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Approximate analytical solutions for threedimensional ascent trajectory of a solid-fuel launch vehicle with time-varying mass flow rate

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Chinese Journal of Aeronautics 2024年第10期37卷 275-293页

作者： qi yu Wanchun CHEN Wenbin yu School of Astronautics Beihang UniversityBeijing 102206China

In the scenario that a solid-fuel launch vehicle maneuvers in outer space at high angles of attack and sideslip for energy management,Approximate Analytical Solutions(AAS)for the threedimensional(3D)ascent flight states are derived,which are the only solutions capable of considering time-varying Mass Flow Rate(MFR)at *** uneven MFR makes the thrust vary nonlinearly and thus increases the difficulty of the problem *** AAS are derived based on a 3D Generalized Ascent Dynamics Model(GADM)with a normalized mass as the independent *** simplify some highly nonlinear terms in the GADM,several approximate functions are introduced carefully,while the errors of the approximations relative to the original terms are regarded as minor ***,a finite series with positive and negative exponents,called Exponent-Symmetry Series(ESS),is proposed for function approximation to decrease the highest exponent in the AAS so as to reduce computer round-off *** calculate the ESS coefficients,a method of seeking the Optimal Interpolation Points(OIP)is proposed using the leastsquares-approximation *** to the artful design of the approximations,the GADM can be decomposed into two analytically solvable subsystems by a perturbation method,and thus the AAS are obtained ***,to help implement the AAS,two indirect methods for measuring the remaining mass and predicting the burnout time in flight are put forward using information from *** results verify the superiority of the AAS under the condition of time-varying MFR.

关键词： Approximate analytical solutions 3D ascent trajectory Solid-fuel launch vehicle Uneven thrust Energy management

Phosphatase and Tension Homolog Overexpression in Insulin Resistant Diabetic Adipose Tissue

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Chinese Medical Sciences Journal 2014年第3期29卷 167-173页

作者： Jing-bo zeng yun Zhang qi Sun yu-xiu Li Department of Endocrinology Key Laboratory of Endocrinology of the Ministry of Health Peking Union Medical College Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Department of Endocrinology Fuxing Hospital Affiliated to Capital University of Medical Sciences

Objective To investigate the expression of phosphatase and tension homolog(PTEN) in adipose tissue of KKAy diabetic mice, a mouse model of type 2 diabetes. Methods KKAy diabetic mice were fed with high fat diet for 4 weeks. After blood glucose met the criteria of diabetes(over 16.7 mmol/L), mice were randomly divided into 3 groups: a control group(without any treatment), a rosiglitazone group(treated with rosiglitazone 12.5 mg/kg·d once per day), and a metformin group(treated with metformin 3 g/kg·d twice daily). After 4 weeks, we then determined the expression of PTEN and phosphoserine 473-Akt(pS473-Akt) in the epididymal adipose tissue with Western blots. The mice in each group were further divided into the insulin(-) subgroup and insulin(+) subgroup, which were intraperitoneally injected with saline and insulin(5 mU/g body weight), respectively. Results The expression of PTEN was elevated in the epididymal adipose tissue obtained from KKAy diabetic mice compared with that from the C57BL/6J mice(P<0.001). In accordance with the enhanced expression of PTEN, the level of pS473-Akt stimulated by insulin was decreased in the adipose tissue of KKAy mice compared to the C57BL/6J mice(P<0.001). Treatment with the insulin-sensitizing agents, rosiglitazone and metformin did not inhibit the elevated expression of PTEN in adipose tissue of KKAy diabetic mice. Conclusion PTEN may play an important role in the development of insulin resistance in adipose tissue of type 2 diabetes mice model.

关键词： insulin resistance phosphatase and tension homolog adipose tissue

Discussions about whether radioactive half life can be changed by mechanic motion

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Science China Chemistry 2009年第5期52卷 693-698页

作者： HE yuJian zeng LiXi qi ShengChu College of Chemistry and Chemical Engineering Graduate University of the Chinese Academy of SciencesBeijing 100049China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China

In this essay, some discussions and comments about the paper entitled "Can the decay rate of 32P be changed by mechanic motion?" (Ding et al., Science in China Series B:Chemistry (Chinese version), 2008, 38(11):1035-1037) are given. It was strongly suggested that its experimental methods, data calculations and conclusion should be reconsidered. After the data were recalculated, the new results supported that the chiral mechanic motion could induce the changes of radioactive half life.

关键词： circular rotation radioactive decay half life chirality

Cystine-assisted accumulation of gold nanoparticles on ZnO to construct a sensitive surface-enhanced Raman spectroscopy substrate

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Frontiers of Chemical Science and Engineering 2023年第1期17卷 15-23页

作者： qi Qu Chuan zeng Jing Huang Mengfan Wang Wei qi Zhimin He School of Chemical Engineering and Technology State Key Laboratory of Chemical EngineeringTianjin UniversityTianjin 300072China School of Life Sciences Tianjin UniversityTianjin 300072China Co-Innovation Centre of Chemistry and Chemical Engineering of Tianjin Tianjin 300072China Tianjin Key Laboratory of Membrane Science and Desalination Technology Tianjin 300350China Technical Centre of Gongbei Customs District of China Zhuhai 519000China

Recently,various semiconductor/metal composites have been developed to fabricate surfaceenhanced Raman spectroscopy ***,low metal loading on semiconductors is still a *** this study,cystine was introduced to increase the accumulation of gold nanoparticles on zinc oxide,owing to the biomineralization_property of_*** analysis revealed that the obtained ZnO/Au/cystine composite not only had a higher metal loading but also formed a porous structure,which is beneficial for Raman *** with ZnO/Au,the ZnO/Au/cystine substrate displayed a 40-fold enhancement in the Raman signal and a lower limit of detection(10^(-11) mol·L^(-1))in the detection of rhodamine ***,the substrate has favorable homogeneity and ***,ZnO/Au/cystine displayed excellent performance toward crystal violet and methylene blue in a test based on river water *** study provided a promising method to fabricate sensitive semiconductor/noblemetal-based surface-enhanced Ramans spectroscopy substrates for Raman detection.

关键词： biomineralization cystine semiconductor/metal composite SERS detection Raman detection

Nonsolvable Groups with Three Nonlinear Irreducible Character Codegrees

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 173-178页

作者： Dongfang YANG yu zeng Department of Mathematics Changshu Institute of TechnologyChangshu 215500JiangsuChina

For an irreducible characterχof a?nite group G,the codegree ofχis de-?ned as|G:ker(χ)|/χ(1).In this paper,the authors determine?nite nonsolvable groups with exactly three nonlinear irreducible character codegrees,... 详细信息

关键词： Character codegree Nonsolvable group

Evolutionary Programming for IP/MIP Problems with Linear Constraints

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Journal of Systems Engineering and Electronics 2000年第3期11卷 59-64页

作者： Ren, qingsheng zeng, Jin qi, Feihu Shanghai Jiaotong Univ Shanghai China

In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem to a linear model or others. The numerical results show that the new algorithm gives a satisfactory performance in which it works of high speed, and accuracy in IP/MIP problems.

关键词： Algorithms Constraint theory Mathematical models Mathematical transformations Problem solving

Cyclopenta-fused perylene: a new soluble, stable and functionalizable rylene building block

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Science Bulletin 2015年第14期60卷 1266-1271页

作者： Wangdong zeng qingbiao qi Jishan Wu Department of Chemistry National University of Singapore Institute of Materials Research and Engineering

We report a facile synthesis of a [l,12-b,c,d]- cyclopenta-fused perylene 5 from the parent perylene via a formylation-oxidative esterification-nucleophilic additionfollowed-by-Friedel-Crafts alkylation strategy. Compared with the perylene, dye 5 exhibits much higher solubility, smaller energy gap, and can undergo regio-selective bromination at the peri-positions. Compared with the N- annulated perylene 8, compound 5 shows lower HOMO energy level and is more stable in air. Therefore, 5 can be regarded a new versatile building block for the development of high-order soluble and stable rylenes and various perylene-based functional materials.

关键词： Organic dye Rylene Perylene Polycyclic aromatic hydrocarbon

Microstructure and Wear Properties of Laser Coating Reinforced by Ti(C_xN_(1-x)) on Adamite Roller

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Journal of Iron and Steel Research International 2009年第3期16卷 78-82,88页

作者： qi Yong-tian ZOU zeng-da School of Material Science and Engineering Shandong University Jinan 250061 Shandong China

Fe-based layer with Ti（CxN1-x） particulates on Adamite roller surface was obtained by a 5 kW traverse-flowing CO2 laser cladding technology. The microstructures of the layer were detected by optical microscopy （OM）,X-ray diffraction （XRD）,scanning electron microscopy （SEM）,and electron probe microscopy analysis （EMPA）. The tests of wear resistance was carried out on the test machine. It was seen that a good metallurgical bonding between the coating and the substrate was achieved. The microstructure contains bulky dendritic crystal and small size Ti（CxN1-x） grains that are uniformly distributed in the solid solution matrix. The wear tests showed that the laser coating provided an excellent wear resistance property at room temperature.

关键词： Ti(CxN1-x) laser cladding in-situ formation adamite roller

Overall water splitting over conjugated polymer photocatalysts with crystal facets modulated

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Science China Chemistry 2020年第11期63卷 1582-1583页

作者： yu qi Fuxiang Zhang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian National Laboratory for Clean EnergyDalian 116023China

Photocatalytic overall water splitting(OWS)for H2 and O2 evolution with a 2:1 stoichiometric ratio is one of the most promising ways to convert solar energy into chemical one,but it confronts huge challenges in consideration of the uphill water oxidation with four-electron transfer[1].During the past half century,great efforts have been made to the inorganic semiconductors-based photocatalysts,and to date the maximal apparent quantum efficiency(AQE)of OWS under ultra violet(UV)light has reached over 95%,as high as that of natural photosynthesis[2].Comparatively,however,the research on water splitting using conjugated polymers or hybrid metal-organic frameworks(MOFs)for photocatalysts is still in the infancy stage,and the achievement of OWS on them is tremendously limited because of additional challenges in addressing their poor charge separation and photochemical stability[3,4].

关键词： splitting conjugated photochemical