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The stable planar conformation of the γ-butyrolactone ring in solution

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Chinese Chemical Letters 2010年第2期21卷 187-190页

作者： Zhi Qiang Feng Cheng lie Yin Institute of Materia Medica Chinese Academy of Medical Sciences Beijing 100050 China Department of Chemistry Beijing Normal University Beijing 100875 China

The conformations ofγ-butyrolactone ring in solution were deduced on the basis of ~1H NMR spectra of geminal protons of the butyrolactone ring.A series of optically pure(Z)-(-)-4-(1 -alkoxyl-1 -carbalkoxy-methylene)-... 详细信息

关键词： β-Methylene-γ-butyrolactone Planar conformation Envelope conformation

ηc Diffractive Production in the Direct Photon Process

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Communications in Theoretical Physics 2003年第4X期40卷 457-460页

作者： YANZhan-Yuan DUANChun-Gui LIGuang-lie DepartmentofAppliedPhysics NorthChinaElectricPowerUniversityBaoding071003China DepartmentofPhysics HebeiTeachers'UniversityShijiazhuang050016China InstituteofHighEnergyPhysics TheChineseAcademyofSciencesP.O.Box918-4(1)Beijing100039China

Based on the factorization theorem for lepton induced hard diffractive scattering and color octet heavy quarkonium production mechanism, ηc diffractive production in the direct photon process is studied. The results show that this process can be measured at DESY HERA, and ηc production has different features from J/Ψ production, which is weakly affected by the initial and final state gluon radiation. Therefore, ηc photoproduction can be viewed as reliable estimate. The experimental study of this process can give valuable insight in the co/or octet heavy quarkonium production mechanism.

关键词：衍射系数因数分解理论色八重态轻子真空量子数衍射散射过程数值计算声子衍射

Suppression of pheromone biosynthesis and mating behavior by RNA interference of pheromone gland-specific fatty acyl reductase in Maruca vitrata

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Insect Science 2022年第4期29卷 1135-1144页

作者： Wook Hyun cha Dae-Weon Lee Department of Biosafety Kyungsung UniversityBusanRepublic of Korea Metabolomics Research Center for Functional Materials Kyungsung UniversityBusanRepublic of Korea

In moths,various enzymes,such as fatty acid synthases,fatty acyl desaturases,and fatty acyl reductases(FARs),are involved in pheromone *** particular,pheromone gland-specific FAR(pgFAR)plays an important role in converting the functional group from carboxylic to alcohol during pheromone biosynthesis.A novel pgFAR of Maruca vitrata,Mvi-pgFAR,was identified through transcriptome sequencing of its pheromone *** investigate the involvement of Mvi-pgFAR in pheromone biosynthesis,Mvi-pgFAR was cloned from the pheromone gland and suppressed by RNA interference(RNAi).Mvi-pgFAR harbored several conserved motifs related to NAD(P)H-binding,N-glycosylation,and adenosine/guanosine triphosphate *** analysis revealed that Mvi-pgFAR with other lepidopteran pgFARs formed an independent ***-pgFAR was specifically expressed only in the pheromone *** real-time polymerase chain reaction showed that the diurnal expression levels of Mvi-pgFAR in the pheromone gland were the highest at 2 h before the *** primarily confirming Mvi-pgFAR suppression by RNAi,(E,E)-10,12-hexadecadienal(E10E12-16:Ald),a major sex pheromone component,was quantified by gas *** Mvi-pgFAR was successfully suppressed,E10E12-16:Ald production was reduced by up to half of that of the control,and the mating rate was subsequently *** results demonstrate that Mvi-pgFAR downregulation can suppress mating behavior by changing the relative sex pheromone component ratio,suggesting that Mvi-pgFAR can be used as a novel control target.

关键词： (EE)-10,12-hexadecadienal gas chromatography Maruca viruta pgFAR RNAi sex pheromone

p—A Drell—Yan Process in the Target Rest Frame

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Communications in Theoretical Physics 2003年第5期39卷 579-582页

作者： DUANChun-Gui QiaoXiu-Mei LIGuang-lie PhysicsDepartment HebeiTeachers‘UniversityShijiazhuang050016China CCAST(WorldLaboratory) P.O.Box8730Beijing100080China PhysicsDepartment HebeiTeachers’UniversityShijiazhuang050016China InstituteofHighEnergyPhysics TheChineseAcademyofSciencesBeijing100039China CenterofTheoreticalNuclearPhysics NationalLaboratoryofHeavyIonAcceleratoryLanzhou730000China

At high energies, Drell-Yan process can be viewed in the target rest frame as bremsstrahlung of massive photons, rather than parton annihilation. In this paper, the ratio of the p-A Drell-Yan cross section per nucleon for an 800 GeV proton beam incident on Fe, W, and Be targets are calculated by means of the color dipole approach in the target rest system. It is shown that our calculations can quite well fit the Fermilab E866 experimental data with considering the nuclear shadowing effect in p-A Drell-Yan process and without the energy loss effect in it.

关键词： Drell-Yan过程格林函数偶极子强子-强子碰撞粒子物理学二次轻子光子测试

Multiplicity and Uniqueness of Positive Solutions for Nonhomogeneous Semilinear Elliptic Equation with Critical Exponent

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Acta Mathematicae Applicatae Sinica 2016年第1期32卷 81-94页

作者： Na BA Yan-yan WANG lie ZHENG School of Science Hubei University of Technology Department of Mathematics Zhoukou Normal University

In this paper,we consider the following problem {-Δu（x）＋u（x）=λ（u^p（x）＋h（x））,x∈R^N,u（x）∈h^1（R^N）,u（x）〉0,x∈R^N,（＊）where λ 〉 0 is a parameter,p =（N＋2）/（N—2）.We will prove that there exists a positive constant 0 〈 A＊〈＋00such that（＊） has a minimal positive solution for λ∈（0,λ＊）,no solution for λ 〉 λ＊,a unique solution for λ = λ＊.Furthermore,（＊） possesses at least two positive solutions when λ∈（0,λ＊） and 3 ≤ N ≤ *** N ≥ 6,under some monotonicity conditions of h we show that there exists a constant 0 〈λ＊＊〈 λ＊ such that problem（＊）possesses a unique solution for λ∈（0,λ＊＊）.

关键词： nonhomogeneous semilinear elliptic problems multiplicity uniqueness

Suppression of Nuclear Drell-Yan Ratio due to Energy Loss

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Chinese Physics Letters 1998年第9期15卷 645-647页

作者： LI Guang-lie YANG Jian-jun CCAST(Wor1d Laboratory) P.O.Box 8730Beijing 100080 Institute of High Energy Physics Chinese Academy of SciencesBeijing 100039 Department of Physics Nanjing Normal UniversityNanjing 210024

Nuclear effect in nuclear Drell-Yan(DY)process is not clear as that in the European muon collaboration(EMC)effect,and many EMC effect models overestimate *** this letter,the energy loss effect in nuclear DY process is studied,and it is found that the nuclear DY ratio is suppressed due to the energy loss which balances the overestimate of the DY ratio in the EMC effect models.

关键词： effect letter estimate

Some Explorations on Two Conjectures About Rademacher Sequences

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Acta Mathematicae Applicatae Sinica 2021年第1期37卷 1-16页

作者： Ze-chun HU Guo-lie LAN Wei SUN College of Mathematics Sichuan UniversityChengdu 610065China School of Economics and Statistics Guangzhou UniversityGuangzhou 510006China Department of Mathematics and Statistics Concordia UniversityMontreal H3G 1M8Canada

In this paper,we explore two conjectures about Rademacher ***(εi)be a Rademacher sequence,i.e.,a sequence of independent{-1,1}-valued symmetric random *** Sn=aiε1+…+anεn for a=(a1,…,an)∈*** first *** says that P(|Sn|≤‖a‖)>1/2 for all a∈Rn and n∈*** second conjecture says that P(|Sn|>‖a‖)≥7/32 for all a∈Rn and n∈*** the first conjecture,we present several new equivalent *** include a topological view,a combinatorial version and a strengthened version of the *** the second conjecture,we prove that it holds true when n<7.

关键词： Rademacher sequence Tomaszewaki’s constant Hitczenko and Kwapien’s constant

Dumb-bell Structures of Nonstoichiometric La(Ni, Sn)_(5+x) Alloys and Their Relationships with the Preparation Methods

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Chinese Journal of Structural Chemistry 2004年第5期23卷 520-524页

作者： YUANZhi-Qing LUGuang-lie WEIFan-Song LEIYong-Quan CentralLaboratory ZhejiangUniversityZhejiang310028China DepartmentofMaterialsScienceandEngineering Zhejiang310027China

Crystal structures of nonstoichiometric La(Ni, Sn)5+x (x = 0.1～0.4) alloys prepared by different methods were investigated by using powder X-ray diffraction and Rietveld refinement analysis. Space group of this type of alloys belongs to P6/mmm, in which Sn only occupies the 3g sites. It has been demonstrated that some of the 1a sites of the nonstoichiometric alloy are replaced by the NiNi dumb-bells which have a strong correlation with the anisotropic thermal parameter B33. The preparation methods have an effect on the number of dumb-bells that can substitute the 1a sites. It was found that the annealed alloys have more NiNi dumb-bells in the structure than the rapid solidified and as-cast alloys have while still keep good crystallinity.

关键词： nonstoichiometric alloy rapid solidified alloy crystallographic structure Rietveld refinement

UNBALANCE RESPONSE AND TOUCH-RUBBING THRESHOLD SPEED OF ROTOR SUBJECTED TO NONLINEAR MAGNETIC FORCES

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 1-4页

作者： JING Minqing LI Zixin LUO Min YU lie College of Mechanical Engineering Xi＇an Jiaotong University Xi＇an 710049 China

Because of the effect of unbalance excitation and nonlinear magnetic force, the large vibration of the rotor supported by active magnetic bearing（AMB） will go beyond the radial gap of the bearing, even causing mechanical touch-rubbing when the system works at an operational speed closer to the critical speed. In order to investigate this problem, the linear model and nonlinear model of the single mass symmetric rigid rotor system supported by AMB are established respectively and the corresponding transfer functions of close-loop system are given. To pass through the numerical calculation by using MATLAB/Simulink, the effect of both the unbalance response and threshold speed of touch-rubbing of the system subjected to nonlinear magnetic forces and nonlinear output current of power amplifier are studied. Furthermore, threshold speed of touch-rubbing of the rotor-bearing system is defined and the results of numerical simulation are presented. Finally, based on above studies, two methods of increasing the touch-rubbing threshold speed are discussed.

关键词： Active magnetic bearing (AMB) Vibration Non-linearity Touch-rubbing speed