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Molecular Dynamics-Based Simulation of Polyethylene Pipe Degradation in High Temperature and High Pressure Conditions

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2139-2161页

作者： Guowei Feng Qing Li Yang Wang Nan Lin Sixi Zha Hang Dong Ping Chen Minjun Zheng School of Mechanical engineering Xinjiang UniversityUrumqi830046China xinjiang yian special inspection engineering company limited Urumqi830063China xinjiang Uygur Autonomous Region inspection Institute of special Equipment Urumqi830000China Pressure Pipe Department China Special Equipment Inspection and Research InstituteBeijing100013China Tarim Oilfield Branch company Korla841000China Yimai Cai Oil and Gas Management Area Tarim Oilfield Branch OfficeKorla841000China

High-density polyethylene(HDPE)pipes have gradually become the first choice for gas networks because of their excellent *** the use of pipes increases,there will unavoidably be a significant amount of waste generated when the pipes cease their operation life,which,if improperly handled,might result in major environmental contamination *** this study,the thermal degradation of polyethylene materials is simulated for different pressures(10,50,100,and 150 MPa)and temperatures(2300,2500,2700,and 2900 K)in the framework of Reactive Force Field(ReaxFF)molecular dynamics *** main gas products,density,energy,and the mean square displacement with temperature and pressure are also *** findings indicate that raising the temperature leads to an increase in the production of gas products,while changing the pressure has an impact on the direction in which the products are generated;the faster the temperature drops,the less dense the air;both temperature and pressure increase impact the system’s energy conversion or distribution mechanism,changing the system’s potential energy as well as its total energy;the rate at which molecules diffuse increases with temperature,and decreases with *** results of this investigation provide a theoretical basis for the development of the pyrolytic treatment of polyethylene waste materials.

关键词： ReaxFF MD high-density polyethylene degradation temperature pressure

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The effect of salt stress on the chlorophyll level of the main sand-binding plants in the shelterbelt along the Tarim Desert Highway

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Chinese Science Bulletin 2008年第S2期53卷 109-111页

作者： XU XinWen XU HaiLiang WANG YanLing WANG XiaoJing QIU YongZhi XU Bo xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China Institute of Environmental engineering Xinjiang Agricultural UniversityUrumqi 830052China Tarim Branch PetroChina Company LimitedKorla 841000China

Based on the fact that only high saline water irrigated to the shelterbelt along the Tarim Desert Highway, the experiment about three species with six degree of salinity was carried out to analyze the relation between chlorophyll content and salt stress. The results show that: (1) the chlorophyll content of tree species decreases with aggravating the salt stress, which explains that salt stress can affect chlorophyll accumulation of three plants; (2) from chlorophyll content with different salinity, the chlorophyll content of three shrubs also has twice obvious decrease, which indicates that some plants adapt to salt stress. We divided salt resistance of the plant into three grades, namely the slight salt resistance, the heavy salt resistance and the extreme salt resistance; and (3) according to the experimental results, the salt stress of each plant was divided, which can provide theoretical guidance for constructing the shelterbelt along the Tarim Desert Highway.

关键词： artificial shelterbelt sand-binding plants salt stress chlorophyll

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Reliability Analysis of a Switched Reluctance Starter/Generator

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Protection and Control of Modern Power Systems 2024年第1期9卷 112-121页

作者： Hao Chen Fan Yang Lijun Xu Qiwei Lu Xiqiang Chang Xing Wang Lijiang Dong Yi Wen Jiang Chen Gang Miao Jianmin Hu Guanjun Wang Wei Li Xiaohua Bao School of Electrical engineering China University of Mining and TechnologyXuzhou 221116China xinjiang Institute of engineering Urumqi 830000China International Joint Research Center of Central and Eastern European Countries on New Energy Electric Vehicle Technology and Equipment Xuzhou 221008China International Cooperation Joint Laboratory of New Energy Power Generation and Electric Vehicles of Jiangsu Province Colleges and Universities Xuzhou 221008China School of Information and Electrical engineering China University of Mining and TechnologyXuzhouChina China University of Mining and Technology(Beijing) BeijingChina State Grid Xingjiang Electric Power Co. Ltd.UrumqiXinjiangChina China University of Mining and Technology XuzhouChina State Grid xinjiang company limited Electric Power Research Institute UrumqiXinjiangChina xinjiang Fukang Pumped Storage Power company limited UrumqiXinjiangChina State Grid Urumqi Electric Power Supply company UrumqiXinjiangChina Wuxi inspection and Testing Certification Research Institute WuxiJiangsuChina Anhui Wannan Electric Machine Co. Ltd.WannanAnhuiChina Hefei University of Technology in Electrical and Automation engineering

In this paper,the combined k-out-of-n:G model and reliability block diagram model is used to analyze the reliability of a switched reluctance starter/generator ***,the different operational modes of a switched reluctance motor starter/generator are analyzed,and the fault states of the system are briefly *** the fault criteria of the system in different operational states are put ***,a relia-bility block diagram model is established to calculate the system-level reliability,and the k-out-of-n:G model is adopted to analyze the reliability of each part of the switched reluctance starter/generator *** verify effectiveness,the first-order Markov model is also used to analyze the reliability of each part of the switched reluc-tance starter/generator *** the compu-tational complexity and accuracy of the system,the k-out-of-n:G model is more suitable for system component level reliability ***,a 6/4 switched reluctance motor is used as the simulated and experimental platform *** final results verify the effectiveness of the reliability analysis model.

关键词： system switched generator

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Growth and sustainability of Suaeda salsa in the Lop Nur,China

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Journal of Arid Land 2018年第3期10卷 429-440页

作者： LI Congjuan LIU Ran WANG Shijie SUN Yongqiang LI Shengyu ZHANG Heng GAO Jie DANG Yanxi ZHANG Lili National engineering Technology Research Center for Desert-Oasis Ecological Construction Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Singapore Deposit Insurance Corporation (SDIC) xinjiang Luobupo Potash Co. Ltd. Urumqi 839000 China Tarim Branch PetroChina Company Limited Korla 841000 China

Extremely saline soils are very harsh environments for the growth and survival of most plant species, however, halophytes can grow well. The underlying mechanism of halophyte to resist high saline is not well understood by us. This study was conducted at the potash mine near the Lop Nur, China, where the effects of the halophyte Suaeda salsa L. on the saline-alkaline soils and its growth and sustainability were investigated. Four plots（in which the salt encrustation layers were removed）, with different soil treatments were evaluated：（1） undisturbed soil, with no additional treatment（T1）;（2） the slag soil zone, in which a 40-cm layer of slag was placed on the undisturbed soil surface（T2）;（3） slag＋sandy soil, in which a 20-cm layer of slag was placed in the lower layer and 20 cm of sandy soil, taken from an area about 70 km away from Lop Nur potash mine, where Tamarix species were growing, was placed in the upper layer（T3）; and（4） a 40-cm sandy soil layer taken from the area where Tamarix species were growing was placed on undisturbed soil（T4）. Soil nutrient contents increased in the four treatments, but salt content only decreased in the T1 treatment. Salt content in the T4 treatment increased over the two-year period, which may be partly attributed to salt deposition from wind-blown dust within the mine and salt accumulation within the surface soil（0–20 cm） in response to high evaporative demands. The S. salsa plants exhibited greater improvements in growth under the T4 treatment than under the T1, T2, and T3 treatments, which demonstrated that low levels of salinity are beneficial for the growth of this species. The T1 treatment was sustainable because of its low cost and superior soil improvement characteristics. Therefore, S. salsa plants not only reduced soil salinity and increased soil nutrient levels, but also ameliorated the plant growth environment, which would be beneficial for both the ecological restoration of the Lop Nur area and similar areas throughout

关键词： Suaeda salsa saline-alkaline soil plant-soil interaction sustainability Lop Nur

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Comprehensive eco-environmental effects of the shelter-forest ecological engineering along the Tarim Desert Highway

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Chinese Science Bulletin 2008年第S2期53卷 190-202页

作者： LEI JiaQiang LI ShengYu JIN ZhengZhong FAN JingLong WANG HaiFeng FAN DongDong ZHOU HongWei GU Feng QIU YongZhi XU Bo xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China Graduate University of the Chinese Academy of Sciences Beijing 100049China Tarim Branch PetroChina Company LimitedKorla 841000China

In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%―80% and 87.45%―99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the "first rapid, then slow" variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed.

关键词： desert shelter-forest engineering environmental effect aeolian environment biodiversity

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Stratigraphy of the Triassic-Jurassic Boundary Successions of the Southern Margin of the Junggar Basin,Northwestern China

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Acta Geologica Sinica(English Edition) 2011年第2期85卷 421-436页

作者： SHA Jingeng Vivi VAJDA PAN Yanhong Linda LARSSON YAO Xiaogang ZHANG Xiaolin WANG Yaqiong CHENG Xiansheng JIANG Baoyu DENG Shenghui CHEN Siwei PENG Bo State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology the Chinese Academy of Sciences Nanjing 210008 China Department of Earth and Ecosystem Sciences Lund University 22362 Lund Sweden PetroChina xinjiang Oil Field company Keramay 834000 China School of Earth Sciences and engineering Nanjing University Nanjing 210093 China Research Institute of Petroleum of Exploration and Development PetroChina Beijing 100083 China

The Triassic-Jurassic （Tr-J） boundary marks a major extinction event, which （～200 Ma）resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr-J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial settings leading to difficulties in linking marine and terrestrial sedimentary successions. Investigation based on palynology and bivalves has been carried out over a 1113 m thick section, which is subdivided into 132 beds, along the Haojiagou valley on the southern margin of the Junggar Basin of the northern xinjiang, northwestern China. The terrestrial Lower Jurassic is conformably resting on the Upper Triassic strata. The Upper Triassic covers the Huangshanjie Formation overlaid by the Haojiagou Formation, while the Lower Jurassic comprises the Badaowan Formation followed by the Sangonghe Formation. Fifty six pollen and spore taxa and one algal taxon were identified from the sediments. Based on the key-species and abundance of spores and pollen, three zones were erected： the Late Triassic （Rhaetian） Aratrisporites-Alisporites Assemblage, the Early Jurassic （Hettangian） Perinopollenites-Pinuspollenites Assemblage, and the Sinemurian Perinopollenites-Cycadopites Assemblage. The Tr-J boundary is placed between bed 44and 45 coincident with the boundary between the Haojiagou and Badaowan formations. Beds with Ferganoconcha （？）, Unio-Ferganoconcha and Waagenoperna-Yananoconcha bivalve assemblages are recognized. The Ferganoconcha （？） bed is limited to the upper Haojiagou Formation,Unio- Ferganoconcha and Waagenoperna- Yananoconcha assemblages are present in the middle and upper members of the Badaowan Formation. The sedimentary succession is interpreted as terrestrial with two mainly lake deposit intervals within Haojiagou and Badaowan formations, yielding fresh water algae and bivalves. However, the presence of brackish water

关键词： Biostratigrapy Triassic-Jurassic Hettangian-Sinemurian palynology bivalve Haojiagou of Junggar Basin northwestern China

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Application of integrated formation evaluation and three-dimensional modeling in shale gas prospect identification

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Journal of Geological Research 2019年第3期1卷 28-39页

作者： Jin Gao Zhe Cao Guangdi Liu Longmei Zhao Lijun Du Yuhua Kong College of Geosciences China University of PetroleumBeijing102249China State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China China United Coalbed Methane National engineering Research Center Corporation limited Beijing100095China Fuyu Oil Production Plant in Jilin Oilfield company PetroChinaSongyuan138000China PetroChina xinjiang Oilfield company Karamay834000China

Identifying the shale gas prospect is crucial for gas extraction from such *** Basin(in Northwest China)is widely considered to have high potential as a shale gas resource,and the Jurassic,the most significant gas source strata,is considered as prospective for shale gas exploration and *** study evaluated the Lower Jurassic Badaowan Formation shale gas potential combined with geochemical,geological,and well logging data,and built a three-dimensional(3D)model to exhibit favorable shale gas *** addition,methane sorption capacity was tested for verifying the *** Badaowan shale had an average total organic carbon(TOC)content of 1.30 wt.%and vitrinite reflectance(Ro)ranging from 0.47%to 0.81%with dominated type III organic matter(OM).X-ray diffraction(XRD)analyses showed that mineral composition of Badaowan shale was fairly homogeneous and dominated by clay and brittle minerals.67 wells were used to identify prospective shale intervals and to delineate the area of ***,three Badaowan shale gas prospects in the Junggar Basin were identified:the northwestern margin prospect,eastern Central Depression prospect and Wulungu Depression *** middle interval of the northwestern margin prospect was considered to be the most favorable exploration target benefitted by wide distribution and high lateral ***,methane sorption capacity of the Badaowan shale was comparable to that of the typical gas shales with similar TOC content,showing a feasible gas potential.

关键词： Shale gas Prospect Prospective interval Badaowan Formation Junggar Basin

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ANALYSIS OF LAND BRIDGE TRANSPORTATION

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Chinese Geographical Science 1991年第4期1卷 47-56页

作者：祁勇王雁 Advisory company of International engineering of China Beijing PRC Institute of Comprehensive Transportation of State Planning Commission of China Beijing PRC

Land bridge transportation means transportation from one seaport to another by railway across continents instead of by ocean ship. At present, there are two common routes for using land bridge transportation in the world. One is Asia-America-Europe land bridge, the other is Europe-Asia land *** land bridge has obvious advantages over Asia-America-Europe land bridge due to its shorter distance, shorter transportation time and special freight rate. China started Eurasia land bridge transportation business in 1980. It mainly used the mode of railway-railway combined transportation. The comparison between using Eurasia land bridge and using shipping transportation from China to Northern and Western Europe shows that Euraria land bridge transportation can save time and get foreign exchange in time, and commodity turnover will be speeded up. According to the port layout and railway network structure, China’s land bridge transportation projects are proposed. They are Suifenhe project, Dalian

关键词： land bridge transportation Eurasia land bridge Suifenhe project Dalian project Tianjin project Lianyungang project.

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