影响煤巷锚梁网支护施工速度因素浅析

通过对煤巷锚杆支护工艺的分析,指出了现场施工中煤巷锚梁网锚杆支护施工速度的影响因素,通过对这些影响因素的分析,找出了提高锚网施工的快速施工方法,技术人员要根据现场实际情况,不断地总结经验、修改设计参数,寻找出适应不同地质条件下的支护设计参数,优化施工工艺,缩短工艺时间,为煤巷锚杆支护实现真正的快速掘进做出各自的贡献.     

元氏矿井东水仓软岩支护研究

介绍了围岩为软岩,受地应力影响情况下水仓为软岩时巷道的设计思路与支护方法,在传统支护形式不能起到有效的效果情况下,将地铁施工技术和井下常规支护相结合,控制井下水对围岩的破坏,通过预留一定的变形量,采取柔性支护和反底拱支护形式,允许巷道有一定的变形量,以抵消围岩的变形;同时将临时支护作为永久支护体的一部分,允许巷道有一定的抗变形能力,通过巷道底板的反底拱支护,控制巷道底鼓,增加巷道底板的强度,提高支护的整体能力.先通过临时柔性支护将围岩的应力释放与卸压,再进行永久刚性支护,刚、柔支护相结合,达到好的支护效果.     

LEED绿色建筑评价体系视角下的可持续施工管理

LEED绿色建筑评价体系是目前国际上最具权威性的绿色建筑评价标准,由美国绿色建筑委员会制定并推行.在结合国内施工阶段现状的基础上,寻找LEED绿色建筑评价体系中与施工阶段的契合点,针对相关要求采取措施,最终达到节能、环保、可持续的目的.表1,参6.     

新型废水生物脱氮的微生物学研究进展

生物脱氮是含氮废水处理公认的最佳处理方式,随着对生物脱氮微生物学原理研究的不断深入,许多新的生物脱氮特殊菌株或菌群及微生物转化机制不断被发现.本文在传统生物脱氮过程机理上,结合最近国内外生物脱氮的新发现,就短程硝化反硝化、同时硝化反硝化、厌氧氨氧化的微生物学原理进行了阐述.图1表2参23     

粉喷桩体的力学性质试验研究

粉喷桩是处理软弱地基的一种重要方法.通过水泥土的室内配合比试验,研究了粉喷桩体的抗拉、抗压和抗剪强度性质及其影响因素,可为粉喷桩施工和设计提供理论指导.图1,表3,参5.     

市政工程施工地周边颗粒污染物扩散特征

为了解市政施工对周边大气环境的影响,通过测定TSP、PM10、PM2.5、PM1等指标,研究了施工工地附近颗粒污染物随天气条件、气象要素、距施工点距离的变化规律,结果表明：（1）粒径较大的颗粒物质量浓度受气象要素的影响较明显,大风和晴天的ρ（TSP）、ρ（PM10）远高于阴雨天;随风速增大,ρ（TSP）、ρ（PM10）、ρ（PM2.5）显著升高。（2）小粒径颗粒物（PM1）受天气条件的影响不明显,湿度、风速变化对PM1影响较小。（3）距离施工工地越远,4种颗粒物质量浓度越低,其中ρ（TSP）、ρ（PM10）、ρ（PM2.5）随距离下降较快。（4）不同施工阶段颗粒物污质量浓度异较大,挖槽阶段颗粒物污染要高于结构装修阶段。     

缓释型二氧化氯固体制剂的制备方法及其缓释性能

二氧化氯是国际上公认的性能优良的第三代消毒剂,被世界卫生组织列为A1级消毒剂.二氧化氯固体制剂按制备原理可分为吸附型和反应型[1].近年来固体缓释消毒剂已成为消毒领域的新热点,部分学者曾用聚乙烯醇等水溶性有机     

产纤维素酶菌株的选育分析及发酵工艺优化

对实验室6株产纤维素酶菌株进行酶活特性研究.首先通过观察纤维素平板的酶溶解透明圈大小进行初步分析,比较6株菌种子发酵液中纤维素酶含量.再根据不同种纤维素酶作用的底物化学键的不同,分别测定菌株的滤纸酶活(FPA)、纤维素内切葡聚糖酶(CMCase)活、纤维素外切葡聚糖酶(CBH)活和β-葡萄糖苷酶酶活,发现菌株中黑曲霉的各产酶指标均高于其它菌株.根据Box-Behnken原理对黑曲霉发酵工艺进行优化设计,得到最适碳源稻草粉含量9.47 g.L-1、麸皮含量49.33 g.L-1,氮源中(NH4)2SO4含量为2.0 g.L-1,发酵后黑曲霉产生的滤纸酶活力达到76.72 U.mL-1,比优化前酶活力提高88.69%.     

基于作业成本管理在建筑企业施工中的应用研究

以作业成本管理理论为基础,研究了建筑施工企业的作业成本核算以及计算模型,通过对作业成本管理应用和导入作业成本管理理论与方案设计的分析,比较了施工企业与项目管理作业.结果表明,其作业成本管理模式完全适用于建筑施工企业作业成本的管理,并能够有效地对建筑施工企业的作业成本进行有效控制.图1,参5.     

DN—1900测氮仪简介

长期以来,分析水中的氮(N)常用比色或滴定法,这就需要麻烦、耗时、费力的前处理.近年来,美国Dohrmann公司推出的DN-1900双通道测氮仪较简便快速,能分析水中总氮(TN),也能解析其形态,从其结构、性能和测量范围看,是目前测量水中N较先进的、有一定特色的仪器.1 结构与原理     

某大型储罐复合地基沉降计算分析

从某大型储罐复合地基沉降机理分析入手,合理选择沉降计算公式,对建造在该类复合地基上的大型储罐沉降量作计算,并经实测沉降资料对比后,验证该类储罐沉降计算方法的适用性,为今后类同工程地质条件下,储罐基础的优化设计积累经验.图1,表1,参3.     

广东省耕地分等中的土壤肥力评价指标体系

土壤肥力评价是耕地分等的基础及重要组成部分。土壤肥力评价的关键是评价指标体系的确定，指标的选择原则主要有主导性原则、稳定性原则、差异性原则、分层次控制原则、定量分析与定性分析相结合原则。指标分值和权重的确定方法主要是模糊评价法和层次分析法，但必须依据土壤学的研究成果和生产实践经验。     

基于ASP毕业论文选题系统的设计

毕业论文选题系统包括后台数据库的建立以及前端应用程序的开发两个方面.教师可以利用IE浏览器发布自己的课题,学生则可以选择自己喜欢的课题.对于教师发布的选题,还可以通过先来先到原则进行自动筛选,此外学生还可以自主命题.图1,参4.     

高校主体性人力资源职业生涯发展管理研究

本文深入探讨了高校主体性人力资源的特点及其职业生涯发展的主要特征，针对高校当前在职业生涯发展管理上存在的主要问题，提出了进行管理创新的几个基础性工作，为全面有效地进行职业生涯发展管理奠定坚实的基础．     

Whole-community mutualism: associated invertebrates facilitate a dominant habitat-forming seaweed

Many habitat-forming, or foundation, species harbor diverse assemblages of associated taxa that benefit from the refuges from predators or harsh physical conditions that foundation species provide. Growing numbers of studies show how specific taxa associated with foundation species can benefit their hosts, but the aggregate effects of the entire community of associated species remain poorly understood. Here, we evaluate the role that a diverse assemblage of invertebrates plays in mediating the dominance of a foundation species, the green filamentous seaweed Cladophora columbiana Collins, in rocky intertidal habitats. Cladophora is a fast-growing seaweed with a high nitrogen demand, and we suggest that it persists in nutrient-limited high-intertidal pools because of local-scale nitrogen excretion by the invertebrate taxa living within its filaments. Removal of associated invertebrates resulted in a fourfold increase in the rate of water-column nitrogen depletion by Cladophora, and ammonium concentrations inside Cladophora turfs with invertebrates present were seven times higher than in the adjacent tide-pool water. The ammonium excreted by invertebrate meiofauna far surpassed the nitrogen used by Cladophora, suggesting that all of Cladophora's nitrogen requirements could be met by the invertebrates associated with it. This study links host performance to the total aggregate biomass of mutualists rather than the particular traits of any one species, suggesting the potential for important feedbacks between individual hosts and the communities of associated species that they support.     

Conservation of biodiversity through taxonomy,data publication,and collaborative infrastructures

Taxonomy is the foundation of biodiversity science because it furthers discovery of new species. Globally, there have never been so many people involved in naming species new to science. The number of new marine species described per decade has never been greater. Nevertheless, it is estimated that tens of thousands of marine species, and hundreds of thousands of terrestrial species, are yet to be discovered; many of which may already be in specimen collections. However, naming species is only a first step in documenting knowledge about their biology, biogeography, and ecology. Considering the threats to biodiversity, new knowledge of existing species and discovery of undescribed species and their subsequent study are urgently required. To accelerate this research, we recommend, and cite examples of, more and better communication: use of collaborative online databases; easier access to knowledge and specimens; production of taxonomic revisions and species identification guides; engagement of nonspecialists; and international collaboration. “Data‐sharing” should be abandoned in favor of mandated data publication by the conservation science community. Such a step requires support from peer reviewers, editors, journals, and conservation organizations. Online data publication infrastructures (e.g., Global Biodiversity Information Facility, Ocean Biogeographic Information System) illustrate gaps in biodiversity sampling and may provide common ground for long‐term international collaboration between scientists and conservation organizations.     

非洲爪蟾在生态毒理学研究中的应用（Ⅲ）——生殖内分泌干扰作用的评价

两栖动物生殖内分泌系统(如性别分化、性腺发育、第二性特征)对性激素的敏感性,使得该类动物可用于研究内分泌干扰物(Endocrine Disrupting Chemicals,EDCs)对生殖内分泌系统的干扰作用.两栖动物非洲爪蟾是发育生物学研究的经典模型动物,多年来积累的有关其生殖内分泌的资料可以为生殖内分泌干扰的研究提供参考.论文分析了非洲爪蟾作为评价生殖内分泌干扰作用模型动物的理论基础,总结了评价生殖内分泌干扰作用目前使用的几个指标(性别分化、性腺形态、性腺组织学结构、性激素水平、卵黄蛋白原表达等生物标记),综述了非洲爪蟾在评价酚类化合物、阿特拉津、多氯联苯等几种EDCs的生殖内分泌干扰作用中的应用,最后讨论了非洲爪蟾作为一种评价EDCs生殖内分泌干扰作用的模型动物目前存在的问题.毫无疑问,非洲爪蟾是生殖内分泌干扰研究的良好模型动物,为促进该模型动物更好的应用,需要加强非洲爪蟾生殖生物学和内分泌学的研究.     

北京城市温室气体排放清单基础研究

回顾中国城市,主要是北京温室气体排放研究和排放状况,结合目前国际上主要采用的城市清单方法,梳理北京温室气体排放清单,并利用收集的北京市基本资料进行相关分析,作为北京和洛杉矶温室气体清单比较研究的基础.通过分析可以看出,中国城市温室气体清单的编制需要大量精确的数据作为支撑,但目前由于在统计口径上与国际上通用的排放清单有差...     

Solitary nesting and reproductive success in the paper wasp Polistes aurifer

Female Polistes paper wasps are capable of independent nesting, yet many populations demonstrate a mixture of solitary and cooperative nest foundation. Previous studies of Polistes have found survival and/or productivity advantages of cooperative nest foundation compared to solitary nesting, and reproductive skew models have been designed to predict the dynamics of such flexible cooperation. In this paper, we examine the success of different nesting strategies in a previously unstudied population of Polistes aurifer in southern California. The colony cycle of this population is less synchronous than that of other temperate species, and the frequency of solitary nesting averages 86.2%. Our data suggest that this low rate of cooperative nest founding is adaptive, as demonstrated by the lack of survival or productivity advantages for cooperative foundress associations. Due to foundress turnover and nest foundation later in the season, many nests produce only one set of offspring. This results in a loss of the eusocial nature of some nests in the population. Data from a small sample of multifoundress nests show significant positive reproductive skew, despite concession model predictions that skew should be low in populations with low ecological constraints on independent nesting. This lack of support for the concessions skew model reflects a diminished incentive for cooperation.Communicated by L. Keller