44 research outputs found
A Study on the Structural Reliability of Structual Support of tunnel in Broken Rock Mass
对地下矿山开采而言,保证巷道开挖与支护稳定是矿山安全生产的前提。随着人们对矿山地下巷道矿山压力分布和破坏规律的逐渐掌握,支护设计理论也得到了较大的发展,但由于地下巷道复杂多变的地质条件,围岩多具有多样的物理力学特性,加上岩土参数的变异性都极大地影响着矿山地下巷道的支护设计,特别是随着近年来开采水平的不断深入,以及破碎软弱等复杂多变地质条件下的工程日益增多,使得巷道的支护设计更加困难,以往的按照工程类比和经验等确定性设计方法来分析问题显然存在一定的缺陷。结构可靠度设计方法正是针对这些不确定因素而发展起来的,这种设计方法已经在建筑、铁路、公路中得到了较为广泛的应用,但在巷道支护中的应用相对较少,因...It means to the underground mine that the stability to the excavation and support of the roadway is the precondition for the safe production in mine. The Support theory have great developed as people gradually know mine underground roadway of mining pressure distribution and damage laws. But geotechnical engineering was natural material,it have multiform physics and mechanics character,the design ...学位:工学硕士院系专业:建筑与土木工程学院土木工程系_岩土工程学号:2242008115151
近地表上覆岩层直壁塌陷机理及稳定性分析
介绍了川口钨矿塌陷区岩层的地质条件、岩石的力学性质和工程地质调查与评价的结果;通过井下和地表现场调查和勘察测定,给出了井下采空区的边界范围和地表塌陷范围的对照图,分析了上覆岩层的塌陷特点,确定了采空区上覆岩层呈现典型的筒状直壁塌陷。根据采空区围岩和上覆岩层的节理裂隙发育程度不同,采用太沙基地压理论解释了采空区周边围岩和上覆岩层的力学作用机理和破坏特点,对太沙基理论进行了改进,并给出了力学分析图、推导了地压计算公式;进而采用极限破坏理论对不同开采跨度时上覆岩层的稳定性进行了分析和计算,并给出了在保证不产生筒形塌陷条件下、不同覆盖层厚度时的安全开采跨度和安全系数之间的量化关系
三门峡铝矿巷道支护机理分析及工程实践
根据三门峡铝矿岩层特点及工程概况,研究复杂地质条件下巷道围岩特性,结合现场勘察试验情况,得出围岩的破坏成因,并阐述围岩支护结构的作用机理,借鉴国内外相关的支护经验,给出有针对性的支护方案,详细阐明支护方案的施工要点及其工艺过程,从而达到全面合理的评价效果
Corrosion environment evaluation and durability design requirements of coastal concrete bridge
依据JTg/T b07—01—2006《公路工程混凝土结构防腐技术规范》和gb/T 50476—2008《混凝土结构耐久性设计规范》,结合海南一个沿海混凝土大桥的具体环境条件和工程结构情况,对大桥所处腐蚀环境评价中环境分区、环境作用分级以及耐久性设计要求等问题进行了研究。大桥的环境作用分为一般环境、土中环境、海洋环境和滨海环境四个区域。一般环境处于海南东北部沿海腐蚀偏高范围,腐蚀性较高,分级提高加以考虑。土中环境主要由于砖红壤地质腐蚀加重的影响,在工程详细勘探和耐久性设计时给于关注。海洋环境由于海南炎热地区水温高、盐度高会加重腐蚀,耐久性设计中给于考虑。滨海环境主要考虑海洋大气影响范围扩大、影响程度增高、海水入侵和盐渍化影响会不断扩大范围和程度等,对滨海大气和滨海土壤环境的耐久性加以重视。在大桥的设计、施工的不同阶段贯彻和实施规范的技术措施是保证耐久性的关键,对特殊形式和部位的构件和结构耐久性要给于专门措施。According to JTG/T B07—01—2006"Specification for deterioration prevention of highway concrete structures"and GB/T 50476—2008"Code for durability design of concrete structures",The corrosion environmental classification,environmental action grade and durability design requirements of a coastal concrete bridge in Hainan province are researched combining the bridge environment condition and engineering structure.The environment condition of the bridge is divided into four districts:the general environment,soil environment,ocean environment and coastal environment.The general environment is placed in northeast coast of Hainan and belongs to higher corrosion scope.The corrosion is higher so the grade is exalted.The influence in soil environment mainly is the Latosols geology corrosion.at the detailed investigation and design this must pay attention.because of in the south blazing hot region,the water temperature is high and the salt degree is high so the ocean environment will aggravate corrosion,the durability design must considered.The coastal environment mainly considers the ocean atmosphere spread,increasing corrosion degree,the sea water invading and salinization.The durability of the coastal atmosphere and coastal soil environment should be attached importance to.At the different stage of bridge design and construction the specialized technique measure is the key that promises durability.The special form and the part of bridge must carry out the specialized measure
Ethical Reflection on Standardized Management of Intestinal Microbiota Transplantation
肠道微生态系统是人体健康所必需的重要且复杂的生物系统。肠道微生态系统的紊乱参与人体多种疾病的发生发展过程。而肠菌移植技术可有效调节肠道菌群,修复失衡的肠道微生态,为当今多种胃肠道及胃肠以外疾病的治疗带来新的突破。然而,目前尚缺乏完整的、系统性的肠菌移植技术管理规范。就肠菌移植技术规范化管理所涉及的内容进行探讨,并从医学伦理学角度思考规范化管理中所涉及的伦理问题,以期推动肠菌移植技术的临床应用。Intestinal microecology is an important and complex biological system necessary for human health. Its disorder is involved in the development of various diseases of human body. The technology of intestinal microbio- ta transplantation can effectively regulate the intestinal flora, repair the imbalance of the intestinal microecology, and bring a new breakthrough for the treatment of many diseases of gastrointestinal tract and outside gastrointestinal tract. However, there is still no systematic and complete management standard for intestinal microbiota transplanta- tion technology. This paper discussed related content involved in standardized management of intestinal microbiota transplantation technology and reflected the ethical problems involved in standardized management from the perspec- tive of medical ethics, in order to promote the clinical application of intestinal microbiota transplantation technology
CLSI EP15-A3在临床生化正确度验证中的应用
目的探讨美国临床和实验室标准化协会(CLSI)EP15-A3文件在正确度验证中的应用价值。方法按照EP15-A3文件5×5实验设计方案,用IFCC提供的Rela A(水平1)和Rela B(水平2)样品、美国国家标准与技术研究院(NIST)909C参考物质分别验证肌酐(Cr)、尿素(Urea)、尿酸(UA)、总胆固醇(TC)、三酰甘油(TG)、葡萄糖(Glu)的正确度。每个样品每天1批,每批重复5次,共5 d,每个样品获得25个数据。用Grubbs’法计算离群值,单因素方差分析(ANOVA)计算用户的批内不精密度(SR)和实验室内不精密度(SWL),基于SR和SWL计算结果的均值及其标准差,计算靶值(TV)及其标准误差,最后计算出TV的确认区间(VI),观察各指标检测均值是否在VI内,如通过则用户证明了候选方法的偏差可接受;若不通过则计算均值和TV的相对偏差,观察该相对偏差是否小于用户定义的可接受范围(<1/2 TEa),若是则证明候选方法的偏差可接受。否则,需查找原因或与厂家联系。结果6个生化项目的测定结果均通过Grubbs’法离群值检查,各项目无离群值。该次验证实验中,除NIST 909C参考物质样品Urea、TC,Rela样品Cr水平2均值不在VI内,但相对偏差均小于1/2 TEa外,其他均值都在VI内。结论用EP15-A3文件进行验证的6个生化项目的正确度均符合临床要求。国家自然科学基金(81572088);;“十二五”国家科技支撑计划(2013BAI02B04,2012BAI37B01);;广东省中医院拔尖人才项目(2014-47);广东省中医院综合标准化示范项目(YN2015BZ10
Concentrations and distribution of polycyclic aromatic hydrocarbons and organo chlorides in surface sediment of Xiamen Western Harbour and Minjiang Estuary
参考美国EPA标准方法对厦门西港和闽江口的表层沉积物样品中持续性有机污染物PAHs、PCBs、和DDTs的含量及分布进行分析和考察 ,并对若干污染特征及成因进行探讨 .结果表明 ,厦门西港沉积物样品中总PAHs含量 (ng/ g(干重 ) )较闽江口海域为高 ,其中厦门样品测值范围是 42 5 3 - 15 2 2 4,大多高于 10 0 0 ,推断主要来源于石油类污染 ;闽江口为 316 8-12 6 0 7,大多低于 10 0 0 ,化石燃料燃烧可能是其主要来源 .PCBs和DDT的分析结果表明 ,PCBs并非两海域的主要污染物 ,其含量 (ng/ g(干重 ) )测值范围是厦门西港 9 72— 33 72 ,闽江口 8 71— 30 5 5 ;DDT类含量测值 (ng/g(干重 ) )厦门西港高于闽江口 ,范围分别为 8 6 1— 73 70和 6 17— 30 70 (河口高值站位为 6 3 88) ,空间分布呈近岸高于远岸趋势 .同时表明 ,在厦门海域表层沉积物中DDD是主要降解产物 ,而在闽江口DDE为主要降解产物The U.S.EPA analytical methods were employed to examine surface sediment concentrations of polycyclic aromatic hydrocarbons (PAHs) and organo chlorides (PCBs and DDTs) in Xiamen Western Harbour (XM),in June,1999,and Min River Estuary (MJ) in Oct., 1996.The spatial distribution and main possible sources of these pollutants were discussed.The ranges of PAHs concentration (ng/g(DW)) are 425-1520,with most values higher than 1000 in XM samples,and 315-1260,with most values lower than 1000 in MJ samples respectively.The main possible sources of sediment PAHs were identified as petroleum pollutants for Xiamen Western Harbour,and fossil fuel combustion products by river input for Minjiang Estuary,respectively.Sediment PCBs were found not the main pollutants in the study areas,with concentrations(ng/g(DW))ranging from 9.72 to 33.72,and from 8.71 to 30.55,in XM samples and MJ samples,respectively.Concentrations (ng/g(DW)) of sediment DDT and its degraded compounds show the trend of decreasing off the shore,while ranging from 20 to 70,and 6 to 30,in XM samples and MJ samples,respectively.Meaningful information also displays that the main degradation products are DDD in XM samples and DDE in MJ samples.As for the general results,the disadvantage of hydrodynamics,industrial and municipal wastewater discharge,and harbour activities are inferred as the main aspects of the factors affecting pollution in Xiamen Western Harbour,comparing with those in Minjiang Estuary,which is significantly affected by Minjiang River input.Measures for pollution prevention thus should be taken differently in the two areas
Removal of Iron During Copper Sulfate Production from Bioleaching Reextraction Solution
[中文文摘]利用三种方法分别对某铜矿山生物浸铜反萃液生产饲料级五水硫酸铜的重要步骤———除铁工艺进行了深入研究,结果表明:采用黄铵铁矾法除铁,控制温度在95℃、pH=1 6,除铁率可以达到91 2%;采用氢氧化铁沉淀法,于70℃,pH=3 8的条件下,除铁率可达98 1%。但上述方法除+、Na+和Ca2+等杂质带入硫酸铜溶液;采用一步结晶法,控制结晶温度在60℃、结铁过程会将NH4晶时间为6h,除铁率可以达98 5%,该工艺操作简单,产品符合饲料级硫酸铜的国家标准。[英文文摘]Iron removal is crucial to the process of feed-additive copper sulfate pentahydrate production from bioleaching reextraction solution.In this paper,three iron removal methods were examined.A series of experiments were conducted in different conditions and the results indicated that when iron was removed by precipitating in the form of ammonium jarosite(95 ℃,pH=1.6),the iron removal efficiency was 91.2%,while by precipitating in the form of ferric hydroxide(70 ℃,pH=3.8),the iron removal efficiency was 98.1% However ,by these two methods ,the use of oxidant and neutralization reagents introduced unwanted
NH+4 ,Na + ,Ca2 + into copper sulfate solution. Crystallizating copper sulfate from reextraction solution ,a simple
process ,could remove iron effectively without adding any additives and the iron removal efficiency could reach 98.5% under the condition of 60 ℃and 6 h ,and the quality of copper sulfate met national standards of feed additive.福建紫金矿业股份有限公司资助项
广州戊型病毒性肝炎暴发株和散发株部分序列比较
目的了解广州某部新兵连戊型病毒性肝炎(戊型肝炎)暴发流行的分子病毒学特征,并与当地散发毒株比较,以查找病原可能来源。方法用逆转录聚合酶链反应(RT-PCR)法,对抗HEV-IgM阳性的34例暴发性戊型肝炎及46例散发性戊型肝炎患者的血清和粪便标本进行HEVRNA检测,并对HEVRNA阳性标本的基因开放读码框(ORF)2部分片段进行克隆测序分析。结果34例暴发流行病例标本中检测出12株病毒,46例散发病例标本中检到2株。经克隆测序分析,各暴发毒株的核苷酸同源性为95.3%~100%;氨基酸同源性为94.0%~100%。且暴发毒株和散发毒株的核苷酸及氨基酸的同源性也较高,分别为95.3%~99.3%和94.0%~100%;暴发毒株和散发毒株与各型中的标准株相比,与Jap1株同源性最高,其核苷酸同源性为92.0%~95.3%,氨基酸同源性为96.0%~100.0%。进化树分析提示本次戊型肝炎暴发流行病毒株与戊型肝炎病毒基因Ⅳ型距离最近。结论本次戊型肝炎暴发流行的病原可能来于广州本地;广州地区戊型肝炎流行毒株属戊型肝炎基因型Ⅳ型
Video-assisted Thoracoscopic 3D Mode Operation for Solitary Pulmonary Nodules
目的探讨三维胸腔镜手术(3d VIdEO-ASSISTEd THOrACIC SurgEry,3d-VATS治疗孤立性肺结节(SOlITAry PulMOnAry nOdulE,SPn)的效果。方法回顾性分析2013年3月~2014年3月50例SPn的资料,采用3d-VATS手术模式楔形切除结节,根据快速病理结果决定是否行肺叶切除加淋巴结清扫术。统计手术时间(去除快速冰冻时间)、术后24 H引流量、总引流量、引流管拔除时间、淋巴结清扫数及术后并发症等。结果 3d-VATS模式下,50例均行肺结节楔形切除,其中23例病理为恶性,继续行肺癌根治术,手术顺利。肺癌根治术手术时间(62±12)MIn,术中出血量(35±5)Ml,清扫淋巴结(19±3)个,术后24 H引流量(120±20)Ml,术后胸管引流时间(4±1)d,术后住院时间(7±2)d。并发症3例,其中术后肺炎2例,阵发性心房纤颤1例,均治愈。无围手术期死亡。随访2~12个月,平均6.3月。1例术后3个月脑转移,1例术后5个月肺癌复发。结论胸腔镜3d模式下治疗SPn是一种新的选择方式,安全可行,值得推广应用。Objective To evaluate the effects of surgical treatment for solitary pulmonary nodules under thoracoscopic 3D mode(3D-VATS).Methods A total of 50 cases of solitary pulmonary nodules from March 2013 to March 2014 were retrospectively analyzed.Intraoperative wedge pulmonary resection with 3D-VATS was utilized.According to intraoperative pathological findings,lobectomy plus lymph node dissection was given or not.Intraoperative time( minus fast freezing time),drainage volume for 24 h,total drainage volume,drainage tube removal time,number of lymph node dissected,and postoperative complications were recorded.Results Under 3D-VATS mode,50 cases of solitary pulmonary nodules were treated with wedge resection,including 23 cases of malignant pathology receiving radical resection, which was smoothly.The radical resection time( lung lobectomy plus lymphadenectomy) was(62 ± 12) min,the bleeding volume was(35 ± 5) ml,the lymphadenectomy number was 19 ± 3,the drainage volume for 24 h was(120 ± 20) ml,the postoperative chest tube removal time was(4 ± 1) days,and the postoperative hospital stay was(7 ± 2) days.Postoperative complications occurred in 3 cases,including 2 cases of pneumonia and 1 case of paroxysmal atrial fibrillation.No perioperative deaths were observed.All the cases were followed up for 2- 12 months,with an average of 6.3 months.Brain metastases was found in 1 case at the third postoperative month and recurrence of lung cancer was noted in 1 case at the fifth postoperative month.Conclusion Thoracoscopic 3D mode treatment for solitary pulmonary nodules is a new,safe,and feasible alternative and should be widely applied