中国科技人才资源区域差异与类型

中国科技人才资源的地区和部门分布具有明显的区域差异.在三大地带间、地区内和各省市间差异程度不同且有扩大趋势,在三个重要部门中配置也表现出明显的地域差异.根据科技人才资源赋存状况及部门配置的区位熵值,将各省市区分成5种类型:科技人才资源高度型、中高度型、中度型、中低度型、低度型,这些区域类型与我国的区域经济发展格局相适应.     

Anatomical and physiological divergences and compensatory effects in two Leymus chinensis (Poaceae) ecotypes in Northeast China

The purpose of this study was to investigate the anatomical and physiological differences between two Leymus chinensis ecotypes coexisted in semi-humid meadow and semi-arid steppe. The study addressed the hypothesis that, at same habitat, the two ecotypes exhibit remarkable divergences in adaptive strategies under drought and salinity, and the function of these strategies is compensatory. Leaf samples were collected from each type at the two sites in field. Sections of 2 cm × 2 cm were cut from the middle of fully expanded leaves and fixed in FAA. Leaf anatomical traits (e.g. stomatal density, leaf thickness and vessel diameters) were examined, and leaf mass per area (LMA), relative water content (RWC), proline, K⁺ and Na⁺ were measured. Compared with the gray green type (GG), the yellow green type (YG) with relative greater LMA and leaf thickness, lower stomatal density and index exhibited more obvious xerophil-liked anatomical traits, while higher RWC, proline, K⁺ and K⁺/Na⁺ for the GG type suggested that the ability of osmotic adjustment and salt tolerance of the GG type were stronger than the YG type. Stronger xerophytic anatomical traits were the supplementary strategies of the YG type for its low ability of osmotic adjustment and salt tolerance to drought and salinity.Concluding, there exist significant differences in anatomical and physiological strategies between the two ecotypes and the compensatory effects of these strategies enable the two ecotypes coexist at similar habitat.     

Do newborn domestic rabbits Oryctolagus cuniculus compete for thermally advantageous positions in the litter huddle?

Competition among mammalian siblings for scarce resources can be severe. Whereas research to date has focused on competition for the mother’s milk, the young of many (particularly altricial) species might also be expected to compete for thermally favorable positions within the nest, den, or litter huddle. We investigated this in newborn pups of the European rabbit Oryctolagus cuniculus, a species in which the altricial young are not brooded by the mother, and in which competition for milk is severe. In eight unculled litters (N = 86 pups) of a domestic chinchilla strain, we calculated huddling indexes for individual pups on postnatal days 2–5 as a measure of the degree of insulation they received from littermates. Pups maintained almost constant physical contact with the litter huddle. They performed brief but frequent rooting and climbing behaviors, which usually improved their huddling index, interspersed with longer periods of quiescence during which their huddling index declined. As expected, we found a significant positive relation between pups’ mean huddling index and body temperature. Unexpectedly, however, we did not find a relation between huddling index and pups’ birth weight, survival, milk intake, or efficiency of converting milk to body mass. We conclude that rather than competing for thermally advantageous positions within the huddle newborn rabbits share out thermally advantageous positions as they move in a continual dynamic flow through it. Thus, in newborn rabbits, competition for the mother’s milk exists alongside mutual “cooperative” benefits of littermate presence. This contribution is part of the special issue “Sibling competition and cooperation in mammals” (guest editors: Robyn Hudson and Fritz Trillmich).     

Association patterns among wild chimpanzees (<Emphasis Type="Italic">Pan troglodytes schweinfurthii</Emphasis>) reflect sex differences in cooperation

Theory predicts that frequent dyadic association should promote cooperation through kin selection or social tolerance. Here we test the hypothesis that sex differences in the strength and stability of association preferences among free-ranging chimpanzees conform to sex differences in cooperative behavior. Using long-term data from the Kanyawara chimpanzee (Pan troglodytes schweinfurthii) community (Kibale National Park, Uganda), we calculated indices of intra-sexual dyadic association over a 10-year period. We found that (1) male–male dyads had significantly stronger association indices than female–female dyads, (2) the pattern of association preferences in both sexes changed little over the entire study period, and (3) when comparing periods with different alpha males, changes in association strength were more frequent among males. These results demonstrate that both the strength and stability of association patterns are important components of social relationships. Male chimpanzees, which are characterized by frequent cooperation, had association preferences that were both strong and stable, suggesting that forming long-term bonds is an important dominance strategy. However, the fact that male association patterns were sensitive to upheaval in the male dominance hierarchy suggests that males also take advantage of a changing social climate when choosing association partners. By contrast, the overall strength of female associations was relatively weak. Female association preferences were equally stable as males’; however, this reflected a dyad’s tendency to be found in the same party rather than to associate closely within that party. Therefore, in this community, female association patterns appear to be more a consequence of individual ranging behavior rather than a correlate of cooperation.     

Crash rates over time among younger and older drivers in the SHRP 2 naturalistic driving study

Objective: To examine crash rates over time among 16–17-year-old drivers compared to older drivers. Methods: Data were from a random sample of 854 of the 3,500 study participants in SHRP 2, a U.S. national, naturalistic driving (instrumented vehicle) study. Crashes/10,000 miles by driver age group, 3-month period, and sex were examined within generalized linear mixed models. Results: Analyses of individual differences between age cohorts indicated higher incidence rates in the 16–17-year old cohort relative to older age groups each of the first four quarters (except the first quarter compared to 18–20 year old drivers) with incident rate ratios (IRR) ranging from 1.98 to 18.90, and for the full study period compared with drivers 18–20 (IRR = 1.69, CI = 1.00, 2.86), 21 to 25 (IRR = 2.27, CI = 1.31, 3.91), and 35 to 55 (IRR = 4.00, CI = 2.28, 7.03). Within the 16–17-year old cohort no differences were found in rates among males and females and the decline in rates over the 24-month study period was not significant. Conclusions: The prolonged period of elevated crash rates suggests the need to enhance novice young driver prevention approaches such as Graduated Driver’s Licensing limits, parent restrictions, and post-licensure supervision and monitoring. Practical Applications: Increases are needed in Graduated Driver’s Licensing limits, parent restrictions, and postlicensure supervision and monitoring.     

基于投入产出方法的中国居民虚拟水消费研究

居民在消费商品或服务的过程中,即在消费隐含其中的虚拟水,并且虚拟水的消费量远大于实物形态的水的消耗。不同消费模式对水资源的需求差异很大。文章借助投入产出方法计算了2002年中国各省及城乡居民的虚拟水消费情况,并分析了造成虚拟水消费差距的原因。结果表明,人均虚拟水消费量省际间及城乡间差异显著,基本是发达地区高于欠发达地区,城镇高于农村;每万元消费的虚拟水含量省际间及城乡间也有所不同,基本是欠发达地区高于发达地区,农村高于城镇。分析认为,消费水平和消费结构是造成这种差异的根本原因。     

我国(讨论稿)和欧洲关于行人保护法规的异同点

通过对欧洲和我国讨论稿关于行人保护法规的分析比较研究,在定义方面有着相同和不同;在下腿型冲击器对保险杠的试验、上腿型冲击器对保险杠的试验、儿童头型冲击器对发动机罩的试验、成人头型冲击器对发动机罩的试验等实验中,使用的实验仪器设备、实验手段和方法、实验程序、评价指标存在着相同和不同之处。与欧洲法规相比,我国讨论稿的一些评价指标值有待进一步完善,试验手段和方法需要进一步改进,通过比较分析来不断修订我国行人保护法规讨论稿,以利于我国未来正式颁布行人保护法规。     

中国农业生态效率测度及时空差异研究

农业生态效率测度对于促进农业生态化和可持续发展具有重要作用。基于1993—2013年农业投入产出相关数据,采用劳动、土地、化肥、农药、农膜、机械动力、灌溉、役畜八类投入指标,农业碳排放和农业污染两类非期望产出指标以及农业总产值作为期望产出指标,利用SBM-Undesirable扩展模型测算全国、东中西、八经济区及省际农业(种植业)生态效率,并分解无效率项。结果显示:1样本期内中国农业生态效率总体呈现"降-升-降-升"平缓右偏型"W"结构,总体上中国农业生态效率趋于提升;2东中西部三个地区和八大经济区农业生态效率总体趋势与全国基本一致,但又各具特点,三区域中东部地区差异较大,八经济区中西北地区和西南地区差异较大;3省际农业生态效率总体上也存在差别,农业生态效率总体较高的省份既有上海、江苏等经济发达的沿海地区,又有贵州、新疆等经济落后地区。从效率损失结构来看,农业生态效率损失总体上主要是由投入冗余和非期望产出冗余导致的,但投入和非期望产出冗余内部结构又存在诸多不同。总体而言,化肥、农药、农膜过度使用及其负面作用在较多地区表现较为突出。农业生态效率测度实质是平衡农业投入、期望产出和非期望产出三者的关系,提升农业生态效率,促进农业生态化发展和可持续发展。同时,在农业生态效率评价中,要基于资源禀赋现实、基于要素替代关系、基于生态负面影响等,结合地区发展现实和不同的发展阶段进行相应调整,有区别地促进农业生态化发展。     

两种填埋结构中氨氮的空间变化规律研究

依据准好氧填埋和厌氧填埋的原理,构建了准好氧和厌氧填埋的实验室模拟装置,研究了2种填埋结构渗滤液中氨氮的空间分布规律。结果表明,准好氧填埋结构3层渗滤液中氨氮浓度都呈不断稳定下降的趋势,29周时上层、中层和下层渗滤液中氨氮浓度分别从填埋初的931.8、1796和3019 mg/L下降到25.6、328.9和820.1 mg/L;厌氧填埋结构3层渗滤液中氨氮浓度下降趋势不明显且波动性较大。准好氧填埋与厌氧填埋结构渗滤液中氨氮浓度表现出明显的空间层次效应,为下层>中层>上层。     

长江流域农业地域分异及专业化生产研究

长江流域是我国农业生产的重要区域,农业发展总体水平高于全国平均,但流域内农业发展的自然条件,资源状况、人文特点等不尽一致,各省市农业发展在农业、农村经济、农业生产投入、农业及粮食生产等方面存在较大的地域差异。运用主分量分析法,得出各 综合评价结果;并在此基础上,根据主导农产品专业化生产和发展方向的分异,将长江流域划分为３个大区１７个亚区。