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Stable seasonal migration patterns in giant pandas

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Zoological Research 2023年第2期44卷 341-348页

作者： Meng Wang Yong-Gang Nie Ronald R.Swaisgood Wei Wei Wen-Liang Zhou ze-jun zhang Gui-Ming Wang Fu-Wen Wei Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Giant Panda Research San Diego Zoo Institute for Conservation ResearchEscondidoCalifornia 92027USA Department of Wildlife Fisheries and AquacultureMississippi State UniversityMississippi 39762USA

A critical function of animal movement is to maximize access to essential resources in temporally fluctuating and spatially heterogeneous *** mediated resource fluctuations may influence animal movements,enabling them to track changing resource distributions,resulting in annual migration *** conservation-dependent giant panda(Ailuropoda melanoleuca) displays seasonal movement patterns;however,the key factor driving these seasonal migration patterns remains poorly ***,we used GPS tracking collars to monitor the movements of six giant pandas over a 12-year period across different elevations,and performed statistical analysis of seasonal migration directions,routes,habitat revisitation,home range overlap,first arrival events,and *** results revealed a compelling pattern of seasonal migrations that facilitated the ability of the pandas to forage at the appropriate time and place to maximize nutritional *** results indicated that pandas utilize spatial memory to locate reliable food resources,as evidenced by their annual return to the same or similar winter and summer home ranges and the consistently maintained percentage of home range *** novel insights into giant panda foraging and movement ecology not only enhance our understanding of its ability to adapt to nutritionally poor dietary resources but also provide important information for the development of resource utilization-based protection and management strategies.

关键词： Giant panda Seasonal migration Home range Foraging ecology Spatial memory

Experimental study of reservoir damage of water-based fracturing fluids prepared by different polymers

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Petroleum Science 2024年第5期21卷 3298-3306页

作者： Guo-Dong Wu Li-Kun Wang Chun-Yan Zhao ze-jun zhang Jian-Yu Yin Maryamgul Anwaier Hong-Da Ren Dan Yang Shu-Li Yin Zhuo-Lin Cai Dao-Yi Zhu Engineering Technology Research Institute Xinjiang Oilfield Company Luliang Oilfield Operation Area Xinjiang Oilfield Company China University of Petroleum-Beijing at Karamay

Fracturing operations can effectively improve the production of low-permeable reservoirs. The performance of fracturing fluids directly affects the fracturing efficiency and back flow capacity. As polymerbased fracturing fluids(such as guar gum（GG）, polyacrylamide（HPAM）, etc.) are high-viscosity fluids formed by viscosifiers and crosslinking agents, the degree of gel breakage after the fracturing operation directly influences the damage degree to the reservoir matrix and the mobility of oil angd gas produced from the reservoir into the wellbore. This study compared the viscosity, molecular weight, and particle size of the fracturing fluid after gel breakage prepared by GG and HPAM as viscosifiers, as well as evaluate their damage to the core. Results show that the viscosities of the gel-breaking fluid increased with the concentration of the viscosifier for both the HPAM-based and GG-based fracturing fluids. For the breaking fluid with the same viscosity, the molecular weight in the HPAM-based gel-breaking fluid was much larger than that in the GG-based system. Moreover, for the gel-breaking fluid with the same viscosity, the molecular particle size of the residual polymers in the HPAM-based system was smaller than that in the GG-based system. The damage to the core with the permeability of 1 × 10-3μm2caused by both the HPAM-based and GG-based gel-breaking fluids decreased with the increase in the solution viscosity. For the gel-breaking fluid systems with the same viscosity（i.e., 2-4 mPa s）, the damage of HPAM-based fracturing fluid to low-permeability cores was greater than the GG-based fracturing fluid（45.6%-80.2%） since it had a smaller molecular particle size, ranging from 66.2% to 77.0%. This paper proposed that the damage caused by hydraulic fracturing in rock cores was related to the partilce size of residual polymers in gel-breaking solution, rather than its molecular weight. It was helpful for screening and optimizing viscosifiers used in hydraulic fracturi

关键词： Fracturing fluid Guar gum HPAM Gel-breaking fluid Formation damage

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拉曼光谱技术在高分子表征研究中的应用

高分子学报 2021年第9期52卷 1206-1220页

作者：袁媛王梦梵曲云菲张泽军张建明青岛科技大学高分子科学与工程学院橡塑材料与工程教育部重点实验室青岛266042 北京化工大学碳纤维及复合材料教育部重点实验室北京100029 北京航空航天大学化学学院北京100191

拉曼光谱作为一种强大的工具,被广泛应用于聚合物结构的表征.随着共振拉曼光谱、扫描角度拉曼光谱、高分辨率拉曼成像、极化拉曼光谱、表面增强拉曼散射等拉曼技术的迅速发展,拉曼光谱的应用范围不断扩大.本文首先介绍了拉曼光谱设备的... 详细信息

拉曼光谱作为一种强大的工具,被广泛应用于聚合物结构的表征.随着共振拉曼光谱、扫描角度拉曼光谱、高分辨率拉曼成像、极化拉曼光谱、表面增强拉曼散射等拉曼技术的迅速发展,拉曼光谱的应用范围不断扩大.本文首先介绍了拉曼光谱设备的基本原理和组成,总结了拉曼技术的实验技巧和数据处理中需要注意的问题,讨论了红外光谱和拉曼光谱的区别,在此基础上,综述了近十年来拉曼技术在聚合物结构表征领域的最新应用和研究进展.其应用包括以下六个方面:高分子链的构象、聚合物的聚集状态、聚合物结晶度的计算、高分子链的取向、外场作用下的结构转化、高分子共混物化学或物理成分的识别.最后,对拉曼光谱在聚合物研究中的发展进行了展望.希望本文能够对试图从拉曼光谱中获取聚合物结构信息的学者有所帮助.

关键词：拉曼光谱结构表征原理应用

Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun zhang Shengtao Gao Xingzhao zhang Dacheng Ma Chuanlei Zhu jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)

Incident energy dependence of dilepton production in an expanding baryon-rich quark-gluon fireball

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Nuclear Science and Techniques 1998年第1期9卷 5-7页

作者： He ze jun 1,2 , zhang Jia Ju 3, Wang Zi Xing 2 and Liu Bo 4 ( 1CCAST (World Laboratory ), P.O.Box 8730, Beijing 100080 2Shanghai Institute of Nuclear Research, the Chinese Academy of Sciences, Shanghai 201800 3Computing

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关键词：重离子碰撞双轻子产生夸克-胶子火球

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污水中常见违禁药物分析方法优化及验证

环境科学 2017年第1期38卷 201-211页

作者：高婷婷杜鹏徐泽琼杨军张华方李喜青北京大学城市与环境学院地表过程与分析实验室北京100871 北京市城市排水监测总站有限公司北京100012

违禁药物作为一种新型污染物得到了环境科学界的广泛关注.本文根据国内外已有研究,比较了污水样的前处理条件如SPE柱和水样pH值、冲洗、酸化及复溶过程.结果表明,对实际污水样的前处理应将样品pH值调为2,选用Oasis MCX柱,无需除杂质的... 详细信息

违禁药物作为一种新型污染物得到了环境科学界的广泛关注.本文根据国内外已有研究,比较了污水样的前处理条件如SPE柱和水样pH值、冲洗、酸化及复溶过程.结果表明,对实际污水样的前处理应将样品pH值调为2,选用Oasis MCX柱,无需除杂质的冲洗和氮吹过程的酸化步骤,因两种上机测定方法 HILIC-UPLC-MS/MS和C18-UPLC-MS/MS不同而分别选择200μL乙腈和100μL乙腈+100μL 5 mmol·L^(-1)乙酸铵复溶.通过比较HILIC法和C18法的保留时间及检出限、定量限、回收率和基质效应等方法评价指标,确定污水样的测定应选用C18-UPLC-MS/MS.最后,将优化后的测定方法用于分析北京市12家污水处理厂的进、出水样,验证了方法的可靠性,为违禁药物的污水流行病学研究和环境风险评价奠定了基础.

关键词：违禁药物污水固相萃取超高效液相色谱-串联质谱回收率

Antiviral therapy for hepatitis B virus infection is beneficial for the prognosis hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2025年第1期17卷 1-9页

作者： Hui Wan Yu-Xin zhang Guan-Yue Shan jun-Ya Cheng Duan-Rui Qiao Yi-Ying Liu Wen-Na Shi Hai-jun Li Institute of Translational Medicine The First Hospital of Jilin UniversityChangchun 130061Jilin ProvinceChina Department of Bioengineering Pharmacy School of Jilin UniversityChangchun 130061Jilin ProvinceChina Institute of Liver Diseases Institute of Translational MedicineThe First Hospital of Jilin UniversityChangchun 130061Jilin ProvinceChina

In this editorial,we comment on the article by Mu et al,published in the recent issue of the World Journal of Gastrointestinal *** pay special attention to the immune tolerance mechanism caused by hepatitis B virus(HBV)infection,the pathogenesis of hepatocellular carcinoma(HCC),and the role of antiviral therapy in treating HCC related to HBV *** infection leads to systemic innate immune tolerance by directly inhibiting pattern recognition receptor recognition and antiviral signaling pathways,as well as by inhibiting the immune functions of macrophages,natural killer cells and dendritic *** addition,HBV leads to an immunosuppressive cascade by expressing inhibitory molecules to induce exhaustion of HBV-specific cluster of differentiation 8+T cells,ultimately leading to long-term viral *** loss of immune cell function caused by HBV infection ultimately leads to ***-term antiviral therapy can improve the prognosis of patients with HCC and prevent tumor recurrence and metastasis.

关键词： Hepatitis B virus Hepatocellular carcinoma Hepatitis B virus-DNA Immune tolerance Antiviral therapy

Interleukin-17A facilitates tumor progression via upregulating programmed death ligand-1 expression in hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2025年第1期17卷 176-198页

作者： Zhong-Xia Yang Li-Ting zhang Xiao-jun Liu Xue-Bin Peng Xiao-Rong Mao The First School of Clinical Medicine Lanzhou UniversityLanzhou 730000Gansu ProvinceChina Department of Infectious Diseases The First Hospital of Lanzhou UniversityLanzhou 730000Gansu ProvinceChina Department of Radiotherapy Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina

BACKGROUND Hepatocellular carcinoma(HCC)is an inflammation-associated tumor with a dismal *** has become an important treatment strategy for HCC,as immunity is closely related to inflammation in the tumor *** regulates the expression of programmed death ligand-1(PD-L1)in the immunosuppressive tumor microenvironment and affects im-munotherapy ***-17A(IL-17A)is involved in the remodeling of the tumor microenvironment and plays a protumor or antitumor role in different *** hypothesized that IL-17A participates in tumor progression by affe-cting the level of immune checkpoint molecules in *** upregulation of PD-L1 expression in HCC cells by IL-17A was assessed by reverse transcription PCR,western blotting,and flow *** studies were conducted with gene knockout models and pathway *** function of IL-17A in immune evasion was explored through coculture of T cells and HCC *** effects of IL-17A on the malignant biological behaviors of HCC cells were evaluated in vitro,and the antitumor effects of an IL-17A inhibitor and its synergistic effects with a PD-L1 inhibitor were studied in *** IL-17A upregulated PD-L1 expression in HCC cells in a dose-dependent manner,whereas IL-17A receptor knockout or treatment with a small mothers against decapentaplegic 2 inhibitor diminished the PD-L1 expression induced by ***-17A enhanced the survival of HCC cells in the coculture ***-17A increased the viability,G2/M ratio,and migration of HCC cells and decreased the apoptotic *** D1,VEGF,MMP9,and Bcl-1 expression increased after IL-17A treatment,whereas BAX expression *** combination of IL-17A and PD-L1 inhibitors showed synergistic antitumor efficacy and increased cluster of differentiation 8+T lymphocyte infiltration in an HCC mouse *** IL-17A upregulates PD-L1 expression via the IL-17A receptor/phosphorylation-small mothers against

关键词： Interleukin-17A Programmed death ligand-1 Interleukin-17A receptor Small mothers against decapentaplegic 2 Hepatocellular carcinoma Immunotherapy

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TiAl合金中的氧扩散及恒温氧化研究现状

宇航材料工艺 2017年第3期47卷 10-13,18页

作者：赵瑞峰吴泽恩吴珺张铁邦李金山西北工业大学凝固技术国家重点实验室西安710072

TiAl合金由于高比强度和优异的高温力学性能,是一种极具应用潜力的轻质高温结构材料,但存在脆性大、室温塑性差以及800℃以上抗氧化能力不足是其工程应用的最大障碍。本文对TiAl合金的恒温氧化行为、氧扩散以及氧化后力学性能变化规律... 详细信息

TiAl合金由于高比强度和优异的高温力学性能,是一种极具应用潜力的轻质高温结构材料,但存在脆性大、室温塑性差以及800℃以上抗氧化能力不足是其工程应用的最大障碍。本文对TiAl合金的恒温氧化行为、氧扩散以及氧化后力学性能变化规律进行了总结。基于服役环境条件下合金中的氧扩散规律及受控机制,对改善合金高温抗氧化性能的表面处理和合金化研究现状进行了归纳。分析了TiAl合金高温抗氧化行为研究及其控制技术在今后一段时期的发展趋势。

关键词： TiAl合金氧化氧扩散力学性能研究现状