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Synthetic and Systems Biotechnology 2023年第1期8卷 107-113页

作者： Chen-yang xia Bo-Wen Lu Ji-Yun Cui Bai-yang Wang Yue-yang Sun Fei Gan Hubei Key Laboratory of Cell Homeostasis College of Life ScienceWuhan UniversityWuhanChina TaiKang Center for Life and Medical Science Wuhan UniversityWuhanChina Hubei Provincial Cooperative Innovation Center of Industrial Fermentation WuhanChina

Terpenoids constitute the largest class of natural products with complex structures,essential functions,and versatile *** of new building blocks beyond the conventional five-carbon(C_(5))units,dimethylallyl diphosphate(DMAPP)and isopentenyl diphosphate,expands significantly the chemical space of ***-guided engineering of an S-adenosylmethionine-dependent geranyl diphosphate(GPP)C2-methyltransferase from Streptomyces coelicolor yielded variants converting DMAPP to a new C_(6) unit,*** of the Gly residue at the position 202 resulted in a smaller substrate-binding pocket to fit DMAPP instead of its native substrate *** of Phe residue at the position 222 with a Tyr residue contributed to DMAPP binding via hydrogen ***,using Escherichia coli as the chassis,we demonstrated that 2-methyl-DMAPP was accepted as a start unit to generate noncanonical trans-and cis-prenyl diphosphates(C_(5n+1))and *** work provides insights into substrate recognition of prenyl diphosphate methyltransferases,and strategies to diversify terpenoids by expanding the building block portfolio.

关键词： Protein engineering Terpenoid biosynthesis Methyltransferase Noncanonical building block

A Variable Parameter Linear Tracking Differentiator and Its Application in Large Ground-based Telescopes

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Research in Astronomy and Astrophysics 2022年第12期22卷 273-283页

作者： xiao-xia yang Yong-Ting Deng Jian-Li Wang Bin Zhang Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

This paper is concerned with the characteristics of a tracking differentiator(TD)in arranging transition process for the physical *** order to overcome disadvantages of linear TD(LTD)in practice,a novel variable parameter linear tracking differentiator(VLTD)is *** designing the speediness factor as a function of the tracking error,the VLTD can track a large range of set values with reasonable speed and *** shows that VLTD can converge to its set value under certain ***,the speed and acceleration bounds are added to the VLTD,which guarantees that the proposed transition signal really plays a transitional *** numerical simulation results emphasize necessity for adding speed and acceleration bounds to the *** comparing VLTD with the nonlinear TD(NLTD)in the simulations and experiments,VLTD can achieve almost the same performance as the NLTD while it is easier to be implemented.

关键词： methods:data analysis methods:analytical methods:numerical telescopes

Determination of Some Heavy-metal-ions Using a Sulfur Ion Modified BZ Oscillating System

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Chinese Chemical Letters 2006年第9期17卷 1221-1224页

作者： Hua CHEN Wu yang Hong xia DAI xiao xia WEI Jie QU Jin Zhang GAO College of Chemistry ＆ Chemical Engineering Northwest Normal University Lanzhou 730070

A highly sensitive method is developed for the determination of trace amounts of some heavy metal ions in aqueous solution based on the classical Belousov-Zhabotinskii （BZ） oscillating chemical system. Introducing of S^2- ion makes the new oscillating system Ce（SO4）2 - KBrO3 - CH2（COOH）2 - Na2S - H2SO4 have to a high sensitivity for some heavy metal ions such as Ag^＋, Pb^2＋, Hg^2＋, Cd^2＋, Cu^2＋and Bi^3＋ with detection limits down to 10^-12 mol·L^- 1

关键词： BZ oscillating system kinetic determination heavy-metal-ion sulfur ion.

HETEROAROMATIC POLYMERS—HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3',4'-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

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Chinese Journal of Polymer Science 2005年第5期23卷 521-529页

作者： Hai-xia yang Jin-gang Liu xiao-juan Zhao Yan-feng Li Lin Fan Shi-yong yang School of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 China Laboratory of Advanced Polymer Materials Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

A new type of aromatic tetraarnine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin＇s reaction. 3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis（3＇,4＇-diaminophenyl）-4-biphenyl pyridine （DPPA）. A series of polypyrrolones （PPys） were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure. All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen. The polymers exhibit no apparent glass transition temperatures （Tgs） except PPy-1 （Tg= 327℃）, which is derived from tetraamine DPPA and 2,2-bis[4-（3＇,4＇-dicarboxyphenoxy）-phenyl]propane dianhydride （BPADA）. In addition, the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa. The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.

关键词： Tetraamine Polypyrrolone Pyridine High temperature polymers Film Hydrolysis-resistance.

Extended state observer-based control with an adjustable parameter for a large ground-based telescope

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Research in Astronomy and Astrophysics 2021年第12期21卷 509-518页

作者： xiao-xia yang Yong-Ting Deng Bin Zhang Jian-Li Wang Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

The high-precision requirements will always be constrained due to the complicated operating conditions of the ground-based telescope. Owing to various internal and external disturbances, it is necessary to study a control method, which should have a good ability on disturbance rejection and a good adaptability on system parameter variation. The traditional proportional-integral(PI) controller has the advantage of simple and easy adjustment, but it cannot deal with the disturbances well in different situations. This paper proposes a simplified active disturbance rejection control law, whose debugging is as simple as the PI controller, and with better disturbance rejection ability and parameter adaptability. It adopts a simplified second-order extended state observer(ESO) with an adjustable parameter to accommodate the significant variation of the inertia during the different design stages of the telescope. The gain parameter of the ESO can be adjusted online with a recursive least square estimating method once the system parameter has changed significantly. Thus, the ESO can estimate the total disturbances timely and the controller will compensate them accordingly. With the adjustable parameter of the ESO, the controller can always achieve better performance in different applications of the telescope. The simulation and experimental verification of the control law was conducted on a 1.2-meter ground based telescope. The results verify the necessity of adjusting the parameter of the ESO, and demonstrate better disturbance rejection ability in a large range of speed variations during the design stages of the telescope.

关键词： extended state observer large ground based telescope recursive least square disturbance rejection

Effect of resilience on quality of life and anxiety in patients with breast cancer

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World Journal of Psychiatry 2024年第10期14卷 1458-1466页

作者： Ling-xia Kong Yong-xia yang Qian Zhao Zhi-Lin Feng Department of Breast Surgery The First Affiliated Hospital of Hebei North UniversityZhangjiakou 075000Hebei ProvinceChina Department of Psychiatry Zhangjiakou Shalingzi Hospital(Zhangjiakou Mental Health Center)Zhangjiakou 075200Hebei ProvinceChina

BACKGROUND The incidence of breast cancer is high,with serious implications in terms of lives and *** data show that there are approximately 1 million new cases of breast cancer reported annually,with a rising *** patients have poor treatment effects and are prone to anxiety and other negative emotions,which affect their quality of life(QoL).AIM To explore the correlation between mental resilience,QoL,and anxiety in patients with breast *** Using convenience sampling,200 patients with breast cancer were selected from the First Affiliated Hospital of Hebei North *** patients were investigated using the Conner-Davidson Resilience Scale,Self-Rating Anxiety Scale,and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire to analyze the impact of resilience in patients with breast cancer on their QoL and *** The mean(SD)mental resilience score of the patients with breast cancer was 59.68(±9.84)points,the anxiety score was 49.87(±8.26)points,and the QoL score was 59.73(±8.29)***,they showed low mental resilience,mild anxiety,and medium *** was negatively correlated with mental resilience and QoL(r=-0.275,r=-0.289,P<0.05).QoL was positively correlated with mental resilience(r=0.513,P<0.05).Anxiety was a mediating variable between mental resilience and QoL,accounting for 8.58%of the mediating *** Regarding psychological elasticity,anxiety plays an intermediary role in QoL among patients with breast *** staff can improve patients'mental resilience by reducing their anxiety and improving their QoL.

关键词： Breast cancer Mental resilience Quality of life Anxiety Psycho-oncology Mediation effect

Revisiting Scientific Issues for Industrial Applications of Lithium–Sulfur Batteries

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Energy & Environmental Materials 2018年第4期1卷 196-208页

作者： Bo Liu Ruyi Fang Dong Xie Wenkui Zhang Hui Huang yang xia Xiuli Wang Xinhui xia Jiangping Tu State Key Laboratory of Silicon Materials Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang ProvinceSchool of Materials Science&EngineeringZhejiang UniversityHangzhou 310027China College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China Guangdong Engineering and Technology Research Center for Advanced Nanomaterials School of Environment and Civil EngineeringDongguan University of TechnologyDongguan 523808China

Inspired by high theoretical energy density(-2600 W h kg^(-1))and cost-effectiveness of sulfur cathode,lithium–sulfur batteries are receiving great attention and considered as one of the most promising next-generation high-energy-density ***,over the past decades,the energy density and reliable safety levels as well as the commercial progress of lithium-sulfur batteries are still far from satisfactory due to the disconnection and huge gap between fundamental research and practical application.

关键词： energy storage lithium lithium-sulfur batteries safetyissue sulfurcathode

Production induced fracture closure of deep shale gas well under thermo-hydro-mechanical conditions

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Petroleum Science 2024年第3期21卷 1796-1813页

作者： Shi-Ming Wei yang xia Yan Jin Xu-yang Guo Jing-Yu Zi Kai-Xuan Qiu Si-Yuan Chen College of Science China University of Petroleum(Beijing)Beijing102249China CNOOC Research Institute Ltd Beijing100028China The University of Hong Kong Hong Kong999077China

Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through *** multi-stage fractured horizontal well is the key to exploiting the deep shale gas ***,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas *** this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas *** we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale *** the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture *** with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the *** simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary *** creep and proppant embedment both increase the degree of fracture *** reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the ***,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield *** study is helpful to understand the mechanism of hydraulic fracture ***,it provides the theoretical guidance for maintaining the long

关键词： Shalegas Fracture closure Fluid-solid-heat coupling Discontinuous discrete fracture

Single-molecule fluorescence imaging of membrane-bound proteins for studies of cell signal transduction

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Chinese Science Bulletin 2011年第11期56卷 1063-1067页

作者： yang Yong, xia Tie ZHANG Wei FANG xiaoHong Beijing National Laboratory for Molecular Sciences Key Laboratory of Molecular Nanostructures and Nanotechnology Institute of ChemistryChinese Academy of Sciences Beijing 100190 China

Fluorescence imaging of single molecules is becoming a powerful tool to examine biological processes at the molecular *** total internal reflection fluorescence microscopy (TIRFM),it has been possible to study the dynamic behavior of single molecules on living cell ***,we briefly review the application of TIRFM-based single-molecule imaging in studies of membrane receptors involved in signal ***,we discuss several examples of our own research on growth factor receptors,including TGF-β receptors,HER2,and EGFR,and speculate possible applications of this technique to investigate other cellular events occurring on or near the plasma-membrane.

关键词：细胞信号转导单分子膜荧光成像结合蛋白生长因子受体荧光显微镜单分子成像生物过程

Petrology and phase equilibrium of newly found eclogites from Kekesu Valley in eastern part of southwest Tianshan HP-UHP metamorphic belt,China,and its tectonic significance

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Science China Earth Sciences 2014年第5期57卷 117-131页

作者： xia Bin ZHANG LiFei xia yang MOE Key Laboratory of Orogenic Belt and Crustal Evolution School of Earth and Space SciencesPeking University

Eclogites and omphacite-bearing blueschists have been newly found in the eastern segment of the southwest Tianshan orogenic belt, Xinjiang, northwest China. After detailed petrological study, three samples including one fresh eclogite TK003, one blueschist sample TK026-8 and one retrograded eclogite TK027, were selected for phase equilibrium modeling under NC（K）MnFMASHO （N20-CaO-K20-MnO-FeO-MgO-A1203-SiO2-H：O-O） system, by thermocalc 3.33 software. Composition analyses of garnets in these three samples show typical growth zoning with Xpy and Xgrs increasing, Xspss decreasing from core to rim. Pseudosection modeling of the garnet zonation reflects that the eclogites and blueschist experienced a similar P-T evo- lution trajectory, with a near iso-baric heating in the early stage, and reached eclogite facies metamorphic field with peak P-T regime of 480-515~C, 2.00-2.30 GPa. Subsequently the rocks experienced an early iso-thermal decompression retrograde stage with P-T conditions of 515-519~C, 1.78-1.93 GPa. Variations of mineralogy and modes of these rocks are probably due to different retrograde paths as a consequence of different bulk-rock composition, as well as a variation in fluid activity during exhumation. P-T calculation and a peak geothermal gradient of 6-7~C/km indicate HP rocks in the Kekesu Valley experienced cold subducted eclogite facies metamorphism. Thus a huge oceanic subduction eclogite facies metamorphic belt in southwest Tianshan has been recognized, extending from the Kekesu Valley in the east to the Muzhaerte Valley in the west for nearly 200 kin. However, UHP evidence has not been found in the Kekesu terrane, perhaps because the slab in east part of southwest Tianshan did not subduct into such a great depth.

关键词： blueschist eclogite phase equilibrium Kekesu Valley southwest Tianshan

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