中国大河流域开发与国家文明发育

水是生命之源。大河流域既是地球淡水资源的关键载体,也是人类文明发育的主要摇篮。作为世界文明古国和现代发展中大国,中国的情况更是如此。长期的实践表明,大河流域的开发具有明显的生态效应极化特征:即在人文生态系统获取快速发育的同时,严重干扰和破坏了流域自然生态的系统发育及其多样化的发展。流域开发的程度越高,这种极化效应的特征也就越明显。论文的实证分析表明,由于缺乏流域开发生态效应的正确认识和过分追求人文发展利益发育最大化,黄河和长江两大流域的资源环境承载能力正在面临着日趋严峻的挑战。例如,河水断流、水质污染、湿地萎缩和水生物种消亡。为国家现代文明的永续发展计,亟需改变目前传统的"重开发、轻保护"大河流域资源环境开发观。     

Fringe View: Problems and Construction of Human Settlement Environment for Village-in-City

1 INTRODUCTIONAs a special pattern of community in city, "village-in-city"has objectively existed for many years, but it is only inrecent years that the phenomenon of "village-in-city" hasreally aroused the attention of scholars, government andmedia. The attention of government and media is mainlyfocused on the urban managerial problems that areproduced by "village-in-city", while the academic circlestry to explain the phenomenon of "village-in-city" andput forward measures in the academic…     

生态足迹动态预测模型构建与分析——以武汉市为例

生态足迹的动态预测能够为区域可持续发展政策的制定提供科学的理论依据,但其研究仍处于探索阶段.以武汉市为例,选取表征社会经济发展的重要指标建立了社会经济系统指标体系,在对武汉市1978～2004年生态足迹时间序列计量的基础上,应用偏最小二乘算法构建了生态足迹动态预测模型,并根据VIP值的大小分析了各指标对生态足迹的影响机制.结果表明,武汉市"十一五"规划期间生态足迹呈上升趋势,其中规划期末2010年的人均生态足迹为2.810 5 hm2,高于全球生态阈值(人均生态足迹为2.200 0 hm2);根据VIP值得出人口、能源消费量和第三产业所占比重为最重要的影响因子,并就如何实现武汉市"十一五"规划目标提出了政策性建议.将科技进步贡献率、能源消费量等重要因子纳入社会经济系统指标体系,弥补了在生态足迹定量测度中忽略社会、经济、科技因素对其影响的不足;另一方面,引入偏最小二乘算法中的VIP值更准确地评价了各指标对生态足迹变化的影响,为生态足迹动态预测研究作了进一步地完善与改进.     

硫酸参与的湿热流域化学风化对河流水化学影响研究综述

河流水化学组成可以提供反映流域内岩石化学风化过程及河流离子来源等生物地球化学的信息。化学风化是全球碳循环的重要环节,湿热流域的水热条件可以促进流域岩石化学风化。硫酸和碳酸一样可以作为侵蚀介质参与流域岩石的化学风化,硫酸参与的湿热流域碳酸盐类化学风化可释放CO₂,但其参与的硅酸盐类化学风化对大气CO₂没有显著影响,故若不考虑硫酸作用将会导致对岩石化学风化作用下大气CO₂消耗通量的高估。水化学组成受到流域岩石化学风化的影响,通过对河流水化学组成和溶解无机碳（DIC）稳定同位素组成（δ¹³C）的分析可以确定河流水化学类型并揭示硫酸对流域岩石化学风化的定量影响。目前关于硫酸对河流水化学影响的研究逐渐增多,未来关于小流域尺度上硫酸对河流水化学的影响、硫酸影响下河流CO₂的脱气过程以及人类活动对河流水化学的影响等方面需要更多关注。     

不同铅暴露区人体离体牙铅含量和年龄关系及指示意义

人体牙釉质是记录环境铅（Pb）暴露信息的较好载体。本研究采用微波消解-电感耦合等离子体质谱仪（ICP-MS）联用的方法测定来自高Pb暴露区（铅锌冶炼厂地区）和Pb暴露对照区（农业种植区）附近长期居住/不同年龄段人体离体牙的Pb含量,结果显示：高Pb暴露区离体牙表现出Pb含量高且随居民年龄增长而增高的趋势,离体牙Pb含量从6—12岁儿童的(60.8±15.3) μg?g^?1增加到65岁以上老年人的(200.1±30.5) μg?g^?1;而铅暴露对照区人体离体牙Pb含量低且基本随年龄增长变化不大。Pb主要通过呼吸道和消化道进入人体并在牙齿中富集,因此,牙齿中的Pb含量与生活环境密切相关。研究结果表明：生活在高Pb暴露区的人群,环境中的Pb可能通过各种介质（空气、水、实物等）不断进入人体,其牙齿不断蓄积环境来源的Pb。因此人体离体牙Pb有可能作为人体长期Pb暴露生物标 志物。     

城市食物系统演化的人地耦合启示及驱动力——以北京食物系统为例

为探明“城市化如何驱动食物系统变化”以及“食物系统变化蕴含何种人地耦合关系”的问题,本文以北京食物系统为例,研究了该食物系统自1978年以来的演变过程,揭示食物系统演变蕴含的人地耦合关系;并建立食物系统变化指标体系和城市化驱动力指标体系,运用驱动力评价、格兰杰因果关系检验、回归分析与网络分析相结合的方法研究北京食物系统演变的驱动力及作用机制。结果发现：近40多年来北京食物系统总体经历了本地农业生产不断弱化、食物消费需求持续增长、食物流通里程不断增加的演变过程。这种变化从地理学视角来看本质上是城市食物消费蕴含的人地耦合关系从邻近扩展到更远距离的过程——即食物系统近远程耦合的演化过程。在驱动该过程的影响因素中,居民收入增长是主要的初始驱动力,要素非农化是主要中间环节,人口集聚则具有最广泛的影响,最终导致外埠供应比例不断上升,食物里程持续增长。研究表明：蕴含在食物系统中的人地关系不只局限于特定的地点、特定的区域,而是以“流空间”与地点空间相互连接、相互渗透的形式呈现出来。因此,需要采取一种整合“流空间”与地点空间的理论视角及研究方法来认知此类开放系统中的人地耦合关系。     

Toxic effect of microcystin-LR on blood vessel development

Abstract

The effect of microcystin-LR (MC-LR) at 50–1000?nmol/L on blood vessel development of zebrafish embryos has been explored. Upon exposure 72-h-post-fertilization (hpf), the hatching rate was significantly reduced and malformation and fatality rates were increased in a dose-dependent manner. MC-LR induced cell cycle arrest in the G0/G1-phase and damaged DNA structure in a dose-dependent manner. In human umbilical vein endothelial cells (HUVECs), MC-LR led to decreased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and increased lipid peroxidation. These findings indicated that MC-LR could cause oxidative DNA damage, which mediated cell cycle arrest and inhibited cell proliferation afterwards, and retarded the blood vessel development.     

Passenger muscle responses in lane change and lane change with braking maneuvers using two belt configurations: Standard and reversible pre-pretensioner

Abstract

Objective: The introduction of integrated safety technologies in new car models calls for an improved understanding of the human occupant response in precrash situations. The aim of this article is to extensively study occupant muscle activation in vehicle maneuvers potentially occurring in precrash situations with different seat belt configurations.

Methods: Front seat male passengers wearing a 3-point seat belt with either standard or pre-pretensioning functionality were exposed to multiple autonomously carried out lane change and lane change with braking maneuvers while traveling at 73?km/h. This article focuses on muscle activation data (surface electromyography [EMG] normalized using maximum voluntary contraction [MVC] data) obtained from 38 muscles in the neck, upper extremities, the torso, and lower extremities. The raw EMG data were filtered, rectified, and smoothed. All muscle activations were presented in corridors of mean?±?one standard deviation. Separate Wilcoxon signed ranks tests were performed on volunteers’ muscle activation onset and amplitude considering 2 paired samples with the belt configuration as an independent factor.

Results: In normal driving conditions prior to any of the evasive maneuvers, activity levels were low (<2% MVC) in all muscles except for the lumbar extensors (3–5.5% MVC). During the lane change maneuver, selective muscles were activated and these activations restricted the sideway motions due to inertial loading. Averaged muscle activity, predominantly in the neck, lumbar extensor, and abdominal muscles, increased up to 24% MVC soon after the vehicle accelerated in lateral direction for all volunteers. Differences in activation time and amplitude between muscles in the right and left sides of the body were observed relative to the vehicle’s lateral motion. For specific muscles, lane changes with the pre-pretensioner belt were associated with earlier muscle activation onsets and significantly smaller activation amplitudes than for the standard belt (P?<?.05).

Conclusions: Applying a pre-pretensioner belt affected muscle activations; that is, amplitude and onset time. The present muscle activation data complement the results in a preceding publication, the volunteers’ kinematics and the boundary conditions from the same data set. An effect of belt configuration was also seen on previously published volunteers’ kinematics with lower lateral and forward displacements for head and upper torso using the pre-pretensioner belt versus the standard belt. The data provided in this article can be used for validation and further improvement of active human body models with active musculature in both sagittal and lateral loading scenarios intended for simulation of some evasive maneuvers that potentially occur prior to a crash.     

医疗器械中人的可靠性分析

医疗器械产品是一类直接关系到人生命健康的特殊产品.长期以来,医疗器械产品的使用安全性一直是亟待解决的重大问题.在医疗器械产品设计中进行人的可靠性分析能够进一步提高医疗质量,防止医疗事故.但是,这方面的工作目前还处于起步阶段.本文主要从医疗器械人的可靠性方面人手,定性及定量的分析人在使用器械时的可靠性问题.用SHEL模型来定性的分析医疗器械中人的可靠性的影响因素；用故障树方法及概率树对具体的多功能医用手术床进行定量分析；用第二代可靠性分析方法-CREAM解决定量分析的主观性问题；最后提出建立医疗器械人的可靠性数据库.以此为医疗器械产品设计提供了人的可靠性分析的方法.     

Conservation and the 4 Rs,which are rescue,rehabilitation, release,and research

Vertebrate animals can be injured or threatened with injury through human activities, thus warranting their “rescue.” Details of wildlife rescue, rehabilitation, release, and associated research (our 4 Rs) are often recorded in large databases, resulting in a wealth of available information. This information has huge research potential and can contribute to understanding of animal biology, anthropogenic impacts on wildlife, and species conservation. However, such databases have been little used, few studies have evaluated factors influencing success of rehabilitation and/or release, recommended actions to conserve threatened species have rarely arisen, and direct benefits for species conservation are yet to be demonstrated. We therefore recommend that additional research be based on data from rescue, rehabilitation, and release of animals that is broader in scope than previous research and would have community support.