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Persistence of fertilization effects on soil organic carbon in degraded alpine wetlands in the Yellow River source region

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Journal of Mountain Science 2024年第4期21卷 1358-1371页

作者： duan Peng wei Rongyi WANG Fangping LI Yongxiao SONG Ci HU Bixia YANG Ping ZHOU Huakun YAO Buqing ZHAO Zhizhong Qinghai University Xining 810016China Qinghai Transportation Planning and Design Institute Co.Ltd Xining 810000China Key Laboratory of Adaptation and Evolution of Plateau Biota Chinese Academy of SciencesXining 810008China Key Laboratory of Restoration Ecology of Cold Area in Qinghai Province Northwest Institute of Plateau BiologyChinese Academy of SciencesXining 810008China Qinghai University of Science and Technology Xining 810016China

In the restoration of degraded wetlands,fertilization can improve the vegetation-soil-microorganisms complex,thereby affecting the organic carbon ***,it is currently unclear whether these effects are *** study employed Biolog-Eco surveys to investigate the changes in vegetation characteristics,soil physicochemical properties,and soil microbial functional diversity in degraded alpine wetlands of the source region of the Yellow River at 3 and 15 months after the application of nitrogen,phosphorus,and organic mixed *** following results were obtained:The addition of nitrogen fertilizer and organic compost significantly affects the soil organic carbon content in degraded *** months after fertilization,nitrogen addition increases soil organic carbon in both lightly and severely degraded wetlands,whereas after 15 months,organic compost enhanced the soil organic carbon level in severely degraded *** equation modeling indicates that fertilization decreases the soil pH and directly or indirectly influences the soil organic carbon levels through variations in the soil water content and the aboveground biomass of *** months after fertilization,nitrogen fertilizer showed a direct positive effect on soil organic ***,organic mixed fertilizer indirectly reduced soil organic carbon by increasing biomass and decreasing soil *** 15 months,none of the fertilizers significantly affected the soil organic carbon *** summary,it can be inferred that the addition of nitrogen fertilizer lacks sustainability in positively influencing the organic carbon content.

关键词： Degraded alpine wetlands Fertilizer Soil organic carbon Temporal variation Vegetation aboveground biomass Yellow River source region

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Perceptual video quality assessment: a survey

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Science China(Information Sciences) 2024年第11期67卷 20-76页

作者： Xiongkuo MIN Huiyu duan wei SUN Yucheng ZHU Guangtao ZHAI Department of Electronic Engineering Shanghai Jiao Tong University

Perceptual video quality assessment plays a vital role in the field of video processing due to the existence of quality degradations introduced in various stages of video signal acquisition, compression,transmission and display. With the advancement of Internet communication and cloud service technology,video content and traffic are growing exponentially, which further emphasizes the requirement for accurate and rapid assessment of video quality. Therefore, numerous subjective and objective video quality assessment studies have been conducted over the past two decades for both generic videos and specific videos such as streaming, user-generated content, 3D, virtual and augmented reality, high dynamic range, high frame rate, audio-visual, etc. This survey provides an up-to-date and comprehensive review of these video quality assessment studies. Specifically, we first review the subjective video quality assessment methodologies and databases, which are necessary for validating the performance of video quality metrics. Second, the objective video quality assessment measures for general purposes are categorized and surveyed according to the methodologies utilized in the quality measures. Third, we overview the objective video quality assessment measures for specific applications and emerging topics. Finally, the performance of the state-of-the-art video quality assessment measures is compared and analyzed. This survey provides a systematic overview of both classical works and recent progress in the realm of video quality assessment, which can help other researchers quickly access the field and conduct relevant research.

关键词： video quality assessment human visual system subjective quality assessment objective quality assessment survey

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大腔体静高压技术的发展及应用

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物理 2022年第4期51卷 228-238页

作者：李帅锜贺端威张佳威四川大学原子与分子物理研究所成都610065 四川大学高能量密度物理及技术教育部重点实验室成都610065

大腔体静高压技术在现代工业和高压科学研究中具有基础性的重要意义,已被广泛应用于工业和科研领域,如超硬材料的合成、凝聚态物质在高温高压极端条件下的行为与物性研究等。经过逾半个世纪的不懈努力,以国产铰链式六面顶压机为代表的... 详细信息

大腔体静高压技术在现代工业和高压科学研究中具有基础性的重要意义,已被广泛应用于工业和科研领域,如超硬材料的合成、凝聚态物质在高温高压极端条件下的行为与物性研究等。经过逾半个世纪的不懈努力,以国产铰链式六面顶压机为代表的大腔体静高压技术与设备取得了长足的发展和丰硕的成果,改变了长期以来我国大腔体静高压技术落后于国外的局面。文章以四川大学高压科学与技术实验室为例,对我国大腔体静高压技术及装置从起步研制到世界领先的发展历程和技术特点进行了介绍。同时,基于典型大腔体静高压技术、装置及主要应用,展望了我国相关领域的发展前景。

关键词：大腔体静高压二级高压装置高压科学与技术六面顶压机

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Rectus sheath hematoma combined with COVID-19:A case report

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World Journal of Clinical Cases 2024年第20期12卷 4325-4330页

作者： wei Wang Jie duan Department of Obstetrics&Gynecology Wuhan University of Science and TechnologyWuhan 430070Hubei ProvinceChina Department of Obstetrics&Gynecology Hubei Maternal and Child Health HospitalWuhan 430070Hubei ProvinceChina

BACKGROUND Rectus sheath hematoma(RSH)is uncommon,and because people have limited knowledge about it,it is difficult to recognize the symptoms in time,often delaying optimal *** SUMMARY herein,we report a case of a 77-year-old female with *** patient was treated at our hospital for coronavirus disease *** treatment was administered during this period because of *** the 8th d of treatment,the patient complained of abdominal *** revealed a solid cystic mass in the pelvic *** emergency laparotomy was performed,and a huge hematoma was found in the deep layer of the rectus abdominis *** used anticoagulants with caution based on the patient’s *** Optimal management of patients with RSH s depends on timely diagnosis and when to reintroduce anticoagulants.

关键词： Clinical manifestations COVID-19 Diagnosis Rectus sheath hematoma Treatment Case report

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Atomically dispersed Fe sites on hierarchically porous carbon nanoplates for oxygen reduction reaction

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Journal of Energy Chemistry 2024年第3期90卷 7-15,I0002页

作者： Ruixue Zheng Qinglei Meng Hao Zhang Teng Li Di Yang Li Zhang Xiaolong Jia Changpeng Liu Jianbing Zhu Xiaozheng duan Meiling Xiao wei Xing State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina Laboratory of Advanced Power Sources Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesJiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhou 215123JiangsuChina State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina

Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air *** Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active *** by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) *** a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N *** from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(*** hydrogen electrode(Rhe)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 *** dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR *** situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C *** work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.

关键词： Fe single atom catalysts Oxygen reduction reaction Mesoporous structure Active sites Zinc-air battery

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Evaluation of the injection and plugging ability of a novel epoxy resin in cement cracks

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Petroleum Science 2024年第2期21卷 1211-1220页

作者： Guang-Yao Leng wei Yan Hai-Mu Ye Er-Dong Yao Ji-Bin duan Zheng-Xian Xu Ke-Pei Li Jing-Ru Zhang Zhong Li State Key Laboratory of Petroleum Resource&Prospecting China University of Petroleum(Beijing)Beijing102249China CNPC Liaohe Oilfield Gas Storage Co.LTD Panjin124000LiaoningChina CNOOC Research Institute Co. Ltd.Beijing100028China

Sustained casing pressure(SCP)is a crucial issue in the oil and gas production *** resins,exhibiting exceptional compressive strength,ductility,and shear bonding strength,have the potential to form reliable *** injectivity and sealing capacity of the epoxy resin is crucial parameters for the success of shallow remediation *** study aimed to develop and assess a novel solid-free resin sealant as an alternative to Portland cement for mitigating fluid *** investigation evaluated the viscosity,compressive strength,and brittleness index of the epoxy resin sealant,as well as its tangential and normal shear strengths in conjunction with casing *** flow characteristics and sealing abilities of conventional cement and epoxy resin were comparatively analyzed in *** results showed that the application of a viscosity reducer facilitated control over the curing time of the epoxy resin,ranging from 1.5 to 6 h,and reduced the initial viscosity from 865.53 to 118.71 m Pa,*** mechanical properties of the epoxy resin initially increased with a rise in curing agent content before experiencing a minor *** epoxy resin containing 30%curing agent exhibited optimal mechanical *** a 14-day curing period,the epoxy resin's compressive strength reached81.37 MPa,2.12 times higher than that of cement,whereas the elastic modulus of cement was 2.99 times greater than that of the epoxy *** brittleness index of epoxy resin is only 3.42,demonstrating high flexibility and *** tangential and normal shear strengths of the epoxy resin exceeded those of cement by 3.17 and 2.82 times,*** a 0.5 mm-wide crack,the injection pressure of the epoxy resin remained below 0.075 MPa,indicating superior injection and flow ***,the injection pressure of cement surged dramatically to 2.61 MPa within 5 *** breakthrough pressure of0.5 PV epoxy resin reached 7.53 MPa,decreasing the crack's perme

关键词： Sustained casing pressure Epoxy resin sealant Curing agent Viscosity reducer Mechanical properties Crack sealing

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立方烧绿石Gd_2Zr_2O_7的高温高压合成

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原子能科学技术 2010年第4期44卷 394-399页

作者：唐敬友陈晓谋潘社奇牟涛贺端威西南科技大学核废物与环境安全国防重点学科实验室四川绵阳621010 中国工程物理研究院四川绵阳621900 四川大学原子与分子物理研究所四川成都610065

为探索高温高压固相反应法合成Gd2Zr2O7烧绿石的可能性,以Gd2O3和ZrO2的混合粉体为原料,在5.2GPa压力、1473～1873K温度范围内进行了实验研究。通过XRD对合成样品进行了结构表征,结果证实,在5.2GPa和1873K条件下,保温保压30min,成功地... 详细信息

为探索高温高压固相反应法合成Gd2Zr2O7烧绿石的可能性,以Gd2O3和ZrO2的混合粉体为原料,在5.2GPa压力、1473～1873K温度范围内进行了实验研究。通过XRD对合成样品进行了结构表征,结果证实,在5.2GPa和1873K条件下,保温保压30min,成功地合成出单一物相的、具有立方烧绿石结构的Gd2Zr2O7化合物。这种新的合成方法对于开展武器级多余钚和含钚高放废物固化具有重要的科学价值和实际意义。

关键词： Gd2Zr2O7 烧绿石高温高压合成放射性废物固化体

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Nutrient enrichment driven by canopy rainfall redistribution:Mechanism,quantification,and pattern

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Science China Earth Sciences 2024年第5期67卷 1529-1544页

作者： Chuan YUAN Xiaoping YUE Yafeng ZHANG Yu ZHANG Yanting HU Qiang TANG Li GUO Shuai WANG Xingwu duan Wenhua XIANG Xiaohua wei Xiaoyan LI College of Forestry and Biotechnology Zhejiang A&F UniversityHangzhou 311300China Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqing 400715China Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China School of Geographical Sciences Hebei Normal UniversityShijiazhuang 050024China Faculty of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Yunnan Key Laboratory of Soil Erosion Prevention and Green Development Institute of International Rivers and Eco-securityYunnan UniversityKunming 650091China Department of Earth Environmental and Geographic SciencesUniversity of British Columbia(Okanagan)KelownaBritish Columbia V1V 1V7Canada

Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community *** advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely *** address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure *** aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and *** results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to *** particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment *** climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid *** the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing *** addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural *** findings emphasize the need for increased attentions to artificial ecosystems,such as urban

关键词： Ecohydrology Rainfall redistribution Nutrients transport Enrichment characteristics Climate zones

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On-chip ultra-high rejection and narrow bandwidth filter based on coherency-broken cascaded cladding-modulated gratings

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Photonics Research 2024年第5期12卷 979-985页

作者： JINZHAO WANG TING LI YANG FENG JIEWEN LI WANXIN LI LUwei DING YONG YAO JIANAN duan wei LIU FENG he YI ZOU XIAOCHUAN XU Guangdong Provincial Key Laboratory of Integrated Photonic-Electronic Chip Guangdong Provincial Key Laboratory of Aerospace Communication and Networking TechnologyHarbin Institute of TechnologyShenzhenShenzhen 518055China School of Information Science and Technology ShanghaiTech UniversityShanghai 201210China

Bragg filters are of essential importance for chip-scale photonic ***,the implementation of filters with sub-nanometer bandwidth and rejection beyond 70 dB is hindered by the high index contrast of the siliconon-insulator platform,which makes filters prone to fabrication *** this paper,we propose to combine coherency-broken cascading architecture and cladding modulation to circumvent the intrinsic *** cascading architecture effectively prevents the accumulation of phase errors,while the cladding modulation offers additional design freedom to reduce the coupling coefficient.A bimodal Bragg filter with a testingequipment-limited rejection level of 74 dB and a 40 dB bandwidth of 0.44 nm is experimentally *** minimum feature size is 90 nm,which significantly relieves the fabrication constraints.

关键词： filter cladding narrow

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高温高压固态复分解反应法生长氮化镓的应变性质研究

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光散射学报 2011年第2期23卷 133-137页

作者：马瑶龚敏马欢贺端威四川大学物理科学与技术学院微电子技术四川省重点实验室成都610064 四川大学原子与分子物理研究所成都610065

本文采用高温高压下固态复分解反应法生长氮化镓。用X射线衍射仪、扫描电子显微镜、激光拉曼光谱仪对其进行分析,结果表明生成了六角纤锌矿结构的氮化镓晶体。该样品在宏观上受到了张应力的作用,退火后,宏观的应变状态由张应变向压应变... 详细信息

本文采用高温高压下固态复分解反应法生长氮化镓。用X射线衍射仪、扫描电子显微镜、激光拉曼光谱仪对其进行分析,结果表明生成了六角纤锌矿结构的氮化镓晶体。该样品在宏观上受到了张应力的作用,退火后,宏观的应变状态由张应变向压应变转变;晶体微观应力减小,晶粒尺寸变大,晶体质量变好。

关键词：氮化镓 X射线衍射拉曼光谱应变应力退火

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