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Frequency and Correlation of Nearest Neighboring Nucleotides in Human Genome

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Chinese Journal of Chemical Physics 2009年第1期22卷 27-33页

作者： Neng-zhi Jin Zi-xian liu Wen-yuan Qiu Department of Chemistry State Key Laboratory of Applied Organic Chemistry Lanzhou Universiry. Lanzhou 730000 China

Zipf＇s approach in linguistics is utilized to analyze the statistical features of frequency and correlation of 16 nearest neighboring nucleotides （AA, AC, AG, …, TT） in 12 human chro- mosomes （Y, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, and 12）. It is found that these statistical features of nearest neighboring nucleotides in human genome：（i） the frequency distribution is a linear function, and （ii） the correlation distribution is an inverse function. The coefficients of the linear function and inverse function depend on the GC content. It proposes the correlation distribution of nearest neighboring nucleotides for the first time and extends the descriptor about nearest neighboring nueleotides.

关键词： Zipf's law Nearest neighboring nucleotide Frequency distribution Correlation distribution

MANAGING REDISTRIBUTION OF TOLL REVENUE WITH USER HETEROGENEITY

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Journal of Systems Science and Systems Engineering 2014年第3期23卷 330-342页

作者： Shu-xian Xu Tian-Liang liu Hai-Jun Huang School of Economics and Management Beihang University

With the explicit consideration of user heterogeneity, i.e., each user has a different value of time （VOT）, this paper examines the system efficiency and social equity of toll revenue redistribution in a bi-mode transportation system. Three schemes of distributing the road toll revenue are proposed, which respectively consider efficiency, equity, as well as efficiency and equity together. With mild assumptions, we prove that the number of auto-motorists decreases and the total social cost increases with transit subsidy share when only marginal operating cost of the transit is covered by its fare. However, when average fixed cost of the transit is further covered, the total social cost is a ＂U＂ shape curve against the transit subsidy share. Numerical results show that the well designed toll revenue redistribution schemes can make the system more equitable while keeping high efficiency. With the increase of user heterogeneity, the Gini coefficient becomes larger while the total social cost goes down.

关键词： Mode choice value of time toll revenue redistribution efficiency equity

Cell Fate Switch during In Vitro Plant Organogenesis

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Journal of Integrative Plant Biology 2008年第7期50卷 816-824页

作者： xiang Yu Zhao Ying Hua su ZhiJuan Cheng xian Sheng Zhang State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai'an 271018 China

Plant mature cells have the capability to reverse their state of differentiation and produce new organs under cultured conditions. Two phases, dedifferenUation and redifferentiation, are commonly characterized during in vitro organogenesis. In these processes, cells undergo fate switch several times regulated by both extrinsic and intrinsic factors, which are associated with reentry to the cell cycle, the balance between euchromatin and heterochromatin, reprogramming of gene expression, and so forth. This short article reviews the advances in the mechanism of organ regeneration from plant somatic cells in molecular, genomic and epigenetic aspects, aiming to provide important information on the mechanism underlying cell fate switch during in vitro plant organogenesis.

关键词： cell fate dedifferentiation plant organogenesis redifferentiation regeneration.

Periodic Layered Structure Formed during Interfacial Reaction

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Journal of Iron and Steel Research International 2016年第11期23卷 1127-1133页

作者： xian-man ZHANG Hong-feng LUO liu-yong SHI Institute of Electrical and Mechanical Engineering Hainan University

A review of the periodic layered structure （PLS） formed during reactive diffusion was presented. The formation of PLS is a very interesting and complex phenomenon during the reactive diffusion process. It was firstly discovered occasionally. The formation of PLS has been reported in various solid state diffusion couples such as Zn/ Ni3 Si, Mg/SiO2, Zn/Cux Tiy and so on, and some controversial theoretical models and formation mechanism of PLS were put forward. However, there have been few reports about the PLS formed during hot dip. The development of PLS was reviewed, and the recent progress referring to the formation of PLS during the hot dip aluminizing of a no- vel Fe-Cr-B cast steel was especially introduced. However, not all of the borides could form PLS in their interracial reaction with molten Al. PLS only formed at the Cr-rich Fe2B/Al interface, while Mo-rich Fe2B fractured. A general qualitative description for the interracial reaction of Fe-Cr-B cast steel with molten Al was represented. Further inves- tigation on the constituents of the alternating phases and formation mechanism of PLS needs to be done. At last, the development trends of PLS were proposed.

关键词： periodic layered structure interfacial reaction reactive diffusion formation mechanism Fe-Cr-B cast steel

AN EXPERIMENTAL STUDY OF FLOW AROUND A BIO-INSPIRED AIRFOIL AT REYNOLDS NUMBER 2.0×10~3

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Journal of Hydrodynamics 2012年第3期24卷 410-419页

作者： SHI Sheng-xian liu Ying-zheng CHEN Jian-min Key Laboratory of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong University Shanghai 200240 China

The fluid flow around a bio-inspired airfoil with corrugated surfaces and its smooth counterpart at chord Reynolds number Re = 2.0×10^3. and different Angle-Of-Attack （AOA = 0°, 4°, 8° and 12°） were measured by using Particle Image Velocimetry （PIV）. The global characteristics of the fluid flow around two airfoils were analyzed by ensemble-averaged velocity field, distribution of reverse flow intermittency, and time-series flow visualizations. At AOA = 0°, no significant variation of the global flow patterns was recognized for both configurations. The statistical results of reverse flow intermittency results demonstrated that the protruding peaks of the corrugated airfoil delay flow separation occur at AOA = 4°. At large AOAs （8° and 12°）, however, the flow is massively separated in both configurations, the combination of large separation bubble above the corrugated airfoil and small recirculation zones in the upstream upper valley results in earlier separation of the flow. At AOA=8°, the wake region behind the corrugated airfoil is considerably shortened in comparison to the smooth one, indicating a remarkable reduction of the time-mean lift and drag forces, however, at AOA - 12°, the wake region behind the corrugated one is slightly larger than that behind the smooth one. For the case of AOA = 8° and 12°, the time-series flow visualizations demonstrate the intensified vortex shedding process of the corrugated airfoil, which would give rise to enhanced dynamic loading. Due to the fact that dragonfly wing is practically flexible, it is speculated that the wing structure of a gliding dragonfly might be sophisticatedly deformed in response to the periodic loading to reduce the drag.

关键词： corrugated airfoil separated flow Particle Image Velocimetry (PIV) dragonfly gliding flight

Plant cell totipotency: Insights into cellular reprogramming

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Journal of Integrative Plant Biology 2021年第1期63卷 228-240页

作者： Ying Hua su Li Ping Tang xiang Yu Zhao xian Sheng Zhang State Key Laboratory of Crop Biology College of Life SciencesShandong Agricultural UniversityTai'an 271018China

Plant cells have a powerful capacity in their propagation to adapt to environmental change, given that a single plant cell can give rise to a whole plant via somatic embryogenesis without the need for fertilization. The reprogramming of somatic cells into totipotent cells is a critical step in somatic embryogenesis. This process can be induced by stimuli such as plant hormones, transcriptional regulators and stress. Here, we review current knowledge on how the identity of totipotent cells is determined and the stimuli required for reprogramming of somatic cells into totipotent cells. We highlight key molecular regulators and associated networks that control cell fate transition from somatic to totipotent cells. Finally,we pose several outstanding questions that should be addressed to enhance our understanding of the mechanisms underlying plant cell totipotency.

关键词： cell reprogramming plant cell totipotency somatic embryogenesis totipotent cell

Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

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Chinese Journal of Aeronautics 2024年第6期37卷 127-136页

作者： xian YU Zhiwei liu Jiaming LENG Mingjing QI Xiaojun YAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijng 100191China Beijing Key Laboratory of Aero-Engine Structure and Strength Beihang UniversityBeijing 100191China

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the *** this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled *** micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 *** distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size *** enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 ***,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements *** findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

关键词： Microairvehicle Aircraft control Self-powered micro blimp Flapping-wing thruster Wireless flight

Bi nanoparticles in situ encapsulated by carbon film as high-performance anode materials for Li-ion batteries

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Journal of Energy Chemistry 2022年第6期31卷 524-530,I0015页

作者： Jun Yang Jiahui xian Qinglin liu Yamei sun Guangqin Li MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-Sen UniversityGuangzhou 510006GuangdongChina

Bismuth (Bi) has indeed inspired great interests in lithium-ion batteries (LIBs) due to the high capacity,but was still limited by the low electrical conductivity and large volume ***,a composite material based on Bi nanoparticles in situ encapsulated by carbon film (Bi@CF) is prepared successfully through a facile metal–organic framework (MOF)-engaged *** anode materials for LIBs,the Bi@CF composites achieved high reversible capacities of 705 and 538 mAh g^(-1)at 0.2 and 0.5 A g^(-1) after200 cycles,and long cycling performance with a stable capacity of 306 mAh g^(-1)at 1.0 A g^(-1) even after 900 *** situ X-ray diffraction (XRD) measurements clearly revealed the conversion between Bi and Li_(3)Bi during the alloying/dealloying process,confirming the good electrochemical reversibility of Bi@CF for *** reaction kinetics of this Bi@CF composite was further studied by galvanostatic intermittent titration technique (GITT).This work may provide an inspiration for the elaborate design and facile preparation of alloy-type anode materials for high-performance rechargeable batteries.

关键词： Bi nanoparticles Carbon film Anode materials Lithium-ion batteries In situ XRD

A hypothesis study on a four-period prevention model for high altitude disease

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Military Medical Research 2018年第2期5卷 183-188页

作者： xian-Sheng liu xiang-Rong Yang Lu liu xian-Kui Qin Yu-Qi Gao Institute of Medicine and Hygienic Equipment for High Altitude Region College of High Altitude Military MedicineThird Military Medical UniversityNo.30 Gaotanyan StreetShapingba DistrictChongqing 400038China Department of Medical Affairs The 5th Hospital of the Chinese PLANo.893 Shengli StreetXingqing DistrictYinchuanNingxia 750003China Key Laboratory of High Altitude Environmental Medicine Third Military Medical UniversityMinistry of EducationNo.30 Gaotanyan StreetShapingba DistrictChongqing 400038China Key Laboratory of High Altitude Medicine of PLA No.30 Gaotanyan StreetShapingba DistrictChongqing 400038China Department of Health Service Training Base of Health ServiceThird Military Medical UniversityNo.30 Gaotanyan StreetShapingba DistrictChongqing 400038China Department of Outpatient PLA No.96819 UnitNo.2 Heping RoadChaoyang DistrictBeijing 100085China

Background:High altitude disease(HAD)can reduce combat effectiveness and damage the health of soldiers at high *** objective of this hypothesis study is to build a four-period prevention model for high altitude disease that can be applied at high altitudes of over 3000 *** of the hypothesis:We divided the time at high altitude into nine periods,with three stages from the ascent preparation to the descent to the plain,and applied a continuous dynamic and systematic four-period prevention model across the nine *** period of three stages has its own different measures and targets high altitude health care services for the prevention of high altitude disease.A standard four-period prevention model for high altitude disease was constructed for the high altitude health services at the population *** the hypothesis:Our hypothesized HAD prevention model represents a continuous dynamic and systematic four-period prevention model across the nine *** hypothesis can be tested from three *** first one is assessment of soldiers’operating *** second is comparison of the long-term high altitude population health basic data and development and utilization of big *** third is descent population health status comparative study and historical retrospective study on ***:As we know,it is necessary to protect soldiers’health through the ascent and *** the standard four-period model,we can protect soldiers’health by preventing high altitude diseases,screening the susceptible population,securely tracking their location and maintaining soldiers’health statuses;we also maintain their operational capabilities,eliminate their psychological fears and ease their family troubles.

关键词： High altitude disease High altitude health service Prevention model