检索结果-南通市图书馆

Effects of Shear Fracture on In-depth Profile Modification of Weak Gels

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2007年第1期4卷 55-60页

作者： Li Xianjie Song Xinwang Yue Xiang＇an Hou Jirui Fang Lichun Zhang huazhen Center for Enhanced Oil Recovery China University of Petroleum Beijing 102249 China Research Institute of Geological Science Shengli Oilfield Company Ltd. Sinopec Dongying Shandong 257015 China

Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the indepth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs, and the weak gels in these two cases became small gel particles after water flooding. The differences were： the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor （FRR） caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack, which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack, while in the quartz sand pack, the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water, the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.

关键词： Weak gel shear fracture in-depth profile modification glass bead pack quartz sand pack

Gut microbiota-derived short chain fatty acids are potential mediators in gut inflammation

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2022年第1期8卷 350-360页

作者： Muhammad Akhtar Yan Chen Ziyu Ma Xiaolong Zhang Deshi Shi Jawaria AKhan huazhen Liu Department of Basic Veterinary Medicine College of Animal Science and Veterinary MedicineHuazhong Agricultural UniversityWuhan430070China Department of Preventive Veterinary Medicine College of Animal Science and Veterinary MedicineHuazhong Agricultural UniversityWuhan430070China Department of Veterinary Medicine Faculty of Veterinary ScienceUniversity of Veterinary and Animal SciencesLahore54000Pakistan

Gut inflammation is a challenging concern in humans and animals,which disturbs normal growth and leads to severe bowel *** chain fatty acids(SCFA)are the gut microbiota metabolites produced from fermentation of non-digestible carbohydrates,and have been reported to modulate gut *** have been implicated as the potential therapeutic bioactive molecules for gut inflammatory diseases,and could be an alternative to antibiotic growth promoters(AGP).In this review,the existing knowledge about the types of SCFA,the related gut microbes producing SCFA,the roles of SCFA in maintaining gut homeostasis,and how SCFA modulate gut inflammation is *** therapeutic application of SCFA in the treatment of inflammatory bowel disease(IBD)is also highlighted

关键词： Gut microbiota Short chain fatty acid Gut inflammation Gut homeostasis Inflammatory bowel disease

Novel Cs-Mg-Al mixed oxide with improved mobility of oxygen species for passive NO_(x)adsorption

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第10期9卷 1581-1591页

作者： Yimeng Yin Chizhong Wang Lei Qiu Xing Li Feilin Zhao Jie Yu Jinchi Han huazhen Chang School of Environment and Natural Resources Renmin University of ChinaBeijing100872China Department of Earth System Science Tsinghua UniversityBeijing100084China

The development of passive NO_(x)adsorbers with cost-benefit and high NO_(x)storage capacity remains an on-going challenge to after-treatment technologies at lower temperatures associated with cold-start NO_(x)***,Cs_(1)Mg_(3)Al catalyst prepared by sol-gel method was cyclic tested in NO_(x)storage under 5 vol%*** 100°C,the NO_(x)storage capacity(1219 μmol g^(-1))was much higher than that of Pt/BaO/Al_(2)O_(3)(610 μmol g^(-1)).This provided new insights for non-noble metal catalysts in low-temperature passive NO_(x)*** addition of Cs improved the mobility of oxygen species and thus improved the NO_(x)storage *** XRD,XPS,IR spectra and in situ DRIFTs with NH3 probe showed an interaction between CsO_(x)and AlO_(x)sites via oxygen species formed on Cs_(1)Mg_(3)Al *** improved mobility of oxygen species inferred from O2-TPD was consistent with high NO_(x)storage capacity related to enhanced formation of nitrate and additional nitrite species by NO_(x)***,the addition of Mg might improve the stability of Cs_(1)Mg_(3)Al by stabilizing surface active oxygen species in cyclic experiments.

关键词： Passive NO_(x)adsorber Low-temperature NO_(x)storage Cesium O_(x)ygen mobility

Catalytic oxidation of CO over Pt/Fe3O4 catalysts:Tuning O2 activation and CO adsorption

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第4期14卷 115-123页

作者： Zihao Li Yang Geng Lei Ma Xiaoyin Chen Junhua Li huazhen Chang Johannes W.Schwank Department of Chemical Engineering University of MichiganAnn ArborMI 48109USA School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Environment Tsinghua UniversityBeijing 100084China School of Environment and Natural Resources Renmin University of ChinaBeijing 100872China

The self-inhibition behavior due to CO poisoning on Pt metal particles strongly impairs the performance of CO *** is an effective method to use reducible metal oxides for supporting Pt metal particles to avoid self-inhibition and to improve catalytic *** this work,we used in situ reductions of chloroplatinic acid on commercial Fe3O4 powder to prepare heterogeneousstructured Pt/Fe3O4 catalysts in the solution of ethylene *** heterogeneous Pt/Fe3O4 catalysts achieved a better catalytic performance of CO oxidation compared with the Fe3O4 *** temperatures of 50%and 90%CO conversion were achieved above 260℃and 290℃at Pt/Fe3O4,***,they are accomplished on Fe3O4 at temperatures higher than 310℃.XRD,XPS,and H2-TPR results confirmed that the metallic Pt atoms have a strong synergistic interaction with the Fe3O4 *** results and transient DRIFTS results proved that the Pt metal particles facilitate the release of lattice oxygen and the formation of oxygen vacancies on *** combined results of O2-TPD and DRIFTS indicated that the activation step of oxygen molecules at surface oxygen vacancies could potentially be the rate-determining step of the catalytic CO oxidation at Pt/Fe3O4 *** reaction pathway involves a Pt-assisted Mars-van Krevelen(MvK)mechanism.

关键词： Strong metal-support interaction(SMSI) Surface oxygen vacancy Lattice oxygen Magnetite Platinum metals

Dual-templating surface gel into thin SSZ-13 zeolite membrane for fast selective hydrogen separation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aggregate

Aggregate 2022年第6期3卷 157-165页

作者： huazhen Rong Yixing Guan Jun Li Ziyi Li Dan Ma Jingjing Zhang Terence Xiaoteng Liu Xiaoqin Zou Faculty of Chemistry Northeast Normal UniversityChangchunChina School of Energy and Environmental Engineering University of Science and Technology BeijingBeijingChina Department of Mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle Upon TyneUK

Highly permeable zeolite membranes are desirable for fast gas separation in the *** the membrane’s thickness is deemed to be an optimal solution for permeability ***,we report the synthesis route of thin SSZ-13 zeolite membranes via the conversion of template-contained surface *** synthesis gel is fully crystallized into crack-free SSZ-13 membranes assisted with dual templates of N,N,N-trimethyl-1-adamantammonium hydroxide(TMAdaOH)and tetraethylammonium hydroxide(TEAOH).The specific functions of TMAdaOH for structure directing and TEAOH for crystallization regulating are well *** surface gel layer is impregnated onto porous alumina with subsequent crystallization into a 500 nm thick *** submicron-thick membrane exhibits high H_(2)permeance with 50×10^(-8)mol s^(-1)m^(-2)Pa^(-1)during hydrogen ***,the separation factors are retained around 23.0 and 31.5 for H_(2)/C_(2)H_(6)and H_(2)/C_(3)H_(8),*** approach offers a possibility for obtaining high-quality zeolite membranes for efficient hydrogen separation.

关键词： gas separation hydrogen selectivity zeolite membrane

Research on the path of medical service combination from the perspective of departmental cooperation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International English Education Research 2018年第3期 59-61页

作者： YANG huazhen Shanghai University Of Engineering Science ShanghaiChina

As an innovative mode of social endowment, combining medical care with modern medical care technology and old-age service is an important direction of a series of social problems caused by the deepening of aging and the intensification of aging process in China. It is the inevitable choice for the development of Chinese characteristics for the aged. At present, with the continuous development of the combination of medical care and rehabilitation, the process of combination of medical care and breeding is slow, and the problems of inter departmental cooperation, high cost of resource integration and low service efficiency have emerged. The paper puts forward that multi head management of different responsibility management body is a bottleneck problem that hinders the integration of medical care. From the objective and subjective two points of view, the administrative system level barrier and the inter departmental interest game are the important reasons that obstruct the medical support and break through the estrangement of the Department and realize the cooperation. Then, according to the theory of large part system reform, the author boldly proposes the idea of establishing a new comprehensive functional department that specializes in the management of pension related affairs.

关键词： medical service combination new pension service mode department cooperation bottleneck problem

Splicing Signals in the Human Hemoglobin Genes at the Sequence and Folding Levels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2011年第2期16卷 93-100页

作者： ZHANG Wen XIE huazhen LI Qing ZHANG Lu LIU Ciquan Modem Biology Research Center Yunnan University Kunming650091 Yunnan China Department of Cell Biology and Genetics Kunming MedicalCollege Kunming 650031 Yurman China Kunming Institute of Zoology Chinese Academy of SciencesKunming 650223 Yunnan China

Identification of the splice sites is a critical and tough issue in eukaryotic genome annotation. Here, a statistical study is introduced for detecting the splicing signals in the human hemoglobin （Hb） pre-mRNAs by using the approaches of regional pairwise alignment, splicing weight matrix scoring, and dynamic extended folding. First, the regional pairwise alignment results show that the coding regions of the human Hb genes are at a high level for both conservation and fluctuation. Second, the weighted matrix scoring results indicate that, although the authentic splicing motifs are always scored the highest in a sequence, the sequence motif alone is inadequate to precisely define the splice sites. Finally, we deduce the RNA frame structures by applying an extended folding approach to analyze the stable folding elements. We find out that the splice sequences tend to take stretching and partially paired conformations, which benefit recognition and competitive binding of the splicing factors. These results indicate that precise splicing is an integrated effect of multiple mechanisms of signal recognition at the level of sequence and structure.

关键词： splice site regional pairwise alignment splicing weight matrix dynamic extended folding

Back Frame Section Size Optimization of Large Aperture Telescope

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2023年第4期30卷 76-84页

作者： Qinglong Wu Zhan Yao Tanhui Wu Yangqing Hou huazhen Zhang Qian Xu Na Wang Shanghai YueSheng Information Technology Co Ltd.Shanghai 201109China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

The back frame structure of a large radio telescope is an important component supporting the reflecting surface,which is directly related to the surface *** optimal design is of key significance for ensuring the surface precision and reducing structural *** methods are constructed to optimize the cross-section size of the telescope back frame in this paper,the criterion method and the first-order optimization *** criterion method is based on the Lagrangian multiplier method and Kuhn-Tucker *** method first establishes the mathematical model by taking the inner and outer radiuses of the back frame beams as the design variables,the structural weight as the constraint condition,and the structural compliance as the objective function,then derives the optimization *** first-order optimization method takes the inner and outer radiuses of the beams as the design variables,the back frame RMS as the objective function,and the structural weight as the constraint *** of RMS,structural stress uniformity and optimization efficiency shows that both algorithms can effectively reduce structural deformation and improve RMS,but the criterion method has relatively better result than the first-order method.

关键词： radio telescope back frame size optimization RMS criterion method first-order method

Ablative fractional CO_(2)laser surgery improving sleep quality,pain and pruritus in adult hypertrophic scar patients:a prospective cohort study

在线全文

学校读者我要写书评

暂无评论

Burns & Trauma 2021年第1期9卷 372-382页

作者： Kaiyang Lv huazhen Liu Haiting Xu Caixia Wang Shihui Zhu Xiaozhen Lou Pengfei Luo Shichu Xiao Zhaofan Xia Department of Plastic Surgery Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092People’s Republic of China Department of Burn Surgery the First affiliated Hospital to Naval Medical UniversityShanghai 200433People’s Republic of China Department of Burn and Plastic Surgery Shandong Provincial Hospital Affiliated to Shandong UniversityJinanShandong 250021People’s Republic of China Department of Plastic Surgery The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhouZhejiang 325000People’s Republic of China Shanghai Institute of Laser Technology Shanghai 200233People’s Republic of China

Background:Poor sleep quality is associated with a decrease in quality of life in patients with major burn scars,combined with pruritus and *** interventions have been reported to improve the sleep quality of patients with *** the current prospective cohort study,we investigated the efficacy of CO_(2)-ablative fractional laser(AFL)surgery vs conventional surgery in post-burn patients with hypertrophic scars with sleep quality as the primary study ***:In total 68 consecutive patients undergoing scar surgical treatment were recruited,including a CO_(2)-AFL surgery cohort(n=35)and a conventional surgery cohort(n=33).A subgroup from the AFL cohort was *** quality,pain and pruritus were *** linear regression analyses were performed to reveal the effect of CO_(2)-AFL ***:The CO_(2)-AFL surgery cohort had significantly lower Pittsburgh sleep quality index(PSQI)global scores than the conventional surgery cohort after the last surgical *** the subgroup of patients receiving hardware sleep monitoring,CO_(2)-AFL markedly increased deep sleep time,deep sleep efficiency and reduced initial sleep *** to the conventional surgery cohort,the CO_(2)-AFL cohort presented significantly lower pain and pruritus *** analysis showed pain and pruritus were significantly associated with PSQI scores,and there were also significant correlations between pain and pruritus *** linear regression analysis showed that surgery method was negatively linearly correlated with visual analog scale(VAS)pain score,brief pain inventory(BPI)total,VAS pruritus score,5-D itch scale total,four-item itch questionnaire(FIIQ)total and PSQI ***:CO_(2)-AFL surgery significantly improved sleep quality and reduced pain and pruritus of hypertrophic scar *** alleviation of sleep disorder was associated with improvement of deep sleep quality including deep sleep time and deep sleep deficiency

关键词： Burn scar Ablative CO_(2)fractional laser Cardiopulmonary coupling Sleep quality Pain Pruritus