遥感技术在山区土地荒漠化评价中的应用--以东川市为例

通过遥感数字图像统计分析与处理,确定了分类图,沟谷图,绿度指数图是评价山区土地荒漠化的有效图象,进行了沟谷指标,绿度指数分级,肯定了遥感技术应用于山区土地荒漠化评价的可能性。     

论海洋深度空间控制权——从海洋深度空间能源开发谈起

论文在提出海洋和“新海洋”广度、深度空间概念的基础上,进一步诠释了作为新的海洋权益的控制权,及其在未来政治、经济、外交、军事等领域的重要作用。由于海洋蕴藏着巨大的可再生能源,论文从能源开发利用的视角分析了开发利用海洋深度空间的重要战略意义,并对解决我国海洋争端,开发海洋新能源及综合践行海洋深度空间权战略提出了应对策略。     

南极乔治王岛环境质量现状调查

本文以１９９２／１９９３年度中国第九次南极考察期间对南极乔治王岛的表土、地衣、苔藓等样品的分析资料为基础，研究探讨了８种无机重金属元素、５种有机污染物的浓度水平。其结果表明，重金属在三种环境样品中的含量分布存在着明显的差异；地衣、苔藓两种植物呈现对不同重金属元素的不同富集能力；∑６６６、∑ＤＤＴ和ＰＣＢｓ及油的沾污亦很明显。本文还对污染物质的来源、南极环境样品历次调查分析的结果以及世界部分地区的背景水平进行了讨论和比较     

高脂饮食大鼠肾脏HMGCS2表达及调控研究

目的 探讨高脂饮食大鼠肾脏3-羟基-3甲基戊二酰辅酶A合成酶2（HMGCS2）表达及可能调控机制。方法 断乳Wistar 雄性大鼠27只分为3组：正常对照组（CON）、高脂组（HFG）、绿茶多酚（green tea polyphenols,GTPs）组（G）。CON组大鼠喂养普通饲料,HFG组及GTPs组给予高脂饲料,GTPs组同时自由摄食绿茶多酚浓度为1.6g/L水溶液。26周后测定空腹血糖（FPG）、血清胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）、高密度脂蛋白（HDL）。免疫印迹法测定肾脏HMGCS2和Sirt3蛋白表达水平。结果 与CON组比较,HFG组大鼠体重和脂肪系数升高,血清FPG、TC、TG、LDL-C/HDLC均升高,差异有统计学意义（P<0.05）;与HFG组比较,GTPs降低大鼠体重和脂肪系数,差异有统计学意义（P<0.05）,GTPs组血清FPG、TC、TG、LDL-C/HDLC均不同程度降低,差异有统计学意义（P<0.05）。与CON组比较,肾脏组织HMGCS2的表达降低,差异有统计学意义（P<0.05）;与HFG组比较,GTPs组增加肾脏HMGCS2的表达,差异有统计学意义（P<0.05）。高脂饮食、正常饮食和GTPs干预后,大鼠肾脏组织Sirt3蛋白表达差异无统计学意义。结论 高脂饮食可降低肾脏组织HMGCS2表达,绿茶多酚可逆转此效应;高脂饮食及绿茶多酚对肾脏组织HMGCS2表达的调控不经Sirt3途径。     

Multi‐scale spatiotemporal analyses of moose–vehicle collisions: a case study in northern Vermont

Moose–vehicle collisions (MVCs) pose a serious safety and environmental concern in many regions of Europe and North America. For example, in the state of Vermont, one‐third of all reported MVCs resulted in motorist injury or fatality while collisions have increased from two in 1982 to 164 in 2002. Our work used a MVC dataset from 1983 to 1999 in the Northeastern Highlands of Vermont (four major roads) to perform space, time and spatiotemporal analyses and guide future mitigation strategies. An adapted kernel density estimator was implemented for exploratory analyses to detect high density collision hotspots on roads. The kernel in space showed seven major density peaks which varied in magnitude and spread between roads. The kernel estimator in time for all roads showed an exponentially increasing trend with annual periodicity and a seasonal cyclic component, where the majority of collisions occurred from May to October. Spatiotemporal kernel estimation exhibited discontinuous density hotspots in time and space suggesting changing animal movement patterns across roads. We used an adapted Ripley's K‐function to test the hypothesis that MVCs clustering occurred at multiple scales in space, in time and in space–time combined. Statistically significant spatial clustering was evident on all roads at spatial scales from 2 to 10 km. A more consistent clustering in time occurred on all roads at a scale distance of 5 years. Similar to the kernel estimation, annual periodicity was also evident. Positive space–time clustering was present at small spatial (5 km) and temporal scales (2 years) indicating that where MVCs occur is also influenced by when they occur. In retrospect, using multiple road lengths, and the combined kernel estimation and Ripley's K‐function in time and space, provided a powerful methodology to study varying spatiotemporal patterns of wildlife collisions along roads. This can greatly assist transportation planners in identifying optimal mitigation strategies along specific roads, such as deciding on location and spatial length for permanent and expensive measures (e.g. crossing structures and associated fencing) versus less permanent and inexpensive structures (e.g. wildlife signage and reduced speed limits).     

我国林业系统湿地类型自然保护区分析与对策

自然保护区是我国社会经济可持续发展赖以实现的重要自然基础,林业系统占了我国自然保护区的绝大多数。本文对林业系统内湿地类型的自然保护区的类别、级别、区域和面积进行了统计和分析,并根据存在的问题提出了针对性的解决对策。     

Acute toxicities of potassium permanganate, formalin, and Lugol’s iodine solution to a marine ciliate, Pleuronema coronatum (ciliophora, scuticociliatida)

Acute toxicities of potassium permanganate, formalin, and Lugol’s iodine solution to a commonly occurred marine ciliate Pleuronema coronatum (Ciliophora, Scuticociliatida) were measured. Linear regression analysis of the results highlighted the close relationships between doses of the medicines and mortalities of the organisms, thus providing a capability to predict toxicity effects from the dose. Toxic effects of the medicines on the ciliates were described in the present paper, and the median lethal concentrations (LC₅₀ values) were given. Results of measurements indicated that 2 h-LC₅₀ and 12 h-LC₅₀ values of formalin on P. coronatum were 59.00×10⁻⁶ and 43.57×10⁻⁶, while those of Lugol’s solutions were 90.13 and 67.84×10⁻⁶ respectively. The tolerance of P. coronatum to formalin is apparently lower than that to Lugol’s iodine solution and potassium permanganate is a suitable medicine to kill ciliates in short time.     

中国上市公司的时空变化及机制研究

针对在中国地区发展不均衡的态势下,上市公司分布格局时空演变问题,该文对2009-2017年中国大陆各省上市公司的数量和总资产采用Local Moran’s I指数与Getis-Ord Gi*统计量进行研究,分析了中国大陆上市公司的空间分布格局和时间演变趋势,总结出中国上市公司相关指标的高值聚集和高低聚集分布格局、热点区域及其经济辐射能力。并且以北京、上海和广东为热点区域典型代表,从上市公司产业结构和区域经济发展两方面对时空变化机制的成因进行深入探讨。     

Properties of iron alloys under the Earth's core conditions

The Earth's core is constituted of iron and nickel alloyed with lighter elements. In view of their affinity with the metallic phase, their relative high abundance in the solar system and their moderate volatility, a list of potential light elements have been established, including sulfur, silicon and oxygen. We will review the effects of these elements on different aspects of Fe–X high pressure phase diagrams under Earth's core conditions, such as melting temperature depression, solid–liquid partitioning during crystallization, and crystalline structure of the solid phases. Once extrapolated to the inner–outer core boundary, these petrological properties can be used to constrain the Earth's core properties.