检索结果-南通市图书馆

Mechanism investigation on coal and gas outburst: An overview

International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 872-887页

作者： Yan-kun Ma bai-sheng nie Xue-qiu He Xiang-chun Li Jun-qing Meng Da-zhao Song State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology(Beijing)Beijing 100083China Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources China University of Mining and Technology(Beijing)Beijing 100083China Xinjiang Institute of Engineering Urumqi 830023China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 10083China

Coal and gas outburst is a frequent dynamic disaster during underground coal mining *** about 150 years of exploration,the mechanisms of outbursts remain unclear to *** on outburst mechanisms worldwide focused on the physicochemical and mechanical properties of outburst-prone coal,laboratory-scale outburst experiments and numerical modeling,mine-site investigations,and doctrines of outburst *** mechanisms are divided into two categories:single-factor and multi-factor *** multi-factor mechanism is widely accepted,but all statistical phenomena during a single outburst cannot be explained using present *** topics about outburst mechanisms are proposed by summarizing the phenomena that need precise *** most appealing research is the microscopic process of the interaction between coal and *** physical-chemical methods can help characterize the natural properties of outburst-prone *** experiments can compensate for the deficiency of first-hand observation at the *** the original outburst scene by constructing a geomechanical model or numerical model and reproducing the entire outburst process based on mining environment conditions,including stratigraphic distribution,gas occurrence,and geological structure,are *** studies can explore outburst mechanisms at the microscale.

关键词： coal and gas outburst outburst mechanism outburst model outburst simulation microscopic pore structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Engineering N3C vacancies in hierarchical porous carbon nitride nanosheets for room temperature ultradeep photocatalytic aerobic oxidative desulfurization

引用

Science China Chemistry 2025年

作者： Yina nie Weijie Yang Xin Wang Xiang Li Lele Wei Xiaolin bai Lin Liu Feng Fu Jun Wan College of Chemistry & Chemical Engineering Research Institute of Comprehensive Energy Industrial Technology Shaanxi Key Laboratory of Chemical Reaction Engineering Yan'an University Anhui Engineering Research Center of Carbon Neutrality College of Chemistry and Materials Science Anhui Normal University

The production of ultra-low sulfur clean fuels holds global significance for improving energy efficiency and reducing environmental pollution. Photocatalytic aerobic oxidative desulfurization（PODS） offers an attractive approach to efficiently remove refractory heterocyclic aromatic sulfur compounds under mild conditions. However, the sluggish charge dynamics,insufficient molecule activation, and slow mass transfer within photocatalysts restrict the overall desulfurization efficiency,hindering the widespread application of this technology. Herein, we developed a defective g-C3N4（M1U3CN） photocatalyst with bridged N3Cvacancies and hierarchical porous structures to address these limitations. This catalyst not only demonstrates outstanding dibenzothiophene（DBT） removal efficiency of 99.6% for model oil with high conversion and selectivity but also achieves complete sulfur removal from gasoline as well as 96.7% sulfur removal for distilled diesel at room temperature,successfully achieving ultradeep aerobic oxidative desulfurization. The introduction of rich N3Cvacancies and abundant micromeso-macroporous distribution in M1U3CN enhances kinetic efficiencies by promoting charge carrier separation, mass transfer,and molecular activation simultaneously; resulting in exceptional PODS performance. This work provides a collaborative strategy to overcome kinetic challenges in aerobic oxidative desulfurization via defect and structural engineering of the catalyst.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于碎屑锆石及水文观测的黄河多沙粗沙区重要支流来沙变化分析

引用

工程科学与技术 2025年第1期57卷 37-47页

作者：白婷范念念王远见聂锐华刘兴年四川大学山区河流保护与治理全国重点实验室四川成都610065 黄河水利科学研究院河南郑州450099

巨大的来沙量是造成黄河水沙灾害的重要原因。近年来,黄河及其主要支流实测输沙量明显减少,但产沙输沙的多时空尺度特征仍不明确。以多沙粗沙区的重要支流皇甫川和窟野河为例,利用现代水文资料和碎屑锆石物源结合的方法,分析产沙输沙变... 详细信息

巨大的来沙量是造成黄河水沙灾害的重要原因。近年来,黄河及其主要支流实测输沙量明显减少,但产沙输沙的多时空尺度特征仍不明确。以多沙粗沙区的重要支流皇甫川和窟野河为例,利用现代水文资料和碎屑锆石物源结合的方法,分析产沙输沙变化的多时空属性特征。通过统计检验方法对实测水文资料进行分析,发现年径流量和年输沙量均呈显著的减小趋势,其中:皇甫川径流、输沙序列的突变点发生在1978年和1998年,且均发生明显减小;窟野河径流的突变点发生在1979年、1997年和2011年,前两个突变点明显减小,最后一个突变点明显增加,而输沙的突变点发生在1979年和1997年,均明显减小。对皇甫川和窟野河现代河流沉积物(2020年)和几千年前的河流阶地沉积物分别进行了碎屑锆石测试分析,得出两条河流的泥沙主要由黄土和基岩组成,而现代河流泥沙中黄土的贡献率比阶地更大。造成这种输沙量急剧减小、黄土比例增加现象的原因是人类扰动加速了黄土侵蚀,但流域地表水和地下水资源的开采及水土保持措施减少了水量,使得泥沙的输移比减小,大量从坡面上侵蚀的黄土沉积在沟道之中,没有被输送到流域的出口,为极端天气下的来沙提供了物源。本文采用现代尺度的水文观测资料分析与地质沉积学的方法,结合不同尺度的方法,对黄河多沙粗沙区重要支流的来沙变化进行分析,可为调控治理黄河水沙灾害的相关研究提供一定的思路。

关键词：黄河径流量输沙量碎屑锆石物源

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

电子工业挥发性有机物排放及健康风险评价

引用

中国环境科学 2025年第2期45卷 1074-1087页

作者：吕喆李国昊白画画刘晓宇邵霞聂磊北京市生态环境保护科学研究院国家城市环境污染控制工程技术研究中心城市大气挥发性有机物污染防治技术与应用北京市重点实验室北京100037

为研究电子工业挥发性有机物(VOCs)排放特征及其健康风险影响,选取10家典型的电子企业,对其生产过程中产生的工艺废气进行样品采集和VOCs检测,并通过美国EPA和ACGIH方法评估其对人体健康的影响.结果表明:不同电子企业排气筒VOCs排放存... 详细信息

为研究电子工业挥发性有机物(VOCs)排放特征及其健康风险影响,选取10家典型的电子企业,对其生产过程中产生的工艺废气进行样品采集和VOCs检测,并通过美国EPA和ACGIH方法评估其对人体健康的影响.结果表明:不同电子企业排气筒VOCs排放存在差异,半导体器件与电子终端产品行业VOCs浓度相对高于显示器及光电子器件与印制电路板行业,其VOCs浓度分别为13.41~13.63,3.34~86.11,7.86~9.75和4.31~4.67mg/m^(3);半导体器件排气筒废气中VOCs以烷烃为主(70.56%~70.78%),质量分数最高的VOCs物种为二甲基戊烷(32.03%~33.60%);显示器及光电子器件和印制电路板企业排气筒废气中VOCs均以OVOCs为主,质量分数分别为(93.48%~95.87%)和(92.27%~93.05%),且质量分数最高的分别为丙酮(91.89%~94.99%)和异丙醇(80.36%~83.07%);电子终端产品行业由于生产产品不同,导致排气筒废气中VOCs组分存在差异,但以OVOCs、芳香烃和烷烃为主;不同企业间分歧系数为0.67~0.91,即VOCs源成分谱必不相似;半导体器件的非致癌风险HR最高(484.35),其次为显示器及光电子器件(447.46)、电子终端产品(11.74~87.35)和印制电路板(2.25),即各电子行业长期暴露均会造成非致癌健康危害;半导体器件(1.63×10^(-3))、电子终端产品(1.64×10^(-4)~5.16×10^(-3))行业LCR值较高,会产生确定的致癌风险;显示器及光电子器件、印制电路板行业LCR值分别为1.74×10^(-5)和1.40×10^(-5),有大概率致癌风险;电子终端产品子行业的总Ei值相对较大,显示器及光电子器件行业的总Ei值最小,但所有电子行业的Ei值均低于0.1,表明电子行业VOCs排放可能不会对工人产生健康影响.EPA和ACGIH方法评估致癌风险的结果差异较大,主要是因为两种方法对VOCs物种暴露参考浓度的限定指标不同.但整体来看,电子终端企业产品及半导体器件行业排放的VOCs健康风险远高于其他两个子行业,因此,应重点加强两个行业VOCs管控以保护工人健康.

关键词：电子工业挥发性有机物(VOCs) 排放特征健康影响

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chaotic characteristics of electromagnetic emission signals during deformation and fracture of coal

引用

Mining Science and Technology 2009年第2期19卷 189-193页

作者： nie bai-sheng HE Xue-qiu LIU Fang-bin ZHU Cheng-wei WANG Ping School of Resource and Safety Engineering China University of Mining ＆ Technology Beijing 100083 China State Key Lab of Coal Resources and Safe Mining China University of Mining ＆ Technology Beijing 100083 China

Electromagnetic emission(EME) is a kind of physical phenomenon accompanying the process of deformation and fracture of loaded coal and rock and it is of importance in quantitatively analyzing its *** will reveal the process of deformation and fracture of coal and predicting dynamic disasters in coal *** this study,the G-P(Grassberger and Procaccia) algorithm,calculation steps of the(if only 1 dimension) correlation dimension of time series and the identification standards of chaotic signals are ***,the correlation dimensions of EME and the acoustic emission(AE) signals of time series during deformation and fracture of coal bodies are calculated and *** results show that the time series of pulses number of EME and the time series of AE count rate are chaotic and that the saturation embedding dimensions of a K3 coal sample are,respectively,5 and *** results can be used to provide basic parameters for predicting of EME and AE time series.

关键词： coal and rock electromagnetic emission correlation dimension chaotic characteristics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Postoperative radiotherapy for thymus salivary gland carcinoma:A case report

引用

World Journal of Clinical Cases 2022年第26期10卷 9484-9492页

作者： Rui Deng Nan-Jing Li Liang-Liang bai Shi-Hong nie Xiao-Wen Sun Yong-sheng Wang Clinical Trial Center National Medical Products Administration Key Laboratory for Clinical Research and Evaluation of Innovative DrugsDepartment of Thoracic OncologyWest China HospitalSichuan UniversityCheng Du 610041Sichuan ProvinceChina Department of Radiation Oncology Cancer CenterWest China HospitalSichuan UniversityCheng Du 610041Sichuan ProvinceChina

BACKGROUND Salivary gland cancer is a rare disease in which cancer cells form in the tissues of the salivary *** mostly occurs in the glands that have secretion functions,such as the parotid gland,sublingual gland and submandibular *** is very rare when it occurs in other nonsecreting ***,we report one case of salivary gland carcinoma occurring in the thymus and discuss related diagnoses and treatment *** SUMMARY One 33-year-old middle-aged man presented with a thymus mass without any clinical symptoms when he underwent regular physical ***,the patient was admitted to the hospital for further *** tomography(CT)showed that there was a mass of 3 cm×2.8 cm×1.5 cm in the thymus *** patient had no symptom of discomfort or tumor-related medical history *** completing the preoperative examinations,it was confirmed that the patient had indications for *** surgeon performed a transthoracoscope"thymectomy+pleural mucostomy"for *** the operation,the tumor tissue was quickly frozen,and the symptomatic section showed a malignant *** final pathological result suggested thymus salivary gland carcinoma-mucoepidermoid carcinoma(MEC).In the second month after surgery,we performed local area radiotherapy for the patient,with a total radiation dose of 50.4 Gy/*** 12 mo of surgery,the patient underwent positron emission tomography-CT examination,which indicated that there was no sign of tumor recurrence or *** 16 mo of operation,CT scan re-examination showed that there was no sign of tumor recurrence or *** of the time of publication,the patient was followed up for one and a half *** had no sign of tumor recurrence and continued to *** The incidence of MEC in the thymus is low,and its diagnosis needs to be combined with clinical features and imaging *** analysis plays a key role in the diagnosis of the *** w

关键词： Thymic tumor Salivary gland carcinoma Mucoepidermoid carcinoma Postoperative Radiotherapy Case report

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

SAMES： deadline-constraint scheduling in MapReduce

引用

Frontiers of Computer Science 2015年第1期9卷 128-141页

作者： Xite WANG Derong SHEN Mei bai Tiezheng nie Yue KOU Ge YU College of Information Science & Engineering Northeastern University Shenyang 110819 China

MapReduce is a popular parallel data-processing system, and task scheduling is one of the kernel techniques in MapReduce. In many applications, users have requirements that their MapReduce jobs should be completed before specific deadlines. Hence, in this paper, a novel scheduling algorithm based on the most effective sequence （SAMES） is proposed for deadline-constraint jobs in MapReduce. First, according to the characteristics of MapReduce, we propose a novel sequence-based execution strategy for MapReduce jobs and a new concept, the effective sequence （ES）. Then, we design some efficient approaches for finding ESes and choose the most effective sequence （MES） for job execution. We also propose methods for MES-updates and exception handling. Finally, we verify the effectiveness of SAMES through experiments. The experimental results show that SAMES is an efficient scheduling algorithm for deadline-constraint jobs in MapReduce.

关键词： MapReduce scheduling deadline

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Life cycle assessment of HFC-134a production by calcium carbide acetylene route in China

引用

Chinese Journal of Chemical Engineering 2022年第2期35卷 236-244页

作者： Suisui Zhang Jingying Li Yan nie Luyao Qiang Boyang bai Zhiwei Peng Xiaoxun Ma School of Chemical Engineering Northwest UniversityXi’an 710069China Chemical Engineering Research Center of the Ministry of Education(MOE)for Advanced Use Technology of Shanbei Energy Xi’an 710069China Shaanxi Research Center of Engineering Technology for Clean Coal Conversion Xi’an 710069China Collaborative Innovation Center for Development of Energy and Chemical Industry in Northern Shaanxi Xi’an 710069China International Scientific and Technological Cooperation Base of the Ministry of Science and Technology(MOST)for Clean Utilization of Hydrocarbon Resources Xi’an 710069China

HFC-134a is a widely used environment-friendly *** present,China is the largest producer of HFC-134a in the *** production of HFC-134a in China mainly adopts the calcium carbide acetylene ***,the production route has high resource and energy consumption and large waste emission,and few of the studies addressed on the environmental performance of its production *** study quantified the environmental performance of HFC-134a production by calcium carbide route via carrying out a life cycle assessment(LCA)using the CML 2001 *** uncertainty analysis by Monte-Carlo simulation was also carried *** results showed that electricity had the most impact on the environment,followed by steam,hydrogen fluoride and chlorine,and the impact of direct CO_(2) emissions in calcium carbide production stage on the global warming effect also could not be ***,the clean energy(e.g.,wind,solar,biomass,and natural gas)was used to replace coal-based electricity and coal-fired steam in this study,showing considerable environmental *** the same time,the use of advanced production technologies could also improve environmental benefits,and the environmental impact of the global warming category could be reduced by 4.1%via using CO_(2) capture and purification *** Chinese database of HFC-134a production established in this study provides convenience for the relevant study of *** the production of HFC-134a,this study helps to better identify the specific environmental hotspots and proposes useful ways to improve the environmental benefits.

关键词： HFC-134a Calcium carbide Life cycle assessment Environmental impact Carbon capture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Methoxy n-fatty acids in surface soils from the Gongga and Kunlun Mountains:Ecological implications

引用

Chinese Science Bulletin 2010年第21期55卷 2258-2267页

作者： bai Yan FANG XiaoMin nie Junsheng MENG QiangXiang CHI YunPing Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China Key Laboratory of Western China's Environmental Systems Ministry of Education of China and College of Resources and Environment Lanzhou University Lanzhou 730000 China Department of Geological Sciences Jackson School of Geosciences University of Texas Austin TX 78712 USA Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China

GC-MS characteristics of surface soil samples from the eastern and northern Tibetan Plateau provide tentative identification of 8(-14)-Methoxy hexadecanoic acid(iME-16:0)and 9(-17)-methoxy octadecanoic acid(iME-18:0).Sixty surface soil samples were collected from the eastern slope of Gongga Mountain,at elevations ranging from～1230 to 4500 m(eastern Tibetan Plateau),and from the northern slope of West Kunlun Mountains,ranging from～1300 to 5500 m(northern Tibetan Plateau).This study also analyzed the methoxy n-fatty acids(MFAs)of Gongga Mountain tree leaves from six common living species,at the elevation of 2900-4200 *** dominate these samples,with more centrally located methoxy groups eluting earlier than those with methoxy groups located closer to the end of the main carbon *** occur prominently in most of the Gongga Mountain soil samples(and from six tree samples)from dominantly coniferous and deciduous broadleaved *** than in two narrow vegetation zones between 4000-4350 m and 2900-3300 m,no MFAs were found in 19 Kunlun Mountains soil samples from areas covered mainly with montane desert and alpine desert steppe *** on the inventory of plants and soils from which MFAs have been isolated,we conclude that the MFAs most probably originate from specific woody *** we can exclude some particular grasses as sources,MFAs may be specific woody plants-derived biomarkers;thus they would serve as an important additional proxy for comprehensive and precise ecological reconstructions.

关键词：表层土壤西昆仑山生态重建甲氧基脂肪酸欧米茄青藏高原东部土壤样品

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the recovery of ionic liquids from dilute effluent by electrodialysis method and the fouling of cation-exchange membrane

引用

Science China Chemistry 2013年第12期56卷 1811-1816页

作者： bai Lu WANG XiaoLiang nie Yi DONG HaiFeng ZHANG XiangPing ZHANG SuoJiang Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex SystemsInstitute of Process Engineering Chinese Academy of Science College of Chemistry and Chemical Engineering University of Chinese Academy of Sciences

With the wide application of ionic liquids(ILs)in various fields,developing efficient techniques to recover ILs from effluent is an urgent demand for the cost reduction and the environmental *** this study,an electrodialysis(ED)method was used to recover 1-butyl-3-methylimidazolium chloride([Bmim]Cl)IL from aqueous solution as model *** influences of initial IL concentration and applied voltage on the current efficiency,removal ratio,desalination ratio,membrane flux and specific energy consumption during the ED process were *** was found that the removal ratio and desalination ratio increases with the increasing of initial IL concentration and applied *** current efficiency decreases with the increasing of initial IL concentration and the current efficiency reached the maximum value of 94.3%at 25 ***,as the applied voltage increases,the membrane flux increases and the specific energy consumption ***,the fouling of cation-exchange membrane was also discovered after the desalination of *** deposits on the surface or into the membrane which is probably caused by[Bmim]+was characterized by scanning electron microscopy,elemental analysis and Fourier transform infrared.

关键词： ionic liquid electrodialysis membrane effluent recovery

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：