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Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

Petroleum Science 2024年第4期21卷 2830-2838页

作者： Yi-Jian Zhu xiao-mei yang Xing Huang Hao Li xiao-Hui Wang Yi-Fei Sun Peng xiao Chang-Yu Sun Guang-Jin Chen State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： gas hydrate bentonite illite P-wave velocity amplitude

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The Products of Three Theta Functions and the General Cubic Theta Functions

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Acta Mathematica Sinica,English Series 2010年第6期26卷 1115-1124页

作者： xiao mei yang Department of Mathematics East China Normal University Shanghai 200241 P. R. China

In this paper we establish two theta function identities with four parameters by the theory of theta functions. Using these identities we introduce common generalizations of Hirschhorn-Garvan-Borwein cubic theta functions, and also re-derive the quintuple product identity, one of Ramanujan＇s identities, Winquist＇s identity and many other interesting identities.

关键词： Jacobi theta function quintuple product identity Winquist's identity Ramanujan identity

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INVESTIGATION OF SPECIFIC AB_2 TYPE HYPERBRANCHED POLYESTERIFICATION REACTION WITH MONTE CARLO SIMULATION

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Chinese Journal of Polymer Science 2013年第3期31卷 371-371,372-376页

作者： Long Wang xiao-mei yang 何学浩 Department of Polymer Science and Engineering School of Chemical Engineering and TechnologyTianjin University Department of Chemistry School of ScienceTianjin University

The AB2 type bulk polymerization of 3,5-bis（trimethylsiloxy）benzoyl chloride is studied by the reactive 3d bond fluctuation lattice model （3d-BFLM）. Through tuning the reactivity parameters, the experimental data are fitted well via an iterative dichotomy method. By using the optimized reactivity parameters, the number-average degree of polymerization and degree of branching obtained in simulation are very close to experimental data. Meanwhile, the information about the weightaverage degree of polymerization and the polydispersity index is provided, and the internal structural properties of hyperbranched polyesters are investigated. Simulation results demonstrate that the 3d-BFLM can be used to study specific hyperbranched polymerizations semi-quantitatively which is helpful to deep understand the kinetics of reactions and make predictions for specific polymerization systems.

关键词： Hyperbranched polyesterification Monte Carlo Iterative dichotomy method.

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Theoretical study on the reaction of NbS^+(~3∑^-,~1Γ) with CO

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Chinese Chemical Letters 2009年第6期20卷 755-758页

作者： Shi Wen Yu TaoHong Li xiao mei yang Li Qing Yin Li Feng Yao xiao Guang Xie Department of Chemistry Yunnan University Kunming 650091 China Department of Chemistry Qujing Normal University Qujing 650011 China Faculty of Chemistry Southwest Forestry University Kunming 650224 China Yunnan University of Traditional Chinese Medicine Kunming 650091 China

Two possible reactions of NbS＋（3∑^-, 1Г） with CO in the gas phase have been studied by using B3LYP and CCSD（T） methods： the O/S exchange reaction （NbS^＋＋ CO → NbO^＋＋ CS） and the S-transfer reaction （NbS＋＋ CO → Nb^＋＋ COS）. The two reactions have a one-step mechanism. The barriers of the O/S exchange reaction on the triplet and singlet surfaces are 51.2 and 52.4 kcal/mol, respectively, and the barriers of the S-transfer reaction are 58.3 and 78.0 kcal/mol, respectively. The results indicate that the Stransfer and the O/S exchange reaction of the 3∑^- ground state of NbS＋ are competing, but, for the S-transfer reaction, the 1F exited state is more reactive. The differences between the reactions of NbS＋（3∑^_, 1Г） and VS＋（3∑^_, 1Г） are discussed.

关键词： Niobium sulfide cation CO Reaction CCSD(T)

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Effect of admission hypertriglyceridemia on the episodes of severe acute pancreatitis

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World Journal of Gastroenterology 2008年第28期14卷 4558-4561页

作者： Li-Hui Deng Ping Xue Qing Xia xiao-Nan yang mei-Hua Wan Department of Integrated Traditional Chinese and Western Medicine West China Hospital Sichuan University Chengdu 610041 Sichuan Province China

AIM： To investigate the effect of admission hypertriglyceridemia （HTG） on the episodes of severe acute pancreatitis （SAP）. METHODS： One hundred and seventy-six patients with SAP were divided into HTG group （n = 45） and control group （n = 131） according to admission triglyceride （TG） ≥ 5.65 mmol/L and 〈 5.65 retool/L, respectively. Demographics, etiology, underlying diseases, biochemical parameters, Ranson＇ s score, acute physiology and chronic heath evaluation Ⅱ （APACHE Ⅱ） score, Balthazar＇s computed tomography （CT） score, complications and mortality were compared. Correlation between admission TG and 24-h APACHE Ⅱ score was analyzed. RESULTS： SAP patients with HTG were younger （40.8 ± 9.3 years vs 52.6 ± 13.4 years, P 〈 0.05） with higher etiology rate of overeating, high-fat diet （40.0% vs 14.5%, P 〈 0.05） and alcohol abuse （46.7% vs 23.7%, P 〈 0.01）, incidence rate of hypocalcemia （86.7% vs 63.4%, P 〈 0.01） and hypoalbuminemia （84.4% vs 60.3%, P 〈 0.01）, 24-h APACHE Ⅱ score （13.6 ± 5.7 vs 10.7 ± 4.6, P 〈 0.01） and admission serum glucose （17.7 ± 7.7 vs 13.4 ± 6.1, P 〈 0.01）, complication rate of renal failure （51.1% vs 16.8%, P 〈 0.01）, shock （37.9% vs 14.5%, P 〈 0.01） and infection （37.4% vs 18.3%, P 〈 0.01） and mortality （13.1% vs 9.1%, P 〈 0.01）. Logistic regression analysis showed a positive correlation between admission TG and 24-h APACHE Ⅱ score （r = 0.509, P = 0.004）.CONCLUSION： The clinical features of SAP patients with HTG are largely consistent with previous studies, HTG aggravates the episodes of SAP.

关键词： Clinical study Hypertriglyceridemia Severe acute pancreatitis Clinical features Outcome

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Synthesis,structural characterization and solubility of 2-(1-substituted-1,11-undecylidene)-5-arylimino-△~3 -1,3,4-thiadiazolines

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Chinese Chemical Letters 2009年第11期20卷 1267-1270页

作者： Shu Hui Jin xiao mei Liang Xu yang Fu Heng Chen Dao Quan Wang Key Laboratory of Pesticide Chemistry and Application Technology Department of Applied Chemistry China Agricultural University Beijing 100193 China

A series of novel 2-（1-substituted-1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines （4） were synthesized and their structure was characterized by ^1H NMR, ^13C NMR and elemental analysis. Their solubility in both polar and non-polar solvents is significantly improved owing to the introduction of ethyl or methylthio group at cyclododecyl ring as compared with parent compounds [1, 2-（1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines]. However, their fungicidal activity against Rhizoctonia solani is less than that of parent compounds. X-ray diffraction analysis of a representative compound （4d） showed that the conformation of 12-membered ring is still [3333], in which the ethyl group present at the side-exo position and the thiadiazoline ring at the comer carbon. The thiadiazoline plane is perpendicular to the cyclododecyl one.

关键词： 2-(1-Substituted-1,11-undecylidene)-5-arylimino-△^3-1,3,4-thiadiazoline Solubility Crystal structure Synthesis

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Induced pluripotent stem cells:origins, applications, and future perspectives

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第12期14卷 1059-1069页

作者： Jing ZHAO Wen-jie JIANG Chen SUN Cong-zhe HOU xiao-mei yang Jian-gang GAO School of Life Sciences Shandong University

Embryonic stem(ES)cells are widely used for different purposes,including gene targeting,cell therapy,tissue repair,organ regeneration,and so ***,studies and applications of ES cells are hindered by ethical issues regarding cell *** circumvent ethical disputes,great efforts have been taken to generate ES cell-like cells,which are not derived from the inner cell mass of blastocyst-stage *** 2006,Yamanaka et *** reprogrammed mouse embryonic fibroblasts into ES cell-like cells called induced pluripotent stem(iPS)*** one year later,Yamanaka et *** Thomson et *** reprogrammed human somatic cells into iPS *** the first generation of iPS cells,they have now been derived from quite a few different kinds of cell *** particular,the use of peripheral blood facilitates research on iPS cells because of safety,easy availability,and plenty of cell *** iPS cells have been used for cell therapy,disease modeling,and drug *** this review,we describe the generations,applications,potential issues,and future perspectives of iPS cells.

关键词： Induced pluripotent stem cells Origin Peripheral blood cells Application Potential issues

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Conditional gene manipulation:Cre-ating a new biological era

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第7期13卷 511-524页

作者： Jian ZHANG Jing ZHAO Wen-jie JIANG Xi-wei SHAN xiao-mei yang Jian-gang GAO School of Life Science Shandong University Jinan 250100China

To solve the problem of embryonic lethality in conventional gene knockouts, site-specific recombinase （SSR） systems （Cre-loxP, FIp-FRT, and φC31） have been used for tissue-specific gene knockout. With the combination of an SSR system and inducible gene expression systems （tetracycline and tamoxifen）, stage-specific knockout and transgenic expression can be achieved. The application of this ＂SSR＋inducible＂ conditional tool to genomic manipulation can be extended in various ways. Alternatives to conditional gene targeting, such as conditional gene trapping, multipurpose conditional alleles, and conditional gene silencing, have been developed. SSR systems can also be used to construct precise disease models with point mutations and chromosomal abnormalities. With these exciting achievements, we are moving towards a new era in which the whole genome can be manipulated as we wish.

关键词： Site-specific recombinase Gene targeting Gene trapping Inducible systems φC31 system

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In vivo observation of cerebral microcirculation after experimental subarachnoid hemorrhage in mice

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Neural Regeneration Research 2018年第3期13卷 456-462页

作者： xiao-mei yang Xu-hao Chen Jian-fei Lu Chang-man Zhou Jing-yan Han Chun-hua Chen Department of Human Anatomy and Embryology Peking University Health Science Center School of Basic Medical Sciences Peking University Health Science Center Tasly Microcirculation Research Center Peking University Health Science Center

Acute brain injury caused by subarachnoid hemorrhage is the major cause of poor prognosis. The pathology of subarachnoid hemorrhage likely involves major morphological changes in the microcirculation. However, previous studies primarily used fixed tissue or delayed injury models. Therefore, in the present study, we used in vivo imaging to observe the dynamic changes in cerebral microcirculation after subarachnoid hemorrhage. Subarachnoid hemorrhage was induced by perforation of the bifurcation of the middle cerebral and anterior cerebral arteries in male C57/BL6 mice. The diameter of pial arterioles and venules was measured by in vivo fluorescence microscopy at different time points within 180 minutes after subarachnoid hemorrhage. Cerebral blood flow was examined and leukocyte adhesion/albumin extravasation was determined at different time points before and after subarachnoid hemorrhage. Cerebral pial microcirculation was abnormal and cerebral blood flow was reduced after subarachnoid hemorrhage. Acute vasoconstriction occurred predominantly in the arterioles instead of the venules. A progressive increase in the number of adherent leukocytes in venules and substantial albumin extravasation were observed between 10 and 180 minutes after subarachnoid hemorrhage. These results show that major changes in microcirculation occur in the early stage of subarachnoid hemorrhage. Our findings may promote the development of novel therapeutic strategies for the early treatment of subarachnoid hemorrhage.

关键词： nerve regeneration subarachnoid hemorrhage microcirculation disturbance leukocyte adhesion albumin extravasation cerebral blood flow vasoconstriction early brain injury neural regeneration

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Time evolutions of scalar field perturbation in Schwarzschild de-Sitter black hole from Einstein-scalar–Gauss–Bonnet theory

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Communications in Theoretical Physics 2024年第1期76卷 76-81页

作者： Cheng Xu Zhen-Hao yang xiao-mei Kuang Rui-Hong Yue Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou225009China

The scalar-free black hole could be unstable against the scalar field perturbation when it is coupled to a Gauss–Bonnet(GB)invariant in a special *** is known that the tachyonic instability in this scenario is triggered by the sufficiently strong GB *** this paper,we focus on the time domain analysis of massive scalar field perturbation around the Schwarzschild de-Sitter black hole in Einstein-scalar–Gauss–Bonnet *** analyzing the scalar field propagation,we find that the scalar field will finally grow when the GB coupling is large *** could lead to the instability of the background black ***,we demonstrate how the mass of the scalar field and the GB coupling strength affect the onset of tachyonic instability.

关键词： black hole perturbation scalar-Einstein-Gauss-Bonnet gravity time domain evolution me

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