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Acta Mechanica Solida Sinica 2017年第1期30卷 11-19页

作者： q.F.lü M.l.Deng W.q.Zhu Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsKey Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang University

A stochastic averaging method of quasi integrable and resonant Hamiltonian systems under excitation of fractional Gaussian noise （fGn） with the Hurst index 1/2 〈 H 〈 1 is proposed. First, the definition and the basic property of fGn and related fractional Brownian motion （iBm） are briefly introduced. Then, the averaged fractional stochastic differential equations （SDEs） for the first integrals and combinations of angle variables of the associated Hamiltonian systems are derived. The stationary probability density and statistics of the original systems are then obtained approximately by simulating the averaged SDEs numerically. An example is worked out to illustrate the proposed stochastic averaging method. It is shown that the results obtained by using the proposed stochastic averaging method and those from digital simulation of original system agree well.

关键词： quasi integrable and resonant Hamiltonian system Fractional Brownian motion Fractional Gaussian noise Stochastic averaging method Internal resonant

纳升解吸电喷雾电离质谱成像方法的近期研究进展

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色谱 2025年第1期43卷 43-49页

作者：王靖博李小兰范瑞霞吕萍尹瑞川四川大学华西药学院四川成都610041

常压质谱成像无需复杂的样品处理步骤,能在大气压下直接对组织切片中成百上千种分析物进行原位分析。目前,该领域正处于蓬勃发展的时期。已报道的常压电离技术种类众多,并呈现出“百花齐放”的良好态势;其中,纳升解吸电喷雾电离(nano-DE... 详细信息

常压质谱成像无需复杂的样品处理步骤,能在大气压下直接对组织切片中成百上千种分析物进行原位分析。目前,该领域正处于蓬勃发展的时期。已报道的常压电离技术种类众多,并呈现出“百花齐放”的良好态势;其中,纳升解吸电喷雾电离(nano-DESI)是近年发展迅速的一种基于液滴萃取的常压电离技术。脂质结构的复杂性给nano-DESI脂质成像带来了极大的挑战,而新型nano-DESI联用技术使脂质精细结构的鉴定与成像成为可能。与电喷雾电离(ESI)类似,nano-DESI倾向于产生多电荷态的分子离子,因而在蛋白质大分子的成像中具有显著的优势。本文聚焦于近3年nano-DESI在离子源研发、脂质结构分析和空间蛋白质组学方面的研究进展,并探讨了nano-DESI领域中亟需解决的关键问题。

关键词：纳升解吸电喷雾电离常压质谱成像脂质结构分析空间蛋白质组

Kinetics of the reaction of OH radical with ethylfluoroacetate,ethyl 4,4,4-trifluorobutyrate,and butylfluoroacetate

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Journal of Environmental Sciences 2025年第5期151卷 273-283页

作者： Pedro l.lugo Vianni Straccia Mariano A.Teruel María B.Blanco laboratorio Universitario de química y Contaminación del Aire(l.U.q.C.A) Institute for Research in Physical Chemistry of Córdoba(I.N.F.I.Q.C.)Department of Physical ChemistryFaculty of Chemical SciencesNational University of CórdobaUniversity CityCórdoba 5000Argentina Institute for Atmospheric and Environmental Research University of WuppertalWuppertal DE-42097Germany

Kinetics of the gas-phase reactions of•OH radicals with a series of fluoroesters were studied for the first time at 298±3 K and atmospheric *** rate coefficients were determined by in situ FTIR spectroscopy in nitrogen and GC-FID in air to monitor the decay of reactants and *** following coefficient values(in 10^(−12)cm^(3)/(molecule•sec))were obtained for ethyl fluoroacetate(EFA),ethyl 4,4,4-trifluorobutyrate(ETB),and butyl fluoroacetate(BFA),respectively:k_(1)(EFA+OH)=1.15±0.25 by FTIR and 1.34±0.23 by GC-FID;k_(2)(ETB+OH)=1.61±0.36 by FTIR and 2.02±0.30 by GC-FID;k_(3)(BFA+OH)=2.24±0.37 by *** trends were developed and correlated with the number of CH_(3)and F substituents in the fluoroester,and structure-activity relationships(SARs)calculations were *** addition,the tropospheric lifetimes of EFA,ETB,and BFA upon degradation by OH radicals were calculated to be 9,6,and 5 days,respectively,indicating that these fluorinated compounds could have a possible regional effect from the emission *** small photochemical ozone creation potentials of 9,7,and 19 were estimated for EFA,ETB,and BFA,*** GlobalWarming Potentials(GWPs)for EFA,ETB,and BFA were calculated for different time *** a 20-year time horizon,the GWPs were 1.393,0.063,and 0.062,*** the case of a 100-year time horizon,the GWPs were 0.379,0.017,and 0.017,and for a 500-year time horizon,the GWPs were 0.108,0.005,and 0.005 for EFA,ETB,and BFA.

关键词： CFC replacements sinks in situ FTIR SAR Acidification potentials Greenhouse gases

Reliability of quasi integrable and non-resonant Hamiltonian systems under fractional Gaussian noise excitation

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Acta Mechanica Sinica 2020年第4期36卷 902-909页

作者： q.F.lu W.q.Zhu M.l.Deng Department of Mechanics State-Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou 310027China

The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is *** rather flat fGn power spectral density(PSD)in most part of frequency band,the fGn is innovatively regarded as a wide-band ***,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(SDEs).Reliability function and mean first passage time are obtained by solving the associated backward Kolmogorov equation and Pontryagin *** validity of the proposed procedure is tested by applying it to an example and comparing the numerical results with those from Monte Carlo simulation.

关键词： Reliability Fkst passage time quasi integrable and non-resonant Hamiltonian systems Fractional Gauss noise

Metabolome and RNA-seq reveal discrepant metabolism and secretory metabolism profile in skeletal muscle between obese and lean pigs at different ages

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Science China life Sciences 2025年

作者： liu Guo Junfei Xu Wenyue Zhou Sisi Chen Hanjing Shi Mengmeng Han Zekun Yang Yehui Duan Weijun Pang Yulong yin Fengna li laboratory of Animal Nutritional Physiology and Metabolic Process Key Laboratory of Agro-ecological Processes in Subtropical Region Institute of Subtropical Agriculture Chinese Academy of Sciences University of Chinese Academy of Sciences laboratory of Animal Fat Deposition and Muscle Development College of Animal Science and Technology Northwest A&F University College of Advanced Agricultural Sciences University of Chinese Academy of Sciences

Metabolites and metabolism-related gene expression profiles in skeletal muscle change dramatically under obesity, aging and metabolic disease. Since obese and lean pigs are ideal models for metabolic research. Here, we compared metabolome and transcriptome of longissimus dorsi(lD) muscle between Taoyuan black(TB, obese) and Duroc(lean) pigs at different ages. We defined the “window phase” of intramuscular fat(IMF) deposition in TB pig, which has significantly higher IMF than Duroc pig. Our results displayed discrepant lipid composition and different expression genes(DEGs) enriched in lipid metabolism, and both metabolome and transcriptome analyses revealed stronger energy expenditure and more active amino acid and protein metabolism in Duroc pig. 10 up-and 51 down-regulated biomarker metabolites with age-and breed-specificity were identified. Potential secretory metabolites, including organic acid(fumaric acid, succinate,malic acid, and gamma-aminobutyric acid), amino acid(l-lysine, and l-glutamic acid), lipid(2-hydroxyisovaleric acid, and l-carnitine) were demonstrated a significant correlation with IMF deposition. Our research highlights the huge difference of metabolic spectrum in skeletal muscle between obese and lean model and muscle-derived secretory metabolites might act as an ambassador of intercellular communication to regulate systematic metabolism.

关键词：

Highly selective synthesis and near-infrared photothermal response of heterometallic double trefoil knot and D-type[2]catenanes

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Science China Chemistry 2025年

作者： ying Zhao Jian-Xin Yang yin-Hang Chai Yao He Peng Wang Francisco Aznarez Bo li li-long Dang lu-Fang Ma College of Chemistry and Chemical Engineering Luoyang Normal University College of Chemical and Pharmaceutical Engineering Nanyang Normal University

The selective construction of sophisticated supramolecular topologies has always attracted the remarkable attention of ***,various molecular knots and catenanes have recently been reported and were obtained either accidentally or by following a previously planned synthetic ***,we introduce a series of supramolecular topologies including double trefoil knot (1),trefoil knot (2) and[2]catenanes (4,5),which were prepared via an elaborated self-assembly strategy by using half-sandwich units based on a flexible pyridyl linker *** formation of all the structures has been confirmed by single crystal X-ray diffraction analysis and NMR spectroscopy,and ***,the central potassium ion of 1 coordinates six oxygen atoms belonging to six amide groups from two trefoil *** double trefoil knot 1 and[2]catenanes 4,5 are stabilized by parallel-displacedπ···πstacking interactions (of interlayer distance 3.34–3.82?) between the pyridyl fraction and phenyl moieties of three ligands l1,and by edge-to-face-type CH···πinteractions (2.64–2.83?) between BiBzIm conjugated planes and phenyl hydrocarbon ***,the addition/removal of potassium ions resulted in topological transformation between the double trefoil knot 1 and the trefoil knot *** addition,the addition of DMF-d7to a methanolic solution of the double trefoil knot 1 induced its structural conversion into the metallamacrocycle *** photothermal studies of 1,4,and 5 showed different photothermal responses in solid and solution ***,the photothermal conversion efficiencies of 4,and 5 were within the limit of 16.8%–45.1%based on different power areas,the number and the fashion ofπ···πstacking interactions can directly affect the photothermal conversion efficiency,and EPR experiments confirmed the recorded results.

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威克汉姆西弗酵母遗传操作系统的建立及其合成四乙酰基植物鞘氨醇的应用

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生物工程学报 2025年第1期41卷 397-415页

作者：刘浏尹正安潘力华南理工大学生物科学与工程学院广东广州510006

威克汉姆西弗酵母(Wickerhamomyces ciferrii,W.c)是一种异宗生殖的非常规酵母,能够大量生产并分泌四乙酰基植物鞘氨醇(tetraacetyl phytosphingosine,TAPS)。由于其在TAPS生产方面的优异性能,本研究旨在构建W.c的遗传操作系统,以提升... 详细信息

威克汉姆西弗酵母(Wickerhamomyces ciferrii,W.c)是一种异宗生殖的非常规酵母,能够大量生产并分泌四乙酰基植物鞘氨醇(tetraacetyl phytosphingosine,TAPS)。由于其在TAPS生产方面的优异性能,本研究旨在构建W.c的遗传操作系统,以提升四乙酰基植物鞘氨醇(TAPS)的产量,并通过诱变和基因工程手段筛选高产菌株,从而为进一步开发鞘脂类代谢产物的工业生产奠定基础。本研究通过选取2个自主复制元件(CEN,2μ)并挖掘11个内源启动子元件以建立威克汉姆西弗酵母中的遗传操作系统,发现过量表达鞘脂代谢内部途径的Syr2和lcb2能显著提高TAPS的产量。同时使用逆转录聚合酶链式反应(reverse transcription-polymerase chain reaction,RT-PCR)和流式细胞术建立了威克汉姆西弗酵母单倍体交配型鉴定方法,从双倍体ATCC 14091出发,筛选到5株单倍体菌株。其中a-型单倍体W.c 140生产TAPS水平最高,产量达到4.74 mg/g,滴度达到32.61 mg/l。使用常压室温等离子体诱变(atmospheric and room temperature plasma,ARTP)技术和本研究构建的遗传操作技术获得诱变菌株W.c 140-A9和W.c 140-A11及过表达重组菌株W.c 140 OElcb2和W.c 140 OESyr2。与出发株W.c 140相比,诱变株TAPS产量分别提高了61.39%和67.09%。过表达重组菌株产量提高至原来的2.24和2.56倍,达到10.60 mg/g和12.14 mg/g,超过了双倍体ATCC 14091的产量。本研究所构建的遗传操作系统和获得的出发菌株为后续在威克汉姆西弗酵母中建立更多遗传工程技术奠定了基础。

关键词：威克汉姆西弗酵母四乙酰基植物鞘氨醇鞘脂代谢启动子筛选单倍体筛选

Searching Radio Signals from Two Magnetars and a High-magnetic Field Pulsar and the Serendipitous Discovery of a New Radio Pulsar PSR J1935+2200

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Research in Astronomy and Astrophysics 2025年第1期25卷 110-115页

作者： lang Xie J.l.Han Z.l.Yang W.C.Jing D.J.Zhou W.q.Su Yi Yan Tao Wang Nan-Nan Cai P.F.Wang Chen Wang National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences National Key laboratory for Radio Astronomy Chinese Academy of Sciences

Magnetars are slowly rotating, highly magnetized young neutron stars that can show transient radio phenomena for radio pulses and fast radio bursts. We conducted radio observations from two magnetars SGR J1935+2154 and3XMM J185246.6+003317 and a high-magnetic field pulsar PSR J1846–0258 using the Five-hundred-meter Aperture Spherical radio Telescope（FAST）. We performed single pulse and periodicity searches and did not detect radio signals from them. From the piggyback data recorded by other FAST telescope beams when we observed the magnetar SGR 1935+2154, we serendipitously discovered a new radio pulsar, PSR J1935+2200. We carried out the follow-up observations and obtained the timing solution based on these new observations and the archive FAST data. PSR J1935+2200 is an isolated old pulsar, with a spin period of 0.91 s, a spin-period derivative of9.19 × 10-15s s-1, and a characteristic age of 1.57 Myr. It is a weak pulsar with a flux density of 9.8 μJy at1.25 GHz. Discovery of a new pulsar from the long FAST observations of 30 minutes implies that there may be more weak older pulsars in the Galactic disk to be discovered.

关键词： (stars:) pulsars: individual (PSR J1935+2200) stars: neutron

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模块化气动软体爬行机器人的设计与分析

机械传动 2025年第1期49卷 64-73页

作者：尹宏飞吕跃东宋晓娟内蒙古工业大学机械工程学院呼和浩特010051 内蒙古自治区特殊服役智能机器人重点实验室呼和浩特010051 内蒙古北方重工业集团有限公司特钢事业部包头014033

【目的】模块化软体机器人具备高柔韧性与理论上的无限自由度,可以适应各种复杂的环境和任务需求。为此,设计了一种仿蜂巢软体驱动单元,将多个该单元连接组成可以实现不同功能的模块化驱动软体机器人。【方法】对设计的仿蜂巢软体驱动... 详细信息

【目的】模块化软体机器人具备高柔韧性与理论上的无限自由度,可以适应各种复杂的环境和任务需求。为此,设计了一种仿蜂巢软体驱动单元,将多个该单元连接组成可以实现不同功能的模块化驱动软体机器人。【方法】对设计的仿蜂巢软体驱动单元进行了材料选择与力学分析,建立了软体驱动单元内部驱动气压与变形量之间的非线性关系模型,并采用有限元仿真验证了该模型的有效性;基于仿蜂巢软体驱动单元模块,设计了伸缩型软体机器人和双向弯曲型软体机器人,并对两种构型的软体机器人进行有限元仿真;最后,进行了软体机器人的制作以及模块化驱动软体机器人的试验研究。【结果】仿真结果表明,双向弯曲型软体机器人比相同长度的伸缩型软体机器人在伸缩变形范围上更大,其承载能力较伸缩型软体机器人也更好。试验结果表明,双向弯曲型软体机器人可以实现仿蠕虫的直线爬行与转向运动。并且两种构型的软体机器人试验结果与仿真结果基本保持一致。

关键词：模块化气动软体机器人非线性模型结构仿真分析

Self-Assembly and Photocatalysis of Mesoporous TiO2 Nanocrystal Clusters

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Nano Research 2011年第1期4卷 103-114页

作者： qiao Zhang Ji-Bong Joo Zhenda lu Michael Dahl Diana q. l. Oliveira Miaomiao Ye Yadong yin Department of Chemistry University of California Riverside California 92521 USA

Mesoporous nanocrystal clusters of anatase TiO2 with large surface area and enhanced photocatalytic activity have been successfully synthesized. The synthesis involves the self-assembly of hydrophobic TiO2 nanocrystals into submicron clusters, coating of these clusters with a silica layer, thermal treatment to remove organic ligands and improve the crystallinity of the clusters, and finally removing silica to expose the mesoporous catalysts. With the help of the silica coating, the clusters not only maintain their small grain size but also keep their mesoporous structure after calcination at high temperatures （with BET surface area as high as 277 m2/g）. The etching of SiO2 also results in the clusters having high dispersity in water. We have been able to identify the optimal calcination temperature to produce TiO2 nanocrystal clusters that possess both high crystallinity and large surface area, and therefore show excellent catalytic efficiency in the decomposition of organic molecules under illumination by UV light. Convenient doping with nitrogen converts these nanocrystal clusters into active photocatalysts in both visible light and natural sunlight. The strategy of forming well-defined mesoporous clusters using nanocrystals promises a versatile and useful method for designing photocatalysts with enhanced activity and stability.

关键词： Mesoporous titanium dioxide photocatalysis self-assembl~ nitrogen doping nanocrystals