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741.
Based on the flood affected area (FA) data of the provinces in China from 1950 to 2005, the article discusses the change of the flood patterns in China, and investigates its relationship with climate change and human activities. The flood center shifted from North China and the Yangtze-Huaihe basin in the 1950s towards the south, north and west of China, and located in the south of the Yangtze River and South China after the 1990s. The FA in the western provinces was continuously on the rise since the 1950s. There are two characteristics for the future flood pattem in China. The pattern of "flood in the south and drought in the north" depends on the north-south shift of the maximum rainfall region in eastern China. The flood intensification to the west of Hu Huanyong's line mainly results from the increase of rainfall, extreme precipitation and the melting of glaciers under the background of human activity magnification. 相似文献
742.
Steven Leonard 《Environmental management》2009,44(3):430-440
Fire is widely used in conservation management of native grasslands. Burning is often carried out under conditions that are
marginal for sustained fire spread, and therefore it would be useful to be able to predict fire sustainability. There is currently
no model allowing such prediction in temperate grasslands. This study aims to identify the environmental variables that determine
whether fires will sustain in native grasslands in Tasmania, Australia, and develop a model for predicting fire sustainability
in this vegetation. Fuel characteristics and weather conditions were recorded for 111 test fires. Logistic regression modeling
identified dead fuel moisture content, fuel load, and percentage dead fuel as predictors of fire sustainability. Classification
tree modeling identified dead fuel moisture and fuel load threshold values for sustaining fires. There was also evidence indicating
a percentage dead fuel threshold. The logistic regression model and a model combining the results of the classification tree
and the percentage dead fuel threshold accurately predicted the outcomes of a small set of experimental fires. These models
are likely to have utility in predicting fire sustainability in Tasmanian grasslands and are also likely to be applicable
to similar grasslands elsewhere. 相似文献
743.
人不安全行为的心理测量与分析 总被引:1,自引:0,他引:1
分析人不安全行为心理测量与一般心理测量的区别;阐述人不安全行为心理测量量表的编制依据和具体的编制方法;给出了人不安全行为心理测量的初步施测量表,即包括8个分量表的总计750条指标项目。在确定施测范围、选取测量对象的基础上,实施对人不安全行为初步施测量表的心理测量,通过对初试量表测定数据的统计与分析,从750条指标项目中约减择取152条重要性程度较大的指标,组成人不安全行为心理测量的综合量表。通过对综合心理测试量表的现场施测,结果表明:该综合量表具有较高的信度和效度,可满足人不安全行为心理测量的要求。 相似文献
744.
745.
The formation and maintenance of crayfish hierarchies: behavioral and self-structuring properties 总被引:4,自引:0,他引:4
Behavioral changes in fighting and the development of dominance relationships were analyzed in groups of juvenile crayfish
(Astacus astacus) using quantitative behavioral techniques. When individuals were placed into an aquarium, the number of agonistic challenges,
their mean duration, and maximum intensity reached were high initially but then decreased steadily as the hierarchy developed.
In all groups, linear hierarchies emerged which became increasingly stable over time. Winning influenced subsequent fighting
behavior on two distinct time scales. In the short term, recent winners became progressively less likely to retreat. Second,
individuals occupying dominant positions for days became increasingly likely to escalate to higher intensities early in the
encounter. Both effects biased the outcome of future interactions such that winning enhanced further success and losing decreased
an individual’s subsequent chances for dominance.
Received: 11 November 1999 / Revised: 1 March 2000 / Accepted: 3 May 2000 相似文献
746.
Summary. We tested responses to prey chemicals by lizard hatchlings of an oviparous species and neonates of a viviparous species,
neither of which had never eaten. Both species responded more strongly to prey chemicals than to odorous and odorless control
stimuli presented on cotton swabs. Although only a few species have been examined, all that have been tested have an innate
capacity for prey chemical discrimination, suggesting that this innate response to prey chemicals is widespread among lizards
that use the lingual-vomeronasal system to locate and identify prey. Innate prey chemical discrimination has the great advantage
of permitting lizards lacking prior experience with food to respond appropriately to chemical cues associated with food. Both
species discriminated prey chemicals from control substances at age three days, earlier than previously known. Our data hint
that Mabuya macularia may be capable of discrimination on its day of birth, but further study is needed to determine the exact onset. A stronger
tendency to attack swabs bearing prey chemicals by Scincella lateralis than by M. macularia may be explained by differences in defensiveness near an experimenter or by differences in the importance of visual prey
cues for confirmation of chemical cues in the natural habitats of these species. In M. macularia responses to the control stimuli declined over days of testing, suggesting habituation, but responses to prey chemicals did
not habituate by the third day of testing, which is interpreted as a possible adaptive response to permit location of food.
In the standard method of stimulus presentation, a cotton swab bearing a chemical stimulus is placed anterior to a lizard's
snout. We tested a new method in which the swab was placed in continuous contact with the lizard's anterior labial scales.
The new method elicited significantly stronger responses from M. macularia. We discuss reasons for this finding and applications for the new method.
Received 2 September 1999; accepted 15 December 1999 相似文献
747.
Pan JiahuaClobal Change Economic Development Program the Chinese Academy of Social Sciences Beijing China 《中国人口.资源与环境(英文版)》2004,2(1)
Based on an investigation of the meaning of development, the neo-classical economic approach to development, and the post-welfarist theory of development, this paper proposes a conceptual framework for understanding human development potentials, while undertaking empirical analysis using cross-sectional and time series data on human development. Human development is associated with basic necessities for subsistence, the quality of life, and political and civil rights, in addition to income indicators. Our analysis suggests that the concept of human development potentials has two dimensions: the rights of development and limits to human development. Both are largely ignored in the neoclassical theory of development. However, human development is not unbounded, which approaches to a relatively fixed constant at given economic, technological and institutional conditions. This conceptual understanding is supported by results from the empirical examination of the relationships between demands for carbon emis 相似文献
748.
In this study, the surface chemical functional groups of Bacillus cereus biomass were identified by Fourier transform infrared (FTIR) analytical technique. It had been shown that the B. cereus cells mainly contained carboxyl, hydroxyl, phosphate, amino and amide functional groups. The potentiometric titration was conducted to explain the surface acid-base properties of aqueous B. cereus biomass. The computer program FITEQL 4.0 was used to perform the model calculations. The optimization results indicated that three sitesthree pKas model, which assumed the cell surface to have three distinct types of surface organic functional groups based on the IR analysis results, simulated the experimental results very well. Moreover, batch adsorption experiments were performed to investigate biosorption behavior of Cu(Ⅱ) and Pb(Ⅱ) ions onto the biomass. Obviously, the adsorption equilibrium data for the two ions were reasonably described by typical Langmuir isotherm. 相似文献
749.
Af Wåhlberg AE 《Journal of Safety Research》2008,39(1):41-46
PROBLEM: The driver celeration behavior theory predicts that celerations are associated with incidents for which the driver has some responsibility in causing, but not other incidents. METHOD: The hypothesis was tested in 25 samples of repeated measurements of bus drivers' celeration behavior against their incidents for two years. RESULTS: The results confirmed the prediction; in 18 samples, the correlation for culpable incidents only was higher than for all incidents, despite the higher means of the latter. Non-culpable incidents had correlations close to zero with celeration. DISCUSSION: It was pointed out that most individual crash prediction studies have not made this differentiation, and thus probably yielded underestimates of the associations sought, although the effect is not strong, due to non-culpable accident involvements being few (less than a third of the total). The methods for correct identification of culpable incident involvements were discussed. 相似文献
750.
Quick BL Stephenson MT Witte K Vaught C Booth-Butterfield S Patel D 《Journal of Safety Research》2008,39(3):329-338
PROBLEM: The National Institute for Occupational Safety and Health's [NIOSH] National Occupational Research Agenda (DHHS Publication No. 96-115) reports that approximately 50% of miners will experience hearing loss by age 50, compared to only 9% of the general population. The present investigation examines three antecedents believed to be associated with miner's use of hearing protection. METHOD: A posttest-delayed-posttest-control group field research design was employed to assess antecedents toward wearing hearing protection. RESULTS: Following the initial posttest, miners' attitudes and subjective norms were antecedents to intentions to wear hearing protection devices. Also, intentions toward wearing hearing protection predicted hearing protection behaviors. Approximately six weeks later, miners' attitudes and perceived behavioral control were each significant predictors of intentions to wear hearing protection and again, intentions were positively associated with hearing protection behaviors. IMPACT ON INDUSTRY: Our results indicate that appeals to normative influences may be the most effective antecedent to employ when persuading coal miners to wear hearing protection. However, messages designed to impact attitudes and perceived behavioral control were also effective. 相似文献