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Three-dimensional anisotropic induced polarization modeling using finite element method

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Earthquake Research Advances 2021年第S01期1卷 49-52页

作者： junjie liu Xiaoping Wu School of Earth and Space sciences University of Science and Technology of ChinaHefeiChina

With the development of geophysical exploration technology,the anisotropy of underground media has got more and more *** present,there are few studies on the anisotropy of the induced polarization *** article explores the effect of anisotropy on the underground media of the induced polarization method under three-dimensional complex *** research work transforms the underground electric field control equation into a variational problem,and use the unstructured finite element method to construct a large linear equation system for solving electric *** the sparse matrix compression technique and symmetric successive over-relaxation preconditioned conjugate gradient algorithm(SSOR-PCG)to solve the equation ***,the article uses the classic central gradient array method to obtain the forward apparent polarizability *** calculation results of the model find that different anisotropic conditions will significantly affect the forward results which show a strong directional correlation,revealing the importance of considering anisotropy in practical work.

关键词： Three-dimensional anisotropic finite element method

Coupling changes of soil functional gene abundances and extracellular enzyme activities across the diagnostic horizons of agricultural Isohumosols

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Pedosphere 2024年第3期34卷 540-552页

作者： Zhuxiu liu Haidong GU Xiaojing HU Zhenhua YU Yansheng LI junjie liu Jian JIN Xiaobing liu Guanghua WANG State Key Laboratory of Black Soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Academy of SciencesHarbin 150081(China) University of Chinese Academy of Sciences Beijing 100049(China)

Soil functional microbial taxa and extracellular enzymes are involved in a variety of biogeochemical cycling *** many studies have revealed the vertical change patterns of microbial communities along soil profile,the general understanding of the coupling changes in the functional gene abundances(FGAs)and extracellular enzyme activities(EEAs)in soil profiles is still limited,which hinders us from revealing soil ecosystem ***,we comparatively investigated the FGAs and EEAs in the diagnostic A,B,and C horizons of soil profiles obtained from two suborders of Isohumosols(Mollisols),Ustic and Udic Isohumosols,in Northeast China based on quantitative real-time polymerase chain reaction and standard fluorometric techniques,*** distribution patterns of both FGAs and EEAs significantly distinguished by the two soil suborders and were also separated from A to C ***,the variations of EEAs and FGAs were greater in Udic Isohumosols compared to Ustic Isohumosols along soil profiles,and greater changes were observed in C horizon than in A *** FGAs and EEAs correspondently decreased along the soil ***,when normalized by soil organic carbon,the specific EEAs significantly increased in deep soil horizons,suggesting that microorganisms will input more resources to the production of enzymes to ensure microbial nutrient requirements under resource *** importantly,we revealed that soil microbial nutrient demands were limited by carbon(C)and phosphorus(P),and the C and P limitations significantly increased along soil profiles with a greater C limitation observed in Ustic Isohumosols than in Udic ***,our findings provided solid evidence showing the links between FGAs,EEAs,and microbial nutrient limitations,which would be helpful for a better understanding of the ecosystem processes in soil profiles.

关键词： ecoenzymatic stoichiometry microbial nutrient limitation microbial nutrient requirement Mollisols soil ecosystem process soil profile

Boosting 5-ALA-based photodynamic therapy by a liposomal nanomedicine through intracellular iron ion regulation

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Acta Pharmaceutica Sinica B 2021年第5期11卷 1329-1340页

作者： Airong Li Chenglin Liang Lihua Xu Yiyang Wang Wei liu Kaixiang Zhang junjie liu Jinjin Shi Henan Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases School of Pharmaceutical SciencesZhengzhou UniversityZhengzhou 450001China

5-Aminolevulinic acid(5-ALA)has been approved for clinical photodynamic therapy(PDT)due to its negligible photosensitive ***,the curative effect of 5-ALA is restricted by intracellular biotransformation inactivation of 5-ALA and potential DNA repair of tumor *** by the crucial function of iron ions in 5-ALA transformation and DNA repair,a liposomal nanomedicine(MFLs@5-ALA/DFO)with intracellular iron ion regulation property was developed for boosting the PDT of 5-ALA,which was prepared by co-encapsulating 5-ALA and DFO(deferoxamine,a special iron chelator)into the membrane fusion liposomes(MFLs).MFLs@5-ALA/DFO showed an improved pharmaceutical behavior and rapidly fused with tumor cell membrane for 5-ALA and DFO ***@5-ALA/DFO could efficiently reduce iron ion,thus blocking the biotransformation of photosensitive protoporphyrin IX(Pp IX)to heme,realizing significant accumulation of ***,the activity of DNA repair enzyme was also inhibited with the reduction of iron ion,resulting in the aggravated DNA damage in tumor *** findings showed MFLs@5-ALA/DFO had potential to be applied for enhanced PDT of 5-ALA.

关键词： 5-Aminolevulinic acid Biotransformation interference Iron ion regulation DNA repair inhibition ALKBH2 Membrane fusion liposomes Photodynamic therapy Drug delivery

A universal direct tensile testing method for measuring the tensile strength of rocks

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International Journal of Mining Science and Technology 2024年第10期34卷 1443-1451页

作者： Yang Wu Jianfeng liu Zhide Wu junjie liu Yonghui Zhao Huining Xu Jinbing Wei Wen Zhong State Key Laboratory of Hydraulic and Mountain River Engineering Sichuan UniversityChengdu 610065China College of Water Resource and Hydropower Sichuan UniversityChengdu 610065China CNPC Key Laboratory of Oil and Gas Underground Storage Engineering Langfang 065007China College of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

There is limited applicability to the current method for testing the direct tensile strength of rocks because it places stringent requirements on the testing *** work suggests a universal method based on the‘‘compression-to-tensiono idea in response to these *** applying pressure,this technique makes it possible to test the tensile strength of rocks directly with any conventional compression test *** was utilized as the test material in order to validate this suggested testing method,and the results showed what *** determining the true fracture area through digital reconstruction,an average calculated tensile strength of 5.97 MPa with a Cvof 0.04 was *** is a positive correlation between tensile strength and the joint roughness coefficient(JRC)of the failure *** aggregation mode of AE events with the loading process conforms to the damage characteristics of rock tensile *** direct tensile testing method proposed in this study not only has high universality but also produces test results with outstanding ***,factors influencing the results of the tensile test are pointed out,and recommendations for optimizing the suggested testing method are offered.

关键词： Rocks Direct tensile strength Granite Acoustic emission JRC

Recent Progress on High-Z Metal-Based Nanomaterials for Cancer Radiosensitization

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Chinese Journal of Chemistry 2023年第19期41卷 2545-2556页

作者： Xiu Zhao Jun Li Qiongwei Wang Zhenzhong Zhang junjie liu Chaofeng Zhang Jinjin Shi School of Pharmaceutical Sciences Zhengzhou UniversityZhengzhouHenan450001 China Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases ZhengzhouHenan450001 China Key Laboratory of Advanced Drug Preparation Technologies Ministry of EducationZhengzhouHenan450001 China

Radiotherapy is a mainstay treatment for malignant tumors in clinical ***,enhancing radiation damage to tumor cells meanwhile sparing normal tissues is still a great challenge in *** with high atomic number(Z)values are promising radiosensitizers by promoting the radiation energy deposition in irradiated tumor cells,thus enhancing the therapeutic ratio of *** this review,we described the mechanisms of high-Z element based-radiosensitizers and systematically summarized the recent progress on high-Z metal-based nanomaterials,including high-Z metal-based nanoparticles,high-Z metal-based nanoscale metal-organic frameworks and high-Z metal-doping ***,further potential and challenges in this field were discussed.

关键词： Radiotherapy Nanoradiosensitizers High-Z metal Energy deposition Nanomaterial

Latitudinal differentiation and patterns of temperate and subtropical plants in the Qinling-Daba Mountains

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Journal of Geographical Sciences 2023年第5期33卷 907-923页

作者： liu junjie ZHANG Baiping YAO Yonghui ZHANG Xinghang WANG Jing YU Fuqin LI Jiayu State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China University of Chinese Academy of Sciences Beijing100049China

Geographically,the Qinling-Daba Mountains serve as the main body of the north-south transitional zone of ***,the transitional patterns of their plant species still need to be *** study analyzed latitudinal variations of plant species richness,relative importance values(RIV),and plant species abundance based on plant community field survey data for 163 sample sites along three north-south transect lines in the eastern,middle,and western parts of the study *** difference in RIV between subtropical and temperate species(SND-RIV)was selected to reveal the latitudinal interlacing pattern of northern and southern plant *** the eastern(Sanmenxia-Yichang),middle(Xi’an-Dazhou),and western(Tianshui-Guangyuan)transects,the richness and RIV of subtropical plant species increased while those of temperate plant species decreased from north to *** the eastern transect,temperate plant species richness and RIV were the highest at Shennongjia and Funiu Mountain,respectively,because of their high *** the middle transect,subtropical plant species richness and RIV were the highest in the Daba *** the western transect,richness and RIV were higher for subtropical than temperate plant species from the south of *** crisscrossing areas of northern and southern plant species were∼180 km,∼100 km,and∼60 km wide for the eastern,middle,and western transects,respectively,showing a narrowing trend from east to *** the eastern and western transects,decreases in subtropical plant species distribution from south to north could be attributed to a decrease in mean annual precipitation in the same ***,for the middle transect,mean annual temperature had a slightly greater influence on plant species’latitudinal distribution than the moisture *** study provides a more solid scientific basis for future investigations of this key geographical boundary in China.

关键词： latitudinal plants variation north-south climate dividing line north-south transition zone of China Qinling-Daba Mountains transition pattern

Hydrogel-mediated drug delivery for treating stroke

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Chinese Chemical Letters 2023年第9期34卷 65-75页

作者： Wenyan Yu Enpeng Gong Bingbing liu Lei Zhou Chengyuan Che Shu Hu Zhenzhong Zhang junjie liu Jinjin Shi School of Pharmaceutical Sciences Zhengzhou UniversityZhengzhou 450001China Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases Zhengzhou 450001China Collaborative Innovation Center of New Drug Research and Safety Evaluation Zhengzhou 450001China

Stroke is a common disease and is the major cause of death and *** occurs and generates devastating neurological deficits when cerebral blood vessel is blocked(ischemic stroke,IS)or ruptured(hemorrhagic stroke,HS).Hydrogel,being biodegradable and biocompatible,have shown attractive advantages in stroke therapy as a new biomaterial with desirable mechanical properties and tunability of structure,owing to special ability to load different cargoes for multiple treatment strategies,such as pharmacotherapy based on drug-delivery systems and cell therapy including mesenchymal stem cells(MSCs)and neural progenitor cells(NPCs)for improving functional ***,a comprehensive review of the functional hydrogel for treatment of stroke is still ***,in this work,the main pathological mechanisms of stroke including IS and HS are comprehensively *** benefits of hydrogel for stroke treatment are also summarized regarding the natural advantages and the delivery ***,the application development of hydrogel for treatment of stroke is ***,the unique considerations and challenges in the design and application of hydrogel is discussed for treatment of stroke and clinical application in the future.

关键词： Drug delivery Functional hydrogel Stroke therapy Bioactive biomaterials Biological applications

Chronic effects of different fertilization regimes on nirS-type denitrifier communities across the black soil region of Northeast China

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Pedosphere 2020年第1期30卷 73-86页

作者： Xiaojing HU junjie liu Dan WEI Ping ZHU Xi'an CUI Baoku ZHOU Xueli CHEN Jian JIN Xiaobing liu Guanghua WANG Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and AgroecologyChinese Academy of SciencesHarbin 150081(China) Institute of Soil and Fertilizer and Environment Resources Heilongjiang Academy of Agricultural SciencesHarbin 150086(China) Institute of Agricultural Resource and Environment Jilin Academy of Agricultural SciencesChangchun 130033(China) Heihe Branch of Heilongjiang Academy of Agricultural Sciences Heihe 164300(China) Institute of Plant Nutrition and Resources Beijing Academy of Agricultureand Forestry SciencesBeijing 100097(China)

Denitrification is one of the major processes causing nitrogen loss from arable *** study aimed to investigate the responses of nir S-type denitrifier communities to different chronic fertilization regimes across the black soil region of Northeast *** samples were collected from sites located in the north(NB),middle(MB),and south(SB)of the black soil region of Northeast China,each with four chronic fertilization regimes:no fertilizer(No F),chemical fertilizer(CF),manure(M),and chemical fertilizer plus manure(CFM).Methods of quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing were applied to assess the abundance and composition of denitrifier communities by targeting the nir S *** results showed that the M and CFM regimes significantly increased the abundances of nir S-type denitrifiers compared with No F at the three *** majority of nir S sequences were grouped as unclassified denitrifiers,and the different fertilizers induced little variation in the relative abundance of known nir S-type denitrifier *** 90%of the sequences were shared among the four fertilization regimes at each location,but none of the abundant operational taxonomic units(OTUs)were shared among the three *** coordinate analysis(PCo A)revealed that the communities of nir S-type denitrifier were separated into three groups that corresponded with their *** similar fertilization regimes did not induce consistent changes in the nir S-type denitrifier communities,soil p H and NO-3-N content simultaneously and significantly influenced the structure of nir S-type denitrifier communities at the three *** results highlight that geographical separation rather than chronic fertilization was the dominant factor determining the nir S-type denitrifier community structures,and similar chronic fertilization regimes did not induce consistent shifts of nir S-type denitrifier communities in the black soils.

关键词： denitrification denitrifier diversity denitrifying gene geographical separation Illumina MiSeq sequencing manure Mollisols nirS gene quantitative polymerase chain reaction

Effects of MFC-modified GCC as Filler on the Opacity of Pulp Handsheets

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Paper And Biomaterials 2020年第3期5卷 62-69页

作者： Yanqun Su junjie liu Jingang liu Ruijuan Zhang Jinghuan Chen Yanfen Du China National Pulp and Paper Research Institute Co. Ltd.Beijing100102China National Engineering Laboratory for Pulp and Paper Beijing100102China

Microfibrillated cellulose(MFC)was obtained by mechanical grinding of different ***-modified ground calcium carbonate(GCC)was prepared in two different ways,designated MFC-GCC composite filler and MFC-GCC flocs *** opacity of pulp handsheets loaded with MFCmodified GCC was *** effects of MFC originated from different pulps,pretreatment method,and filler modification on the opacity of handsheets loaded with MFC-modified GCC were *** results show that MFC originated from alkaline peroxide mechanical pulp(APMP)was optimal for improving the opacity of the handsheets and PFI grinding pretreatment for MFC provided a denser structure in the corresponding MFCAPMP-GCC floc filler while enzyme pretreatment was more effective in increasing the opacity of the filled *** the experimental conditions,the opacity of handsheets increased from 81.0%to 82.7%when the unmodified GCC was replaced by an equivalent amount of MFCAPMP-GCC composite filler,while other properties were unchanged.

关键词： microfibrillated cellulose ground calcium carbonate modification opacity