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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

Enhanced potassium storage of carbon nanofibers as binderfree anodes enabled by coupling ultra-small amorphous Sb_(2)O_(3),graphene modification and sulfur doping

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Rare Metals 2024年第1期43卷 51-64页

作者： Zhao Huang Yu-Kang Lou Lin peng yuan peng Meng-Meng Wang Ming zhang College of Railway Transportation Hunan University of TechnologyZhuzhou 412007China College of Semiconductors(College of Integrated Circuits) Changsha Semiconductor Technology and Application Innovation Research InstituteHunan UniversityChangsha 410082China Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China

Considering the intrinsic advantages of natural copiousness and cost-effectiveness of potassium resource,potassium-ion batteries(KIBs) are booming as prospective alternatives to lithium-ion batteries(LIBs) in large-scale energy storage scenarios. Nevertheless, lacking desirable electrodes for reversibly hosting the bulky K+hinders the widespread application of KIBs, and it needs to be urgently solved. Hereon, the porous S-doped Sb_(2)O_(3)-graphene-carbon(SAGC) nanofibers are manufactured through an adjustable and facile approach, which involves electrospinning, in situ etching and sulfuration. The synthesized SAGC is featured by the ultra-small amorphous Sb_(2)O_(3) homogeneously wrapped inside the carbon matrix, as well as the co-incorporation of graphene and sulfur. Tentatively,the SAGC nanofiber sheets are applied as binder-free anodes for KIBs, exhibiting a prominent cycling life(256.72 m Ah·g^(-1) over 150 cycles at 100 m A·g^(-1)) and rate·g^(-1) over 100 cycles at 1 A·g^(-1)). The positive synergy among all the active components accounts for the distinguished performances of the SAGC. By reinforcing the tolerability to the swelling stress, producing the valid electrochemical active sites, and promoting the charge transferring for reversible K+uptake, the SAGC finally renders the excellent cyclability, capacity, and rate capability. Moreover, the extrinsic electrochemical pseudocapacitance characteristics induced by the porous carbon substrate elevate the K-storage capacity of the SAGC as well. It is hoped that the conclusions drawn may offer new insights into a direction for the high-performance binderfree KIB anodes.

关键词： S-doped Sb_(2)O_(3)-graphene-carbon Nanofibers Binder-free Anodes Potassium-ion batteries

Preparation, Crystallization and Mechanical Properties of Potassium Aluminosilicate Glass-ceramics

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Journal of Wuhan university of technology(Materials Science) 2024年第3期39卷 587-595页

作者：郑伟宏黄猛 GAO Zipeng zhang Hang yuan Jian TIAN Peijing peng Zhigang State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Shahe Research Institute of Glass technology Shahe 054100China

In this study,transparent K_(2)O-Al_(2)O_(3)-SiO_(2)(KAS)glass-ceramics with leucite as the main crystalline phase were prepared by melting-quench method and two-step heat *** effects of SiO_(2)/Al_(2)O_(3) ratio and heat treatment on crystallization and mechanical properties were *** crystallization kinetics and X-Ray Diffraction(XRD)results showed that SiO_(2)/Al_(2)O_(3) ratio and heat treatment system had a direct impact on the crystallization behavior of potassium aluminosilicate *** heat-treated at 680℃/2 h and 780℃/1 h,cracks generated on the surface of the sample with the addition of SiO_(2)/Al_(2)O_(3)=4.8(in mol)due to the huge difference in the coefficient of thermal expansion between glass matrix and *** the addition of SiO_(2)/Al_(2)O_(3)(in mol)was 4,the sample with leucite as the main crystalline phase showed an excellent fracture toughness(1.46 MPa·m^(0.5))after the heat treatment of 680℃/2 h and 780℃/5 *** there was a phase transformation from kaliophilite to *** crystalline phases of the sample heat-treated at 680℃/8 h and 780℃/1 h were leucite and kaliophilite,which resulted in the visible light transmittance of 63%and the fracture toughness of 0.91 MPa·m^(0.5).Furthermore,after the heat treatment of 680℃/2 h and 780℃/5 h,the main crystalline phase of the sample with SiO_(2)/Al_(2)O_(3)=3.2(in mol)was still *** leucite only grows on the surface of the sample and is hard to grow inward,it is hard to achieve the bulk crystallization of leucite in the sample with SiO_(2)/Al_(2)O_(3)=3.2(in mol).

关键词： leucite glass-ceramic kaliophilite crystallization kinetics

Perpendicularly assembled oriented electrospinning nanofibers based piezoresistive pressure sensor with wide measurement range

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Nano Research 2024年第7期17卷 6493-6501页

作者： Xiaoxue Bi Zhigang Duan Xiaojuan Hou Shuo Qian Mengjiao yuan Jiajun Hu Jie zhang Yuchen Lu Yanli liu Jian He Zhiling peng Xiujian Chou School of Mechanical and Electrical Engineering North University of ChinaTaiyuan 030051China Science and technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan 030051China School of Software North University of ChinaTaiyuan 030051China School of Information and Communication Engineering North University of ChinaTaiyuan 030051China

With the rapid development of wearable electronics,flexible pressure sensors have attracted wide attention in human–computer interaction and intelligent ***,it is a challenge to achieve a sensor with high sensitivity,wide measurement range,and wearing ***,we develop an oriented electrospinning thermoplastic polyurethane/polyacrylonitrile(TPU/PAN)nanofibers(OETPN)based piezoresistive pressure sensor(PONPS)in which the active layer and the electrode are assembled *** interdigital electrode is fabricated by spraying silver nanowires(AgNWs)on the OETPN through a mask *** active layer is composed of OETPN coated with MXene,encapsulated on the electrode by polyurethane(PU)*** porous structure of nanofibers membrane broadens the measurement range of the *** oriented nanofibers as active layer can improve the sensitivity in low pressure,because oriented nanofibers without interweaving nanofibers are more compressible than disordered *** prepared using the spraying method creates nanoscale microstructure and increases *** perpendicular assembly has greater response between the active layer and the electrode than the parallel assembly to improve the *** sensor exhibits high sensitivity(6.71 kPa^(−1),0.02–2 kPa)and wide measurement range(0.02–700 kPa).The sensor can detect weak signals such as radial artery.A pressure array constructed precisely represents the distribution of *** intelligent throat is created by combining machine learning algorithms with the *** can detect and recognize subtle throat vibrations while speaking,achieving recognition accuracy up to 100%using support vector machine(SVM)for five words with different *** fabricated sensor shows promising prospects in personal healthcare and intelligent robots.

关键词： oriented nanofibers perpendicular assembly parallel assembly intelligent throat machine learning algorithms

Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

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Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie Xue-yuan Jiang Hai-yan Tang ·Gen Li Yu-hang Wang Jia-quan zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel Institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

Five quinolizidine alkaloids with anti-tobacco mosaic virus activities from two species of Sophora

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Chinese Chemical Letters 2024年第6期35卷 380-384页

作者： Ji zhang Tong zhang Qiao An peng zhang Cai-Yan Tian Chun-Mao yuan Ping Yi Zhan-Xing Hu Xiao-Jiang Hao State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical UniversityGuiyang 550014China Natural Products Research Center of Guizhou Province Guiyang 550014China School of Pharmaceutical Sciences Guizhou Medical UniversityGuiyang 550025China School of Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China State Key Laboratory of Phytochemistry and Plant Resources in West china Kunming Institute of BotanyChinese Academy of ScienceKunming 650201China Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical SciencesKunming 650201China

Three novel matrine-type alkaloids(1-3)and two unprecedented aloperine-type alkaloids(4 and 5)were isolated from the root of Sophora tonkinensis and the seeds of Sophora alopecuroides ***,compound 1 possessed an unprecedented 6/5/6 tricyclic skeleton,while compounds 2 and 3 characterized by rare 6/6/5/6 tetracyclic system and 6/6/6/6/6 pentacyclic system ***,compound 4 possessed an unprecedented 6/7/6/6 tetracyclic core,and compound 5 characterized by rare 6/6/6/6tetracyclic *** structures were elucidated by comprehensive spectroscopic data analysis and electronic circular dichroism(ECD)*** tests indicated that compound 5 displayed significant anti-tobacco mosaic virus(TMV)activity compared with the positive control ningnanmycin.

关键词： Matrine-type alkaloids Aloperine-type alkaloids Sophora tonkinensis Sophora alopecuroides Anti-tobacco mosaic virus

Regio-and Stereoselective Polymerization of Bio-based Ocimene by Rare-Earth Metal Catalysts

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Chinese Journal of Polymer Science 2024年第2期42卷 223-229,I0008页

作者： Qi-yuan Wang Li-peng Sang Zhen zhang Yang Jiang Hui Tian Xia Zhao Xiang Guo Shi-Hui Li State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China Science and technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechonologyXiangyang441003China Shanxi Coal Chemical Industry technology Research Institute Xi’an710000China Hubei Institute of Aerospace Chemotechonology Xiangyang441003China

Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity.

关键词： Biobased monomer Terpenes Ocimene Rare-earths Polymerization Regio/stereoselectivity Elastomer

Progress in technology for the 2005 height determination of Qomolangma Feng (Mt. Everest)

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Science china Earth Sciences 2006年第5期49卷 531-538页

作者： CHEN Junyong1,2, yuan Janli1,2, GUO Chunxi1,2, zhang Yanping1 & zhang {3.1,2 1. State Bureau of Surveying and Mapping, beijing 100830, china 2. School of Geodesy and Geomatics, Wuhan university, Wuhan 430079, china 1. State Bureau of Surveying and Mapping Beijing 100830 China 2. School of Geodesy and Geomatics Wuhan University Wuhan 430079 China

In 2005 china carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2005 campaign are presented in the paper. GPS positioning was the key technique in the campaign. After summarizing the experiences and lessons of the GPS positioning on the QF summit in the previous QF height determination campaigns, some measures were taken to raise the accuracy and reliability of the height determination with GPS techniques. In order to raise the accuracy of the height deter- mination of the QF summit with classical geodetic techniques, laser ranging was used together with the trigonometric levelling in the 2005 campaign. It is the first time in china the thickness of the ice-snow layer on the QF summit was measured by ground penetrating radar integrated with GPS. The local gravity field and geoid in the QF area was improved on the basis of earth gravity field model integrated with new ground gravity data, DTM data and GPS leveling data in the QF area. In the 2005 campaign the normal height and orthometric height (height above sea level) of the snow surface of the QF summit were obtained as 8846.67 m and 8847.93 m respectively. The orthometric height of the rock surface of the QF summit is 8844.43 m,and the thickness of the ice-snow layer on the QF summit is 3.50 m.

关键词： Qomolangma Feng, Mt. Everest, height determination, GPS, gravity field, ground penetrating radar.

Perioperative toripalimab plus neoadjuvant chemotherapy might improve outcomes in resectable esophageal cancer:an interim analysis of a phase Ⅲ randomized clinical trial

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Cancer Communications 2024年第10期44卷 1214-1227页

作者： Yan Zheng Guanghui Liang Dongfeng yuan Xianben liu Yufeng Ba Zimin Qin Sining Shen Zhenxuan Li Haibo Sun Baoxing liu Quanli Gao peng Li Zongfei Wang Shilei liu Jianping Zhu Haoran Wang Haibo Ma Zhenzhen liu Fei Zhao Jun zhang He zhang Daoyuan Wu Jinrong Qu Jie Ma peng zhang Wenjie Ma Ming Yan Yongkui Yu Qing Li Jiangong zhang Wenqun Xing Department of Thoracic Surgery The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Immunotherapy The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Endoscopy The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Pathology The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Radiology The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Biobank The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Strategic Development The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouHenanP.R.China Department of Statistics LinkDoc Technology Co.LtdBeijingP.R.China Department of Cancer Epidemiology The Affiliated Cancer Hospital of Zhengzhou UniversityHenan Cancer HospitalZhengzhouP.R.China

Background:In the era of immunotherapy,neoadjuvant immunochemotherapy(NAIC)for the treatment of locally advanced esophageal squamous cell carcinoma(ESCC)is used clinically but lacks of high-level clinical *** study aimed to compare the safety and long-term efficacy of NAIC followed byminimally invasive esophagectomy(MIE)with those of neoadjuvant chemotherapy(NAC)followed by ***:A prospective,single-center,open-label,randomized phase Ⅲ clinical trial was conducted at Henan Cancer Hospital,Zhengzhou,*** were randomly assigned to receive either neoadjuvant toripalimab(240mg)plus paclitaxel(175 mg/m^(2))+cisplatin(75 mg/m^(2))(toripalimab group)or paclitaxel+cisplatin alone(chemotherapy group)every 3 weeks for 2 *** surgery,the toripalimab group received toripalimab(240 mg every 3 weeks for up to 6 months).The primary endpoint was event-free survival(EFS).The pathological complete response(pCR)and overall survival(OS)were key secondary *** events(AEs)and quality of life were also ***:Between May 15,2020 and August 13,2021,252 ESCC patients ranging fromT1N1-3M0 to T2-3N0-3M0were enrolled for interim analysis,with 127 in the toripalimab group and 125 in the chemotherapy *** 1-year EFS rate was 77.9%in the toripalimab group compared to 64.3%in the chemotherapy group(hazard ratio[HR]=0.62;95%confidence interval[CI]=0.39 to 1.00;P=0.05).The 1-year OS rates were 94.1%and 83.0%in the toripalimab and chemotherapy groups,respectively(HR=0.48;95%CI=0.24 to 0.97;P=0.037).The patients in the toripalimab group had a higher pCR rate(18.6%vs.4.6%;P=0.001).The rates of postoperative Clavien-Dindo grade Ⅲb or higher morbidity were 9.8%in the toripalimab group and 6.8%in the chemotherapy group,with no significant difference observed(P=0.460).The rates of grade 3 or 4 treatment-related AEs did not differ between the two groups(12.5%versus 12.4%).Conclusions:The interim results of this ongoing trial showed that in resec

关键词： esophageal squamous cell carcinoma minimally invasive esophagectomy neoadjuvant chemotherapy neoadjuvant immunochemotherapy survival