渭北黄土高原苹果优质气候层带分析

本文利用元帅系苹果定位试验的品质测定资料,分析研究了苹果品质(含糖量、含酸量、硬度等)与海拔高度及其垂直气候层带的关系,认为我国渭北黄土高原海拔1000—1500m 范围的半湿润、半干旱地区,是全国苹果品质最佳的优质气候区。这一层带的气候-土壤生态条件,适宜于发展优质苹果生产和建立商品生产基地。     

构造运动与中国沿岸平原的地质灾害

中国海岸穿过构造沉降带和隆起带，沉降带及隆起带断陷盆地的持续下降吸引了源远流长的大河在此人海，而隆起带内入海的河流多为近源小河，从而引起河流泥沙沿岸分配的不均和海岸沉积物的差异。沉降带内每公里海岸线接受的沉积物是隆起带的数十倍，且以砂质沉积物为主．隆起带河流泥沙来量少．而且砂质沉积物占了压倒的优势．河流泥沙沿岸分配的不均决定了中国沙质和淤泥质海岸的基本类型和分布格局、沉降带和隆起带松散沉积层的厚度和结构，山此产生了中国沿岸与第四纪沉积层有关的灾害和环境问题的有规律的分布。地面沉降主要分布于沉降带内，而地下海水入侵多出现在依赖地下水的隆起带内，底辟构造、浅层天然气往往在大河三角洲构成灾害和潜在的地质灾害．沉降带和隆起带断陷盆地内的海岸低地通常是海平面上升的主要脆弱地区．此外，丰富的河流泥沙使中国海岸对全球海平面上升的响应也不相同，如海岸湿地的再生和海岸侵蚀原因的复杂性等．     

Effectiveness of primary enforcement safety belt laws and enhanced enforcement of safety belt laws: a summary of the Guide to Community Preventive Services systematic reviews

BACKGROUND: The use of safety belts is the single most effective means of reducing fatal and nonfatal injuries in motor-vehicle crashes. This paper summarizes the systematic reviews of two interventions to increase safety belt use: primary enforcement safety belt laws and enhanced enforcement of safety belt laws. The reviews were previously published in the American Journal of Preventive Medicine. METHODS: We conducted the systematic reviews using the methodology developed for the Guide to Community Preventive Services. RESULTS: These reviews provide strong evidence that primary laws are more effective than secondary laws in increasing safety belt use and decreasing fatalities and that enhanced enforcement is effective in increasing safety belt use. Increases in belt use are generally highest in states with low baseline rates of belt use. DISCUSSION: Primary safety belt laws and enhanced enforcement programs tend to result in greater increases in usage rates for target groups with lower baseline rates. Concerns regarding public opposition to these interventions may impede their implementation in some jurisdictions. However, surveys indicate that a substantial majority of the public supports implementation of both primary laws and enhanced enforcement programs. CONCLUSION: Based on the strong evidence for effectiveness of primary safety belt laws and enhanced enforcement programs, the Task Force on Community Preventive Services recommended that all states enact primary safety belt laws and that communities implement enhanced enforcement programs.     

Plant cover synanthropization in the pechora-Ilych biosphere reserve along an altitudinal gradient

Trends in plant cover synanthropization along a plain-foothills-mountains gradient have been revealed in the reserve. Characteristics of plant communities in anthropogenically disturbed habitats, centers of concentration of anthropophytes and apophytes, and pathways of their migration are described.     

长江流域水环境的主要问题,原因及对策探讨

从几个触目惊心的实例出发，分析出长江流域水环境存在的主要问题是水污染、泥沙淤积、对洪涝的环境容量不高和未能充分发挥水环境的多功能特别是生态功能的作用。其原因主要是工业、农业、城市和流动源排污，土壤侵蚀和人类活动不遵守持续发展原则，管理不善。作者在本文末尾提出了对策。     

Altitudinal zonality and diversity of butterflies in the southern Far East and Transbaikalia

Species richness, taxonomic diversity, and qualitative composition of the butterfly fauna (Lepidoptera, Diurna) are discussed in the light of data on the altitudinal zonality of local faunas in the southern Far East and Transbaikalia. It is shown that qualitative elevation-dependent changes in the fauna occur only in the western and northern parts of the region.     

Restraint use and seating position among children less than 13 years of age: Is it still a problem?

Introduction

The purpose of this study was to calculate national estimates and examine the extent to which children prematurely use adult seat belts and ride in the front seat of a vehicle during a 30 day period.

Methods

Data were obtained from a nationally representative cross-sectional random-digit-dial telephone survey that included child-specific questions on motor vehicle restraint use and seating position.

Results

Among children less than 13 years, parents reported an estimated 618,337 who rode unrestrained and more than one million who rode in the front seat of a vehicle at least some of the time in the past 30 days. During the same time period, close to 11 million children 8 years and younger reportedly used only adult seat belts.

Discussion

Our results highlight the need for continued outreach to parents regarding optimal restraint use and rear seating position for children every trip, every time.     

生物多样性的海拔分布格局研究及进展

生物多样性的海拔分布格局受制于气候、空间、环境等多种因子的影响,综合大量研究发现,无论是动植物还是微生物,环境因子对其影响与驱动的作用最明显。海拔梯度是决定分布格局的重要因素之一,因此探讨生物多样性在环境因子驱动下的海拔分布格局具有重要意义。文章分别探讨了植物、土壤动物和土壤微生物多样性沿海拔梯度的变化规律,揭示了温度、湿度及人为干扰等因素下植物多样性沿海拔梯度的5种分布格局及可能机制,土壤动物多样性沿海拔梯度的3种分布格局及可能机制,同时揭示土壤微生物在海拔分布格局虽然有物种模式,但是机制不是很明确;最后对植物、土壤动物、土壤微生物生物多样性耦合关系的认识作了阐述。并在此基础上,认为生物多样性的分布格局与尺度密切相关,因此开展不同尺度的生物多样性的研究以及它们对全球气候变化的响应是未来研究的重要方向;土壤动物群落的多样性的变化规律研究,应致力于其生理型、营养型、生态型的多样性的研究;在不同的研究尺度上,驱动微生物群落构建机制的差异导致了群落演变规律的变化,仍需要以地理学和生物学等相关学科理论为支撑,并与微生物群落构建理论相结合,对海拔分布格局下生物多样性的保护和生态系统稳定性研究提供科学依据。     

岩溶山地生态退化的海拔空间变异

为揭示岩溶山地生态退化的海拔空间变异,应用地统计学对地处滇黔桂连片岩溶腹地,海拔变化范围广的贵州省毕节地区生态退化指标的垂直梯度空间变异进行分析.石化率的半变异函数最佳理论模型为线性有基台模型,植被覆盖率、土壤砾石率为球状模型.植被覆盖率的空间异质比为22.32%,具有强烈的垂直梯度空间相关性,主要受到随海拔梯度变化的自然性控制因素的作用;石化率、土壤砾石率的空间异质比分别为34.38%、25.97%,均具有中等程度的垂直梯度空间相关性,受随机因素的作用较大.土壤砾石率、植被覆盖率的变程分别为968.10、859.48 m,受因素影响的海拔范围都较宽;石化率的变程为52.28 m,受因素影响的海拔范围很窄.石化率、植被覆盖率的Moran′s Ⅰ系数随海拔梯度变化的趋势相类似,但土壤砾石率的Moran′s Ⅰ系数随海拔梯度变化的趋势与石化率、植被覆盖率的差别较大.