Physical and Temporal Isolation of Mountain Headwater Streams in the Western Mojave Desert,Southern California1

Abstract: Streams draining mountain headwater areas of the western Mojave Desert are commonly physically isolated from downstream hydrologic systems such as springs, playa lakes, wetlands, or larger streams and rivers by stream reaches that are dry much of the time. The physical isolation of surface flow in these streams may be broken for brief periods after rainfall or snowmelt when runoff is sufficient to allow flow along the entire stream reach. Despite the physical isolation of surface flow in these streams, they are an integral part of the hydrologic cycle. Water infiltrated from headwater streams moves through the unsaturated zone to recharge the underlying ground‐water system and eventually discharges to support springs, streamflow, isolated wetlands, or native vegetation. Water movement through thick unsaturated zones may require several hundred years and subsequent movement through the underlying ground‐water systems may require many thousands of years – contributing to the temporal isolation of mountain headwater streams.     

高寒条件下振弦式传感器在线测量尾矿坝浸润线的误差分析及对策

为减少和消除高寒条件下振弦式传感器在线测量浸润线的误差,通过理论分析和现场试验,对造成误差的因素及其影响情况进行了深入研究。结果表明,振弦式传感器产生测量误差的主要来源为设备安装深度的测量误差与尾矿水密度及重力加速度的取值误差,并提出了减少或消除误差的方法和工程技术措施,为高寒地区的浸润线在线精确测量提供了重要指导意义。     

二氧化碳灭火系统扑灭风电机组舱内火灾试验研究

为有效遏制全国多地风力发电机组火灾事故的势头,基于灭火系统在风电机组防火设计中的重要性,提出采用二氧化碳灭火系统对风电机舱进行灭火保护的解决方案。在建造国内首台风电机组火灾模拟试验装置的基础上,通过试验研究二氧化碳灭火系统在常温状态和低温状态下对风电机组火灾的灭火能力。结果表明,该灭火系统能够对风力发电机组进行全淹没灭火保护,适用于空间狭小且结构复杂的风电机舱;在低温条件下,其喷放时间和灭火时间虽比常温状态下长,但灭火效能并未降低。     

An easy method to design gas/vapor relief system with rupture disk

Tank discharge gas/vapor flow problems are frequently encountered in both practice and design. To perform this type of design calculation, the first step is to identify whether the flow is choked or not through a trial-and-error solution of an equation for adiabatic flow with friction from a reservoir through a pipe. Developing a direct method without any trial-and-error to identify a choking condition would be helpful for expediting the flow calculations. This paper presents an easy and quick method to identify the choking of gas flow for an emergency relief system consisting of a rupture disk and vent piping. This greatly simplifies the design calculations. The proposed method for validating the venting adequacy of existing ERS circumvents the iteration calculation and the use of Lapple charts. Three case studies for the design of vent piping for rupture disks support the proposed method.     

生态文明建设实现合作治理的条件、主体和路径分析研究

生态文明建设是政府、市场、非政府组织和公民等多元主体合作治理的整体性系统性实践活动,多元主体合作治理的实现依赖于制度环境、组织因素、共同目标和信息沟通等多个关键条件,同时,合作治理需要各主体按照生态文明建设的要求明确和重塑角色定位,进而通过健全多元主体参与生态文明建设法律保障体系,健全生态补偿和生态支出竞争使用机制,建立信息交互制度,寻求多元合作模式,最终实现统筹协调、联动增效的生态文明建设合作治理.     

Geographic range size and extinction risk assessment in nomadic species

Geographic range size is often conceptualized as a fixed attribute of a species and treated as such for the purposes of quantification of extinction risk; species occupying smaller geographic ranges are assumed to have a higher risk of extinction, all else being equal. However many species are mobile, and their movements range from relatively predictable to‐and‐fro migrations to complex irregular movements shown by nomadic species. These movements can lead to substantial temporary expansion and contraction of geographic ranges, potentially to levels which may pose an extinction risk. By linking occurrence data with environmental conditions at the time of observations of nomadic species, we modeled the dynamic distributions of 43 arid‐zone nomadic bird species across the Australian continent for each month over 11 years and calculated minimum range size and extent of fluctuation in geographic range size from these models. There was enormous variability in predicted spatial distribution over time; 10 species varied in estimated geographic range size by more than an order of magnitude, and 2 species varied by >2 orders of magnitude. During times of poor environmental conditions, several species not currently classified as globally threatened contracted their ranges to very small areas, despite their normally large geographic range size. This finding raises questions about the adequacy of conventional assessments of extinction risk based on static geographic range size (e.g., IUCN Red Listing). Climate change is predicted to affect the pattern of resource fluctuations across much of the southern hemisphere, where nomadism is the dominant form of animal movement, so it is critical we begin to understand the consequences of this for accurate threat assessment of nomadic species. Our approach provides a tool for discovering spatial dynamics in highly mobile species and can be used to unlock valuable information for improved extinction risk assessment and conservation planning.     

基于函数极值条件下的中国碳达峰碳中和情景分析

基于函数极值条件提出了碳达峰出现时间和需要满足的理论条件,并对主要发达国家作了验证,同时对中国现状做了分析,最后采用了基准和强化两种情景分析了中国实现2030年碳达峰后进入2060年碳中和时期的二氧化碳排放量。研究结果显示：（1）根据IPAT恒等式将碳排放函数分解成人口、人均GDP和碳强度三个因素时,碳峰值出现时间为三个因素年增长率之和由正转负的正数值年度,发达国家的历史数据证实了这一条件。（2）中国三个因素年增长率之和自2003年起已经开始降低,最近几年一直在0.01~0.02徘徊,表明总体上朝着有利于碳达峰的方向发展,同时按照三个因素的预期发展目标计算得出中国2030年碳排放峰值的上限为112.2亿t,若2021—2035年保持相同的人均GDP年均复合增长率,碳强度年均复合增长率的绝对值需要比人均GDP年均复合增长率高0.14个百分点。（3）在能源消费总量逐渐回落的前提条件下,2060年基准情景下非化石能源占比约为65%,产生的二氧化碳量约为31.4亿t,强化情景下非化石能源占比约为70%,二氧化碳排放约为26.6亿t,而碳汇和CCUS等固碳技术还存在不确定性,碳中和任务依然艰巨。实现碳达峰碳中和最终需要控制能源消费,践行低碳消费行为。     

Household income,living and working conditions of dumpsite waste pickers in Bantar Gebang: Toward integrated waste management in Indonesia

This paper clarifies household income, living and working conditions of dumpsite waste pickers at Bantar Gebang final disposal site for municipal solid waste generated in Jakarta, and investigates the feasibility of integrating the informal sector into formal waste management in Indonesia. The first author did fieldwork for totally 16 months at the site and quantitative field surveys were conducted twice during the period. All respondents in the first round quantitative survey (n = 1390) were categorized as follows: waste pickers, family workers, wage labors, bosses, family of the bosses, housewives, pupils/students, preschoolers, the unemployed, and others. Based on the results of the second round quantitative survey (n = 69 households), their average household income was estimated to be approximately US 216 dollars per month (n = 59 households), which was virtually equivalent to the minimum wage in Jakarta in 2013. Living conditions of scavengers at the site were horrible, and their working conditions were dangerous due to medical waste and other sharp waste. Polluted groundwater was one of the serious environmental problems at the site. Despite the social, health and environmental problems, they were attracted to the freedom of entering the informal recycling system in Bantar Gebang and withdrawing from the system, in which a lot of opportunities were provided for the people having few marketable skills to obtain cash earnings. The freedom of their choice should be guaranteed as a prerequisite before integrating the informal sector into formal waste management. Furthermore, special attentions are required when incomes of scavengers are the same level as minimum wages and the national economy is rapidly growing, because scavengers cannot easily change their jobs due to few marketable skills. Indonesian national waste laws and regulations should be properly applied to facilitate a socialization process at final disposal sites. Measures need to be taken to prevent children from working as informal recycling actors, especially for waste pickers aged 15 or younger.     

陕西省1990年自然灾害和救灾工作回顾：兼谈1991年减灾对策

本文在回顾1990年陕西省灾情及救灾工作基础上,提出了强化政府在减灾中的职能,搞好灾情预测预报、及早制定防灾预案及灾前准备工作的减灾对策。     

农业开发的企业化经营

目前企业化经营已被越来越多地运用于农业开发的生产管理中。本文阐述了农业开发中企业化经营形式及其重要性,分析了当前企业化经营优势尚未充分发挥的原因,提出了加强农业开发企业化管理的对策。