检索结果-南通市图书馆

Instantaneous Formulation for Transitions Between Two Instantaneous Bound States and Its Gauge Invariance

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2006年第3X期46卷 467-480页

作者： chang chao-hsi CHEN Jiao-Kai WANG Guo-Li Institute for Advanced Study Princeton New Jersey 08540 USA CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China Institute of Theoretical Physics the Chinese Academy of Sciences P.O. Box 2735 Beijing 100080 China Department of Physics Harbin Institute of Technology Harbin 150006 China

We have precisely derived a ＂rigorous instantaneous formulation＂ for transitions between two bound states when the bound states are well-described by instantaneous Bethe-Salpeter （BS） equation （i.e. the kernel of the equation is instantaneous ＂occasionally＂）. The obtained rigorous instantaneous formulation, in fact, is expressed as an operator sandwiched by two ＂reduced BS wave functions＂ properly, while the reduced BS wave functions appearing in the formulation are the rigorous solutions of the instantaneous BS equation, and they may relate to Schroedinger wave functions straightforwardly. We also show that the rigorous instantaneous formulation is gauge-invariant with respect to the Uem（1） transformation precisely, if the concerned transitions are radiative. Some applications of the formulation are outlined.

关键词： instantaneous formulation transitions between bound states Bethe-Salpeter equation

在线全文

学校读者我要写书评

暂无评论

B_c Meson Studies

高能物理与核物理 2002年第Z1期26卷 1-10页

作者： chang chao-hsi (Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080, China) Inst. of Theor. Phys. Chinese Acad. of Sci. Beijing 100080 China

Our studies on the meson Bc arc briefly *** decays of the meson Bc to a P-wave charmonium Xc or hc are reported comparatively precisely because they are fresh

关键词：高能物理核物理增刊张肇西 B_c Meson Studies Rev

Lifetime of Doubly Charmed Baryons

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第4期49卷 993-1000页

作者： chang chao-hsi LI Tong LI Xue-Qian WANG Yu-Ming CCAST （World Laboratory） P.O. Box 8730 Beijing 100080 China Institute of Theoretical Physics the Chinese Academy of Sciences P.O. Box 2735 Beijing 100080 China Department of Physics Nankai University Tianjin 300071 China Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918 Beijing 100049 China

In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams are also included. The hadronic matrix elements are evaluated in the simple non-relativistic harmonic oscillator model. Our numerical results are generally consistent with that obtained by other authors who used the diquark model. However, all the theoretical predictions on the lifetimes are one order larger than the upper limit set by the recent SELEX measurement. This discrepancy would be clarified by the future experiment. If more accurate experiment still confirms the value of the SELEX collaboration, there must be some unknown mechanism to be explored.

关键词： doubly charmed baryons harmonic oscillator model

Laser Powder Bed Fusion of Beta-Type Titanium Alloys for Biomedical Application:A Review

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 17-28页

作者： Xuan Luo chao Yang Dongdong Li Lai-chang Zhang State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic MaterialsSouth China University of TechnologyGuangzhou510640China Centre for Advanced Materials and Manufacturing School of EngineeringEdith Cowan University270 Joondalup DriveJoondalupPerthWA6027Australia

Additive manufacturing ofβ-type titanium alloy is expected to replace Ti-6Al-4V alloy in the field of orthopedic implantation because of their low elastic modulus,excellent corrosion resistance,and *** briefly introducing the laser powder bed fusion(LPBF)process and physical phenomena,this paper reviews the recent progresses in LPBF-edβ-type Ti *** strategies to strengthening and tougheningβ-type Ti alloys are critically *** is followed by the processing routes employed to achieve to low modulus for orthopedic applications,especially a new methodology for tailoring crystallographic orientation called multi-track coupled directional *** effect of processing and compositions on performance metrics ofβ-type Ti alloys included corrosion behavior,and biocompatibility is *** the end,challenges in additive manufacturing ofβ-type Ti alloys in future are highlighted,with the aim to ensue clinical application of LPBF-edβ-type Ti alloys.

关键词： β-type Ti alloys Laser powder bed fusion Mechanical properties Elastic modulus Biocompatibility

Leptonic di-flavor and di-number violation processes at high energyμ^(±)μ^(±)colliders

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第4期48卷 34-50页

作者：杨金磊张肇西冯太傅 CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China Department of Physics Hebei UniversityKey Laboratory of High-precision Computation and Application of Quantum Field Theory of Hebei ProvinceBaoding 071002China

The leptonic di-flavor violation (LFV) processes μ^(±)μ^(±)→e^(±)e^(±) and μ^(±)μ^(±)→τ^(±)τ^(±) and leptonic di-number violation (LNV) processes μ^(±)μ^(±)→W_(i)^(±)W_(j)^(±) (i,j=1,2) at same-sign high energy μ^(±)μ^(±) colliders are studied. The new physics (NP) factors that may play roles in these processes are highlighted by cataloging them into three types. Taking into account the experimental constraints, the processes at μ^(±)μ^(±) colliders are computed, and the results are presented properly. The results lead to the conclusion that observing the NP factors through the LFV and LNV processes at TeV-energy μ^(±)μ^(±) colliders has significant advantages that cannot be achieved elsewhere. Therefore, once the techniques for muon acceleration and collision are developed successfully, the option of building same-sign high energy muon colliders should be seriously considered.

关键词： μ^(±)μ^(±)collider neutral lepton Majorana components

Effect of nocturia in patients with different severity of obstructive sleep apnea on polysomnography: A retrospective observational study

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Urology 2024年第3期11卷 486-496页

作者： Chin-Heng Lu Hung-Min chang Kuang-hsi chang Yen-Chuan Ou chao-Yu Hsu Min-Che Tung Frank Cheau-Feng Lin Stella Chin-Shaw Tsai Division of Urology Department of SurgeryTungs’Taichung Metroharbor HospitalTaichungTaiwanChina Rong hsing Research Center for Translational Medicine Chung Hsing UniversityTaichungTaiwanChina College of Life Sciences Chung Hsing UniversityTaichungTaiwanChina Department of Otolaryngology Tungs’Taichung Metroharbor HospitalTaichungTaiwanChina Department of Medical Research Tungs’Taichung Metroharbor HospitalTaichungTaiwanChina General Education Center Jen-Teh Junior College of MedicineNursing and ManagementMiaoliTaiwanChina Graduate Institute of Biomedical Sciences China Medical UniversityTaichungTaiwanChina Department of Post-Baccalaureate Medicine College of MedicineChung Hsing UniversityTaichungTaiwanChina Department of Nursing Jen-Teh Junior College of MedicineNursing and ManagementMiaoliTaiwanChina Department of Surgery Chung Shan Medical UniversityTaichungTaiwanChina College of Medicine Chung Shan Medical UniversityTaichungTaiwanChina

Patients with suspected OSA were examined using *** were divided into two groups based on the presence of *** was defined as a patient who needed to void at least *** index(AHI)was employed to classify patients according to degrees of severity:AHI<5 events/h,5 events/hAHI<15 events/h,15 events/hAHI<30 events/h,and AHI30 events/h,defined as normal,mild OSA,moderate OSA,and severe OSA,*** variables,PSG parameters,International Prostate Symptom Scores(IPSSs),and quality of life scores due to urinary symptoms were ***:In total 140 patients,114 patients had OSA(48 had mild OSA;34 had moderate OSA;and 32 had severe OSA)and 107 patients had *** total IPSS was significantly higher in nocturia patients in all groups except the group of severe OSA *** the increasing severity of OSA,more correlated factors related to nocturia were *** mild OSA patients,nocturia related to increased age(p=0.025),minimum arterial blood oxygenation saturation(p=0.046),and decreased AHI of non-rapid eye movement(p=0.047),AHI of total sleep time(p=0.010),and desaturation index(p=0.012).In moderate OSA patients,nocturia related to increased age(p<0.001),awake time(p=0.025),stage 1 sleep(p=0.033),and sleep latency(p=0.033),and decreased height(p=0.044),weight(p=0.025),and sleep efficiency(p=0.003).In severe OSA patients,nocturia related to increased weight(p=0.011),body mass index(p=0.009),awake time(p=0.008),stage 1 sleep(p=0.040),arousal number(p=0.030),arousal index(p=0.013),periodic limb movement number(p=0.013),and periodic limb movement index(p=0.004),and decreased baseline arterial blood oxygenation saturation(p=0.046).Conclusion:Our study revealed that there were more correlated factors related to nocturia with increasing severity of *** study helps in clinical education and treatment for OSA patients with different severity.

关键词： Nocturia Obstructive sleep apnea Polysomnography Apneaehypopnea index International Prostate Symptom Score

A systematic evaluation of computational methods for predicting translated non-canonical ORFs from ribosome profiling data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2024年第1期51卷 105-108页

作者： Tianyu Lei Yue chang chao Yao Hong Zhang College of Ecology Lanzhou UniversityLanzhouGansu 730000China Cuiying Honors College Lanzhou UniversityLanzhouGansu 730000China

Ribosome profiling(Ribo-Seg)enables genome-wide survey of translational activities at nucleotide resolution by enriching and sequencing ribosome-protected fragments(RPFs)in the cell(Ingolia et al.,2009).Based on the characteristic distribution of RPFs in Ribo-Seq,such as enrichment in open reading frames(ORFs)and three-nucleotide periodicity,many computational methods have been developed to detect translated ORFs from Ribo-Seq data(Wang et al.,2020a).

关键词： translated enable canonical

Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第1期23卷 187-194页

作者： Qi Zhang Wenqin Zhan chao Li Ling chang Yi Dong Jiang Zhang State Key Laboratory of Biocatalysis and Enzyme Engineering School of Life SciencesHubei UniversityWuhan 430062China Oil Crops Research Institute Chinese Academy of Agricultural SciencesWuhan 430062China Agricultural Genomics Institute at Shenzhen Chinese Academy of Agricultural SciencesShenzhen 518000China

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect *** green peach aphid,Myzus persicae,feeds on over 400 species of host *** napus(rape)is the second most important oilseed crop *** persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life *** this study,we tested the RNAi effects of transgenic rape plants on *** in vitro feeding *** with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi ***-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of *** next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic *** to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to *** assays revealed that feeding transgenic rape plants to *** significantly decreased MpPar6 expression and survival rate and impaired ***,we showed that the resistance levels to *** are positively correlated with ds Par6 expression levels in transgenic rape *** study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from *** with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

关键词： oilseed rape pest control aphid double-stranded RNA RNA interference

Three‑dimensional numerical simulation of dynamic strength and failure mode of a rock mass with cross joints

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2024年第2期11卷 35-52页

作者： Tingting Liu Wenxu Huang chang Xiang Qian Dong Xinping Li chao Zhang Hubei Key Laboratory of Blasting Engineering Jianghan UniversityWuhan 430056China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China Hainan Institute Wuhan University of TechnologySanya 572025China

To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure,considering the cross angleαand joint persistence ratioη,a numerical model of the biaxial Hopkinson bar test system was established using the finite element method–discrete-element model coupling *** validity of the model was verified by comparing and analyzing it in conjunction with laboratory test ***-static combined impact tests were conducted on specimens under various conditions to investigate the strength characteristics and patterns of crack initiation and *** study revealed the predominant factors influencing intersecting joints with different angles and penetrations under impact *** results show that the peak stress of the specimens decreases first and then increases with the increase of the cross ***α<60°,regardless of the value ofη,the dynamic stress of the specimens is controlled by the main ***α≥60°,the peak stress borne by the specimens decreases with increasingη.Whenα<60°,the initiation and propagation of cracks in the cross-jointed specimens are mainly controlled by the main joint,and the final failure surface of the specimens is composed of the main joint and wing ***α≥60°orη≥0.67,the secondary joint guides the expansion of the wing cracks,and multiple failure surfaces composed of main and secondary joints,wing cracks,and co-planar cracks are *** lateral confinement significantly increases the dynamic peak stress able to be borne by the *** triaxial conditions,the degree of failure of the intersecting jointed specimens is much lower than that under uniaxial and biaxial conditions.

关键词： Cross joints Joint distribution form Dynamic failure characteristics FEM–DEM BHPB