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Syntheses and properties of associative acrylamide copolymers containing short hydrophobic chains used in a friction reducer for slick-water fracturing

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Petroleum Science 2024年第3期21卷 1889-1901页

作者： ya-Xing Dai Xian-Li Zhang Si-Yuan Liu Feng-Run-Ze Zhang Yi-Xi Zhang Yu-tong Sang Jing-Xi Zheng Zhao-Sheng Liu Peng Zhang College of Chemistry and Chemical Engineering Chongqing University of Science and TechnologyChongqing401331China College of Ecology and Environment Chongqing Resources and Environmental Protection of UniversityChongqing401331China China China Property Project Department of Dezhou Mining Property Service CenterShengli Oilfield Company of SinopecDezhou253000ShandongChina

Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2),were synthesized and used to prepare modified polyacrylamide *** new drag reducers were synthesized from acrylamide(AM),sodium acrylate(Na AA)and a cationic modified monomer(AQAS1 or AQAS2)via aqueous solution polymerization,and the copolymers were named P(AM/Na AA/AQAS1)and P(AM/Na AA/AQAS2),*** structures of the drag reduction agents were confirmed by IR and1H NMR *** molecular weight(Mw)of P(AM/Na AA/AQAS1)was 1.79×10^(6)g/*** the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min,in fresh water the highest drag reduction rate was 75.8%,in 10,000 mg/L Na Cl solution the drag reduction rate decreased to 72.9%.The molecular weight of P(AM/Na AA/AQAS2)was 3.17×10^(6)g/*** the copolymer concentration was500 mg/L and the flow rate was 45 L/min,the drag reduction rate reached 75.2%,and in 10,000 mg/L Na Cl solution the drag reduction rate was 73.3%,decreased by approximately 1.9%.The drag reduction rate for partially hydrolyzed polyacrylamide(HPAM)was also investigated,and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2%and 49.0%in brine,*** with HPAM,both of the above copolymers presented better drag reduction capacities.

关键词： Shale gas Slick water Drag reducer Modified monomer Copolymerization

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Four decades of full-scale nitrous oxide emission inventory in China

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National Science Review 2024年第3期11卷 137-149页

作者： Minqi liang Zheyan Zhou Peiyang Ren Han Xiao Xu-Ri Zhongmin Hu Shilong Piao Hanqin Tian Qing tong Feng Zhou Jing Wei Wenping Yuan School of Atmospheric Sciences Guangdong Province Data Center of Terrestrial and Marine Ecosystems Carbon Cycle Sun Yat-sen University State Key Laboratory of Tibetan Plateau Earth System Resources and Environment Institute of Tibetan Plateau Research Chinese Academy of Sciences Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province Hainan University Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking University Schiller Institute for Integrated Science and Society Department of Earth and Environmental Sciences Boston College Institute of Energy Environment and Economy Tsinghua University Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)

China is among the top nitrous oxide（N2O）-emitting countries, but existing national inventories do not provide full-scale emissions including both natural and anthropogenic sources. We conducted a four-decade（1980–2020） of comprehensive quantification of Chinese N2O inventory using empirical emission factor method for anthropogenic sources and two up-to-date process-based models for natural sources. Total N2O emissions peaked at 2287.4（1774.8–2799.9） Gg N2O yr-1in 2018, and agriculture-developed regions, like the East, Northeast, and Central, were the top N2O-emitting regions. Agricultural N2O emissions have started to decrease after 2016 due to the decline of nitrogen fertilization applications, while, industrial and energetic sources have been dramatically increasing after 2005. N2O emissions from agriculture, industry,energy, and waste represented 49.3%, 26.4%, 17.5%, and 6.7% of the anthropogenic emissions in 2020,respectively, which revealed that it is imperative to prioritize N2O emission mitigation in agriculture,industry, and energy. Natural N2O sources, dominated by forests, have been steadily growing from 317.3（290.3–344.1） Gg N2O yr-1in 1980 to 376.2（335.5–407.2） Gg N2O yr-1in 2020. Our study produces a Full-scale Annual N2O dataset in China（FAN2020）, providing emergent counting to refine the current national N2O inventories.

关键词： nitrous oxide four decades anthropogenic sources natural sources

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Treatment of multisystem inflammatory syndrome in children

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World Journal of Pediatrics 2024年第4期20卷 325-339页

作者： tong tong Yi-Hua Jin Min Wang Fang-Qi Gong Department of Cardiology Children's HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthNo.3333 Binsheng RoadHangzhou 310052China

Background Multisystem inflammatory syndrome in children(MIS-C),a relatively uncommon but severe pediatric complication,is associated with coronavirus disease 2019(COVID-19).A variety of treatment approaches,including intravenous immunoglobulins(IVIGs),glucocorticoids(GCs)and biologic agents,such as anakinra and infliximab,have been described for the management of COVID-19-related *** therapy is also ***,a well-developed treatment system has not been established,and many issues remain *** recently published articles related to the treatment of MIS-C have been ***,in this review,we identified relevant articles published recently and summarized the treatment of MIS-C more comprehensively and *** sources We reviewed the literature on the treatment of MIS-C through 20 September *** PubMed/Medline,Web of Science,EMBASE,and Cochrane Library databases were searched with the combination of the terms"multisystem inflammatory syndrome","MIS-C","PIMS-TS","therapy","treatment","drug","IVIG","GCs","intravenous immunoglobulin","corticosteroids","biological agent",and"aspirin".Results The severity of MIS-C varies,and different treatment schemes should be used according to the specific *** research and data collection are vital to better understand the pathophysiology and optimal management of *** MIS-Cis a disease involving multiple systems and has great *** the accumulation of additional experience,we have garnered fresh insights into its treatment ***,there remains a critical need for greater standardization in treatment protocols,alongside the pressing necessity for more robust and meticulously conducted studies to deepen our understanding of these protocols.

关键词： Coronavirus disease 2019-Corticosteroids Intravenous immunoglobulin Multisystem inflammatory syndrome in children-Treatment

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Bioinspired Double-stranded yarn with Alternating Hydrophobic/Hydrophilic Patterns for High-efficiency Fog Collection

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Chinese Journal of Polymer Science 2024年第7期42卷 968-975,I0008页

作者： Lan-Lan Hou Meng-Na Qiu ya-Qiong Wang tong-Hua Bai Zhi-Min Cui Jing-Chong Liu Ying-Qun Qi Nü Wang Yong Li Yong Zhao Beijing Institute of Graphic Communication Beijing102600China Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education Beijing Key Laboratory of Bioinspired Energy Materials and DevicesSchool of ChemistryBeijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing100191China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China Beijing Key Laboratory for Bioengineering and Sensing TechnologyDaxing Research InstituteSchool of Chemistry and Biological EngineeringUniversity of Science and Technology BeijingBeijing100083China

Efforts to develop innovative water harvesting strategies offer powerful solutions to alleviate the water crisis,especially in remote and arid *** by the hydrophobic/hydrophilic pattern of desert beetles and water self-propulsion property of spider silks,a double-strand hydrophobic PVDF-HFP/hydrophilic PAN nanofibers yarn is proposed by electrospinning and twisting *** double-strand cooperation approach allows for water deposition on hydrophobic PVDF-HFP segment and transport under the asymmetric capillary driving force of hydrophilic PAN segment,thus speeded up the aggregation and growth of *** effects of the composition and the diameter ratio of the two primary yarns were studied and optimized for boosting fog collection *** double-strand anisotropic yarn not only provide an effective method for water harvesting,but also hold the potential to inspire innovative design concepts for fog collection materials in challenging environments.

关键词： Fog collection Wettability Electrospinning Nanofibers Spider silk

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Upconversion luminescence and temperature sensing performance of Er^(3+) ions doped self-activated KYb(MoO_(4))_(2) phosphors

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Journal of Rare Earths 2024年第8期42卷 1507-1513,I0004页

作者： Ye tong Wenpeng Liu Shoujun Ding School of Microelectronics and Data Science Anhui University of TechnologyMaanshan243002China Advanced Laser Technology Laboratory of Anhui Province Hefei230037China Anhui Institute of Optics and Fine Mechanics Chinese Academy of SciencesHefei230031China

In this work,a series of self-activated KYb(MoO_(4))_(2) phosphors with various x at% Er^(3+) doping concentrations(x=0.5,1,3,5,8,10,15) was synthesized by the solid-state reaction *** phase structure of the as-prepared samples was analyzed by X-ray diffraction(XRD),XRD Rietveld refinement and Fourier transform infrared(FT-IR) *** as-prepared samples retain the orthorhombic structure with space group of Pbcn even Er^(3+) doping concentration up to 15 at%.High-purity upconversion(UC) green emission with green to red intensity ratio of 55 is observed from the as-prepared samples upon the excitation of 980 nm semiconductor laser and the optimum doping concentration of Er^(3+) ions in the self-activated KYb(MoO_(4))_(2) host is revealed as 3 at%.The strong green UC emission is confirmed as a two-photon process based on the power-dependent UC *** addition,the fluorescence intensity ratios(FIRs) of the two thermally-coupled energy levels,namely ^(2)H_(11/2) and ^(4)S_(3/2).of Er^(3+) ions were investigated in the temperature region 300-570 K to evaluate the optical temperature sensor behavior of the *** maximum relative sensitivity(S_(R)) is determined to be 0.0069 K^(-1) at300 K and the absolute sensitivity(S_(A)) is determined to be 0.0126 K^(-1) at 300 *** S_(A) of self-activated KYb(MoO_(4))2:Er^(3+)is almost twice that of traditional KY(MoO_(4))2:Er^(3+)/Yb^(3+)codoping *** results demonstrate that Er^(3+) ions doped self-activated KYb(MoO_(4))2 phosphor has promising application in visible display,trademark security and optical temperature sensors.

关键词： Er^(3+)ions doped KYb(MoO_(4))_(2) Self-activated phosphors Upconversion luminescence Solid-state reaction method Optical temperature sensors Rare earths

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Exclusive Hypothesis Testing for Cox's Proportional Hazards Model

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Journal of Systems Science & Complexity 2024年第5期37卷 2157-2172页

作者： WU Qiang tong Xingwei DUAN Xiaogang School of Statistics Beijing Normal University

Exclusive hypothesis testing is a new and special class of hypothesis testing. This kind of testing can be applied in survival analysis to understand the association between genomics information and clinical information about the survival time. Besides, it is well known that Cox's proportional hazards model is the most commonly used model for regression analysis of failure time. In this paper,the authors consider doing the exclusive hypothesis testing for Cox's proportional hazards model with right-censored data. The authors propose the comprehensive test statistics to make decision, and show that the corresponding decision rule can control the asymptotic Type Ⅰ errors and have good powers in theory. The numerical studies indicate that the proposed approach works well for practical situations and it is applied to a set of real data arising from Rotterdam Breast Cancer Data study that motivated this study.

关键词： Comprehensive test statistics Cox’s proportional hazards model exclusive hypothesis testing right-censored data Type I error

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MAL2 DNA methylation serves as a biomarker for the diagnosis and prognosis of glioma

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Genes & Diseases 2024年第5期11卷 36-39页

作者： Hao Luo Xing Xiao Weiliang Hou Jing Cai Ming Chen Qisheng Tang Yusheng tong Zengxin Qi Kaicheng Li liang Chen Department of Neurosurgery Huashan HospitalShanghai Medical CollegeState Key Laboratory of Medical NeurobiologyMOE Frontiers Center for Brain Science and Institutes of Brain ScienceFudan UniversityShanghai 200040China National Center for Neurological Disorders Shanghai 200040China Shanghai Key Laboratory of Brain Function and Restoration and Neural Regeneration Shanghai 200040China Tianqiao and Chrissy Chen Institute Clinical Translational Research Center Shanghai 200040China Shanghai QuietD Biotechnology Co. Ltd.Shanghai 201210China

Glioma is a common and malignant brain tumor,and molecular diagnostics for glioma have received increasing attention.1,2 Previous studies have suggested that the MAL2 gene may be involved in the transcytosis of various cancers.3 This study aimed to investigate the potential of MAL2 as a biomarker for *** candidate MAL2 CpG sites were validated by pyrosequencing and used to construct a diagnostic model for *** analysis was also conducted to determine the relationship between highly methylated MAL2-specific CpG sites and the prognosis of *** findings also showed that MAL2 was more highly methylated in glioma than in other *** constructed diagnostic model can distinguish glioma from other cancers with high sensitivity(93.3%)and specificity(86.5%).Additionally,a risk score model was built based on MAL2 methylation to assess the prognosis of glioma。

关键词： glioma diagnosis MAL

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Framework for Preventive Control of Power Systems to Defend Against Extreme Events

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 856-870页

作者： Yuwei Xiang tong Wang Zengping Wang State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

Enhancing power system resilience against extreme events is becoming increasingly critical. This paper discusses a unified framework for preventive control of power systems to enhance system resilience, which includes three parts: resilience assessment, resilience grading, and resilience enhancement. First, the resilience assessment contains facility-level and system-level resilience assessment. The concept of fragility curve is used in the facility-level resilience assessment. Various resilience indices are developed in system-level resilience assessment to roundly depict the impacts of extreme events on power systems and determine the system resilience. On this basis, the resilience is divided into different levels by resilience grading strategy, which can efficiently quantify the severity of the impact of extreme events and provide decision-making for the resilience enhancement strategies. Then, control strategies for enhancing power system resilience are also divided according to different resilience levels. A controlled islanding based preventive control is proposed to enhance system resilience, which aims to strengthen the first defensive line of power systems to deal with extreme events. Finally, taking the typhoon disaster in extreme events as an example, two tests carried out with two typhoons demonstrate the efficiency of the proposed method.

关键词： Controlled islanding extreme events power system resilience preventive control

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Interaction mechanism of cyanide with pyrite during the cyanidation of pyrite and the decyanation of pyrite cyanide residues by chemical oxidation

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 1996-2005页

作者： Wenwen Han Hongying yang Linlin tong Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China

The toxic cyanides in cyanide residues produced from cyanidation process for gold extraction are harmful to the *** is one of the main minerals existing in cyanide *** this work,the interaction of cyanide with pyrite and the decyanation of pyrite cyanide residue were *** revealed that high pH value,high cyanide concentration,and high pyrite dosage promoted the interaction of cyanide with *** cyanidation of pyrite was pseudo-second-order with respect to *** decyanation of pyrite cyanide residue by Na_(2)SO_(3)/air oxidation was *** cyanide removal efficiency was 83.9% after 1 h of reaction time under the optimal conditions of pH value of 11.2,SO_(3)^(2-) dosage of 22 mg·g^(-1),and air flow rate of 1.46 L·min^(-1).X-ray photoelectron spectroscopy analysis of the pyrite samples showed the formation of Fe(Ⅲ)and FeSO_(4) during the cyanidation *** cyanide that adsorbed on the pyrite surface after cyanidation mainly existed in the forms of free cyanide(CN^(-))and ferrocyanide(Fe(CN)_(6)^(4-)),which were effectively removed by Na_(2)SO_(3)/air *** the decyanation process,air intake promoted pyrite oxidation and weakened cyanide adsorption on the pyrite *** study has practical significance for gold enterprises aiming to mitigate the environmental impact related to cyanide residues.

关键词： pyrite cyanide decyanation sodium sulfite/air oxidation cyanide residue

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Advancements in Humanoid Robots: A Comprehensive Review and Future Prospects

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 301-328页

作者： Yuchuang tong Haotian Liu Zhengtao Zhang IEEE CAS Engineering Laboratory for Intelligent Industrial Vision Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

This paper provides a comprehensive review of the current status, advancements, and future prospects of humanoid robots, highlighting their significance in driving the evolution of next-generation industries. By analyzing various research endeavors and key technologies, encompassing ontology structure,control and decision-making, and perception and interaction, a holistic overview of the current state of humanoid robot research is presented. Furthermore, emerging challenges in the field are identified, emphasizing the necessity for a deeper understanding of biological motion mechanisms, improved structural design,enhanced material applications, advanced drive and control methods, and efficient energy utilization. The integration of bionics, brain-inspired intelligence, mechanics, and control is underscored as a promising direction for the development of advanced humanoid robotic systems. This paper serves as an invaluable resource, offering insightful guidance to researchers in the field,while contributing to the ongoing evolution and potential of humanoid robots across diverse domains.

关键词： Future trends and challenges humanoid robots human-robot interaction key technologies potential applications

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