[Objective] The paper was to study the effect of cold plasma on binding strength of bamboo. [Method] The bamboos were treated by 4 kinds of cold plasma nitrogen, oxygen, ammonia and argon, and the changes of contact a...[Objective] The paper was to study the effect of cold plasma on binding strength of bamboo. [Method] The bamboos were treated by 4 kinds of cold plasma nitrogen, oxygen, ammonia and argon, and the changes of contact angle and binding strength of bamboos before and after treatment were tested. [Result] Oxygen cold plasma treatment could increase binding strength of bamboo by 25%-30%. The cold plasma treatment was very fast and effective, but the changes of contact angle was not great in this experiment. [Conclusion] Cold plasma treatment could increase the binding strength of bamboo.展开更多
A thermodynamic model was developed to calculate the hydrogen solubility in molten alloys based on the hydrogen solubility in constitutional pure liquid metals and their interaction parameters. The calculated results ...A thermodynamic model was developed to calculate the hydrogen solubility in molten alloys based on the hydrogen solubility in constitutional pure liquid metals and their interaction parameters. The calculated results have a good agreement with the documented experimental results. The closer the molten alloy to an ideal liquid is, the more accurate the calculated results are. The compound forming ability and molar mixing heat of the constitutional elements take important roles in influencing the hydrogen solubility in molten alloys.展开更多
The non-linear effects of different initial melt temperatures on the microstructure evolution during the solidification process of liquid Mg7Zn3 alloys were investigated by molecular dynamics simulation, The microstru...The non-linear effects of different initial melt temperatures on the microstructure evolution during the solidification process of liquid Mg7Zn3 alloys were investigated by molecular dynamics simulation, The microstructure transformation mechanisms were analyzed by several methods. The system was found to be solidified into amorphous structures from different initial melt temperatures at the same cooling rate of 1×10^12 K/s, and the 1551 bond-type and the icosahedron basic cluster (12 0 12 0 ) played a key role in the microstructure transition. Different initial melt temperatures had significant effects on the final microstructures. These effects only can be clearly observed below the glass transition temperature Tg; and these effects are non-linearly related to the initial melt temperatures, and fluctuated in a certain range. However, the changes of the average atomic energy of the systems are still linearly related with the initial melt temperatures, namely, the higher the initial melt temperature is, the more stable the amorphous structure is and the stronger the glass forming ability will be.展开更多
Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass (BMG) rods were abraded to different surface roughnesses using different types of waterproof abrasive papers and sometimes polishing pastes, and the compressive deformat...Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass (BMG) rods were abraded to different surface roughnesses using different types of waterproof abrasive papers and sometimes polishing pastes, and the compressive deformation behavior was examined. The results show that the yield strength of the BMG is hardly affected while the compressive plasticity increases from 2.3% to 4.5% with decreasing the surface roughness. Observation of the fractured samples under a scanning electron microscope indicates that the rise in plasticity is accompanied with an increase in shear band density. The results suggest that it is necessary to reduce the surface roughness of BMGs for achieving a large plasticity.展开更多
In order to achieve adaptive and efficient service composition, a task-oriented algorithm for discovering services is proposed. The traditional process of service composition is divided into semantic discovery and fun...In order to achieve adaptive and efficient service composition, a task-oriented algorithm for discovering services is proposed. The traditional process of service composition is divided into semantic discovery and functional matching and makes tasks be operation objects. Semantic similarity is used to discover services matching a specific task and then generate a corresponding task-oriented web service composition (TWC) graph. Moreover, an algorithm for the new service is designed to update the TWC. The approach is applied to the composition model, in which the TWC is searched to obtain an optimal path and the final service composition is output. Also, the model can implement realtime updating with changing environments. Experimental results demonstrate the feasibility and effectiveness of the algorithm and indicate that the maximum searching radius can be set to 2 to achieve an equilibrium point of quality and quantity.展开更多
The study researched the inbred population which three genotypes of each pair heterozygous gene with different fitness. Change law by generations of genotype ratio was reflected by difference equations. The result sho...The study researched the inbred population which three genotypes of each pair heterozygous gene with different fitness. Change law by generations of genotype ratio was reflected by difference equations. The result showed that the genotype ratio that parents were all heterozygous population tended to balance, about needing 15 generations. The fitness of Rr was over or equal to two times of RR's or rr, which was the condition of Rr could be reserved for a long time.展开更多
Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflict...Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 (TS9909 hereinafter). Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex (MCC) on the warm, moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.展开更多
The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx(x=10, 12) glass-forming alloyswerestudied by differential thermal analysis combining with ...The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx(x=10, 12) glass-forming alloyswerestudied by differential thermal analysis combining with solidification structure analysis. The results indicate that the undercooling degree of Nd9Fe85-xTi4C2Bx(x=10, 12) alloys significantly increaseswith the rise of melt overheating degree, and two overheating degree thresholds corresponding to the drastic increase of the mean undercooling degree are found for each of the alloys. The existence of two turning points of the mean undercooling degreescan be linked to the structure transitions inside the overheated melts, which result in the evident increase of volume fraction of amorphous phasein the solidified structures.展开更多
Heat treatment of Ti-50.9%Ni (mole fraction) alloy was studied by differential scanning calorimetry, X-ray diffraction, scanning electron microscopey and energy dispersive X-ray analysis to investigate the influence...Heat treatment of Ti-50.9%Ni (mole fraction) alloy was studied by differential scanning calorimetry, X-ray diffraction, scanning electron microscopey and energy dispersive X-ray analysis to investigate the influence of cooling rate on transformation behavior and microstructures of NiTi shape memory alloy. The experimental results show that three-stage phase transformation can be induced at a very low cooling rate such as cooling in furnace. The cooling rate also has a great influence on the phase transformation temperatures. Both martensitic start transformation temperature (Ms) and martensitic finish transformation temperature (Mf) decrease with the decrease of the cooling rate, and decreasing the cooling rate contributes to enhancing the M→A austenite transformation temperature. The phase transformation hysteresis (Af-Mf) increases with the decrease of the cooling rate. Heat treatment is unable to eliminate the textures formed in hot working of NiTi sample, but can weaken the intensity of them. The cooling rate has little influence on the grain size.展开更多
Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibr...Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibrium status of three genotypes of random mating population (i. e. RR, Rr and rr) under different fitness, which exposes that heterosis is the precondition for multiallele to exist in the population. The heterosis protects the genetic diversity and makes the population owning a stronger self-control and evolution potential by improving the hetemzygote's fithess so as not to wash out different types of genes. It deepens Darwin's thoughts of individual section by making the individual fitness consonant with population fitness.展开更多
The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent ...The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent (Him)[trans-RuC14 (dmso-S)(im)] (NAMI-A, im=imidazole), was investigated using density functional theory combined with the conductor-like polarizable continuum model approach. Tile structural characteristics and the detailed energy profiles for the hydrolysis processes of this complex were obtained. For the first hydrolysis step, complex 1 has slightly higher barrier energies than the reported anticancer drug NAMI-A, and the result is in accordance with the experimental evidence indicating larger half-life for complex 1. For the second hydrolysis step, the formation of cis-diaqua species is thermodynamic preferred to that of trans isomers. In addition, on the basis of the analysis of electronic characteristics of species in the hydrolysis process, the trend in nucleophilic attack abilities of hydrolysis products by pertinent biomolecules is revealed and predicted.展开更多
The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was a...The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6 % soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The de-crease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO2 assimilation rate. The stomata played a relatively small part in determining the net CO2 assimilation rate for the same seedling. The relationship between net CO2 assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO2 assimilation rate by waters tress treatments, therefore intrinsic wa-ter-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO2 assimilation rate. Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range.展开更多
An experimental device was set up to study the hydrate formation conditions.Effects of pore size,salinity,and gas composition on the formation and dissociation of hydrates were investigated.The result indicates that t...An experimental device was set up to study the hydrate formation conditions.Effects of pore size,salinity,and gas composition on the formation and dissociation of hydrates were investigated.The result indicates that the induction time for the formation of hydrates in porous media is shorter than that in pure water.The decrease in pore size,by decreasing the size of glass beads,increases the equilibrium pressure when the salinity and temperature are kept constant.In addition,higher salinity causes higher equilibrium pressure when the pore size and temperature are kept constant.It is found that the effects of pore size and salinity on the hydrate equilibrium are quite different.At lower methane concentration,the hydrate equilibrium is achieved at lower pressure and higher temperature.展开更多
In the research, reform of rural collective economy property right system in Beijing rural-urban continuum was explored in terms of background, cause, pro- cess and practice modes by surveying and interviewing, and th...In the research, reform of rural collective economy property right system in Beijing rural-urban continuum was explored in terms of background, cause, pro- cess and practice modes by surveying and interviewing, and the value of system reform on urbanization in rural areas was illustrated from the perspective of farmers who lose lands. The results showed that since reform and opening-up, disadvan- tages of collective economy property are always the fundamental cause of reform; rural-urban contradiction produced from rapid urbanization makes the reform much more urgent; shareholding co-operative system is the essence of reform of collective economy property right system. Rural collective economy property right system in Beijing includes stock-assets quantification shareholding co-operative system, share- capitalization of contractual land management right, farmers as shareholders by investment, and resource and capital mode, with advantages and disadvantages respectively. The common character should be noticed is that all modes have share on contractual right of land, indicating the core of the reform of property system lies in asset quantification and stock quota. In improving urban-rural integration and modern market system, as well as endowing more rights to farmers, reform of rural collective economy property right system is of great significance, which provides a transition space and buffer mechanism for urbanization in rural areas.展开更多
Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including va-sodilatation, neurotransmission and macrophage-mediated immunity. The family of nitric oxide synthases(NOS) compris...Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including va-sodilatation, neurotransmission and macrophage-mediated immunity. The family of nitric oxide synthases(NOS) comprises inducible NOS (iNOS), endothelial NOS (eNOS), and neuronal NOS (nNOS). Interest-ingly, various studies have shown that all three isoforms can be involved in promoting or inhibiting theetiology of cancer. NOS activity has been detected in tumour cells of various histogenetic origins and hasbeen associated with tumour grade, proliferation rate and expression of important signaling componentsassociated with cancer development such as the oestrogen receptor. It appears that high levels of NOSexpression (for example, generated by activated macrophages) may be cytostatic or cytotoxic for tumorcells, whereas low level activity can have the opposite effect and promote tumour growth. Paradoxicallytherefore, NO (and related reactive nitrogen species) may have both genotoxic and angiogenic properties.Increased NO-generation in a cell may select mutant p53 cells and contribute to tumour angiogenesis byupregulating VEGF. In addition, NO may modulate tumour DNA repair mechanisms by upregulating p53,poly(ADP-ribose) polymerase (PARP) and the DNA-dependent protein kinase (DNA-PK). An understand-ing at the molecular level of the role of NO in cancer will have profound therapeutic implications for thediagnosis and treatment of disease.展开更多
基金Supported by Opening Research Project for Key Laboratory of Bamboo in Zhejiang Forestry Academy(2010K04)~~
文摘[Objective] The paper was to study the effect of cold plasma on binding strength of bamboo. [Method] The bamboos were treated by 4 kinds of cold plasma nitrogen, oxygen, ammonia and argon, and the changes of contact angle and binding strength of bamboos before and after treatment were tested. [Result] Oxygen cold plasma treatment could increase binding strength of bamboo by 25%-30%. The cold plasma treatment was very fast and effective, but the changes of contact angle was not great in this experiment. [Conclusion] Cold plasma treatment could increase the binding strength of bamboo.
基金Project (U0837603) supported by Joint Grant of National Natural Science Foundation and Yunnan Province, China Project (2092017) supported by the Beijing Natural Science Foundation, China
文摘A thermodynamic model was developed to calculate the hydrogen solubility in molten alloys based on the hydrogen solubility in constitutional pure liquid metals and their interaction parameters. The calculated results have a good agreement with the documented experimental results. The closer the molten alloy to an ideal liquid is, the more accurate the calculated results are. The compound forming ability and molar mixing heat of the constitutional elements take important roles in influencing the hydrogen solubility in molten alloys.
基金Projects(50831003,51071065,51101022,51102090) supported by the National Natural Science Foundation of China
文摘The non-linear effects of different initial melt temperatures on the microstructure evolution during the solidification process of liquid Mg7Zn3 alloys were investigated by molecular dynamics simulation, The microstructure transformation mechanisms were analyzed by several methods. The system was found to be solidified into amorphous structures from different initial melt temperatures at the same cooling rate of 1×10^12 K/s, and the 1551 bond-type and the icosahedron basic cluster (12 0 12 0 ) played a key role in the microstructure transition. Different initial melt temperatures had significant effects on the final microstructures. These effects only can be clearly observed below the glass transition temperature Tg; and these effects are non-linearly related to the initial melt temperatures, and fluctuated in a certain range. However, the changes of the average atomic energy of the systems are still linearly related with the initial melt temperatures, namely, the higher the initial melt temperature is, the more stable the amorphous structure is and the stronger the glass forming ability will be.
基金Projects (50771064,50831003) supported by the National Natural Science Foundation of ChinaProject (10PJ1405900) supported by Shanghai Pujiang Program,China
文摘Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass (BMG) rods were abraded to different surface roughnesses using different types of waterproof abrasive papers and sometimes polishing pastes, and the compressive deformation behavior was examined. The results show that the yield strength of the BMG is hardly affected while the compressive plasticity increases from 2.3% to 4.5% with decreasing the surface roughness. Observation of the fractured samples under a scanning electron microscope indicates that the rise in plasticity is accompanied with an increase in shear band density. The results suggest that it is necessary to reduce the surface roughness of BMGs for achieving a large plasticity.
基金The National Key Technology R&D Program of Chinaduring the 11th Five-Year Plan Period(No2007BAF23B0302)the Major Research Plan of the National Natural Science Foundation of China(No90818028)
文摘In order to achieve adaptive and efficient service composition, a task-oriented algorithm for discovering services is proposed. The traditional process of service composition is divided into semantic discovery and functional matching and makes tasks be operation objects. Semantic similarity is used to discover services matching a specific task and then generate a corresponding task-oriented web service composition (TWC) graph. Moreover, an algorithm for the new service is designed to update the TWC. The approach is applied to the composition model, in which the TWC is searched to obtain an optimal path and the final service composition is output. Also, the model can implement realtime updating with changing environments. Experimental results demonstrate the feasibility and effectiveness of the algorithm and indicate that the maximum searching radius can be set to 2 to achieve an equilibrium point of quality and quantity.
基金Supported by Science Foundation from Department of Education of Guangxi Zhuang Autonomous Region (200807MS065)~~
文摘The study researched the inbred population which three genotypes of each pair heterozygous gene with different fitness. Change law by generations of genotype ratio was reflected by difference equations. The result showed that the genotype ratio that parents were all heterozygous population tended to balance, about needing 15 generations. The fitness of Rr was over or equal to two times of RR's or rr, which was the condition of Rr could be reserved for a long time.
基金sponsored jointly by the Natural Science Foundation of China (Grant 4040950009402050084)the Project of Planned National Key Basic Research/Development (2004CB418301)
文摘Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 (TS9909 hereinafter). Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex (MCC) on the warm, moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.
基金Projects(51174121,51274125)supported by the National Natural Science Foundation of ChinaProject(2010R50016-30)supported by Zhejiang Province Science and Technology Innovation Team of Key Projects,ChinaProject supported by the K.C.Wong Magna Fund of Ningbo University,China
文摘The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx(x=10, 12) glass-forming alloyswerestudied by differential thermal analysis combining with solidification structure analysis. The results indicate that the undercooling degree of Nd9Fe85-xTi4C2Bx(x=10, 12) alloys significantly increaseswith the rise of melt overheating degree, and two overheating degree thresholds corresponding to the drastic increase of the mean undercooling degree are found for each of the alloys. The existence of two turning points of the mean undercooling degreescan be linked to the structure transitions inside the overheated melts, which result in the evident increase of volume fraction of amorphous phasein the solidified structures.
基金Project (51071056) supported by the National Natural Science Foundation of ChinaProjects (HEUCFR1132, HEUCF121712) supported by the Fundamental Research Funds for the Central Universities of China
文摘Heat treatment of Ti-50.9%Ni (mole fraction) alloy was studied by differential scanning calorimetry, X-ray diffraction, scanning electron microscopey and energy dispersive X-ray analysis to investigate the influence of cooling rate on transformation behavior and microstructures of NiTi shape memory alloy. The experimental results show that three-stage phase transformation can be induced at a very low cooling rate such as cooling in furnace. The cooling rate also has a great influence on the phase transformation temperatures. Both martensitic start transformation temperature (Ms) and martensitic finish transformation temperature (Mf) decrease with the decrease of the cooling rate, and decreasing the cooling rate contributes to enhancing the M→A austenite transformation temperature. The phase transformation hysteresis (Af-Mf) increases with the decrease of the cooling rate. Heat treatment is unable to eliminate the textures formed in hot working of NiTi sample, but can weaken the intensity of them. The cooling rate has little influence on the grain size.
文摘Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibrium status of three genotypes of random mating population (i. e. RR, Rr and rr) under different fitness, which exposes that heterosis is the precondition for multiallele to exist in the population. The heterosis protects the genetic diversity and makes the population owning a stronger self-control and evolution potential by improving the hetemzygote's fithess so as not to wash out different types of genes. It deepens Darwin's thoughts of individual section by making the individual fitness consonant with population fitness.
基金This work was supported by the National Natural Science Foundation of China (No.20903027), the Natural Science Foundation of Guangdong Province (No.9452402301001941), and the Doctor Startup Fund of Guangdong Medical College (No.XB0802 and No.XB0804).
文摘The hydrolysis process of Ru(III) complex (HL)[trans-RuC14L(dmso-S)] (L=l-methyl-l,2,4- triazole and dmso-S=S-dimethyl sulfoxide) (1), a potential antitumor complex similar to the well-known antitumor agent (Him)[trans-RuC14 (dmso-S)(im)] (NAMI-A, im=imidazole), was investigated using density functional theory combined with the conductor-like polarizable continuum model approach. Tile structural characteristics and the detailed energy profiles for the hydrolysis processes of this complex were obtained. For the first hydrolysis step, complex 1 has slightly higher barrier energies than the reported anticancer drug NAMI-A, and the result is in accordance with the experimental evidence indicating larger half-life for complex 1. For the second hydrolysis step, the formation of cis-diaqua species is thermodynamic preferred to that of trans isomers. In addition, on the basis of the analysis of electronic characteristics of species in the hydrolysis process, the trend in nucleophilic attack abilities of hydrolysis products by pertinent biomolecules is revealed and predicted.
基金Innovation Research Pro-ject of Chinese Academy of Sciences (KZCX1-10-03), National Natural Sciences Foundation of China (90102003), and West Development Technol-ogy Project (2001BA901A42).
文摘The water relation and leaf gas exchange of saxoul (Haloxylon Ammodendron Bge, a C4 shrub) seedlings were studied under water stress in 2001. Saxoul seedlings maintained high transpiration when the soil moisture was above 11%. The seedlings were able to take up water from soil with above 6 % soil water content, which was the threshold level of soil moisture for seedlings. The relationship between transpiration and potential evaporation was linear for well-watered seedlings. The de-crease of soil water availability led to different degrees of down-regulation of stomatal conductance, leaf transpiration and net CO2 assimilation rate. The stomata played a relatively small part in determining the net CO2 assimilation rate for the same seedling. The relationship between net CO2 assimilation rate and transpiration was linear diurnally, and reduction scale of leaf transpiration was much bigger than that of net CO2 assimilation rate by waters tress treatments, therefore intrinsic wa-ter-use-efficiency increased. High evaporative demand increased the leaf transpiration but inhibited net CO2 assimilation rate. Because of the effect of VPD on transpiration in this region, the transpiration of well-watered and mild water stress seedlings becomes responsive to change in stomatal conductance over a wider range.
基金Supported by the Key Program of National Natural Science Foundation of China(50736001) the National High Technology Research and Development Program of China(2006AA09A209-5) the Major State Basic Research Development Program of China(2009CB219507)
文摘An experimental device was set up to study the hydrate formation conditions.Effects of pore size,salinity,and gas composition on the formation and dissociation of hydrates were investigated.The result indicates that the induction time for the formation of hydrates in porous media is shorter than that in pure water.The decrease in pore size,by decreasing the size of glass beads,increases the equilibrium pressure when the salinity and temperature are kept constant.In addition,higher salinity causes higher equilibrium pressure when the pore size and temperature are kept constant.It is found that the effects of pore size and salinity on the hydrate equilibrium are quite different.At lower methane concentration,the hydrate equilibrium is achieved at lower pressure and higher temperature.
基金Supported by Major Project of the National Social Science Fund(13&ZD027)National Natural Science Foundation of China(41371177)the National Science and Technology Support Planning(2012BAJ22B03)~~
文摘In the research, reform of rural collective economy property right system in Beijing rural-urban continuum was explored in terms of background, cause, pro- cess and practice modes by surveying and interviewing, and the value of system reform on urbanization in rural areas was illustrated from the perspective of farmers who lose lands. The results showed that since reform and opening-up, disadvan- tages of collective economy property are always the fundamental cause of reform; rural-urban contradiction produced from rapid urbanization makes the reform much more urgent; shareholding co-operative system is the essence of reform of collective economy property right system. Rural collective economy property right system in Beijing includes stock-assets quantification shareholding co-operative system, share- capitalization of contractual land management right, farmers as shareholders by investment, and resource and capital mode, with advantages and disadvantages respectively. The common character should be noticed is that all modes have share on contractual right of land, indicating the core of the reform of property system lies in asset quantification and stock quota. In improving urban-rural integration and modern market system, as well as endowing more rights to farmers, reform of rural collective economy property right system is of great significance, which provides a transition space and buffer mechanism for urbanization in rural areas.
文摘Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including va-sodilatation, neurotransmission and macrophage-mediated immunity. The family of nitric oxide synthases(NOS) comprises inducible NOS (iNOS), endothelial NOS (eNOS), and neuronal NOS (nNOS). Interest-ingly, various studies have shown that all three isoforms can be involved in promoting or inhibiting theetiology of cancer. NOS activity has been detected in tumour cells of various histogenetic origins and hasbeen associated with tumour grade, proliferation rate and expression of important signaling componentsassociated with cancer development such as the oestrogen receptor. It appears that high levels of NOSexpression (for example, generated by activated macrophages) may be cytostatic or cytotoxic for tumorcells, whereas low level activity can have the opposite effect and promote tumour growth. Paradoxicallytherefore, NO (and related reactive nitrogen species) may have both genotoxic and angiogenic properties.Increased NO-generation in a cell may select mutant p53 cells and contribute to tumour angiogenesis byupregulating VEGF. In addition, NO may modulate tumour DNA repair mechanisms by upregulating p53,poly(ADP-ribose) polymerase (PARP) and the DNA-dependent protein kinase (DNA-PK). An understand-ing at the molecular level of the role of NO in cancer will have profound therapeutic implications for thediagnosis and treatment of disease.