一起110kV高压交流电缆外护套烧损故障原因分析

高压单芯交流电缆在城市输电网中得到越来越广泛的应用,但当其接地系统发生异常时会产生不同程度的悬浮电位。在分析一起电缆外护套烧损故障的基础上,对电缆线路的悬浮电位情况进行了讨论研究。铝护套接地异常后产生的悬浮电位,与电缆石墨(半导电)层的接地状态有关。当直接接地断开且石墨层未有效接地时,电缆石墨层悬浮电压可能会达到相电压的90%以上。高悬浮电压必然会导致石墨层对地绝缘薄弱处高频充放电,并不断烧蚀外护套,引发火灾等严重后果。

烟煤锅炉两种方式掺烧褐煤的工程应用

从掺烧褐煤对制粉系统、燃烧过程以及排烟温度3个方面的影响对比分析了炉外掺烧方式与炉内掺烧方式的差异,并采用现场对比试验的实测结果,对分析结论进行了验证。从中得出主要结论:(1)炉内掺烧方式在制粉系统安全性、预防炉内结渣以及降低制粉系统电耗等方面优于炉外掺烧方式;(2)对于某具体褐煤,主煤的含水质量分数存在一个临界值。当主煤含水质量分数大于该临界值时,炉内掺烧方式下的锅炉排烟温度低于炉外掺烧方式,其经济性优于后者;(3)对于大多数烟煤锅炉,其主煤实际含水质量分数通常大于或接近其临界水分值,炉内掺烧方式的运行经济性优于炉外掺烧方式。因此,在条件许可的情况下,电厂应尽可能地采用炉内掺烧方式掺烧褐煤,在褐煤含水质量分数小于35%,主煤含水质量分数大于10%时尤应如此。

蓄热式燃烧技术在中板厂加热炉的应用

论述了国内首座三排布料的步进梁式板坯加热炉的设计要点以及性能指标和经济效益分析。重点阐述了蓄热式燃烧技术和外拉式蓄热烧嘴的合理应用,并提出了保证产量及提高加热质量并实现复杂的过程控制的技术策略。实践证明,蓄热式燃烧技术在板坯加热炉的应用合理有效,实现了高效、优质、节能、降耗等目的。

步进式加热炉燃烧系统及余热回收系统的改造

根据对步进式加热炉的两次改造 ,具体介绍了改造中的技术内容 ,及改造后各系统的实际参数 ,并在对改造中存在的问题提出建议。

电暖气火灾事故原因的认定和分析

本文通过对一起由于电暖气内热引发火灾的调查,分析了此类电暖气的火灾危险性,探讨根据电暖气留下的的相应痕迹判定火灾原因进行鉴定的方法,可为从事火灾调查人员勘查此类火灾现场和认定火灾原因提供参考。

洪月前后看绍兴

洪水即尧说的洪水期，是大禹治水的历史背景。绍兴是现在的绍兴，名出南宋。那为什么不用古称呢？其一，绍兴和会稽、古越，所指同一个地域，故可通，故可通。其二，文章所论为洪水期间的会稽，但为了“通古今之变”，把洪水期间的会稽放到历史发展的长河中来考察，使之与今天及未来相通，所以使用绍兴这一现代名称。文章内容分三部分。第一部分介绍了国外人类学家的最新研究成果，即证明了人类进化史上有过一个“水生”的阶段。漫长的旧石器时代是“敲贝而食”的时代。由此推断，世界四大古代文明都发源于大河流域的滨海之地，中国也不例外，华夏文明不可能发源于西北内陆高原，而发源于东海之滨的会稽山下，即以现在的绍兴为中心的北到山东半岛南到台湾海峡的滨海之地。文章第二部分标题为“中华各民族同根共祖”。这里阐述了人类祖先们学会火的使用后，由“敲贝而食”过渡到“煮贝而食”的阶段。但在陶器产生之前，胡芦器皿成为主要的社会生活用器。河姆渡出土的7000多年前的园种葫芦籽，证明会稽山下的先民在更早的时候已在利用野生葫芦生活用器了。这为过去有人提出的“中国最早的图腾为葫芦崇拜”的观点提供了有力证据：作为中华各族的“人祖”的做羲、女娲，实为葫芦之转音；以及现在尚有三十多个民族还保留着葫芦崇拜的传说和民俗，可以推断，中华各民族其实出于一源，都是长期使用葫芦器皿的以葫芦为原始图腾的会稽山下“九黎”、“三苗”之后裔。文章第三部分标题为“三次大海侵与民族大迁移”。大体说来，伴随10万年前的第一次民族大迁移的是“盘古开天地”的故事，现在的绍兴会稽山，最初称茅山，在那期间就变成了苗山；当时的先民部落由九黎而成三苗。伴随4万多年前的第二次民族大迁移的是“女娲补天”的故事。这时先期内迁的先民已分化成为戎、狄、氐、羌及散居西南的三苗、百越等。这样，随第二次大迁移而来的先民与这众多内地民族之间，既有各种形式的联合、融合等等，也有剧烈的矛盾冲突。所以留了炎黄大战，黄帝战尤等历史故事。发生在4－5千年前的第三次民族大迁移与前二次又有很大的不同，这时已有陶器的发展和原始农业。这些掌握了先进技术的移民在原找到了他们的生存发展空间，成为新兴的农业民族。伴随这段历史的是大禹治水的故事。而大禹治水也由过去的消极的抵抗水患，转变为以兴修水利为主。大禹治水到会稽，毕功于了溪，并在这里大会诸侯，会稽治国之道，标志着远古时代的结束和华夏文明的形成。从此苗山改名为会稽山，历史从这里翻开新的一页。

THE DEVELOPMENT OF BURN SURGERYIN CHINA —A RETROSPECTIVE OVERVIEW

Sheng Zhiyong Burns Institute, 304th Hospital, Beijing 100037

基于蓄热式加热炉升级改造的若干问题与对策研究

本文介绍了宝武鄂城钢铁轧材厂棒二车间蓄热式加热炉存在的诸多问题及隐患,分析了问题的原因,并进行全面升级改造,从多方面采取了升级改造措施,实现了加热炉的设备本体安全稳定和燃烧系统智能化,有效提高了加热能力,改善了职工操作方法,降低了NOx的排放,节能降耗效果显著。

Effect of Dermabrasion and ReCell on Large Superficial Facial Scars Caused by Burn, Trauma and Acnes

Objective To explore the effects of dermabrasion combined with ReCell on large superficial facial scars caused by burn, trauma and acnes. Methods Nineteen patients with large superficial facial scars were treated by the same surgeon with dermabrasion combined with ReCell？. According to the etiology, patients were classified into post-burning group （n=5）, post-traumatic group （n=7） and post-acne group （n=7）. Fifteen patients completed the follow-ups, 5 patients in each group. Healing time, complication rate, the preoperative and 18-month-post-operative assessments using Patient Satisfaction Score （PSS）, Vancouver Scar Scale （VSS）, and Patient and Observer Scar Assessment Scale （POSAS） of each group were analyzed to compare the effect of the combined therapy on outcomes.Results The healing time of post-burning group （19.6±4.0 days）, post-traumatic group （15.8±2.6 days）, and post-acne group （11.4±3.1 days） varied remarkably （F=7.701, P=0.007）. The complication rates were 60%, 20%, and 0 respectively. The post-operative POSAS improved significantly in all groups （P〈0.05）, where the most significant improvement was shown in the post-acne group （P〈0.05）. The post-operative PSS and VSS improved only in the post-traumatic group and post-acne group （all P〈0.05）, where the more significant improvement was also shown in the post-acne group （P〈0.05）. Conclusions The combined treatment of dermabrasion and ReCell has remarkable effect on acne scars, moderate effect on traumatic scars and is not suggested for burn scars. POSAS should be applied to assess the therapeutic effects of treatments for large irregular scars.

ND_5型机车冷却风扇装置外环烧损的原因分析及处理

对ND5型机车GDY - 72型冷却风扇装置电磁涡流离合器的作用原理进行了简要阐述 ,并对冷却风扇装置外环烧损的原因进行了分析 。

Effect of Gasoline Property on Formation of Intake Valve and Combustion Chamber Deposits

The cleanliness of gasoline is related to its components and properties.All commercial gasoline builds up deposits on the engine's injector,intake valve and combustion chamber,which can significantly lower the engine performance and influence exhaust gas emissions.In this study,the intake valve deposits (IVD) and combustion chamber deposits (CCD) produced from combustion of fuel containing 21 v%—42 v% of aromatics and 8 v%—31 v% of olefins have been studied using Ford engine tests,and the characteristics of deposits were studied by IR spectroscopy,TGA and elemental analysis instrument.The test results have shown that deposit formation depends on the fuel composition,especially the aromatic content in the fuel.It is also observed that there are differences in the values of IVD and CCD measured by IR spectrometry and elemental analyses.

Desulfurization of Petroleum Coke by Calcination in Ammonia Atmosphere below 1000℃

The desulfurization efficiency and mechanism of the calcination of petroleum coke in ammonia atmosphere at lower than 1000 ℃ were investigated through a series of conditional experiments and comparison with other gases such as H_2. The topics of efficiency and reaction mechanism are usually discussed through investigation by means of the Fourier transform infrared spectroscopy(FT-IR), the Brunauer-Emmett-Teller(BET) technique, and the thermogravimetry coupled with the mass spectrometry(TG-MS). Results showed that in addition to H_2, ammonia not only could retain a high desulfurization rate but could also reduce coke loss during the desulfurization process of petroleum coke. The best desulfurization conditions covered a petroleum coke particle size of less than 0.1 mm, a calcination temperature of 800 ℃ in ammonia atmosphere with a flow rate of 10 L/h, and a heating duration of more than 120 min. Ammonia decomposition, H_2 generation, decline in the activation energy of the carbon–sulfur bonds, and petroleum coke with a largest specific surface area at 800 ℃ are the key goals of desulfurization studied thereby. As proved by TG-MS analysis, given a large quantity of H_2, ammonia can be decomposed at the same temperature to completely come into contact with the sulfur species in petroleum coke to generate H_2S.

Infrared emissivity of transition elements doped ZnO

Infrared emissivity was studied in Zno.99Mo.olO （M is Mn, Fe or Ni） and Znl_xCoxO （x=0.01, 0.02, 0.03 and 0.04） powders synthesized by solid-state reaction at various temperatures. XRD patterns confirm the wurtzite structure of the prepared samples. No peaks of other phases arising from impurities are detected in Mn- and Co-doped ZnO, hut the peaks of ZnFe204 and NiO are observed in Zno.99Feo.010 and Zno.99Nio.o10. The SEM observations indicate that with larger grain sizes than those of Zn0.99Feo.010 and Zno.99Ni0.010, Co-doped ZnO exhibits smooth grain surfaces. The infrared absorption spectra show that infrared absorptions related to oxygen in Zn0.99M0.010 are much stronger than those in Co-doped ZnO. Co ions are dissolved into the ZnO lattice with Co2＋ state from XPS spectra analysis. The infrared emissivity results imply that the emissivity of Zno.99Ni0.010 is the highest （0.829） and that of Zno.99C00.010 is the lowest （0.784） at 1 200 ℃. The emissivity of Zno.99Co0.010 decreases to the minimum （0.752） at 1 150 ℃ and then increases with growing calcination temperature. As the Co doping content grows, the emissivity of Co-doped ZnO calcined at 1 200 ℃ falls to 0.758 in the molar fraction of 3% and then ascends.

Tuning SnO_2 surface with CuO for soot particulate combustion: The effect of monolayer dispersion capacity on reaction performance

With the objective to investigate the structure-reactivity relationship of CuO/SnO2 and eventually design more applicable catalysts for soot combustion,catalysts with different CuO loadings have been prepared by impregnation method.By using X-ray diffraction and X-ray photoelectron spectroscopy extrapolation methods,it is disclosed that CuO disperses finely on the SnO2 support to form a monolayer with a capacity of 2.09 mmol 100 m^-2,which equals 4.8 wt%CuO loading.When the CuO loading is below the capacity,it is in a sub-monolayer state.However,when the loading is above the capacity,CuO micro-crystallites will be formed that coexist with the CuO monolayer.The soot combustion activity of the catalyst increases with the CuO loading until it reaches the monolayer dispersion capacity.A further increase in the CuO loading has no evident influence on the activity.Raman results have testified that with the addition of CuO onto the SnO2 support,a surface-active oxygen species can be formed,the amount of which also increases significantly with the increase in the CuO loading until it reaches the monolayer dispersion capacity.Increasing the CuO loading further has no evident impact on the amount of surface oxygen.Therefore,an apparent monolayer dispersion threshold effect is observed for soot combustion over CuO/SnO2 catalysts.It is concluded that the amount of surface-active oxygen sites is the major factor determining the activity of the catalyst.

Evaluation on Combustion Characteristics of Finishing Materials for Exterior Walls

Existing fire test methods reply on measurement of the energy released rate to identify the combustion properties of a material. However, they are inadequate when assessing combustion characteristics of a composite material characterized by vertical flame spread and different inside/outside combustion behaviors. In addition, major factors that affect the flame spread outside the building include the combustion characteristics of materials used as well as air flow around a skyscraper. However, since it is highly difficult to analyze and forecast the air flow from a fire engineering viewpoint, an investigation of the flame spread characteristics of exterior walls of a building depends primarily on the combustion characteristics of materials. Hence, this study examined, using ISO 13785-2 testing method, the temperature changes and vertical flame spread behaviors of one of the finishing materials for exterior walls--（generic ＆ fire-resistant） aluminium panels by a real-scale combustion experiment. According to the results of real-scale experiment, the maximum heat temperature of 987.7 ℃ was recorded seven minutes after the fire test was initiated while the fire-resistant aluminium panels showed the maximum heat temperature of 850.2℃ after exposed for approximately 12 min. The vertical flame spread properties put more emphasis on the time required to reach the maximum temperature rather than its magnitude and there was a five minutes difference between the materials.

Heat Transfer Model with Two Heat Transfer Coefficients Along a M ultiperforated Plate-Application to Combustion Chamber Wall Cooling

Walls' cooling of aeronautic propeller combustion chamber is performed with the injection, through the combustion chamber wall, of a part of the air coming from compressors placed upstream. Measurements of the wall thermal fields are made by infrared thermography along the injection wall. This injection wall is pierced by 9 rows of 8 holes (α=90°) in staggered configuration (p/D=s/D=6). We propose a model using two heat transfer coefficients to represent the convective exchanges. The results are non-dimensioned and presented in comparison with the case without holes. The use of this model allows us to define 4 zones. Those 4 zones exist for the 5 blowing rates.

Changes of pulmonary intercellular adhesion molecule-1 and CD11b/CD18 in peripheral polymorphonuclear neutrophils and their significance at the early stage of burns

Objective: To investigate the role of intercellular adhesion molecule 1 (ICAM 1) in the accumulation of polymorphonuclear neutrophils (PMN) in the lungs at the early stage of burns. Methods: Myeloperoxidase content in lung tissues and bronchoalveolar lavage fluid (BALF) were detected. ICAM 1 and its mRNA expression in lung tissues were determined by immunohistochemical method and in situ hybridization. CD11b/CD18 expression on the peripheral PMNs was measured by flowcytometry. Results: The levels of myeloperoxidase in lung tissues and BALF after burn injury were markedly higher than those of control. Expression of ICAM 1 and its mRNA in the lung tissues and CD11b/CD18 on peripheral PMNs surface was significantly increased at 2, 6, 12, 24 h after burns. Conclusions: PMNs accumulation in the lungs is related to increased ICAM 1 expression on pulmonary microvascular endothelial cells and CD11b/CD18 expression on PMN at the early stage of burn injury.