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A comprehensive research on wear resistance of GH4169 superalloy in longitudinal-torsional ultrasonic vibration side milling with tool wear and surface quality

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Chinese Journal of Aeronautics 2024年第4期37卷 556-573页

作者： Baoqi chang Zhaoxi YI Fen ZHANG lian DUAN Ji-an DUAN School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China State Key Laboratory of High Performance and Complex Manufacturing Central South UniversityChangsha 410083China School of Physics and Electronics Central South UniversityChangsha 410083China

To improve the service and machining performance of the workpiece, the tool wear mechanisms, surface machining quality, and wear resistance in conventional side milling(CSM)and longitudinal-torsional ultrasonic vibration side milling(LTUVSM) of GH4169 superalloy at different cutting lengths are investigated systematically. Tool wear mechanisms are revealed and the correlation between machined surface quality with tool wear is analyzed correspondingly. Tool wear patterns mainly include adhesive wear, diffusion wear, abrasive wear, and chipping *** surface quality is achieved in LTUVSM due to a maximum reduction of flank wear bandwidth and wear rate by 71.9% and 71.5%, respectively, compared to CSM. The friction coefficient,initial wear stage time, and wear volume of dry sliding wear were measured to evaluate the workpiece wear resistance. The maximum reductions in friction coefficient and wear volume in LTUVSM are 18.2% and 15.8% compared to CSM. The regular ultrasonic vibration textures suppress the friction and the growth of contact nodes in the contact area, decreasing the degree of surface wear, which is demonstrated by a 38.8% increase in initial wear stage time compared to *** conclusion, the workpiece in LTUVSM exhibits higher wear resistance because of the improvement of tool wear and the guarantee of surface quality.

关键词： Dry sliding wear Surface quality Tool wear Ultrasonic vibration Wear resistance

Assembling molybdenum-doped platinum clusters into a coral-like nanostructure for highly enhanced oxygen reduction

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eScience 2024年第1期4卷 123-131页

作者： Linwei Zheng Mang Niu Tiantian Zeng Xiaohang Ge Yanrui Wang Chun Xian Guo Weiyong Yuan Dapeng Cao lian Ying Zhang chang ming Li Institute of Materials for Energy and Environment Institute of Biochemical EngineeringCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China Institute for Materials Science and Devices School of Materials Science and EngineeringSuzhou University of Science and TechnologySuzhou 215011PR China Ningbo Research Institute Zhejiang UniversityNingbo 315100China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

Regulating the electronic and geometric structures of electrocatalysts is an effective strategy to boost their catalytic ***,a coral-like nanostructure is assembled with Mo-doped Pt clusters to form a highly active catalyst toward the oxygen reduction reaction(ORR).The advantages of a Mo-doped porous skeleton,grain boundaries,and MoOx species on the Pt cluster surfaces synergistically boost the electrocatalytic *** unique architecture delivers 3.5-and 2.8-fold higher mass and specific activities,respectively,than commercial Pt/*** functional theory calculations reveal that the Mo-doped Pt clusters have an optimized Pt–O bond length of 2.110Å,which weakens the adsorption energy of the intermediate O*to yield great ORR ***,the catalyst shows a decay in the half-wave potential of only 8 mV after 10,000 cycles of accelerated durability *** high stability arises from the increased dissociation energy of Pt atoms and the stable architecture of the coral-like structure of clusters.

关键词： Pt clusters Mo doping Porous structure Pt-O bond Oxygen reduction reaction

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加快祁连县畜牧业发展之思考

青海草业 2002年第4期11卷 28-30,41页

作者：常明莲祁连县草原站青海八宝810400

较为系统地阐述了二十世纪后二十年祁连县畜牧业的现状及主要制约畜牧业发展的因素 ,有针对性的提出了较为合理的发展思路、对策及应采取的措施 ,并提出要想使祁连县畜牧业加快发展 ,首先要对现有畜牧业结构进行战略性调整 ,加大推进畜... 详细信息

较为系统地阐述了二十世纪后二十年祁连县畜牧业的现状及主要制约畜牧业发展的因素 ,有针对性的提出了较为合理的发展思路、对策及应采取的措施 ,并提出要想使祁连县畜牧业加快发展 ,首先要对现有畜牧业结构进行战略性调整 ,加大推进畜牧业产业化经营 ,综合治理草地生态环境 ,强化牧业基础设施建设 ;其次是加快畜牧业科技进步 ,实施种子工程 ,搞好畜疫防治 ;另外 ,加强领导、转变工作作风也是加快畜牧业发展的重要措施之一。

关键词：祁连畜牧业发展思考

Efficacy of radiofrequency ablation combined with sorafenib for treating liver cancer complicated with portal hypertension and prognostic factors

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World Journal of Gastroenterology 2024年第11期30卷 1533-1544页

作者： Li-Min Yang Hong-Juan Wang Shan-Lin Li Guan-Hua Gan Wen-Wen Deng Yong-Sheng chang lian-Feng Zhang Department of Gastroenterology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina Department of Gastroenterology Zhoukou Central Hospital of Henan ProvinceZhoukou 466000Henan ProvinceChina Department of Gastroenterology The First Affiliated Hospital of Xinxiang Medical CollegeXinxiang 453000Henan ProvinceChina

BACKGROUND Patients with liver cancer complicated by portal hypertension present complex challenges in *** To evaluate the efficacy of radiofrequency ablation in combination with sorafenib for improving liver function and its impact on the prognosis of patients with this *** Data from 100 patients with liver cancer complicated with portal hypertension from May 2014 to March 2019 were analyzed and divided into a study group(n=50)and a control group(n=50)according to the treatment *** research group received radiofrequency ablation(RFA)in combination with sorafenib,and the control group only received *** short-term efficacy of both the research and control groups was *** function and portal hypertension were compared before and after ***-fetoprotein(AFP),glypican-3(GPC-3),and AFP-L3 levels were compared between the two groups prior to and after *** occurrence of adverse reactions in both groups was *** 3-year survival rate was compared between the two *** data were compared between the survival and non-surviving *** identify the independent risk factors for poor prognosis in patients with liver cancer complicated by portal hypertension,multivariate logistic regression analysis was *** When comparing the two groups,the research group's total effective rate(82.00%)was significantly greater than that of the control group(56.00%;P<0.05).Following treatment,alanine aminotransferase and aspartate aminotransferase levels increased,and portal vein pressure decreased in both *** degree of improvement for every index was substantially greater in the research group than in the control group(P<0.05).Following treatment,the AFP,GPC-3,and AFP-L3 levels in both groups decreased,with the research group having significantly lower levels than the control group(P<0.05).The incidence of diarrhea,rash,nausea and vomiting,and fatigue in the research group was significantly great

关键词： Radiofrequency ablation Sorafenib Liver cancer Portal hypertension Efficacy Prognosis analysis

Comparative studies on Fenton-like reactions catalyzed by Fe_(3)O_(4) loaded inside and outside halloysite nanotubes for the removal of organic pollutants

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Frontiers of Materials Science 2024年第1期18卷 15-28页

作者： Yang Li Jia-Qi Zhou Huan-Yan Xu Li-Min Dong Mao-chang Cao lian-Wei Shan Li-Guo Jin Xiu-Lan He Shu-Yan Qi Heilongjiang Provincial Key Laboratory of CO_(2) Resource Utilization and Energy Catalytic Materials School of Materials Science and Chemical EngineeringHarbin University of Science and TechnologyHarbin 150040China

In this work,Fe_(3)O_(4) nanoparticles(NPs)loaded inside and outside halloysite nanotubes(HNTs)were prepared and developed as the heterogeneous Fenton-like catalysts for the removal of representative organic *** results indicated that the samples with Fe_(3)O_(4) NPs loaded outside the HNTs lumen(Fe_(3)O_(4)/HNTs)and inside the HNTs lumen(Fe_(3)O_(4)@HNTs)were successfully *** samples had typical magnetic hysteresis loops,while Fe_(3)O_(4)@HNTs exhibited higher magnetization *** comparative experiments showed that Fe_(3)O_(4)@HNTs had better Fenton-like catalytic ability than that of Fe_(3)O_(4)/HNTs in the degradation of various organic *** Rhodamine B(RhB)as an example,the adsorption thermodynamics and kinetics of RhB onto Fe_(3)O_(4)/HNTs and Fe_(3)O_(4)@HNTs were also *** comparative results demonstrated that the adsorption ability of Fe_(3)O_(4)/HNTs was better than that of Fe_(3)O_(4)@***,the dissolved concentration of Fe^(2+)and production amount of hydroxyl radical(·OH)in the Fe_(3)O_(4)@HNTs-H_(2)O_(2) system were significantly higher than those in the Fe_(3)O_(4)/HNTs-H_(2)O_(2) *** on aforementioned comparison,the nano-confinement effect in the Fe_(3)O_(4)@HNTs-H_(2)O_(2) system was *** work provides meaningful guidance for the cheap and convenient design of nanoreactors for Fenton-like applications.

关键词： Fe_(3)O_(4) halloysite nanotube adsorption Fenton-like reaction mechanism

Role of gut microbiota in Crohn’s disease pathogenesis:Insights from fecal microbiota transplantation in mouse model

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World Journal of Gastroenterology 2024年第31期30卷 3689-3704页

作者： Qiang Wu lian-Wen Yuan Li-Chao Yang Ya-Wei Zhang Heng-chang Yao liang-Xin Peng Bao-Jia Yao Zhi-Xian Jiang Geriatric Surgery of Department of General Surgery The Second Xiangya HospitalCentral South UniversityChangsha 410011Hunan ProvinceChina

BACKGROUND Inflammatory bowel disease,particularly Crohn’s disease(CD),has been associated with alterations in mesenteric adipose tissue(MAT)and the phenomenon termed“creeping fat”.Histopathological evaluations showed that MAT and intestinal tissues were significantly altered in patients with CD,with these tissues characterized by inflammation and *** To evaluate the complex interplay among MAT,creeping fat,inflammation,and gut microbiota in *** Intestinal tissue and MAT were collected from 12 patients with *** manifestations and protein expression levels were analyzed to determine lesion *** samples were collected from five recently treated CD patients and five control subjects and transplanted into *** intestinal and mesenteric lesions in these mice,as well as their systemic inflammatory status,were assessed and compared in mice transplanted with fecal samples from CD patients and control *** Pathological examination of MAT showed significant differences between CDaffected and unaffected colons,including significant differences in gut microbiota *** microbiota transplantation(FMT)from clinically healthy donors into mice with 2,4,6-trinitrobenzene sulfonic acid(TNBS)-induced CD ameliorated CD symptoms,whereas FMT from CD patients into these mice exacerbated CD ***,FMT influenced intestinal permeability,barrier function,and levels of proinflammatory factors and ***,FMT from CD patients intensified fibrotic changes in the colon tissues of mice with TNBS-induced *** Gut microbiota play a critical role in the histopathology of *** MAT and creeping fat may therefore have potential in the treatment of patients with CD.

关键词： Mesenteric adipose tissue Crohn’s disease Fecal microbiota transplantation Intestinal fibrosis Intestinal barrier

Structural engineering of BaWO_(4)/CsPbX_(3)/CsPb_(2)X_(5)(X=Cl,Br,I)heterostructures towards ultrastable and tunable photoluminescence

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Nano Research 2024年第3期17卷 1636-1645页

作者： Peng Liu Yan Xu Bohan Li Yuchi Zhang Hongzhou lian Jun Lin Department of Chemistry College of SciencesNortheastern UniversityShenyang 110819China State Key Laboratory of Rare Earth Resource Utilization Chang Chun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Construction of lead halide perovskite nanocrystals(LHP NCs)heterostructures is essential to obtain highly stable photoluminescence and expand their ***,a novel self-assembly strategy combining with a solvent-free thermal-assisted synthesis and a water-triggered reaction is developed to subsequently grow BaWO_(4)/CsPbX_(3)/CsPb_(2)X_(5)(X=Cl,Br,I)heterostructures at low nucleation temperature with high *** as-obtained ternary BaWO_(4)/CsPbX_(3)/CsPb_(2)X_(5)(X=Cl,Br,I)heterostructures exhibit remarkably enhanced panchromatic emission and ultrastable luminescence ascribing to the low-defect growth based on lattice *** white light-emitting diodes(WLEDs)have been constructed with a high correlated color temperature(CCT)of 7225 K and luminous efficiency of 74.4 lm·***^(3+)-doped BaWO_(4)/CsPbX_(3)/CsPb_(2)X_(5)(Ln^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Sm^(3+),Yb^(3+)/Er^(3+))nanocomposites are further designed with excitation-dependent photoluminescence and thermochromic properties,making them excellent candidates for high-level anti-counterfeiting and *** work offers a green and universal approach in assembling CsPbX_(3)(X=Cl,Br,I)on lattice-matched tungstate with adjustable panchromatic emission for versatile optical applications.

关键词： inorganic lead halide perovskites solvent-free synthesis panchromatic emission anti-counterfeiting and encryption application

Profound loss of microbial necromass carbon in permafrost thaw-subsidence in the central Tibetan Plateau

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Advances in Climate change Research 2024年第4期15卷 647-657页

作者： Wen-Ting ZHOU Quan-lian LI Shi-chang KANG Xiao-Dong WU Tian MA Xiao-Bo WU Xin XIONG Tanuj SHUKLA Maheswar RUPAKHETI Dipesh RUPAKHETI Da-He QIN Xiu-Feng YIN Cryosphere Research Station on the Qinghai-Tibet Plateau State Key Laboratory of Cryospheric ScienceNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Cryospheric Science and Frozen Soil Engineering Norhwest Instiute of Eco-Evironment and ResourcesChinese Academy of Scienes Lanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems and College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou730020China Lushan Botanical Garden Chinese Academy of SciencesJiujiang 332900China Research Institute for Sustainability-Helmholtz Centre Potsdam Potsdam 14467Germany Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China

Climate warming is causing rapid permafrost degradation,including thaw-induced subsidence,potentially resulting in heightened carbon ***,our understanding of the levels and variations of carbon components in permafrost,particularly during the degradation process,remains *** uncertainties arising from this process lead to inaccurate assessments of the climate effects during permafrost *** vast expanses of permafrost in the Tibetan Plateau,there is limited research available on SOC components,particularly in the central Tibetan *** remarkable variations in hydrothermal conditions across different areas of the Tibetan Plateau,the existing limited studies make it challenging to assess the overall SOC components in the permafrost across the Tibetan Plateau and simulate their future *** this study,we examined the properties of soil organic carbon(SOC)and microbial necromass carbon(MicrobialNC)in a representative permafrost thaw-subsidence area at the southern edge of continuous permafrost in the central Tibetan *** results indicate that prior to the thaw-subsidence,the permafrost had a SOC content of 72.68±18.53 mg g^(-1),with MicrobialNC accounting for 49.6%.The thaw-subsidence of permafrost led to a 56.4%reduction in SOC,with MicrobialNC accounting for 70.0%of the lost *** constitutes the primary component of permafrost SOC,and it is the main component that is lost during thaw-subsidence *** in MicrobialNC are primarily correlated with factors pH,plant input,and microbial *** present study holds crucial implications for both the ecological and biogeochemical processes associated with carbon release from permafrost,and it furnishes essential data necessary for modeling the global response of permafrost to climate *** on this study and previous research,permafrost thawing in the Tibetan Plateau causes substantial loss of ***,there's remarkable heterogeneit

关键词： Tibetan Plateau Thaw-subsidence Soil organic carbon Microbial necromass carbon Amino sugars

应用人延伸因子1α亚基启动子和人工转录激活因子提高外源基因在CHO细胞中的表达

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生物化学与生物物理进展 2004年第2期31卷 118-126页

作者：来大志翁少洁于长明齐连权付玲于婷陈薇北京微生物流行病研究所北京100071

表达载体的设计对于提高外源基因在哺乳动物细胞中的表达量十分重要 .而表达载体中最为重要的元件是启动子 .一些常用病毒来源的启动子 ,如巨细胞病毒即早期启动子 (PCMV IE)仅在S期激活 ,应用这类启动子表达外源蛋白需要宿主细胞不停增... 详细信息

表达载体的设计对于提高外源基因在哺乳动物细胞中的表达量十分重要 .而表达载体中最为重要的元件是启动子 .一些常用病毒来源的启动子 ,如巨细胞病毒即早期启动子 (PCMV IE)仅在S期激活 ,应用这类启动子表达外源蛋白需要宿主细胞不停增殖 ,这对于连续持久大规模培养的宿主细胞不现实 .而人延伸因子 1α亚基启动子 (PEF 1α)不受细胞周期限制 ,且启动子强度高于PCMV IE,对于大规模外源蛋白的生产较为理想 .首先构建了基于PEF 1α启动子的哺乳动物细胞表达载体pED5 ,在增殖缓慢的CHO细胞中 ,此载体表达外源蛋白的能力是应用PCMV IE启动子表达载体的 4 1倍 .由于启动子一般仅能决定基因转录的本底水平 ,而转录激活因子 (transcriptionactivators)对基因转录的影响更大 ,所以另把两个人工转录激活结构域AH和VP2接到λ噬菌体cⅠ蛋白的C端 ,它们通过cⅠ蛋白结合于已插入到PEF 1α启动子的TATA框上游约 2 0 0bp的λ噬菌体OR2 OR1序列上 ,而被“征募”到PEF 1α启动子TATA框附近 ,从而促进基因的转录 .把上述元件均整合进一个表达载体中 ,构建了两个新型表达载体pER AH和pER VP2 .pER AH表达外源蛋白的能力比不含转录激活因子的表达载体略高 ,而pER VP2表达外源蛋白的能力则比不含转录激活因子的表达载体高

关键词：人工转录激活因子人延伸因子1α亚基启动子基因表达 cI蛋白 CHO细胞