL have been confirmed too. It is predictable that the deterioration of prosthesis, under physiological loads (periodical pulse blood pressure etc.), could happen firstly in the weaker zone in vivo.
文摘In this paper, the characteristics of eastern Asian dust storm are examined with emphasis on the satellite measurements of aerosol optical thickness. The reflectivity of solar radiation from the earth's atmosphere depends on the optical thickness. The satellite measurement of radiance of sunlight, scattered by the earth and its atmosphere, is used to derive the properties of aerosol on oceanic surfaces. This paper involves the following: (1) investigation of the measurement of dust storm over the oceanic surface by GMS satellite; (2) investigation of the measurement of dust storm over the land surface by ground-based instruments such as actinometer, lidar, etc.; (3) for comparison, deriving an atmospheric aerosol size distribution over the oceanic surface of calm weather through measurements of NOAA satellite; and (4) the weather process and its mass load of eastern Asian dust storm.
基金Project supported by the Science Fund of Academia Sinica
文摘Invariance principle and strong approximation for error variance estimates in Linear regression model has been discussed. In this article, we consider the rate of error variance estimates by a Wiener process, when the sample is a strongly stationary, φ-mixing sequence. From this we can deduce immediately the weak invariance principle, law of the iterated logarithm, etc.
文摘Phycobiliproteins, the photosynthetic antenna pigments, occur in red algae (Rhodophyta), blue green algae (Cyanophyta) and cryptomonad algae (Cryptophyta). Phycobiliprotein is the collective name of phycoerythrin, phycocyanin and allo-phycocyanin, etc. The chromophores are open tetrapyrroles, covalently attached to apoproteins. The phycoerythrins have been further divided into R-, B-and C-phycoerythrins according to the absorption spectra characteristics.
文摘Based on the study on the city transport systems of some typical cities worldwide,this paper put forward that each city transport system has its own development mode,which is influenced by the city development plan,economic development level,traveling vehicle composition etc..When some problems occur,such as the congestions caused by contradiction between the road capacity and vehicle composition,the city transport system may come into temporary maturity period.If the improvement for road system is limited meanwhile,optimized structure of vehicle composition should be an effective solution in this case.With the development of economy-internationalization,the development speed of city transport modernization is rapid.When traveling easiness is conflicting with efficiency,the advantages of public transport system become more obvious.Correspondingly,the superiority of two-wheel vehicles will reappear.Though the important function of two-wheel vehicles for alleviating city traffic problems is obvious,however,their development strategy must be reasonably proposed,and operation regulations must be performed accordingly.
文摘The gait of the biped robot is described using six parameters such as stature,velocity,length of the step,etc.The algorithm of the Newton-Euler is actualized by object-oriented idea,and then the zero moment point (ZMP) of the dynamically walking biped is calculated.Finally,the gait of biped is optimized using gene algorithm,and the optimized result prove the correctness of the algorithm.
文摘The proposed algorithm for reflectance measured with optical glass has been verified with materials of various forms. The reflectances measured with optical glass ( raw), without glass (true) and corrected by the algorithm are compared. The results show that the corrected reflectance agrees very well with true one and their color differences fall below the acceptable limit, which indicates the validity of the correction algorithm. The algorithm could be used not only for fiber-forming materials, but also for powder-forming, granulate-forming, etc.
文摘Many properties of polyester filaments such as heat shrinkage, tenacity, elongation at break and etc. are greatly influenced by drawing, so post-drawing is important in downstream processing. As more and more profile fibers and multi-variance fibers used in textile industry, the properties of above two kinds of differential polyester filaments after drawing in different heat conditions were studied. Finally following conclusions were obtained: Firstly, the tenacity and elongation at break decreases with the rise of Tp. Secondly, the tenacity rises but the elongation at break decreases with the increase of Tb. Then, when the Tb is low, both the shrinkage in boiling water and hi hot air decreases with the rise of Tp, while, when the Tb is high, both the shrinkage rises with the rise of Tp. The last, both the shrinkage decreases with the rise of Tb.
基金This research was granted and supported by the National Natural Science Foundation of China.
文摘The nature of ESR signals derived from bilirubin-Ⅸα has been studied by focusing onthe samples treated with free radical generating and inhibiting systems, i.e. X-XOD, Fe/EDTA, SOD, mannitol/ascorbate, CO, KCN, etc. In all the cases, the stable signals comprisethose originated from semiquinone radical (g = 2.0012) and superoxide free radical (g_∥=2.041, g_⊥= 2.0040). The superoxide is shown binding with certain metal ions chelated bybilirubin. The free radical scavengers are able to destroy these radicals. The kinetic curveof the regeneration of bilirubin radicals has been determined and the reaction follows azero order mechanism. It is likely that both the physiological and toxic actions of bilirubinare related to the characters of its free radicals. Bilirubin is discussed as "active oxygensink" in mammalians.
文摘Hypothyroidism is not uncommon in dogs,but it is actually very often diagnosed in elderly dogs.When and how does the disease start?What are the first recognizable signs?The first symptoms are usually changes in the behavior.First,these changes are quite subtle,but as the illness progresses,they can get very grave.We do often hear from the worried owners,that their report of a behavioral change to their vet is often ignored,not taken seriously or simply interpreted as unsteady or insufficient dog training/education.This not taking seriously of the first signs is very concerning and a big problem in many ways.It is delaying the finding of the right diagnosis and treatment,which leads to suffering of the animal and the owner.In some cases,it leads to giving the dog up as an unbearable danger to the family.So the dog,who is only ill and could be back to normal with the right medical treatment,finally ends up in a dog shelter or a new family.The common understanding is,that hypothyreoidism is an illness solely occurring in the elderly dog.In contrast to this,the authors found out,that thyroidal problems occur already at relatively young ages.This is a very important finding,considering that many clinically practising veterinarians expect hypothyreoidism only in the aged or elderly dog and will not run any diagnostics in relatively young or middle-aged animals.The authors also found significant differences in the personality traits of emotional stability and extraversion.Therefore,we would like to expand the existing studies,so that this widely underestimated topic finally comes to the fore and hopefully,in the future the right diagnostcal steps can be taken at an early stage of the disease.
基金the National Key Fundamental Research Project (No. G2000048009) SINOPEC, China.
文摘Chemical reactions (such as hydrogenation, hydroformylation, alkylation, esterification, etc.) at supercritical conditions afford opportunities to manipulate the solubility of reactants and products, to eliminate interphase transport limitations in the reaction systems, and to be beneficial to the environment. This review concentrates on the most recent developments after 2001 with only a brief summary of pioneering research work before 2001.
文摘Loess is widely distributed on the Miao Islands, covering mainly the foot of mountains, valleys, cleuches and individual mountain tops. Its thickness, with a tendency of gradual downward-increase, is generally from 3 to 6 m, but up to 15—20 m on the Tuoji Island, the Daheishan Island, the Bozicun of Penglai County on the Miao Island, etc.,
文摘The Ⅲ-Ⅴ compound semiconductor devices such as FET, laser, solar cell, etc. were developed recently. These devices require materials of multiple heterojunction and p-n junction structures. But it is impossible to determine their carrier concentration, layer thickness and the position of p-n junction simultaneously by general C-V method and the Hall measurement. In this aspect some progress has been made by electrochemical methods, nevertheless, the measurement of carrier concentration profile and the position of p-n junction of heterostructure materials have not yet been reported.
文摘Controversy exists on the magnitude and variability of farm nutrient balances and quality of arable land in sub-Saharan Africa with Kenya among those affected negatively. This study investigates quality of arable land by fitting multivariate multilevel model to farm nutrient balance data collected from five agro-climatic zones of Kenya (arable lands). Objectives of the study were to investigate the magnitude and variability of Nitrogen, Phosphorus and Potassium (NPK) farm nutrient balances in arable lands of Kenya, study effects of agro-climatic zones on nutrient balances and to determine effects of household resource endowments on NPK nutrient balances. The study concludes that agro-climatic zones differ with respect to farm nutrient balances;that livestock resource endowments and hired labour have positive effects on the magnitude and direction of farm nutrient balances;and that household ownership of large capital resources do not guarantee a positive effect on farm nutrient balances. The study recommends integration of sound livestock practices and application of agro-climatic zone differentiated interventions in future strategies for addressing farm nutrient balances and arable land quality, and the use of large sample sizes and relevant factors/covariates in future analysis to shed additional insights on farm nutrient balances and on how arable land quality can be improved.
文摘There are different views in the academic circle on the correlation between lunar phases and great earthquakes. Analyses show that such a correlation is not evident when a global inspection is taken, but regional statistics indicate that the earthquakes of different sliding modes or occurring in different geological tectonics are generally corresponding to different lunar phases (the new moon, full moon, first quarter, last quarter, maximum latitude of moon, etc.). In this article discussions on the syzygyearthquakes (M.≥6) in Hebei Province (including Beijing and Tianjin) ave given.
