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Boundary Shift of Potential Suitable Agricultural Area in Farming-grazing Transitional Zone in Northeastern China under Background of Climate Change During 20th Century

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Chinese Geographical Science 2013年第6期23卷 655-665页

作者： ye Yu fang Xiuqi School of Geography Beijing Normal University Key Laboratory of Environment Change and Natural Disaster Ministry of EducationBeijing Normal University

Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded： 1） The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2） The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3） The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.

关键词： land cover changes farming-grazing transitional zone climate change agricultural production

Representations of Frobenius-type Triangular Matrix Algebras

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Acta Mathematica Sinica,English Series 2017年第3期33卷 341-361页

作者： fang LI Chang ye Department of Mathematics Zhejiang University Hangzhou 310027 P. R. China

The aim of this paper is mainly to build a new representation-theoretic realization of finite root systems through the so-called Frobenius-type triangular matrix algebras by the method of reflection functors over any field. Finally, we give an analog of APR-tilting module for this class of algebras. The major conclusions contains the known results as special cases, e.g., that for path algebras over an algebraically closed field and for path algebras with relations from symmetrizable cartan matrices. Meanwhile, it means the corresponding results for some other important classes of algebras, that is, the path algebras of quivers over Frobenius algebras and the generalized path algebras endowed by Frobenius algebras at vertices.

关键词： Frobenius-type triangular matrix algebras reflection functor locally free module rootsystem APR-tilting module

Isolation, Purification, and Characterization of Exopolysaccharide Produced by Leuconostoc Citreum N21 from Dried Milk Cake

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Transactions of Tianjin University 2019年第2期25卷 161-168页

作者： Yanfang Yang fang Feng Qingqing zhou fangkun Zhao Renpeng Du Zhijiang zhou ye Han School of Chemical Engineering and Technology Tianjin University

A strain with high production of exopolysaccharide(EPS) was isolated from dried milk cake(a traditional fermented food from Inner Mongolia). The strain was called N21 and later identified as Leuconostoc citreum( Leu. citreum). The strain was cultured in Man-Rogosa-Sharpe medium containing 50 g/L of sucrose for 48 h at 30 °C and the EPS purified, with a yield of 24.5 g/L. An average molecular weight of 6.07 × 10~6 g/mol was determined by high-performance size-exclusion chromatography. The structure of the purified EPS was investigated through gas chromatography, ~1H and ^(13)C nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy. The results demonstrated a polysaccharide composed of D-glucopyranose units in a linear chain with consecutive α(1 → 6) linkages. No branching was found in the structure of the exopolysaccharide. The purified EPS showed high water solubility and emulsibility. Based on the thermogravimetric curve, the degradation temperature of the EPS was 308.47 °C, which suggested that the dextran in the study exhibited high thermal stability. The results indicated that Leu. citreum N21 could be widely used to produce linear EPS and that the EPS has potential applications in food science and processing as a food additive.

关键词： Exopolysaccharide Dextran Characterization Leuconostoc citreum Structure

Structural Characterization of Glucan Produced by Lactobacillus sake L-7 from Sausage

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Transactions of Tianjin University 2019年第1期25卷 78-84页

作者： fang Feng Qingqing zhou Yanfang Yang fangkun Zhao Renpeng Du ye Han Zhijiang zhou School of Chemical Engineering and Technology Tianjin University

A linear glucan was produced by Lactobacillus sake L-7 isolated from homemade sausage. Cultivation of the strain in Man–Rogosa–Sharpe(MRS) medium containing 50 g/L sucrose yielded 5.3 g/L of purified exopolysaccharide(EPS). The EPS was characterized by gas chromatography(GC), Fourier-transform infrared(FT-IR) spectroscopy, high-performance sizeexclusion chromatography(HPSEC), nuclear magnetic resonance(NMR) spectroscopy, and scanning electron microscopy(SEM). The monosaccharide composition of the EPS was glucose, and its molecular weight was 1 × 10~7 Da. The FT-IR and NMR spectra revealed that the L-7 EPS was a linear glucan with α-(1 → 6) glucosidic bonds. SEM images of the dried EPS revealed a hollow tubular structure. The water solubility index and water holding capacity of L-7 EPS were 96 and 272%, respectively. The results of hydrolysis indicated that L-7 EPS was not susceptible to hydrolysis by physiological barriers and can be used as a soluble dietary fiber with health benefits. All these characteristics suggest that L-7 EPS might have potential applications in the food, cosmetic, and pharmaceutical industries.

关键词： Glucan Exopolysaccharide Structural characterization Lactobacillus sake Hydrolysis

Dehydration melting of amphibolite at 1.5 GPa and 800–950C:Implications for the Mesozoic potassium-rich adakite in the eastern North China Craton

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Geoscience Frontiers 2021年第2期12卷 896-906页

作者： Zhilin ye fang Wan Neng Jiang Jingui Xu Yuanyun Wen Dawei Fan Wenge zhou Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang550081China University of Chinese Academy of Sciences Beijing100049China Minco International Mining Consulting Ltd. Beijing100012China Institute of Geology and Geophysics Chinese Academy of SciencesBeijing100029China Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyang550081China

Mesozoic intermediate-felsic magmatic rocks in the eastern North China Craton commonly show geochemical similarity to ***,the lack of direct constraints from partial melting experiments at high pressures and temperatures fuels a debate over the origin of these *** this work,we performed partial melting experiments at 1.5 GPa and 800–950℃on amphibolite samples collected from the vicinity of the Mesozoic potassium-rich adakitic rocks in the Zhangjiakou area,northern margin of the North China *** experimental melts range from granitic to granodioritic compositions,with SiO_(2)=56.4–72.6 wt.%,Al_(2)O_(3)=16.1–19.3 wt.%,FeO^(*)=2.4–9.6 wt.%,MgO=0.3–2.0 wt.%,CaO=0.6–3.8 wt.%,Na_(2)O=4.7–5.3 wt.%,and K_(2)O=2.6–3.9 wt.%,which are in the ranges of the surrounding Mesozoic potassium-rich adakitic rocks,except for the higher Al_(2)O_(3)contents and the data point at 1.5 GPa and 800℃.Trace element compositions of the melts measured by LA-ICP-MS are rich in Sr(849–1067 ppm)and light rare earth elements(LREEs)and poor in Y(<10.4 ppm)and Yb(<0.88 ppm),and have high Sr/Y(102–221)and(La/Yb)n(27–41)ratios and strongly fractionated rare earth element(REE)patterns,whereas no obvious negative Eu anomalies are *** geochemical characteristics show overall similarity to the Mesozoic potassium-rich adakitic rocks in the area,especially adakites with low Mg#,again except for the data point at 1.5 GPa and 800℃.The results suggest that partial melting of amphibolite can produce potassium-rich adakitic rocks with low Mg#in the eastern North China Craton under the experimental conditions of 1.5 GPa and 850–950℃.The experimental restites consist of hornblende(Hbl)+plagioclase(Pl)+garnet(Grt)±clinopyroxene(Cpx),a mineral assemblage significantly different from that of the nearby Hannuoba mafic granulite xenoliths which consist of Cpx+orthopyroxene(Opx)+Pl±***,the experimental restites contain higher Al_(2)O_(3)but lower MgO and CaO than the Hannuoba ma

关键词： Amphibolite Partial melting Eastern North China Craton Potassium-rich adakitic rocks Hannuoba granulite xenoliths

Numerical study on butterfly wings around inclusion based on damage evolution and semi-analytical method

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Friction 2022年第9期10卷 1335-1352页

作者： ye zhou Caichao ZHU Xiaojin CHEN Wei ye State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400030China College of Aerospace Engineering Chongqing UniversityChongqing 400044China Chongqing Wangjiang Industrial Co. Chongqing 400071China

Butterfly wings are closely related to the premature failure of rolling element *** this study,butterfly formation is investigated using the developed semi-analytical three-dimensional(3D)contact model incorporating inclusion and material property *** 3D elastic field introduced by inhomogeneous inclusion is solved by using numerical approaches,which include the equivalent inclusion method(EIM)and the conjugate gradient method(CGM).The accumulation of fatigue damage surrounding inclusions is described using continuum damage *** coupling between the development of the damaged zone and the stress field is *** effects of the inclusion properties on the contact status and butterfly formation are discussed in *** model provides a potential method for quantifying material defects and fatigue behavior in terms of the deterioration of material properties.

关键词： contact fatigue butterfly wings semi-analytical method damage evolution

不同策略提高间充质干细胞治疗肝纤维化:效果与潜在风险分析

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中国组织工程研究 2025年第23期29卷 5002-5012页

作者：徐岩王雪淞周林周晓磊金煜叶俊松赣南医科大学第一附属医院干细胞临床转化分中心江西省赣州市341000 赣南医科大学康复学院江西省赣州市341000 赣州市干细胞与再生医学重点实验室江西省赣州市341000 组织工程江西省重点实验室江西省赣州市341000 心脑血管疾病防治教育部重点实验室江西省赣州市341000

背景:目前大量研究表明,间充质干细胞联合不同治疗策略能更有效地改善肝纤维化,抑制其向终末期肝病发展。目的:探讨间充质干细胞联合不同策略改善肝纤维化疗效优于单独间充质干细胞治疗的相关机制。方法:由第一作者应用计算机在中国知... 详细信息

背景:目前大量研究表明,间充质干细胞联合不同治疗策略能更有效地改善肝纤维化,抑制其向终末期肝病发展。目的:探讨间充质干细胞联合不同策略改善肝纤维化疗效优于单独间充质干细胞治疗的相关机制。方法:由第一作者应用计算机在中国知网、万方、维普、PubMed、Web of Science和Nature数据库中检索涉及间充质干细胞联合不同策略改善肝纤维化的研究,中文检索词为“间充质干细胞,肝纤维化,联合治疗,肝星状细胞”,英文检索词为“mesenchymal stem/stromal cells,liver/hepatic fibrosis/cirrhosis,combination therapy,hepatic stellate cells/HSCs”,通过快速浏览文章题目及摘要进行筛选,排除与主题关系不密切的文章,最终筛选出104篇文献进行综述分析。结果与结论:间充质干细胞通过分化为肝样细胞、抑制肝星状细胞活化、免疫调节等机制来改善肝纤维化,但间充质干细胞移植后肝脏定植率低、存活率低、作用时间短等原因限制了其临床应用。间充质干细胞联合药物、基因修饰、细胞因子等多种治疗策略改善肝纤维化的疗效优于间充质干细胞单独治疗,并且间充质干细胞联合不同策略通过促进间充质干细胞归巢、抑制肝星状细胞活化、调节微环境、调控信号通路等机制更有效地改善肝纤维化。间充质干细胞还可以通过预处理、miRNA调控及与其他细胞联合,使间充质干细胞在减轻肝纤维化方面表现出更好的肝源性分化、归巢和存活功能。间充质干细胞联合不同策略并不能规避间充质干细胞单独治疗肝纤维化的潜在风险,而且这些策略(药物、基因修饰和细胞因子等)自身安全性也值得考虑。此外,间充质干细胞移植数量和途径等有待进一步研究。

关键词：间充质干细胞肝纤维化肝星状细胞信号通路联合用药基因修饰归巢微RNA

Coupled simulation of recirculation zonal firebox model and detailed kinetic reactor model in an industrial ethylene cracking furnace

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Chinese Journal of Chemical Engineering 2017年第8期25卷 1091-1100页

作者： zhou fang Tong Qiu Weiguo zhou Department of Chemical Engineering Tsinghua University

A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular *** firebox model is based on zone method including combustion,radiation,and convection to simulate heat transfer in the furnace.A two-dimensional recirculation model is proposed to estimate the flow field in *** reactor model integrates the feedstock reconstruction model,an auto-generator of detail kinetic schemes,and the reactor simulation model to simulate the reaction process in the tubular *** coupled simulation result is compared with industrial process and shows agreement within short computation time.

关键词： Ethylene cracking Coupled simulation Tubular furnace Recirculation zone modeling Detailed reaction kinetic

Fractional Dynamics of Fluid-Conveying Pipes Made of Polymer-Like Materials

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Acta Mechanica Solida Sinica 2018年第2期31卷 243-258页

作者： ye Tang Tianzhi Yang Bo fang School of Mechanical and Automotive Engineering Anhui Polytechnic University School of Aerospace Engineering Shenyang Aerospace University Department of Mechanics Tianjin University School of Astronautics Harbin Institute of Technology

The fluid-conveying pipes made of polymer-like materials are widely applied in engineering fields. However, the fractional dynamics of fluid-solid interaction remain unknown. In this work, the fractional dynamics of the pipes subjected to the excitation of supporting foun- dation are studied. A new nonlinear, fractional-order dynamic model is presented. The method of multiple scales is adopted directly to solve the model for the case of primary resonances. Numerical results are presented to show the effects of fractional order, foundation vibration, and other physical parameters on the steady-state response and stability.

关键词： Fluid-conveying pipes Fractional dynamics Method of multiple scales Polymer- like materials