延安市延河防洪水文计算

在实测资料的基础上,利用小流域设计洪水方法,结合延河77.7特大洪水进行延安城市防洪水文计算,并推求出不同设计标准的河道水面线。经分析和讨论,成果合理可靠,可供工程部门应用。     

Introducing the Food Fraud Initial Screening model (FFIS)

Food Fraud is illegal deception for economic gain using food. There are many types of fraud including adulterant-substances, tampering, theft, diversion and gray marketing, simulations, misbranded, and intellectual property rights product counterfeiting. The concept is beginning to be addressed by laws, regulations, standards, and certifications. Regardless of the presence of an actual health hazard, Food Fraud incidents can: negatively impact sales, brand equity, market capitalization; violate regulations such as Sarbanes-Oxley; and even lead to the criminal prosecution of corporate leaders. Emerging regulations and industry standards are requiring risk and vulnerability assessments of Food Fraud as a prerequisite to countermeasures and decision-making systems. These assessments and risk management systems are not familiar food safety tools. It is effective and efficient to utilize an enterprise risk management (ERM) framework, such as developed by the Committee of the Sponsoring Companies of the Treadway Commission (COSO). ERM risk assessment occurs into two stages: (1) a qualitative initial screening followed by (2) a more detailed quantitative assessment. All types of Food Fraud can result in enterprise-wide risks so an enterprise risk management system must cover all types of vulnerabilities. The model developed in this paper addresses the unmet need of the first stage referred to here as the Food Fraud Initial Screening (FFIS).     

化工企业消防安全及管理对策的探讨

概述上海市化工企业的现状,举例分析存在的问题,并针对化工企业生产和安全管理的特点及有关影响因素,提出若干消防管理的对策措施。     

珠江口盆地古近系幕式构造活动与沉积耦合关系——以长昌—鹤山凹陷为例

长昌—鹤山凹陷位于珠江口盆地,具有良好的勘探前景。通过对区域性角度不整合、断裂幕式活动、构造沉降阶段性演化以及古构造格架变化等信息的综合分析,揭示了长昌—鹤山凹陷古近纪构造具有分期异向多幕式裂陷特征,且在不同构造幕,地层沉积受断裂控制作用不同,形成的沉积体系空间展布和配置关系明显不同。主要表现在:早期裂陷幕,沉积地层完全受断层控制,断陷活动强烈,主要发育扇三角洲物源;晚期裂陷幕,断陷活动大大减弱,主要发育近源辫状河三角洲,且该时期圈闭较发育;断拗转换幕,沉积地层分层发育,早期地层完全受断层控制,主要发育浅海三角洲,晚期沉积部分受断层控制,开始接受海相沉积,陆架边缘三角洲伴随陆架不断向海迁移,陆坡的坡度逐渐变陡,开始发育重力流深水扇。     

杨家河水力发电规划对民生改善的促进

杨家河水力发电规划的实施,不仅对纳雍县大力发展水电,着力改善民生,促进经济可持续发展起到积极的推动作用,而且将加快毕节地区农村电气化建设和小水电代燃料工程的进程。     

天人合一与黄河生态保护——第四届黄河国际论坛大会主旨演讲

天人合一是我国传统哲学中占主导地位的命题。儒家提倡“泛爱万物”和“仁爱自然”,道家提倡“见素抱朴”,“道法自然”,都体现了人与自然和谐的理念。中国古代文明至今延绵五千年,得益于对水土资源的珍惜和对于自然生态系统的保护。黄河是中华民族的摇篮,孕育了辉煌的中华文明。近半个世纪黄河流域经济发展和黄河治理的成绩为世人瞩目。可是。成就中隐藏着挑战,黄河巨变引发了生态危机。河流断流、水质污染、河流高度人工化和生物多样性下降,导致流域生态系统退化。近年来,黄河实施水量统一调度和调水调沙,对于遏制生态系统退化已经初见成效。河流生态修复的本质就是老子的“道法自然”。黄河生态修复任重道远,建议加强黄河生态监测网络建设;水文情势恢复;水污染防控;鱼类及栖息地保护;湿地保护和上游水电梯级开发规划论证等工作。     

基于GIS和SWAT模型的清江流域面源污染模拟研究

 水体面源污染评价研究是一项复杂的工作,涉及面广和要求有较长时间序列的数据。面源污染模型很大程度上依赖于对于流域的特征描述的相关参数,因此提高输入模型参数的精度,有利于提升流域面源污染的径流、泥沙和营养物质的产出模拟效果。GIS和面源污染模型的有机结合是当前面源污染模拟研究最有效的方法。本研究建立了基于GIS的基础数据库,其中包括DEM、土壤类型、土地利用、气象数据以及农业耕作管理数据等。面源污染模拟的产生和形成具有很大的不确定性,这更加增加了监测和控制面源污染的难度。探索影响面源污染的主要因素,研究其不确定性对于提出和制定污染控制措施至关重要。本研究进行了清江流域面源污染的参数敏感性分析,根据观测数据对SWAT模型进行验证和率定,并利用SWAT模型进行模拟,揭示了清江流域面源污染的时空分布特征,确定了清江流域水土流失风险区。结果表明清江流域的面源污染主要发生在丰水期,不同的土地利用方式、农业耕作制度以及降水等是影响径流量和营养物质产生的主要因素。     

长江防洪实体模型垂线流速相似性研究

根据实测资料 , 采用3点法、5 点法对比计算分析了原型和长江防洪实体模型的垂线平均流速两者间差异,同时比较分析原型与模型流速沿水深分布偏离程度。采用明渠对数流速公式探讨了模型变态后流速沿垂线分布的规律,在此基础上提出了长江防洪实体模型垂线平均流速与相对水深某位置处点流速的关系,观测资料分析表明,模型相对水深为 0.6 处的点水深处流速与垂线平均流速基本一致。     

南水北调穿黄隧洞内衬预应力锚索应力应变试验研究

南水北调中线穿黄隧洞内衬张拉,采用弧形垫座将内衬预应力锚索导出预留槽,只用一台千斤顶实现无台座张拉,这在盾构隧洞工程中属首次应用,结构创新、工艺复杂可借鉴的资料较少。为了验证结构设计的合理性和可靠性,完善施工工艺,确保在隧洞衬砌中成功应用,通过穿黄隧洞衬砌1∶1仿真模型试验,对内衬钢绞线在张拉过程中应变规律、应力损失、锚束之间的相互影响及锚索与波纹管间的摩阻系数等要素进行研究分析。试验结果显示张拉锚固端应力总损失（包括锚具损失和锚索回缩损失）小于35%;锚具锁定后最大应力为1 044.25 MPa;预应力锚索张拉对相邻锚索的影响较小;锚索与管道间的摩阻系数在规范范围内。     

Flow and water temperature simulation for habitat restoration in the Shasta River,California

Low instream flows and high water temperatures are two factors limiting survival of native salmon in California's Shasta River. This study examines the potential to improve fish habitat conditions by better managing water quantity and quality using flow and water temperature simulation to evaluate potential restoration alternatives. This analysis provides a reasonable estimate of current and potential flows and temperatures for a representative dry year (2001) in the Shasta River, California. Results suggest restoring and protecting cool spring‐fed sources provides the most benefit for native salmon species from a broad range of restoration alternatives. Implementing a combination of restoration alternatives further improves instream habitat. Results also indicate that substituting higher quality water can sometimes benefit native species without increasing environmental water allocations. This study shows the importance of focusing on the limitations of specific river systems, rather than systematically increasing instream flow as a one size fits all restoration approach. Copyright © 2009 John Wiley & Sons, Ltd.