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Morphological and Sulfur-Isotopic Characteristics of Pyrites in the Deep Sediments from Xisha Trough,South China Sea

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Journal of Ocean University of China 2024年第1期23卷 138-148页

作者： CHANG Jingyi LIU Yujia lu Hailong lu Jing’an SU Xin YE Jianliang XIE wenwei College of Engineering Peking UniversityBeijing 100871China Beijing International Center for Gas Hydrate School of Earth and Planetary SciencesPeking UniversityBeijing 100871China School of Marine Science Nanjing University of Information Science and TechnologyNanjing 210044China MLR Key Laboratory of Marine Mineral Resources Guangzhou Marine Geological SurveyMinistry of Land and ResourcesGuangzhou 510075China School of Ocean Sciences China University of GeosciencesBeijing 100083China

Pyrite is one of the common authigenic minerals in marine sediments.Previous studies have shown that the morphological and isotopic characteristics of pyrite are closely related to the geochemical environment where it is formed.To better understand the for-mation mechanism of authigenic pyrite,we analyzed the isotopic composition,morphology,and distribution of pyrite in the sediment at 500m below the seafloor from Xisha Trough,South China Sea.Mineral morphologies were observed by scanning electron micros-copy and Raman spectrography.X-Ray computed tomography was applied to measure the particle size of pyrite.The size of pyrite crystals in the matrix sediment mainly ranged between 25 and 65µm(av.ca.40µm),although crystals were larger(av.ca.50μm)in the veins.The pyrites had a fine-grained truncated octahedral shape with occasionally well-developed growth steps,which implies the low growth rate and weak anaerobic oxidation of methane-sulfate reduction when pyrite was formed.Theδ^(34)S values of pyrites ranged from+20.8‰Vienna-defined Canyon Diablo Troilite(V-CDT)to+33.2‰V-CDT and from+44.8‰V-CDT to+48.9‰,which suggest two growth stages.In the first stage,with the continuous low methane flux,the pyrite possibly formed in an environment with good access to seawater.In the second stage,the pyrites mainly developed in sediment fractures and appeared in veins,probably due to the limited availability of sulfate.The less exposure of pyrite to the environment in the second stage was probably caused by sediment accumulation or perturbation.In this study,an episodic pyritization process was identified,and the paleoenvironment was reconstructed for the sediment investigated.

关键词： pyrite sulfur isotope AOM methane flux Xisha Trough South China Sea

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Long-Term Performance and Microstructural Characterization of Dam Concrete in the Three Gorges Project

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Engineering 2024年第2期33卷 237-262页

作者： Chen Lyu Cheng Yu Chao lu Li Pan wenwei Li Jiaping Liu School of Materials Science and Engineering Southeast UniversityNanjing 211189China State Key Laboratory of High Performance Civil Engineering Materials Sobute New Materials Co.Ltd.Nanjing 211103China China Three Gorges Corporation Wuhan 430010China

This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled from the Three Gorges Dam.The mechanical properties of the laboratory dam concrete,whether cured in natural or standard environments,continued to improve over time.Furthermore,the laboratory dam concrete exhibited good resistance to diffusion and a refined microstructure after 17 years.However,curing and long-term exposure to the local natural environment reduced the frost resistance.Microstructural analyses of the laboratory concrete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form compact micro structures consisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-S-H)gels and a few crystals.No obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic reaction.This dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam concrete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam concrete at a later age.The concrete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that concrete directly exposed to the actual service environment suffered degradation caused by water and wind attacks.In this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of concrete from the Three Gorges Dam after 17 years.Long-term exposure to an actual service environment may lead to microstructural degradation of the concrete surface.Therefore,the retained long-term dam concrete samples need to be further researched to better understand its microstructural evolution

关键词： Three Gorges Dam Long-term performance Microstructural analysis Moderate-heat cement Fly ash

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Promotion mechanism of self-transmissible degradative plasmid transfer in maize rhizosphere and its application in naphthalene degradation in soil

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Journal of Environmental Sciences 2022年第5期34卷 240-252页

作者： Qiuyan Jiang wenwei lu Lei Zhang Yeqing Jin Yujing Wang Jun Chen Ziyi Ye Ming Xiao Development Center of Plant Germplasm College of Life SciencesShanghai Normal UniversityShanghai 200234China Key Laboratory of Urban Agriculture Ministry of AgricultureShanghai 200240China Department of Food Science Shanghai Business SchoolShanghai 200235China Shanghai Landscape Architecture Construction Co. Ltd.Shanghai 200235China

Rhizospheres can promote self-transmissible plasmid transfer,however,the corresponding mechanism has not received much attention.Plant-microbe remediation is an effective way to promote pollutant biodegradation;however,some pollutants,such as naphthalene,are harmful to plants and result in inefficient plant-microbe remediation.In this study,trans-fer of a TOL-like plasmid,a self-transmissible plasmid loaded with genetic determinants for pollutant degradation,among different bacteria was examined in bulk and rhizosphere soils as well as addition of maize root exudate and its artificial root exudate(ARE).The results showed that the numbers of transconjugants and recipients as well as bacterial metabolic activities,such as xylE mRNA expression levels and catechol 2,3-dioxygenase(C23O)activ-ities of bacteria,remained high in rhizosphere soils,when compared with bulk soils.The number of transconjugants and bacterial metabolic activities increased with the increasing exudate and ARE concentrations,whereas the populations of donor and recipient bacteria were substantially unaltered at all concentrations.All the experiments consistently showed that a certain number of bacteria is required for self-transmissible plasmid transfer,and that the increased plasmid transfer might predominantly be owing to bacterial metabolic activ-ity stimulated by root exudates and ARE.Furthermore,ARE addition increased naphthalene degradation by transconjugants in both culture medium and soil.Thus,the combined action of a wide variety of components in ARE might contribute to the increased plasmid transfer and naphthalene degradation.These findings suggest that ARE could be an effectively al-ternative for plant-microbe remediation of pollutants in environments where plants cannot survive.

关键词： Degradative plasmid transfer Naphthalene degradation Rhizosphere Root exudates

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Protein S-nitrosylation regulates the energy metabolism of early postmortem pork using the in vitro model

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Food Materials Research 2022年第1期2卷 38-45页

作者： wenwei lu Qin Hou Wangang Zhang Key Laboratory of Meat Processing and Quality Control Ministry of Education ChinaJiangsu Collaborative Innovation Center of Meat Production and ProcessingQuality and Safety ControlCollege of Food Science and TechnologyNanjing Agricultural UniversityNanjing 210095China

This research aimed to investigate the regulation of energy metabolism by protein S-nitrosylation utilizing the in vitro muscle glycolysis model.Longissimus thoracis(LT)muscles homogenates were treated with nitric oxide donor NOR-3((±)-(E)-4-Ethyl-2-(E)-hydroxyimino-5-nitro-3-hexenamide)and control(0.1 M K_(2)HPO_(4))under different pH conditions(6.5,6.0 and 5.5)in vitro buffer system for 24 h,respectively.Results indicated that the NOR-3 treatment group had a significantly higher pH decline rate than the control group and resulted in a higher lactate accumulation and glycogen degradation at 24 h compared with the control group(p<0.05).Moreover,NOR-3 treatment significantly increased the activities along with S-nitrosylation levels of lactate dehydrogenase and glycogen phosphorylase at pH 6.5 in a concentration-dependent manner(p<0.05).In addition,low pH could weaken the NOR-3 treatment effect and inhibit glycolysis rate.Thus,protein S-nitrosylation could play a role in regulating postmortem glycolysis in vitro model even at low pH conditions.

关键词： metabolism postmortem treatment

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当代腾冲翡翠玉雕工艺的传承与发展路向研究

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宝石和宝石学杂志（中英文） 2024年第1期26卷 76-87页

作者：王文薇卢靭尹作为中国地质大学(武汉)珠宝学院湖北武汉430074 湖北省人文社科研究基地“珠宝首饰传承与创新发展研究中心” 湖北武汉430074 滇西应用技术大学珠宝学院云南腾冲679100

腾冲翡翠玉雕作为国家级非物质文化遗产,不仅是腾冲文化基因的代表,也是中华优秀传统玉文化的重要组成部分。本文通过对腾冲翡翠玉雕加工基地和玉雕非遗传承人进行实地考察,总结归纳了腾冲翡翠玉雕目前存在的困境;同时,以传承发展为主线... 详细信息

腾冲翡翠玉雕作为国家级非物质文化遗产,不仅是腾冲文化基因的代表,也是中华优秀传统玉文化的重要组成部分。本文通过对腾冲翡翠玉雕加工基地和玉雕非遗传承人进行实地考察,总结归纳了腾冲翡翠玉雕目前存在的困境;同时,以传承发展为主线,重点从传统工艺理念的传承与创新,工艺传承队伍的科学构建,地域非遗文化品牌的塑造,多元媒介的动态展示与传播,国际化的交流与互鉴等五个维度对腾冲翡翠玉雕的传承与发展路向展开探讨,以期在当今非遗语境中对区域性玉雕工艺的可持续发展提供有效的参考与范式。

关键词：腾冲翡翠玉雕工艺传承发展路向非物质文化遗产

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投资者情绪如何影响股市泡沫——兼议对股市泡沫监管的建议

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金融监管研究 2024年第1期 61-78页

作者：郭文伟卢立晔钟袁妍广东财经大学金融学院广东财经大学金融学院金融硕士中心

本文基于2010—2022年沪深两市东方财富网股吧的股评,通过构建新型中文口语化金融情感词典来测度沪深两市投资者的正面、负面和综合情绪指数;在此基础上,采用TVP-VAR模型探究投资者情绪与沪深股市泡沫之间的交互影响效应。研究结论表明... 详细信息

本文基于2010—2022年沪深两市东方财富网股吧的股评,通过构建新型中文口语化金融情感词典来测度沪深两市投资者的正面、负面和综合情绪指数;在此基础上,采用TVP-VAR模型探究投资者情绪与沪深股市泡沫之间的交互影响效应。研究结论表明:第一,沪深股市泡沫与投资者情绪之间存在非对称的交互影响和因果关系。深市各类投资者情绪与股市泡沫均存在显著的交互影响效应,而沪市仅投资者正面情绪与股市泡沫存在显著的交互影响效应;第二,沪市投资者情绪所产生的传播效应以及对股市泡沫的冲击远大于深市;第三,重要宏观经济指标及金融市场指标也会对投资者情绪产生显著影响,但影响方向不尽相同。本文的研究结论有助于监管部门更加合理地监测和防范股市泡沫风险,促进股市稳定健康发展。

关键词：投资者情绪股市泡沫交互影响效应文本分析 TVP-VAR

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Timely Data Delivery for Energy-Harvesting IoT Devices

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Chinese Journal of Electronics 2022年第2期31卷 322-336页

作者： lu wenwei GONG Siliang ZHU Yihua School of Computer Science and Technology Zhejiang University of Technology College of Mathematics and Computer Science Zhejiang A&F University

The devices in the Internet of things(Io T) gain capability of sustainable operation when they harvest energy from ambient sources. Fluctuation in the harvested energy may cause the energy-harvesting IoT devices to suffer from frequent energy shortage, which may bring in intolerable packet delay or packet discarding. It is important to design a low-delay packet delivery scheme that adapts to variation in the harvested energy.In this paper, we present the timely data delivery(TDD)scheme for the IoT devices. Using Markov chain, we develop a probability model for the TDD scheme, which leads to the expected number of packets delivered in an operation cycle, the expected numbers of packets waiting in the data buffer in an operation cycle and an energy-harvesting cycle, and the expected packet delay. Additionally, we formulate the optimization problem that minimizes the packet delay in the TDD scheme, and the solution to the optimization problem yields the optimal parameters for the IoT devices to determine when to harvest energy and when to deliver data under the TDD scheme.The simulation results show that the proposed TDD scheme outperforms the existing schemes in terms of packet delay.

关键词： Internet of things Energy harvesting Data delivery Energy management IEEE 802.15.4 standard

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厚松散层薄基岩下分层开采覆岩破坏高度研究

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煤炭工程 2024年第5期56卷 75-83页

作者：王文卫芦晓伟丁坤朋王文焦作煤业集团赵固(新乡)能源有限责任公司河南新乡453000 中国矿业大学安全工程学院江苏徐州221116 河南理工产业技术研究院有限公司河南焦作454000 河南理工大学能源科学与工程学院河南焦作454000

以赵固一矿厚松散层薄基岩下分层工作面为研究对象,采用理论分析、数值模拟研究、钻孔冲洗液漏失量观测及钻孔窥视方法对采后覆岩破坏高度进行研究,研究表明:采用经验公式计算得到下分层工作面采后,顶板垮落带发育高度为6.93~27.72 m,... 详细信息

以赵固一矿厚松散层薄基岩下分层工作面为研究对象,采用理论分析、数值模拟研究、钻孔冲洗液漏失量观测及钻孔窥视方法对采后覆岩破坏高度进行研究,研究表明:采用经验公式计算得到下分层工作面采后,顶板垮落带发育高度为6.93~27.72 m,导水裂缝带发育高度为22.17~71.73 m;数值模拟结果表明下分层采高2.5 m、累计采高6 m时,最大垮采比为2.61,而累计采厚小于6 m、基岩厚度不小于30 m、黏土层厚度大于5 m时可认为黏土层厚度能够阻隔导水裂缝带向上发育;采用现场实测方法得到累计采厚5.8 m处,垮落带15.26 m,垮采比为2.62,导水裂缝带55.59 m,裂采比为9.58。东一盘区下分层工作面后开采覆岩破坏高度的规律,可以为该矿下分层工作面时确定防水、防砂安全煤(岩)柱厚度提供理论依据。

关键词：厚松散层薄基岩垮落带导水裂隙带下分层

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双歧杆菌基于菊粉促进普拉梭菌增殖的探究

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食品与发酵工业 2024年第2期50卷 85-92页

作者：高文玉肖越王鸿超朱金林陆文伟江南大学食品学院江苏无锡214122 江南大学国家功能食品技术研究中心江苏无锡214122

普拉梭菌(Faecalibacterium prausnitzii)是人体肠道中常见的微生物,约占整个肠道菌群含量的5%,是肠道中最主要的产丁酸盐菌,对维护肠道健康具有重要作用。它的丰度在患有炎症性肠病和代谢性疾病患者的肠道中显著降低。然而,由于普拉梭... 详细信息

普拉梭菌(Faecalibacterium prausnitzii)是人体肠道中常见的微生物,约占整个肠道菌群含量的5%,是肠道中最主要的产丁酸盐菌,对维护肠道健康具有重要作用。它的丰度在患有炎症性肠病和代谢性疾病患者的肠道中显著降低。然而,由于普拉梭菌对氧气极其敏感等特点而限制它的应用发展,寻找一种可替代的手段来增殖普拉梭菌具有重要意义。该文通过在体外建立双歧杆菌和普拉梭菌共培养体系发现双歧杆菌可以显著增加普拉梭菌在菊粉中的生长量及产丁酸盐能力,同时通过16S rRNA测序小鼠粪便菌群也发现灌胃双歧杆菌和菊粉可以在一定程度上增加小鼠肠道中普拉梭菌的丰度,为普拉梭菌在人体肠道中增殖提供理论依据。

关键词：普拉梭菌双歧杆菌菊粉增殖

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Economic Critical Resources for the Industrial Exploitation of Natural Gas Hydrate

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Acta Geologica Sinica(English Edition) 2022年第2期96卷 663-673页

作者： CHEN Xuejun lu Hailong ZHANG Jiecheng YE Jianliang XIE wenwei College of Engineering Peking UniversityBeijing 100871China Institute of Ocean Research Peking UniversityBeijing 100871China Beijing International Center for Gas Hydrate School of Earth and Space SciencesPeking UniversityBeijing 100871China Institute for Marine Science and Technology Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China Guangzhou Marine Geological Survey Guangzhou 510075China

Since the implementation of several pilot production tests were in natural gas hydrate(NGH) reservoirs in terrestrial and marine settings, the study of NGH has entered a new stage of technological development for industrial exploitation. Prior to the industrial exploitation of any given NGH reservoir, the economic feasibility should be examined. The first step of economic evaluation of a NGH reservoir is to know whether its resource amount meets the requirement for industrial exploitation. Unfortunately, few relevant studies have been conducted in this regard. In this study, the net present value(NPV) method is employed to estimate the economic critical resources required for the industrial exploitation of NGHs under different production scenarios. Sensitivity analysis is also performed in order to specify the effects of key factors, such as the number of production wells, gas price, technological improvement and tax incentive, on the economic critical resources. The results indicate that China requires the lowest economic critical resource for a NGH reservoir to be industrially exploited, ranging from 3.62 to 24.02 billion m3 methane. Changes in gas price and tax incentives also play significant roles in affecting the threshold and timeline for the industrial exploitation of NGH.

关键词： natural gas hydrate industrial exploitation economic critical resource net present value recovery factor

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