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Simulation of denitrification in groundwater from Chaohu Lake Catchment,China

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Water Science and Engineering 2018年第2期11卷 114-119页

作者： Jia-zhong Qian Xiu-xuan wang Lei Ma Long-ping wang Jian-kui Liu Zhang-xian Yang School of Resources and Environmental Engineering Hefei University of TechnologyHefei 230009China Anhui Institute of Geo-Environment Monitoring Hefei 230009China

The eutrophication of Chaohu Lake in China is mainly attributed to nitrate inflow from non-point sources in the lake catchment. In this study,biological nitrate reduction from groundwater in the Chaohu Lake Catchment was investigated under laboratory conditions in a continuous upflow reactor. Sodium acetate served as the carbon source and electron donor. Results showed that a carbon-to-nitrogen(C/N) molar ratio of 3:1 and hydraulic retention time(HRT) of 8 d could achieve the most rapid nitrate nitrogen(NO_3^--N) depletion(from 100 mg/L to 1 mg/L within120 h). This rate was confirmed when field groundwater was tested in the reactor, in which a NO_3^--N removal rate of 97.71% was achieved(from60.35 mg/L to 1.38 mg/L within 120 h). Different levels of the initial NO_3^--N concentration(30, 50, 70, and 100 mg/L) showed observable influence on the denitrification rates, with an overall average NO_3^--N removal efficiency of 98.25% at 120 h. Nitrite nitrogen(NO_2^--N)accumulated in the initial 12 h, and then kept decreasing, until it reached 0.0254 mg/L at 120 h. Compared with the initial value, there was a slight accumulation of 0.04 mg/L for the ammonia nitrogen(NH4-N) concentration in the effluent, which is, however, less than the limit *** results can provide a reference for evaluating performance of denitrification in situ.

关键词： Chaohu Lake Catchment Denitrification Eutrophication Nitrate Wetland

Identification of hydrovolcanism and its significance for hydrocarbon reservoir assessment: A review

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Journal of Palaeogeography 2018年第4期7卷 346-362页

作者： Ben-Zhong xian Yan-Xin He Hua-Peng Niu Jun-Hui wang Jian-ping Liu Zhen wang College of Geosciences China University of Petroleum (Beijing) State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing)

Investigations of modern volcanic eruptions have demonstrated that ancient volcanic eruptions widely involved water,which was thus named as hydrovolcanic eruptions. Hydrovolcanisms are distinctive in many aspects, such as dynamics,eruptive pattern, texture and structure of rock, and vesicularity. First, normal sediments covered directly by volcanic rocks are the indicators of eruption environments. In addition, microfeatures, special structures, lithofacies or facies associations,and geochemical index of volcanic rocks can also provide significant evidences. Moreover, perlitic texture, quenching fragmentation, surface feature, cementation type, vesicularity, and pillow structure, parallel bedding, large-scale low-angle cross-bedding, antidune cross-bedding of pyroclast are keys to indicating hydrovolcanisms. Clearly,these marks are not equally reliable for identifying eruption environments, and most of them are effective and convincible in limited applications only. For explosive eruptions, the most dependable identification marks include quenching textures, vesicularity in pyroclasts and special large-scale cross-bedding. However, for effusive eruptions,useful indicators mainly include pillow structure, peperite and facies associations. Condensation rate of magma,exsolution of volatile affected by eruptive settings and magma—water interaction, and quenching in hydrovolcanisms have an influence on formation and scale of primary pores, fractures and their evolution during diagenetic ***, this review provides systematic identification marks for ancient hydrovolcanisms, and promotes understanding of the influence of eruptive environments on hydrocarbon reservoirs of volcanic rocks in oil-gas bearing sedimentary basins.

关键词： Hydrovolcanism Volcanic reservoir Eruption environment Hydrocarbon reservoir Oilgas bearing sedimentary basin

New Wronskian Representation of Solution for a Variable-Coefficient Kadomtsev-Petviashvili Equation

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Chinese Physics Letters 2013年第6期30卷 46-49页

作者： WU Jian-ping GENG xian-Guo Department of Mathematics Zhengzhou University100 Kexue RoadZhengzhou 450001

Utilizing the Wronskian technique,a new Wronskian representation is proposed for a variable-coefficient Kadomtsev–Petviashvili(vcKP)***,some particular forms of Wronskian determinant solutions,includingN-soliton solu... 详细信息

关键词： equation. soliton rational

基于粪便DNA宏条形码的人工草地放牧绵羊采食组分研究

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草地学报 2024年第10期32卷 3043-3051页

作者：郭艳萍王月君彭思嘉左淑贤张英俊罗海玲中国农业大学动物科学技术学院畜禽营养与饲养全国重点实验室北京100193 中国林业科学研究院林业研究所北京100091 中国农业大学草业科学与技术学院北京100193

准确获取食草动物食性数据有助于了解草地放牧家畜的营养状况,同时也对掌握草地植物群落的动态变化具有重要意义。本研究通过从滩羊粪便样本中提取DNA,利用ITS2条形码和粪便DNA宏条形码技术(fDNA metabarcoding),基于出现频率(Frequency... 详细信息

准确获取食草动物食性数据有助于了解草地放牧家畜的营养状况,同时也对掌握草地植物群落的动态变化具有重要意义。本研究通过从滩羊粪便样本中提取DNA,利用ITS2条形码和粪便DNA宏条形码技术(fDNA metabarcoding),基于出现频率(Frequency of occurrence,FO)和相对序列丰度(Relative read abundance,RRA)两个指标快速分析获得粪便中的物种组成。分析获得的滩羊食物组成包含28个植物类群,主要有藜属(Chenopodium sp.)、苜蓿属(Medicago sp.)、蒿属(Artemisia sp.)等隶属于13科23属,其中27个鉴定到种水平,物种鉴定分辨率高达96%。藜属FO和RRA均最高,分别为100.0%和31.5%,其次为紫花苜蓿(Medicago sativa),分别为100.0%和26.9%。基于两种算法分析得到的食物比例具有差异性和一致性,其中紫花苜蓿是放牧滩羊的主要采食来源,但摄入比例需要校正。研究证明了基于ITS2片段的粪便DNA宏条形码技术在食草家畜快速准确食性分析中的可行性,为此类研究提供了有力借鉴。建议采用该技术时应完善潜在摄食植物DNA条形码数据库,准确分析目标家畜在特定区域内的采食种类。

关键词：绵羊食性 DNA宏条形码 ITS2 物种鉴定

叶面喷施硅肥对再生水灌溉水稻叶际细菌群落结构及功能基因的影响

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环境科学 2024年第1期45卷 555-566页

作者：梁胜贤刘春成胡超崔二苹李中阳樊向阳崔丙健河北大学生命科学学院生命科学与绿色发展研究院保定071000 中国农业科学院农田灌溉研究所新乡453002 中国农业科学院农业水资源高效安全利用重点开放实验室新乡453002

再生水农业利用被认为是解决水资源短缺和减少水环境污染的有效途径.硅肥可提高作物产量及品质,并增强作物抗逆能力.叶面喷施硅肥对叶际微生物群落的影响仍缺少全面研究.通过盆栽试验,探讨了不同种类硅肥叶面喷施对再生水灌溉水稻叶际... 详细信息

再生水农业利用被认为是解决水资源短缺和减少水环境污染的有效途径.硅肥可提高作物产量及品质,并增强作物抗逆能力.叶面喷施硅肥对叶际微生物群落的影响仍缺少全面研究.通过盆栽试验,探讨了不同种类硅肥叶面喷施对再生水灌溉水稻叶际细菌群落结构组成及多样性和相关功能基因丰度的影响.结果表明,水稻叶际细菌优势菌门主要为厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)、拟杆菌门(Bacteroidota)和疣微菌门(Verrucomicrobiota).芽孢杆菌属(Bacillus)相对丰度较其他处理在再生水灌溉+叶面喷施那优硅(RIS3)处理中更高,再生水灌溉使潜在致病菌泛菌属(Pantoea)和肠杆菌属(Enterobacter)的相对丰度显著增加,其中未分类的菌属也是水稻叶际细菌群落重要的组成部分.硅肥处理显著富集了芽孢杆菌属(Bacillus)、微小杆菌属(Exiguobacterium)、Aeromonas和柠檬酸杆菌属(Citrobacter).功能预测分析表明,指示物种主要参与代谢与降解功能,并且预测的功能类群主要来自化能异养、好氧化能异养、硝酸盐还原和发酵.定量PCR结果显示,各处理中氨氧化古菌(AOA)、氨氧化细菌(AOB)和固氮酶基因(nifH)均处于较低的丰度水平,亚硝酸还原酶基因(nirK)丰度在各处理间也无显著差异.上述研究结果有助于深层次了解叶面喷施硅肥影响水稻叶际细菌群落结构及多样性差异,为硅肥在再生水灌溉农业中的应用提供理论依据.

关键词：硅肥再生水灌溉叶际细菌群落功能基因

Serum gastrin-17 concentration for prediction of upper gastrointestinal tract bleeding risk among peptic ulcer patients

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World Journal of Clinical Cases 2021年第35期9卷 10948-10955页

作者： Jun-xian wang Yu-ping Cao Peng Su Wei He Xiao-ping Li Ya-Meng Zhu Department of Gastroenterology The Second People’s Hospital of Anhui ProvinceHefei 230011Anhui ProvinceChina

BACKGROUND Serum gastrin-17(G-17),pepsinogen I(PGI),and pepsinogen II(PGII)concentrations regulate gastric acid secretion,and hypersecretion of gastric acid increases the risks of peptic ulcer and upper gastrointestinal *** associations suggest that serum G-17,PGI,and(or)PGII may predict gastrointestinal bleeding risk among peptic ulcer *** To evaluate the efficacies of serum G-17,PGI,PGII,and PGI/PGII ratio(PGR)for predicting upper gastrointestinal bleeding among peptic ulcer *** A total of 199 patients diagnosed with peptic ulcer confirmed by gastroscopy and positivity for Helicobacter pylori by the 14C-urea breath test were recruited,including 107 patients with simple peptic ulcer and 92 cases complicated by upper gastrointestinal *** PGI,PGII,G-17,and PGR were measured by immune methods and compared between bleeding and non-bleeding groups by univariate *** specificity and sensitivity of PGs and G-17 for evaluating upper gastrointestinal bleeding risk were then assessed by constructing receiver operating characteristic(ROC)*** Serum G-17 was significantly higher among peptic ulcer patients with upper gastrointestinal bleeding compared to simple peptic ulcer patients(25.34±14.29 vs 8.84±8.03 pmol/L,t=9.822,P0.05).The risk of bleeding was significantly higher among peptic ulcer patients with elevated serum G-17(>15 pmol/L)compared to patients with normal or low serum G-17(73.2%vs 27.4%,χ2=40.72,P<0.01).The area under the ROC curve for serum G-17 was 0.866±0.024,and a cut-off of 9.86 pmol/L yielded 90.2%sensitivity and 68.2%specificity for distinguishing peptic ulcer with and without upper gastrointestinal *** Serum G-17 is significantly upregulated in peptic ulcer patients and higher levels are predictive of upper gastrointestinal ***,serum PGI,PGII,and PGR

关键词： Peptic ulcer Upper gastrointestinal bleeding Gastrin Pepsinogen Receiver operating characteristic curve

Promotion effect of Au single-atom support graphene for CO oxidation

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Chinese Chemical Letters 2022年第11期33卷 4822-4827页

作者： ping Yan Song Shu xian Shi Jianjun Li College of Architecture and Environment Sichuan UniversityChengdu 610065China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 611731China

CO oxidation is a vital catalytic reaction for environmental purification,facing challenges due to the catalysts applied to oxidize CO are mainly rare and expensive noble *** the high atomic availability,catalytic efficiency,and selectivity of single-atom catalysis,it has been widely studied and proven to be brilliant in CO *** single-atom catalysts are regarded as excellent single-atom catalysts in oxidizing CO,whose progress is limited by the indistinct understanding of the reaction mechanism and role of the active ***,DFT calculation was used to investigate CO oxidation processes,active mechanisms,and the role of Au *** involving prominent physical and chemical properties was selected as a model *** single-atom support graphene materials exhibit better CO oxidation activities than pristine graphene,among which CO oxidation property on Au/GP is the highest with a0.38 eV rate-determining barrier following ER *** outstanding performances including excellent electronic structures,adsorption properties,and strong activation of intermediate products contribute to the high CO oxidation activity of Au/GP,and the Au single-atom is the active *** work provides a novel guide for single-atom catalytic CO oxidation,accelerating the development of single-atom catalysis.

关键词： Single-atom Graphene CO oxidation ER mechanism DFT

成都城市轨道交通站城融合启示——以医院与地铁接驳项目为例

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工程建设与设计 2024年第14期 74-76页

作者：颜鲜明陈建平成都轨道资源经营管理有限公司成都610200 西南石油大学成都610500

成都地铁在城市层面未突破红线思维,未完全打通“TOD城市毛细血管”、实现站城深度融合。基于此,相关部门近年来做出了一系列的尝试,以成都市两个医院与地铁接驳项目的TOD一体化规划设计为例,针对医院项目的规划设计痛点,探索医院项目... 详细信息

成都地铁在城市层面未突破红线思维,未完全打通“TOD城市毛细血管”、实现站城深度融合。基于此,相关部门近年来做出了一系列的尝试,以成都市两个医院与地铁接驳项目的TOD一体化规划设计为例,针对医院项目的规划设计痛点,探索医院项目在交通、环境、功能、空间、开发等方面与轨道交通融合的更多的可能性。

关键词：城市轨道交通接驳站城融合

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First Passage Risk Probability Minimization for Piecewise Deterministic Markov Decision Processes

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Acta Mathematicae Applicatae Sinica 2022年第3期38卷 549-567页

作者： Xin WEN Hai-feng HUO xian-ping GUO School of Mathematics Sun Yat-sen UniversityGuangzhou 510275China Guangdong Province Key Laboratory of Computational Science Sun Yat-sen UniversityGuangzhou 510275China School of Science Guangxi University of Science and TechnologyLiuzhou 545006China

This paper is an attempt to study the minimization problem of the risk probability of piecewise deterministic Markov decision processes(PDMDPs)with unbounded transition rates and Borel *** from the expected discounted and average criteria in the existing literature,we consider the risk probability that the total rewards produced by a system do not exceed a prescribed goal during a first passage time to some target set,and aim to find a policy that minimizes the risk probability over the class of all history-dependent *** suitable conditions,we derive the optimality equation(OE)for the probability criterion,prove that the value function of the minimization problem is the unique solution to the OE,and establish the existence ofε(≥0)-optimal ***,we provide two examples to illustrate our results.

关键词： piecewise deterministic Markov decision processes risk probability first passage time ε-optimal policy