Salmonid observations at a Klamath River thermal refuge under various hydrological and meteorological conditions

The Beaver Creek confluence with the main‐stem Klamath River was studied to assess salmonid use in a thermal mixing zone under various summer hydrological and meteorological conditions. Main‐stem flow releases from Iron Gate Dam ranged from 17 cms (615 cfs) to 37 cms (1320 cfs) during the study period and main‐stem water temperatures ranged from 19.5 to 26°C. A grid was constructed to define the thermal refuge as a system of cells. Temperatures were monitored using remote temperature loggers and fish counts were conducted using daytime snorkelling. Most juvenile salmonids were observed moving into the refuge when main‐stem temperatures exceeded 22–23°C. Salmonids in the thermal refuge did not necessarily seek the coolest water, but were generally located in habitats commensurate with species‐specific behavioural needs within their thermal tolerance range. Such ranges largely occurred within refuge areas. Variable meteorological conditions confounded observable biological thermal benefit to fish resulting from higher or lower main‐stem flows. Thermal regime dynamics indicated that under the hydrological and meteorological conditions observed, higher flows from Iron Gate Dam showed some ability to change the structure of the refuge area. It appeared that without the thermal refuge, main‐stem flows alone could not sustain the salmonid population because high water temperatures usually exceeded their published thermal tolerance limits. Copyright © 2007 John Wiley & Sons, Ltd.     

一类相异功能反应的predator-prey扩散系统的稳定性

针对斑块生境下具有庇护所效应的相异功能性反应predator-prey扩散系统,讨论了系统持续生存的条件.运用常微分方程定性理论讨论了系统解的有界性,通过构造Lyapunov函数得到了一定条件下该系统正解是全局渐近稳定的.进一步利用Pioncare定理和Brower定理证明了惟一周期正解的存在性与稳定性.     

救生舱舱门空气幕系统优化设计与试验分析

为采用空气幕阻隔矿用救生舱舱外有害气体,利用数值模拟技术建立了二维舱门空气幕模型,通过对不同的空气幕喷口宽度、送风角度及送风速度下的气幕流场进行分析,对有限气源下空气幕系统进行优化设计,通过试验和数值模拟分析,验证了有限气源下空气幕系统设计的合理性.该研究成果已成功应用于"KJYY-12/96"型矿用紧急救生舱.     

煤矿井下避难硐室系统的构建与应用分析

为进一步减少煤矿事故发生后的人员伤亡、财产损失,在分析国内外煤矿井下避难系统发展的基础上,以何家塔煤矿井下避难硐室系统的构建设计与应用为例,详细介绍了井下避难硐室系统的分类、结构构成、功能需求和配套设施等,并通过紧急避险疏散时间的校验计算,提出避难硐室距离采掘工作面以不超过1 000 m为宜,且应按照“地面最安全,先逃生后避险”原则进行避险救援,为国内其他矿井避难硐室的构建应用和相关标准的制定提供了参考。     

矿用救生舱除湿方式研究

根据我国煤矿现有条件及要求,对煤矿救生舱内除湿技术进行了研究。针对煤矿井下发生事故后的客观条件,从动力缺失、空间大小、简单易用等方面分析其对除湿系统的特殊要求。阐述并比较了冷凝除湿、液体吸收除湿、固体吸附除湿、热泵除湿这些常见除湿方式的优缺点,选用固体动态吸附除湿技术控制矿用救生舱内的湿度。     

内置担架帐篷式救灾背包设计

本文就救灾过程中存在的种种不便之处,研究设计出一种新型救援设备。提出了一种可分离的四折叠框架结构,再配以折叠帆布和帐篷,便制成了一种多功能背包。背包状态可用来运送物资;展开背包变为担架,可用于运送伤员;翻转担架由折叠杆撑起即变为帐篷,可供三人居住。     

Movement patterns of smallmouth and largemouth bass in and around a Lake Michigan harbor: The importance of water temperature

Smallmouth bass Micropterus dolomieu and largemouth bass M. salmoides in southwestern Lake Michigan use shallow, warm harbors for spawning during spring. After the reproductive period ends in early summer, catch rates from standardized sampling of smallmouth bass in harbors decrease. Fishes are presumed to use the main lake during summer but little is known about how black basses use main-lake habitat in Lake Michigan or mechanisms driving this transition. We tracked smallmouth bass (N = 26) and largemouth bass (N = 8) using radio and acoustic telemetry during 2005–2006 near North Point Marina, IL. A temperature difference persisted between inside and outside the harbor for much of May–October where harbor temperatures were generally warmer than those outside the harbor. Smallmouth bass responded to water temperature changes, inhabiting the harbor until temperatures outside the harbor approached 18.5 °C, at which time they left the harbor. Frequent temperature fluctuations of > 3 °C occurred outside the harbor within 24-hour periods. Sudden reductions in water temperature were associated with smallmouth bass temporarily returning to the harbor until the temperature outside the harbor again approached 18.5 °C. As water cooled during fall, smallmouth bass again returned to the harbor. Largemouth bass exhibited comparatively restricted movements during this time and rarely ranged outside the harbor. Thus, home range estimates for smallmouth bass (142.6 ha) were an order of magnitude greater than those of largemouth bass (12.9 ha). Both water temperature and species played a role in determining the degree of movement outside the harbor but both black basses used the harbor as a thermal refuge.     

矿井避险空间生氧净化系统研究与试验

为了分析矿井避险空间生氧净化系统性能,根据其功能及工作原理,确定系统由气源装置、汇流装置、控制装置、CO2净化装置及CO净化装置组成。研究确定80人16 h需要15 MPa,40 L医用氧气瓶10个及4.78×105 g JS-1净化药剂,药剂更换频率为1.51 h。密闭模拟试验表明：药剂去除效率与CO2初始体积分数无关,而与风机位置、风机功率及药剂层厚度相关;当风机位于药剂层下方时,最佳风机功率为185 W,最佳药剂厚度为250 mm,CO2去除效率为91%;组合后的生氧净化系统比独立系统提高了CO2净化性能及空间气体均匀扩散能力。现场载人实验证明：生氧净化系统能够保证空间O2体积分数为19.5%,CO2体积分数为0.6%~0.9%。     

钢骨混凝土高位连体结构悬挂式模板系统施工技术

超高层建筑大型钢骨混凝土连体结构施工过程中,运用施工技术集成创新的方法,将＂大型钢结构高空安装＂、＂钢骨混凝土连体转换梁自承重模板＂、＂无粘结预应力混凝土抗裂＂和＂信息化施工＂等新技术,以及＂在转换层下设置悬挂钢结构楼承板（避难层）作为施工阶段的操作平台＂这一新颖构思,经过整合后形成＂钢骨混凝土连体结构施工成套技术＂成功应用于工程实践,确保了工程进度、质量和施工安全。     

超高层建筑防火设计问题探讨

在参考规范对超高层建筑,尤其是40层(约150m)以上的建筑进行防火设计时遇到一些与建筑安全使用、有效救援相左的问题。以一幢超高层建筑的防火设计为例,从消防登高面、避难层设置、客梯疏散和应急响应预案的编制等方面入手,探讨和解决超高层建筑设计中的问题,力图从源头上最大限度地保证并提高超高层建筑的安全性。