贵州喀斯特地区不同土地利用方式土壤CO_2体积分数变化及影响因素

为了解不同土地利用方式对土壤剖面CO2体积分数的影响,采用气相色谱法对贵州喀斯特地区土壤不同深度空气CO2体积分数进行观测。结果表明：不同土地利用对土壤平均CO2体积分数影响较大,其次序为：次生林（0.35%±0.06%）〉草地（0.34%±0.05%）〉人工林（0.27%±0.03%）〉农田（0.16%±0.03%）。次生林、草地与农田之间土壤CO2体积分数差异性显著,而人工林与农田之间无显著性差异。不同土地利用方式土壤剖面CO2体积分数的时空变化特征比较一致：从春季到夏季逐渐增加而从秋季到冬季又逐渐降低,与该区域的温度和降雨量变化趋势一致。同时随着土壤剖面深度增加CO2体积分数逐渐增大,但在土层12 cm处有突然降低现象（农田除外）。不同土地利用方式土壤空气CO2体积分数变化与大气、土壤温度密切相关（r=0.602~0.886,P〈0.05）,土壤温度升高会导致土壤CO2体积分数上升。土壤湿度虽然也在一定程度上影响了剖面CO2体积分数,但相关性分析表明二者之间并不显著（r=0.105~0.393,P〉0.05）,说明在贵州喀斯特地区,土壤温度对土壤空气CO2体积分数的影响大于土壤湿度。     

高技术产业创新资源绩效的时空分异研究——以全球创新型国家为例

构建了高技术产业创新资源绩效评价的投入产出指标体系,利用《美国科学工程分类指标年鉴》及经济合作与发展组织（OECD） 1995-2011年高技术产业活动相关数据,运用超效率DEA模型和区域差异测度锡尔指数对全球28个国家或地区的高技术产业创新资源绩效及各区域创新资源绩效差异进行分析.结果显示：①全球28个国家或地区的高技术产业创新资源绩效水平呈现两级分化趋势.其中,新加坡、瑞士、瑞典、美国4个国家的得分较高,排名靠前,其他国家或地区绩效水平较低.②欧洲、美洲、亚洲-大洋洲之间的高技术产业创新资源绩效水平差异呈现缩小趋势,欧洲区域内部高技术产业创新资源绩效水平差异呈现逐年扩大趋势.     

Within-population variation in ejaculate characteristics in a prolonged breeder,Peron’s tree frog, <Emphasis Type="Italic">Litoria peronii</Emphasis>

Sperm number is often a good predictor of success in sperm competition; however, it has become increasingly clear that, for some species, variation in probability of paternity cannot be explained by sperm number alone. Intraspecific variation in ejaculate characteristics, such as the number of viable sperm and sperm longevity, may play an equally important role in determining fertilization success. Here, we assess variation among ejaculates in three factors that may contribute to fertilization success (number of sperm per ejaculate, viability, and longevity), in a population of Peron’s tree frog (Litoria peronii). We detected large variation among males in the number of sperm per ejaculate and the proportion of viable sperm within ejaculates, which could not be explained by variation in either male size or body condition. However, the proportion of viable sperm released by males increased over the season. Finally, we assessed sperm longevity (proportion viable sperm determined using a dual-fluorochrome vital dye) at two different temperatures. At 23°C, on average, 75% of sperm remained viable after 2 h, but there were significant differences amongst males with the percentage of viable sperm ranging from 43% to 95%. For sperm incubated at 4°C, ejaculates varied fivefold in sperm longevity with some males having 50% viable sperm after 5 days. Our data suggest that ejaculate characteristics (sperm number, viability, and longevity) vary widely in Peron’s tree frog and may therefore play an important role in determining siring success both in the presence and absence of sperm competition. We discuss the results in relation to selection on ejaculate traits via natural and sexual selection in this and other amphibians.     

基于STIRPAT模型的环境压力空间差异分析——以能源消费为例

定量分析区域人文驱动力对环境的影响,对认识我国区域环境压力及其影响因素具有一定的科学意义.利用STIRPAT模型,以人口数量、富裕度为自变量,以能源消费总量为因变量,应用岭回归函数拟合得到环境压力模型.以研究结果为依据.利用Mapinfo7.0 软件分别绘制人口数量和富裕度对环境压力影响的空间差异图.结果显示,不同省份间人口数量和富裕度对环境压力影响存在显著差异.尽管各省份人口数量对环境压力都产生线性正效应影响,但影响强度有明显差异,最大者是最小者的8.079倍.富裕度对环境压力影响,有正效应或者负效应;有线性作用或者弹性作用.30个考察对象中,北京、上海、四川、新疆4个省市的富裕度二次项系数为负,这说明,在数据观测范围内以上4个省市的结果支持富裕度与环境压力间存在倒"U"型环境库兹涅茨曲线的观点;但这4个省市的环境压力并没有出现下降,这是由于各种人文驱动力影响的净效应决定了环境压力变化趋势.人口数量的增长对环境压力的上升存在较强正效应.因此,控制人口数量的速度对改善环境压力将起到关键作用.     

北京市气溶胶的时间变化与空间分布特征

以MODIS气溶胶遥感数据与同期AERONET监测数据为基础,应用统计分析、对比分析、时间序列分析等技术手段,研究了北京地区气溶胶的时间变化和空间分布特征.结果表明,气溶胶MODIS遥感反演数据和同期AERONET监测数据吻合较好,Pearson积矩相关系数为0 789,误差为ΔAOT550 = -0.077AOT 0.03.北京地区气溶胶550 nm光学厚度AOT和细粒比η的时间变化规律性明显:夏季以城市污染气溶胶为主,光学厚度最高,且具细粒特征;春季城市污染气溶胶和春季沙尘共存,光学厚度比较高,且粗粒占一定比例;冬季以采暖燃煤气溶胶为主,光学厚度不高,但是粗粒占较大比例;秋季大气清澈,气溶胶平均光学厚度仅为0.34.空间分布方面,主要受植被覆盖和产业结构等因素影响,位于西部北部山区的延庆、密云、怀柔和门头沟区气溶胶的光学厚度低,位于东南部平原地区的昌平、顺义、通县、大兴和房山区气溶胶光学厚度总体较高.     

Runoff variation affected by precipitation change and human activity in Hailiutu River basin,China

For recent years, runoff generation and hydrological processes in Hailiutu River basin have been greatly changed by climate change and human activity, especially water and soil conservation construction. In this study, the trends in precipitation, evapotranspiration (ET) and river runoff as well as the effects of precipitation change and human activity on runoff variation have been studied. The results showed that during 1960–2000, annual precipitation and river runoff, monthly precipitation and ET in September and October as well as monthly runoff in all months showed a significant decrease. In addition, peak flow and base flow had a large decrease. Under the joint influence of precipitation change and human activity, the mean annual runoff decreased by 35 million m³ from the baseline period (1960–1985) to the change period (1986–2000), which accounted for 60.9% and 39.1% of the total runoff decrease, respectively. Precipitation change played a primary role in the decrease of annual runoff whereas human activity, particularly water and soil conservation construction, also had remarkable impacts on runoff variation.     

企业粉尘职业危害监督量化分级管理指标体系的筛选

目的是建立粉尘职业卫生监督量化分级管理指标体系,为企业的粉尘职业危害防治提供依据。对象与方法是以59名国内职业卫生领域专家为研究对象。通过编制的调查表,让专家依据各指标的重要程度打分。国内职业卫生领域符合条件的专家以电子邮件方式发送调查问卷70份,收回调查表59份。利用变异系数法,计算每一指标的平均分、变异系数和满分比,评价信度和效度,最终筛选确定粉尘企业职业危害监督量化分级管理的指标体系。结果如下,59名专家积极系数84.3%,8项一级指标和69项二级指标的平均值均超过2.5,变异系数均在50%以下,满分比均介于0-1之间,8项一级指标的克朗巴赫值均大于0.6,相关系数介于0.249-0.705之间。除预防措施和粉尘危害项目存在的问题外,其余均具有统计学意义。结论为企业粉尘职业危害监督量化分级管理指标体系经筛选包括8项一级指标和69项二级指标。     

沙田柚根围AM真菌的生境适宜性和季节变化性

以山地长寿沙田柚成年果树为对象,研究不同生境和季节对丛枝菌根(Arbuscular mycorrhiza,AM)真菌侵染以及根围土壤中AM真菌孢子密度的影响.试验结果表明,不同生境下,菌根侵染率和AM真菌孢子密度都是以梯田最高,坡地次之,洼地最低;在坡地和洼地生境下,生草区均高于清耕区.两块试验地AM真菌的菌丝侵染率均为夏季最高(16.8%±1.9%和16.0%±1.8%),秋季次之,冬季最低;丛枝和泡囊的形成也是夏/秋季较高,春/冬季较低;而根围土壤中AM真菌孢子密度则是秋季最高[(159±19)个/100 g和(167±17)个/100 g],夏季次之,冬季最低.总之,对于长寿沙田柚成年果树,AM真菌的菌根侵染率在夏季梯田最高,根围土壤中的AM真菌孢子密度在秋季梯田最高;在坡地和洼地生境中,生草处理均可显著提高菌根侵染率和AM真菌孢子密度.图4参27     

乌鲁木齐市蔬菜基地土壤有效态镉的空间变异特征

以乌鲁木齐市北郊蔬菜基地为典型区,对干旱区绿洲城市郊区土壤有效态镉含量的结构特征进行分析,得出该区有效态镉的空间分布格局,并揭示了引起这种分布格局的成因和污染来源.结果表明,乌鲁木齐市北郊蔬菜基地有效态镉属中等变异.半方差函数模型拟合表明,有效态镉含量可以用指数函数拟合,且在一定范围内存在空间相关性.采用Kriging...     

Archimedean Copulas在降水变异概率分布特征研究中的应用——以新疆福海县为例

探究二维情况下变异不同步,也就是一个变量发生变异,而另一个变量不发生变异的情况,对Copula联合分布的影响.在气温变化的环境下,降水过程发生了显著变异,而年降水量和年总降水天数的联合分布对长期旱涝情况有重要意义.以Copula函数为基础,计算新疆福海站年降水量和年总降水天数联合分布,用传统变异分析方法进行变异分析.针...