图形图象的浮雕化处理

本文以分形图象为例，设计了一个将二维彩图转化成浮雕图的算法     

Grounding and ground fault protection of multiple generator installations on medium-voltage industrial and commercial power systems - Part 4: Conclusion and Bibliography Working Group Report

This paper discusses typical grounding practices and ground fault protection methods for medium-voltage generator stators, highlighting their merits and drawbacks. Particular attention is given to applications of multiple generators connected to a single bus. The paper also provides an overview of the generator damage mechanism during stator ground faults. Problem areas associated with each type of grounding are identified and solutions are discussed. The paper also provides a list of references on the topic. The paper is intended as a guide to aid engineers in selecting adequate grounding and ground fault protection schemes for medium-voltage industrial and commercial generators for new installations, for evaluating existing systems, and for future expansion of facilities, to minimize generator damage from stator ground faults. These topics are presented in four separate parts, Parts 1-4. Part 1 covers scope, introduction, user examples of stator ground failure, and theoretical basis for the problem. Part 2 discusses various grounding methods used in industrial applications. Part 3 describes protection methods for the various types of grounding and Part 4 provides a conclusion and bibliography of additional resource material.     

An improved method for combined autoradiography and histochemistry: the simultaneous detection of 6-3H thymidine and acid phosphatase activity in cryostat sections of mouse thymus and duodenum

A new method is described that enables the simultaneous detection of 6-³H thymidine incorporation and acid phosphatase activity in the same tissue section. Histochemically, naphthol AS B1 released by tissue based acid phosphatase activity from the substrate naphthyl AS B1 phosphoric acid is coupled with a range of diazonium salts to produce insoluble azo dyes. The azo dye tests result in a particulate localization of lysosomal acid phosphatase and also label diffuse sources associated with cell death. The tests selected permit the application of photographic emulsion without the necessity of an inert barrier layer to separate the emulsion from the histochemically treated cryosections. The localization of 6-³H thymidine incorporation and cell death in mouse thymus and duodenum is demonstrated and comparative counts estimating the distribution of 6-³H thymidine incorporation and hydrolase labelled cell death in the thymus are presented. Young mouse thymus (5 weeks) was found to contain 1·36 ± 0·12% dying cells and 6·78 ± 0·03% thymidine incorporating cells, whilst old mouse thymus (53 weeks) was found to contain 2·34 ± 0·6% dying cells and 5·29 ± 0·37% thymidine incorporating cells.     

Dynamics of a viscous thread on a non-planar substrate

We derive a general reduced model for the flow of a slender thread of viscous fluid on a grooved substrate. Specific choices of the substrate topography allow further analytic progress to be made, and we subsequently focus on a convection–diffusion equation governing the evolution of viscous liquid in a wedge geometry. The model equation that arises also appears in the context of foam drainage, and we take the opportunity to review and compare the results from both applications. After summarising the constant mass results, we introduce a time-dependent fluid influx at one end of the wedge. The analytical results are supported by numerical computations.     

耐根穿刺TPO防水卷材干铺法施工技术研究

种植屋面技术难点在于屋面结构层与功能层的耐根系穿刺能力,而本文即对耐根穿刺型TPO防水卷材的施工技术作为研究对象,简要介绍了该材料在屋面应用中干铺法施工技术实施的方法,并结合施工质量得出相应的保证措施。     

Condom use by South African construction workers

Consistent and proper condom use is pivotal in preventing HIV infection. HIV prevalence in South Africa is among the highest in the world, with the construction industry especially affected, yet little is known about condom use by construction workers and the determinants thereof. Data were gathered from 512 site-based workers in the Western Cape. A theoretical model explaining condom use as a function of demographic factors, HIV knowledge, substance usage and risky sexual behaviour (excluding condom use) was proposed and tested using regression and structural equations modelling. The findings indicated that age, gender and level of education were indirect determinants of condom use, with higher levels of education predicting better AIDS-related knowledge. Higher levels of risky sexual behaviour were associated with more frequent use of condoms, suggesting greater awareness of risk. Condom use was adversely affected by greater alcohol and drug use, probably as a result of diminished capacity to assess risk. Finally, lower and not higher levels of AIDS-related knowledge were associated with better condom use, suggesting that improved knowledge of HIV transmission may work contrary to safe sex practice if it lulls the person into a false sense of confidence. Recommendations for targeted workplace interventions are proposed.     

简捷水热法制备氟化石墨烯及其表征

氟化石墨烯是一种石墨烯衍生物,在润滑材料、电子器件等领域具有广阔的应用前景。采用回流搅拌并水热还原的方法制备氟化石墨烯,并在不加HF的情况下以同样的方式制备了水热还原的还原氧化石墨烯(rGO)。采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、拉曼光谱(Raman)、X射线光电子能谱(XPS)、透射电镜(TEM)等对样品进行形貌观测和表征。FTIR的结果表明氟化产物中含有C-F键和部分未完全还原的含氧基团;由XRD谱可以看出,产物晶型较差,其层间距和原料的性质有关;Raman谱证实了石墨烯的基本结构依然存在,但也存在大量缺陷,并且rGO比FGS的规整度略高;XPS谱表明样品表面有氟元素的存在,意味着FGS制备成功;TEM结果显示该样品为单层和少层。该方法操作简单、原料廉价易得、工艺要求不高,适用于批量生产氟化石墨烯。     

Electro-synthesis of tungsten carbide containing catalysts in molten salt for efficiently electrolytic hydrogen generation assisted by urea oxidation

Energy-efficient production of hydrogen through urea electrolysis is still challenging due to the lack of satisfactory catalysts for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) in urea containing solution. In this study, Ni–W_xC/C (x = 1,2) composite with high activity for urea electrocatalysis was prepared by direct electro-reduction of affordable feedstock of NiO–CaWO₄–C in molten CaCl₂–NaCl at 873–973 K. The addition of graphite in precursor decreases the particle size of Ni. Introducing W_xC into Ni particles can reduce the overpotential for UOR. As a result, the obtained Ni-W_xC/graphite composite exhibits high current density for urea oxidation, which is about 11-folds and 52-folds higher than that of Ni/graphite and Ni (@1.53 V vs. RHE), respectively. After changing the carbon source from graphite to CNTs, the anodic current density was further increased by 43%, reaching 50.31 mA cm^?2. Moreover, the cathodic catalyst W_xC/CNTs obtained by the same preparation process exhibits high performance towards HER, with a low onset potential of 131.5 mV and a Tafel slope of 69.5 mV dec^?1. Assembling an electrolyzer using Ni-W_xC/CNTs as anode and W_xC/CNTs as cathode can yield a current density of 10 mA cm^?2 at merely 1.65 V in 1 M KOH/0.33 M urea aqueous solution, with excellent long-term electrochemical durability. The environmental-friendly production process uses affordable feedstocks for the synthesis of efficient catalysts toward urea electrolysis, promising an energy-saving hydrogen production as well as waste treatment.