330kV输电线路绝缘架空地线专用接地装置的设计与实现

针对330 kV超高压输电线路绝缘架空地线无专用接地线,设计一种串接电阻的新型接地装置,以避免当绝缘架空地线存在过大感应电压时因瞬间直接接地产生的电弧伤害。通过对某330 kV同塔双回输电线路不同情况下绝缘架空地线上产生的感应电压进行仿真分析,为新型接地装置的电气参数选取提供依据,同时详细设计了其机械结构。对新型接地装置进行了现场应用,验证了其相较于传统接地线具有的便携性及安全性优势。     

Preparation of Porous Nanofibers from Electrospun Polyacrylonitrile/Polyvinylidene Fluoride Composite Nanofibers by Inexpensive Salt Using for Dye Adsorption

The high surface area of porous nanofibers enhances their performance for many applications. The present study investigated electrospinning and dye adsorption properties of polymeric nanofibers which were porous by various types of salts. The salt/polyacrylonitrile/polyvinylidene fluoride composite nanofibers were electrospun, and the inexpensive salts such as sodium chloride (NaCl), sodium bicarbonate (NaHCO₃), or calcium chloride (CaCl₂) was used to manufacture the porous fibers. Subsequently, the salt was removed by a selective dissolution, and salt extraction of nanofibers was performed with the solution of hydrochloric acid (10 wt%). Salt/PVDF/PAN and porous PVDF/PAN composite nanofibers have been applied to dye adsorption of solution. The characteristics of nanofibers were studied by Fourier transform infrared microscopy (FTIR) and scanning electron microscopy (SEM) analysis. FTIR showed that the salt was extracted from PVDF/PAN nanofibers successfully, and SEM indicated that many pores were aligned with the nanofibers. The adsorption capacity of salt nanofibers webs and porous nanofibers webs for Basic Blue 41 were compared with each other, and porous fibers were obtained from NaHCO₃ having the highest dye adsorption value. Adsorption of dyes follows the Langmuir isotherm and pseudo-second order kinetics.     

High photocatalytic removal of NO gas over SnO2 nanoparticles under solar light

Environmental Chemistry Letters - Tin oxide nanoparticles (SnO2 NPs) with a diameter less than 10 nm are usually used in waste water treatment via the photocatalytic reaction. However,...     

Recycling sewage sludge into ceramic materials: A review

Environmental Chemistry Letters - Huge amounts of unwanted sewage sludge are generated in the process of wastewater treatment, calling for methods to recycle sewage sludges into value-added...     

湖北省湖库洪水调蓄能力及其空间分异特征

湖泊是抵御湖区水系洪水灾害的天然屏障，而水库是现代防洪工程体系的重要组成部分，两者共同肩负着防洪减灾的重任。为探明湖北省湖库洪水调蓄能力，选取湖泊可调蓄水量、水库防洪库容作为评估指标，通过构建湖库洪水调蓄能力评估模型，分析全省湖库洪水调蓄能力及空间分异特征。结论如下：（1）湖北省湖泊、水库综合洪水调蓄量为416.02×108m3，其中湖泊可调蓄水量为79.69×108m3，水库防洪库容为336.33×108m3，分别占湖库洪水调蓄功能总量的19.16%和80.84%;（2）湖泊可调蓄水量较大的地区包括武汉、荆州、鄂州、黄石等地市以及鄂东丘陵、江汉平原，而单位面积湖泊调蓄洪水能力较强的地区为鄂州、黄石、咸宁、黄冈，其值分别为405.99×104、400.31×104、392.32×104和391.22×104m3/km2;（3）水库防洪库容较大的地区主要为鄂西山地的宜昌和十堰，分别为119.18×108m3和 103.03×108m3，占全省防洪库容总量的66.06%，而鄂州、天门和神农架水库防洪库容极小，不足全省水库总防洪库容的1%;（4）湖库综合调蓄能力空间分布特征与水库洪水调蓄能力空间分布相一致；从湖泊、水库洪水调蓄能力的构成来看，以湖泊防洪为主和以水库防洪为主的地市不相上下，水库在湖北省防洪体系中占绝对主体地位，同时湖泊也发挥着不可或缺的作用。针对湖泊萎缩、水库险病等突出问题，可以通过退田还湖、除险加固等工作提高湖库综合调洪能力。本研究可为湖北省湖库防洪建设提供科学指导。 关键词： 湖泊；水库；洪水调蓄功能；空间分异；湖北省     

教学楼火灾疏散的标识认知应对规律研究

为了研究逃生者在疏散标识引导下的火灾疏散效率与逃生认知应对规律,基于实地调研与问卷调查结果,采用Anylogic软件,对常规标识与增设标识2种教学楼火灾疏散情境进行仿真模拟。研究结果表明:在疏散过程中,增设标识能使各疏散出口的疏散时间相对持平,避免了常规疏散中通道过早闲置的现象;人流在一层教学楼的平均疏散时长缩短了约10%,显著缩短了整栋教学楼的疏散时间。据此火灾标识疏散仿真过程与人的认知反应提出了火灾疏散与标识认知应对规律模型。     

Restructured frame‐of‐reference training improves rating accuracy

The use of heuristic judgments is prevalent in organizations and negatively impacts accurate employee assessments. To minimize the negative impact of heuristic judgments (i.e., anchoring and adjustment), we aim to improve rating accuracy by restructuring frame‐of‐reference (FOR) training. We conducted five studies (N = 1,143) using different samples (three including participants with hiring experience), training environments (onsite and online), and rating contexts (evaluations of sales representatives, teachers, contract negotiation specialists, and retail store managers). Across the five studies, the average improvement in rating accuracy was at least twice as large for restructured FOR (vs. control) training as it was for typical FOR (vs. control) training; the difference in rating accuracy between restructured and typical FOR training was statistically significant. Furthermore, minimizing the anchoring effect rather than increasing opportunities for rating adjustments improved rating accuracy (Study 4). Finally, restructured FOR training achieved higher criterion validity (i.e., a higher strength of the association between ratings regarding a target and the target's objective performance) than did typical FOR training (Studies 3 and 5). We discuss implications for improving the effectiveness of diverse training programs and the accuracy of judgments in organizations.     

Ralstonia sp.strain U2菌株对萘的趋化作用

一株降解萘的细菌Ralstonia sp. strain U2对萘具有趋化现象,萘、水杨酸都可以作为其对萘产生趋化现象的诱导物.U2菌对水杨酸、龙胆酸同样都具有趋化性,但这种趋化性是组成型的,不需要诱导.图3参22     

西双版纳补蚌地区望天树林近20 a来物种多样性变化研究

通过对1988年和2006年西双版纳补蚌地区望天树林样方资料的比较研究,探讨了望天树林群落近20a来在物种多样性方面的变化.研究结果表明,在2006年的样方中,望天树仍然具有最大的优势度,该群落仍然是以望天树为优势种的单优群落.在群落自身演替以及外界环境干扰的影响下,幼树、灌木和藤本植物种类和数量明显增加,而草本植物和附生植物减少.分析乔木层的物种多样性变化发现,尽管2006年样方在植物种类和数量上都要高于1988年样方,但辛普森指数和均匀度指数并未增加,很可能是样方中形成了林窗的结果.另外,乔木层中物种优势度变化非常明显,少数优势种衰退了,少数变得更优势.1988年的两个样方中分别有50%和40%的物种被后来的物种所取代,物种替换现象特别显著,外界环境的干扰可能是导致物种成分替换的主要原因.图2表1参23