农业立体污染综合防治研究的概况与进展

概述了国内外农业污染防治研究领域的历史与现状,阐明了农业污染防治新思路,即农业立体污染综合防治路线与措施,并进一步对农业立体污染综合防治的高效投入机制和集成创新模式进行了深入分析。     

颗粒断层泥黏滑运动的研究进展

地震是一种常见的地质灾害,是地层突然加速运动并释放能量的过程.由于自然界断层交界面的剪切滑动、碎裂、碾磨和黏土矿化等物理化学作用,大多数成熟地层交界面都充满着一层磨损颗粒材料,也即断层泥.已有研究表明断层泥的黏滑运动是浅源地震发生的可能机制,国内外大量学者将颗粒体系作为研究地震的模型体系.本文总结了近年来颗粒断层泥黏滑运动的研究进展,着重对颗粒断层泥黏滑运动的微观机制、黏滑运动的影响因素、机器学习在颗粒断层泥研究中的应用等方面的研究进行系统介绍,并对后续颗粒断层泥黏滑运动的研究趋势进行展望.     

基于高被引论文的国际地下水研究态势分析

为准确掌握国际地下水研究的发展态势、热点研究领域、研究力量分布,探讨我国地下水研究的优势和不足,基于文献计量和文献调研的方法,利用TDA和UCINET软件,对Web of Science的SCIE数据库和SSCI数据库中发表于1950~2015年且引用次数排序前10%(≥44次)的地下水研究论文进行定量分析。结果显示:高影响力论文发表量位居前3的国家是美国、加拿大、英国,高影响力的机构前10位中美国有7个,其中美国地质调查局的影响力最大;环境科学与生态学、水资源、工程学3个学科与地下水研究的关系最为密切;土壤、砷、硝酸盐位列近10年来国际地下水研究20个热点主题的前3位,国际地下水研究更加侧重农业生产对地下水的影响,相比之下中国则侧重对砷污染的防治和地下水污染过程的模拟分析,此外,中国还侧重农业科学领域的研究,在海洋学领域的研究相对薄弱;中国地下水研究存在高被引论文产出低、国际合作深度不足、重点领域研究薄弱、特色研究领域少等突出问题。最后,对中国地下水研究未来发展提出了几点建议。     

四川省水土流失的人类活动响应及其防治策略

选取10个主要因子来评判人类活动干扰度对四川水土流失的影响和响应关系.关联分析表明载畜量、垦殖指数、人口密度、人均GDP、矿产模数和林地覆盖率是6个关联性最强的人类活动要素.干扰度分析表明人口压力、过度和不合理的资源开发活动、人为破坏行为是造成水土流失的主要原因.因此解决各类人为逆向活动、规范人类行为是水土保持的首要任务.为此,在新的历史时期,水土流失的防治是建立在一种生态系统方式基础之上的防治,是一种可持续发展的管理策略.这种方式的基础是水土流失防治的宗旨、观念、方法和领域方面予以系统创新和突破.从理论层次、政策层次、空间层次、技术层次和模式层次上同步跟步;从治理策略上进行系统整合.     

面向近期量子处理器的量子神经网络研究进展

近年来,人工神经网络在各领域得到了广泛的应用,展现出强大的计算智能.与此同时,量子计算硬件也得到了飞速发展,近期量子处理器已具备较稳定的计算能力和抑制退相干能力,多家商用云量子计算机公司已能够为世界各地的学者们提供在线量子计算实验平台.在诸多技术领域的迅猛进展下,量子神经网络这一交叉领域也重获科学界的关注,涌现出了大量新的研究思路并取得了重要的实验进展.本文首先对早期量子神经网络的研究思路作简要阐述,然后对基于近期量子处理器的量子神经网络的数据编码、算法流程和量子电路设计等进行综述分析,最后总结量子神经网络领域的数个关键科学问题,对未来研究方向做出展望.     

基于遥感的作物氮素营养诊断技术:现状与趋势

准确诊断作物氮素营养状况是实现氮肥优化管理的前提.遥感可全覆盖、大面积同步监测作物多种形态和理化参数.将其应用于氮素营养诊断,对指导施肥管理具有重要意义.基于遥感手段开展作物氮素营养诊断研究已有几十年,将其成果加以总结,并分析存在的问题,有利于更好地促进遥感技术在该领域中应用.本文综述了基于遥感的作物氮素营养诊断技术发展现状,分析提炼了科学问题,在此基础上提出了本领域若干研究方向,期望能对相关领域研究者有所启发.     

Garden:一种面向领域语言的集成开发环境

随着计算机技术的发展,通用语言已经不能满足各种领域应用程序开发的需要.由于领域语言提供领域专用术语和符号的概念,支持该领域中的各种处理,能够简洁、有效地构造该领域应用程序,因此,领域语言成为当前计算机语言研究中的热点.文中在面向模型的变换型软件开发方法和语言的抽象与封装机制研究的基础上,设计与实现了一种面向语言的领域语言的集成开发环境Garden,它包括软件开发环境和程序开发环境.软件开发环境以GarAda解释器为核心,用于支持领域语言开发的各过程;程序开发环境以领域语言编译器为核心,用于支持领域用户程序开发的各过程.Garden的研制成功,为领域语言的自动生成探索了一条切实可行的途径.     

数据驱动储能电池新材料的筛选和设计

数据驱动新材料产业发展是第四研究范式促进材料创新,加快材料应用的多学科多领域交叉融合的技术热点.机器学习(machine learning, ML)作为一种重要的数据驱动方法,其结合第一性原理计算在材料科学、化学、物理学和计算机等跨学科领域展现出巨大的优势,为储能电池新材料的快速发展带来了新的机遇.为帮助研究人员了解这一新兴领域,本文系统地详述了高通量计算筛选和ML在储能电池材料研究中的最新进展,概括和总结了目前国内外应用较为广泛的在线材料数据库,举例介绍了新数据库的多层次构建,分析了目前数据采集方面的一些难点.论文进一步介绍了ML方法在高通量计算筛选、材料性质预测、材料结构与电化学性能构效关系研究和材料设计方面的应用实例,最后分析讨论了当前ML在储能电池领域面临的一些挑战,并展望了该领域的前沿研究.     

复杂人机系统设计中认知工作分析理论、技术与应用研究进展

认知工作分析是人机系统设计中的一种重要研究方法.目前在航空、军事、交通运输、能源、石化和医疗等复杂人机系统领域开始得到了推广应用,它对于提高复杂人机系统的安全、扩展系统功能、提高人机交互的适应性、降低系统全生命周期的成本有着十分重要的意义.首先通过对国内外相关文献的总结,论述了认知工作分析理论体系中约束、生态内涵两个核心内容并阐述了两者之间的内在联系;随后详细分析了认知工作分析构建过程中的关键技术及其各维度建模工具的内涵和使用方法;最后针对复杂人机系统设计的发展,采用范围综述的方法对6个复杂人机系统领域内的223篇文献进行了研究,分析了认知工作分析在这些领域中的研究现状、应用中的优势以及在未来的发展趋势.     

美国公共卫生应急系统及其对中国的启示

SARS在中国的流行暴露出我国防治突发性传染病的公共卫生应急系统的弊端：疫情信息发布不公开、不透明，缺乏应对突发性传染病的必要准备，在公共卫生方面投入不足。相比之下，建立了公共卫生应急系统的国家，例如美国，损失则要小得多。我们要借鉴美国公共卫生应急系统的经验，完善我国的公共卫生应急系统。这就要求我们必须建立快捷、畅通、准确、及时的信息传递网络，成立常设的公共卫生应急系统，加大在公共卫生方面的投入。     

坚硬顶板深孔爆破卸压技术及其模拟优化

工作面回采过高冲击危险区时,采用深孔爆破技术,提前释放坚硬顸板内储存的弹性能,可以降低冲击危险,能有效地避免冲击地压灾害发生。以济三煤矿6303工作面实际地质情况为研究背景,从岩石爆破机理出发,计算出合理的钻孔间距;利用Ansys有限元非线性动力学软件,对不同爆破孔间距深孔预爆破方案和爆破效果进行爆破效果模拟,分析了爆破应力波传播规律和裂纹扩展情况,找出最优爆破参数。     

Public perception of climate change and disaster preparedness: Evidence from the Philippines

The Philippines is highly susceptible to both geophysical and climate-related disasters. This article explores Filipinos knowledge and perception of climate change and their association with what action Filipinos take to prepare for rapid onset natural hazards such as typhoons. Data for this study were collected from a nationally representative random survey of 5,184 adults conducted between March and April of 2017. Filipinos self-report relatively low levels of knowledge of climate change and cited increased temperatures, shifts in seasons, and heavier rains as the most likely consequences. Levels of disaster preparedness in the Philippines differ widely by region. Although most Filipinos perceive that natural hazards are a risk to them, only a third of Filipinos undertake measures to prepare for disasters. Filipinos who perceive climate-related changes directly impacting their households report taking greater action to prepare for disasters. Filipinos who believe they have been directly impacted by climate-related changes are also more likely to prepare for disasters, take planning actions, and undertake material actions to prepare, such as dwelling improvements. Other factors associated with disaster preparedness include gender, membership in an association, wealth, risk perception, and prior exposure to and losses due to disasters. The findings imply that, while posing different challenges and requiring different responses, adaptation to climate change and disaster preparedness are inherently associated and potentially mutually reinforcing. Policies and programs would arguably benefit from a more unified intervention framework that links climate change adaptation and disaster preparedness.     

Public perception of climate change and disaster preparedness: Evidence from the Philippines

The Philippines is highly susceptible to both geophysical and climate-related disasters. This article explores Filipinos knowledge and perception of climate change and their association with what action Filipinos take to prepare for rapid onset natural hazards such as typhoons. Data for this study were collected from a nationally representative random survey of 5,184 adults conducted between March and April of 2017. Filipinos self-report relatively low levels of knowledge of climate change and cited increased temperatures, shifts in seasons, and heavier rains as the most likely consequences. Levels of disaster preparedness in the Philippines differ widely by region. Although most Filipinos perceive that natural hazards are a risk to them, only a third of Filipinos undertake measures to prepare for disasters. Filipinos who perceive climate-related changes directly impacting their households report taking greater action to prepare for disasters. Filipinos who believe they have been directly impacted by climate-related changes are also more likely to prepare for disasters, take planning actions, and undertake material actions to prepare, such as dwelling improvements. Other factors associated with disaster preparedness include gender, membership in an association, wealth, risk perception, and prior exposure to and losses due to disasters. The findings imply that, while posing different challenges and requiring different responses, adaptation to climate change and disaster preparedness are inherently associated and potentially mutually reinforcing. Policies and programs would arguably benefit from a more unified intervention framework that links climate change adaptation and disaster preparedness.     

Public perception of climate change and disaster preparedness: Evidence from the Philippines

The Philippines is highly susceptible to both geophysical and climate-related disasters. This article explores Filipinos knowledge and perception of climate change and their association with what action Filipinos take to prepare for rapid onset natural hazards such as typhoons. Data for this study were collected from a nationally representative random survey of 5,184 adults conducted between March and April of 2017. Filipinos self-report relatively low levels of knowledge of climate change and cited increased temperatures, shifts in seasons, and heavier rains as the most likely consequences. Levels of disaster preparedness in the Philippines differ widely by region. Although most Filipinos perceive that natural hazards are a risk to them, only a third of Filipinos undertake measures to prepare for disasters. Filipinos who perceive climate-related changes directly impacting their households report taking greater action to prepare for disasters. Filipinos who believe they have been directly impacted by climate-related changes are also more likely to prepare for disasters, take planning actions, and undertake material actions to prepare, such as dwelling improvements. Other factors associated with disaster preparedness include gender, membership in an association, wealth, risk perception, and prior exposure to and losses due to disasters. The findings imply that, while posing different challenges and requiring different responses, adaptation to climate change and disaster preparedness are inherently associated and potentially mutually reinforcing. Policies and programs would arguably benefit from a more unified intervention framework that links climate change adaptation and disaster preparedness.     

山区道路选线及其相关的环境问题

在西部大开发中，山区道路选线问题突出，本文从地形选线、地质选线和环境选线的角度总结了山区道路选线的研究现状，在分析了山区道路选线中存在的问题的基础上，提出了今后的发展趋势及应该进一步深入研究的问题。为山区道路选线理论与方法的进一步研究提供服务。     

长沟峪急倾斜煤层巷道锚网索支护技术研究

针对北京长沟峪煤矿东二西四槽回采巷道的地质条件,利用FLAC^2D软件模拟研究了该巷道的非对称变形特征及强度薄弱部位,确定了用于这类巷道的合理的锚网索支护方案,通过现场实施,进行了巷道表面位移、围岩深部位移、锚杆（索）动态锚固力等内容的矿压监测。数据显示,该支护方案设计合理,取得了理想的支护效果及显著的经济效益,对类似急倾斜煤层支护提供了有益借鉴。     

Immune responses to DNA vaccines

DNA vaccines, based on plasmid vectors expressing an antigen under the control of a strong promoter, have been shown to induce protective immune responses to a number of pathogens, including viruses, bacteria and parasites. They have also displayed efficacy in treatment or prevention of cancer, allergic diseases and autoimmunity. Immunologically, DNA vaccines induce a full spectrum of immune responses that include cytolytic T cells, T helper cells and antibodies. The immune response to DNA vaccines can be enhanced by genetic engineering of the antigen to facilitate its presentation to B and T cells. Furthermore, the immune response can be modulated by genetic adjuvants in the form of vectors expressing biologically active determinants or by more traditional adjuvants that facilitate uptake of DNA into cells. The ease of genetic manipulation of DNA vaccines invites their use not only as vaccines but also as research tools for immunologists and microbiologists. Received 26 October 1998; received after revision 3 December 1998; accepted 3 December 1998     

横断山区干旱河谷研究现状和发展方向

干旱河谷及其所在的横断山区是独特的自然、气候和地理单元，是我国民族多样性、文化多样性、环境异质性以及生物多样性最为丰富的地区，少数民族分布最为集中的地区之一，也是西南经济最为落后、交通偏远、地质灾害最为严重的区域。干旱河谷以其较好的光热等条件成为整个横断山区人口和城镇分布集中的核心地带，但是由于干旱河谷脆弱的生态系统和特殊的交错带分布格局，决定了干旱河谷具有低阈值生态安全和高风险生态退化的特点。近几十年来在干旱河谷治理方面做了大量工作，在个别区域生态恢复方面取得了一些进展，农林可持续经营模式受到关注，经济资源植物引种和开发日益受到重视，基于地方特色的产业逐步得以兴起并取得初步成效。但从整个区域来看，干旱河谷研究方面还存在研究区域过分集中、人地关系研究缺乏、生态恢复模式过于单一等问题，加上人口和经济发展的压力，干旱河谷治理和开发的选择有限，使整个干旱河谷区次生干旱化仍然在发展中，生态环境退化状况仍在加剧，水土流失严重威胁本地和下游安全，资源和环境压力日益增加。干旱河谷进一步的研究应立足发展的需要，着重从干旱河谷本身演变机制的研究、全球变化背景下干旱河谷响应特征及规律、干旱河谷人地关系与上下游利益协同关系、干旱河谷景观结构和功能演变规律方面入手，在此基础上区分干旱河谷的自然和人为过程，全面制定整个干旱河谷区域的生态环境治理、经济与资源环境可持续战略，实现整个干旱河谷区域经济和环境持续协调发展。     

Physiological and nutritional importance of selenium

Summary The essential trace element selenium has recently attracted attention because of its potentialities in the maintenance of human health. Selenium forms part of the active site of the peroxide-destroying enzyme glutathione peroxidase, and it also has other functions, for example in biotransformation, detoxification and the immune response. Functional and clinical consequences of selenium deficiency states have been described, and the selenium requirement, which is influenced by the usual selenium exposure, has been discussed. Wide variations have been found in selenium status in different parts of the world, and populations or groups of patients exposed to marginal deficiency are more numerous than was previously thought.Current research activities in the field of human medicine and nutrition are devoted to the possibilities of using selenium for the prevention or treatment of degenerative or free radical diseases such as neurological disorders, inflammatory diseases or cancer. Pharmacological selenium doses are also recommended as an adjuvant in some treatments.     

铝土矿地质研究中分析技术应用进展

目前,扫描电子显微镜( SEM)、电子探针(EPMA)、X射线衍射分析仪(XRD)、电感耦合等离子体质谱(ICP - MS)、X射线荧光光谱(XRF)等技术都已运用于铝土矿的矿物分析及化学成分测定.这些现代分析方法的使用为铝土矿的地质研究提供了更准确和快速的技术支持.本文较详细归纳总结了铝土矿分析技术以及其在地质研究中...