人身危险性因素中的动态变因证明

人身危险性研究已经开始进入一个逐渐完善并全面发展的阶段,但在对人身危险性测量的要素选择上却过于静态类型化,不能充分反映人身危险性的动态变化趋势。于人身危险性研究中引入动态变因要素,结合已有的非变量因素将有助于人身危险性的理论完善并为实践测量提供新的发展路径。

Dynamic Changes,Regional Differences,and Influencing Factorsof CO_2 Emission Performance in China

This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO 2 emission performance.With the index,the authors have measured the CO 2 emission performance of 28 provinces and autonomous regions in China from 1996 to 2007;with the convergence theory and panel data regression model,the authors analyze the regional differences and the influencing factors.It is found that the performance of CO 2 emissions in China has been continuously improved mainly due to the technological progress,and the average improvement rate is 3.25%,with a cumulative improvement rate of 40.86%.In addition,the CO 2 emission performance varies across four regions.As a whole,the performance score of eastern China is the highest.The northeastern and central China has relatively lower performance scores,and the western China is relatively backward.The regional differences are decreasing,and the performance of CO 2 emissions is convergent.The influence of some factors on the performance of CO 2 emissions is significant,such as the level of economic development,the level of industrial structure,energy intensity,and ownership structure.The influence of some factors,such as opening-up to the outside world,on the performance of CO 2 emissions is not significant..

Vegetation Dynamics and Its Relationship with Climatic Factors in the Changbai Mountain Natural Reserve

This study examined the temporal variation of the Normalized Difference Vegetation Index （NDVI） and its relationship with climatic factors in the Changbai Mountain Natural Reserve （CMNR） during 2000 - 2009. The results showed as follows. The average NDVI values increased at a rate of 0.0024 year-1. The increase rate differed with vegetation types, such as 0.0034 year-1 for forest and 0.0017 year-1 for tundra. Trend analyses revealed a consistent NDVI increase at the start and end of the growing season but little variation or decrease observed in July during the study period. The NDVI in CMNR showed a stronger correlation with temperature than with precipitation, especially in spring and autumn. A stronger correlation was observed between NDVI and temperature in the tundra zone （2,000-2,600m） than in the coniferous forest （1,100-1,700m） and Korean pine-broadleaved mixed forest （7oo-1,1oom） zones. The results indicate that vegetation at higher elevations is more sensitive to temperature change. NDVI variation had a strong correlation with temperature change （r=0.7311, p〈0.01） but less significant correlation with precipitation change. The result indicates that temperature can serve as a main indicator of vegetation sensitivity in the CMNR.

Ecological footprint of Gansu Province,China between 1997 and 2002:changes and inducement

The calculation of Ecological Footprint （EF） on the basis of Input-Output model （I-O model） was advanced by Bicknell, and modified and improved hy Ferng who corrected the footprint＇s aggregation to each sectors. For the lack of sufficient teehnique to deal with the trade between the research areas and the rest of the world, it it necessary to improve this method. And a dynamic analysis of the change of footprint based on I-O model, which could explore the factor impacting the footprint using the ,special advantage of I-O model, ought to be put into practice. After introducing the new method in detail, we calculate and compare the EF and the change of Gansu Province in the northwest of China in 1997 and 2002. The result shows that there was an increase of EF in 2002 caused by final domestic demand. Further; the inerement in EF export was 2.0 × 10^5 ha and 1.6 × 10^6 ha in import. The out-of- region support dropped from 22.6% to 18. 6%. We introduce three factors causing the EF change based on the character of I-O model： the productivity of the resourve which is explained by the change of resource used to obtain one unit output in a sector, the improvement of the economics and the final demand. Finally, we find that the effects of the three factors on the EF change are not identical except the industry sectors and the change of factors in the agriculture and the industry sectors works notably.

Dynamic change of xylanase activity and gene expression during wheat germination on As（III） stress

Through water cultivating method, the dynamic changes of xylanase activity in seed, root and plumule of wheat with different As （III） concentration treatment were studied. The results indicated that the order of average xylanase activity was seed〉plumule〉root. With the increasing concentration of As （III）, the xylanase activity elevated first then dropped in seed, but it descended first then ascended in root and plumule. As the sampling time prolonged, the xylanase activity of seeds climbed first then dropped on the four as （III） concentration, the same trend also appeared in pulume, as the as （Ill） concentration went up, the xylanase activity moved up simultaneity. Semi-quantity Reverse Transcription Polymerase Chain Reaction was used in the study, the results indicated that, the xylanase gene began to express at 132 h on 0 mg/L As （III） concentration and at 120h on other concentration in the leaves of wheat.

The Characteristics and Driving Factors of the Spatio-temporal Dynamic Evolution of Tourism Ecological Security in the Silk Road Economic Belt

The exploration of ecological safety in tourism sites can provide a concrete path for sustainable tourism development in a region.Based on the“Driver-Pressure-State-Impact-Response”(DPSIR)model,we constructed an index system for the evaluation of tourism ecological security(TES)in the Silk Road Economic Belt(SREB)from 2005 to 2020.This index system was used to explore the characteristics of spatial and temporal dynamic evolution with the help of entropy weight TOPSIS method,dynamic index of TES and Markov probability transfer matrix,and a standard deviational ellipse(SDE)model and GM(1,1)model were constructed for spatial pattern analysis and prediction.The results indicate four key aspects of this system.(1)In terms of spatiotemporal evolution,the tourism ecological safety index(TESI)of the SREB increased,the TES levels of the northwestern and southwestern provinces and cities differed significantly,and the quality conditions of TES in the southwestern provinces and cities were better than in the northwest.(2)In terms of dynamic evolutionary characteristics,the speed of change at each level of the SREB was slow,but the level of TES has improved.The TES level has not shifted by leaps and bounds,and the shifts in the level type show“path dependence”and“self-locking”effects.(3)In terms of spatial and temporal distribution patterns,the spatial pattern of TES in the SREB is a“northwest-southeast”movement trend,and the spatial distribution appeared as“aggregation”from 2005 to 2020.The prediction results show that the center of gravity of TES in the SREB will shift to the southeast from 2025 to 2035,and the spatial spillover effect will be reduced.(4)In terms of driving factors,the number of star-rated hotels,and the amounts of industrial wastewater emissions,tourism foreign exchange earnings,forest coverage,and other parameters are the key factors affecting TES,and the booming tourism industry requires the interconnection and interpenetration of various factors.The results of this study can provide a reference for tourism development and ecological environmental protection in the Silk Road Economic Belt.

Current hypotheses to explain genetic chaos under the sea

Chaotic genetic patchiness （CGP） refers to surprising patterns of spatial and temporal genetic structure observed in some marine species at a scale where genetic variation should be efficiently homogenized by gene flow via larval dispersal. Here we review and discuss 4 mechanisms that could generate such unexpected patterns： selection, sweepstakes reproductive success, collective dispersal, and temporal shifts in local population dynamics. First, we review examples where genetic differentiation at specific loci was driven by diversifying selection, which was historically the first process invoked to explain CGP. Second, we turn to neutral demographic processes that may drive genome-wide effects, and whose effects on CGP may be enhanced when they act together. We discuss how sweepstakes reproductive success accelerates genetic drift and can thus generate genetic structure, provided that gene flow is not too strong. Collective dispersal is another mechanism whereby genetic structure can be maintained regardless of dispersal intensity, because it may prevent larval cohorts from becoming entirely mixed. Theoretical analyses of both the sweepstakes and the collective dispersal ideas are presented. Finally, we discuss an idea that has received less attention than the other ones just mentioned, namely temporal shifts in local population dynamics.