经济植物复层栽培对三峡库区水土保持和移民经济的作用

三峡库区森林覆盖率低，水土流失严重。三峡工程兴建后，由于大量耕地被淹，移民后靠，库区的生态环境与移民经济之间的矛盾将会更加突出。本文提出了经济植物复层栽培方法，对其在减少库区水土流失、改善库区生态环境和解决库区移民经济方面的作用作了全面的论述。经济植物复层栽培是解决三峡库区生态环境和移民经济的基本途径，采用扩大种植农作物的方法来解决三峡库区移民经济问题将会加剧水土流失，使生态环境更加恶化。     

Deflector Designs for Fish Habitat Restoration

Paired current deflectors are structures that are installed on each bank of a river to locally reduce the width of the channel, thereby creating flow acceleration and promoting scouring. These instream habitat structures have been used extensively in restoration projects to create pool habitat for fish, but there are many discrepancies in deflector design recommendations in terms of orientation, height, and length. Our objectives were to (1) examine how the angle, height, and length of paired deflectors affect scour hole dimensions and potential for bank erosion; and (2) test the applicability to paired deflectors of existing equations for scour hole depth and volume. Three deflector angles (45°, 90°, and 135°), two deflector heights (with flow under and over the deflector height), and two lengths (reducing the width by 25% and 50%) were investigated using uniform sand in a laboratory flume. Results showed a 26–30% smaller scour depth resulting from 45° deflectors than from 90° deflectors and a 5–10% smaller scour depth for 135° deflectors compared to 90° deflectors. The volume of scour and the potential for bank erosion were greater when flow was under the height of the deflectors rather than overtopping and when the length of deflector was increased. When flow was under the deflector height, 135° deflectors had the highest amount of bank erosion; whereas during overtopping flow conditions, 90° deflectors had the greatest bank erosion potential. Values predicted by the model of Kuhnle and others were closest to observed scour depth and volume measurements. The assumption that upstream-oriented deflectors always generate the largest scour should be revised.     

Anatomy of an ambush: security risks facing international humanitarian assistance

The 2003 war with Iraq has generated security concerns that present unique challenges to the practice of providing international humanitarian assistance during war and conflict. Objective research studies on security management are lacking. However, case studies have proven to be an important education and training tool to advance situational awareness of security risks. These challenges are illustrated by an analysis of the events surrounding the first ambush of, and assassination attempt on, a senior US aid official in Baghdad. Before deployment to conflict areas, especially those characterised by insurgent activity, humanitarian providers must realistically assess the threats to life and to the mission. They must obtain pre-deployment situational awareness education, security training and optimal protective equipment and vehicles.     

The United Nations' humanitarian pillar: refocusing the UN's disaster and emergency roles and responsibilities

Changes in the nature of humanitarian crises and in the ways that the international community responds to such crises demand a radically overhauled role for the United Nations system. At a time when the UN and its member states are pursuing reform of some of that institution's most fundamental peace and security functions, this paper suggests that reform, too, is required to meet humanitarian crises of the future. This paper proposes a new type of operational role for the UN, while at the same time arguing that the UN has to place itself in the vanguard of humanitarian assistance as "the standard-bearer". The article draws many of its conclusions and recommendations from a recently completed study, requested by the Inter-Agency Standing Committee, concerning the effect for the UN system of changes in humanitarian financing.     

Food Security in Protracted Crises: Building More Effective Policy Frameworks

This paper considers the principal elements that underpin policy frameworks for supporting food security in protracted crisis contexts. It argues that maintaining the food entitlements of crisis-affected populations must extend beyond interventions to ensure immediate human survival. A 'policy gap' exists in that capacities for formulating policy responses to tackle the different dimensions of food insecurity in complex, fluid crisis situations tend to be weak. As a result, standardised, short-term intervention designs are created that fall short of meeting the priority needs of affected populations in the short and long term and only partially exploit the range of policy options available. The paper discusses key attributes of agency frameworks that could support more effective policy processes to address longer term as well as immediate food security needs. Additionally, it points to some main challenges likely to be encountered in developing such frameworks and, with the participation of beneficiaries, translating them into effective action.     

弹性系数视角下风险耦合特性的仿真分析

风险耦合导致风险发生非线性演化,从而给风险的定量评估带来困难。为给出风险耦合控制的有效对策,基于弹性系数视角界定风险耦合弹性系数概念,以此实现对风险耦合强度的定量测度;基于装备研制项目设计论证环节,从风险测度指标节点裕度角度,采用Arena软件仿真分析单指标和全指标在线性和非线性耦合关系下的系统风险熵和后传风险熵的变化情况。结果表明,全指标非线性耦合会显著改变系统性能,而单指标非线性耦合和全指标线性耦合次之,欲实现风险耦合控制应极力制止全局性的非线性耦合关系。     

Furfural residues from straw become complex fertilizer by addition method

ＩｎｔｒｏｄｕｃｔｉｏｎＦｕｒｆｕｒａｌｉｓａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｒａｗｍａｔｅｒｉａｌｉｎｃｈｅｍｉｃａｌｉｎｄｕｓｔｒｙ.Ｗｉｔｈｔｈｅｇｒｏｗｔｈｏｆｉｔｓｕｓｅ,ｉｔｓｐｒｏｄｕｃｔｉｏｎｉｓｉｎｃｒｅａｓｉｎｇａｎｎｕａｌｌｙ.Ｂｕ?..     

糠醛生产废渣直接转化为复合肥—添加剂(Ⅰ)配方与蒸馏条件的研究

 采用复合添加剂（I），以稻草（或麦杆）为原料，用硫酸酸化水解制糠醛，研究了复合添加剂（I）各成分的含量和添加量以及蒸馏条件对渣酸度的影响．结果表明，以20％（wt/wt,%）硫酸，液固比为3∶1～4∶1（wt/wt），复合添加h们）与原料的比为02：1〔WVWt），添加剂（I）配方为：磷酸钙7％，磷酸和重钙5％－10％，亚硫酸氢钠和碳酸钙3％－5％，助剂（III）5％－10％；蒸馏温度110～130℃，时间2.5～3.0h，出醛率可达理论量的80％以上，废渣全部转化为中性复合肥.     

蛇绿岩鉴别的关键问题探讨

蛇绿岩的鉴别足蛇绿岩与地球动力学研究的基本问题之一。不同时代、不同成因及不同构造背景下形成的蛇绿岩，它们的端员组分大多不太完整，并且各不相同，但堆积来岩是必不可少的。蛇绿岩鉴别的关键问题就是堆积来岩的判别研究，应加强对典型蛇绿岩中堆积杂岩的系统研究，以期总结出一套有效的判别标志用于蛇绿岩的鉴别。     

关于建立成矿溶液配合物体系Eh-pH图的研究

Eh－pH图是研究成矿溶液的重要手段之一。在传统元素-水体系的Eh—pH图的基础上，笔者提出和研究了成矿溶液中配合物体系的Eh－pH图的建立方法，为成矿溶液的理论模拟和成矿作用的研究提供了新的途径。