检索结果-南通市图书馆

Projectively Flat Singular Square Metrics with Constant Flag Curvature

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2020年第6期36卷 638-650页

作者： Guang Zu CHEN xin yue cheng School of Science East China Jiao Tong UniversityNanchang 330013P.R.China School of Mathematical Sciences Chongqing Normal UniversityChongqing 401331P.R.China

In this paper,we study and characterize locally projectively flat singular square metrics with constant flag ***,we obtain the sufficient and necessary conditions that singular square metrics are locally pro jectively... 详细信息

关键词： Singular square metric projectively flat metric flag curvature

On Conformally Flat(α,β)-metrics with Special Curvature Properties

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2015年第5期31卷 879-892页

作者： Min Gao YUAN xin yue cheng Department of Mathematical Sciences Indiana University Purdue University Indianapolis School of Mathematics and Statistics Chongqing University of Technology

In this paper, we study a significant non-Riemannian quantity E-curvature, which is defined by S-curvature. Firstly, we obtain the formula of E-curvature for （α,β）-metrics. Based on it, we show that the E-curvature vanishes for a class of （α,β）-metrics. In the end, we get the relation of E-curvature for conformally related Finsler metrics, and classify conformally flat （α,β）-metries with almost vanishing E-curvature.

关键词： (α,β)-metrics conformaliy fiat curvature

The Characterizations and Constructions of Sprays of Isotropic Curvature

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2022年第9期38卷 1612-1620页

作者： xin yue cheng Ke Xiang CAO Chun Yan QING School of Mathematical Sciences Chongqing Normal UniversityChongqing 401331P.R.China

This paper discusses the sprays of isotropic *** first determine the relationship betweenχ-curvatures of two projectively related *** on this,we find an approach to construct sprays of isotropic curvature and find infinitely many sprays of isotropic curvature via some known sprays of isotropic *** particular,by using famous Funk metricΘ,we can construct infinitely many sprays of isotropic curvature,some of which can be induced by Finsler metrics,but others cannot be induced by any Finsler metric.

关键词： Spray spray of isotropic curvature χ-curvature S-curvature Funk metric

Genetic diversity and biogeography of red turpentine beetle Dendroctonus valens in its native and invasive regions

在线全文

学校读者我要写书评

暂无评论

Insect Science 2008年第4期15卷 291-301页

作者： Yan-Wen Cai xin-yue cheng Ru-Mei Xu Dong-Hong Duan Lawrence R. Kirkendall College of Life Sciences Beijing Normal University Beijing Forestry Office of Shanxi Province Taiyuan China Department of Zoology University of Bergen Bergen N-5007 Norway

Sequences of 479 bp region of the mitochondrial COI gene were applied to detect population genetic diversity and structure ofDendroctonus valens populations. By comparing the genetic diversity between native and invasive populations, it was shown that the genetic diversity of Chinese populations was obviously lower than that of native populations with both indices of haplotype diversity and Nei＇s genetic diversity, suggesting genetic bottleneck occurred in the invasive process of D. valens, and was then followed by a relatively quick population buildup. According to phylogenetic analyses of haplotypes, we suggested that the origin of the Chinese population was from California, USA. Phylogenetic and network analysis of native populations of D. valens revealed strong genetic structure at two distinct spatial and temporal scales in North America. The main cause resulting in current biogeographic pattern was supposedly due to recycled glacial events. Meanwhile, a cryptic species might exist in the Mexican and Guatemalan populations.

关键词： biogeography genetic diversity invasive species mitochondrial DNA redturpentine beetle

Synthesis and biological evaluation of 12-benzyl matrinic amide derivatives as a novel family of anti-HCV agents

维普期刊数据库评论

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 Chemical Letters 2016年第7期27卷 1052-1057页

作者： Sheng Tang Zong-Gen Peng xin Zhang xin-yue cheng Wen-Jing Li Jian-Dong Jiang Ying-Hong Li Dan-Qing Song Beijing Key Laboratory of Anti-infective Agents Institute of Medicinal Biotechnology Chinese Academy of Medical Science & Peking Union Medical College

A new series of 12-benzyl matrinic amide/ethanamide derivatives were synthesized from matrinine（1）and evaluated for their anti-HCV activity,taking compound 2 as the *** revealed that the introduction of a suitable substituent at the N’-end of matrinic amide might greatly enhance the *** them,matrinic acid 17 and N’-substituted matrinic amides 18a-d exhibited promising potency with low micromolar EC50 values ranging from 1.03μmol/L to 7.54 μmol/L,and better therapeutic window with SI from 66 to ***,compound 17 displayed an excellent PK and safety profile in vivo,demonstrating good drug-like ***,it has been selected for further investigation,with an advantage of decreased chances of inducing drug-resistance mutations.

关键词： Matrinic acid Matrinic amide Hepatitis C virus Structure–activity relationship

Regulating the oxidation state of Pd to enhance the selective hydrogenation for 5-hydroxymethylfurfural

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第8期72卷 60-68页

作者： xin Li yue Ma Xuning Wang Jianguo Wu Dong Cao Daojian cheng State Key Laboratory of Organic-Inorganic Composites and College of Chemical Engineering Beijing University of Chemical TechnologyBeijing 100029China

The highly selective hydrogenation of 5-hydroxymethylfurfural to 2,5-dihydroxymethylfuran is an important reaction in the field of biomass hydrogenation,because it is a bridge between biomass resources and chemical ***,we precisely constructed carbon nitride supported Pd-based catalysts by a simple impregnation-reduction *** changing the reduction temperature,catalysts with different oxidation state could be precisely ***,the important correlation between the ratio of Pd^(0)/Pd^(2+)and catalytic activity is revealed during the selective hydrogenation of *** Pd/g—C_(3)N_(4)—300 catalyst with a Pd^(0)/Pd^(2+)ratio of 3/2 showed the highest catalytic activity,which could get 96.9%5-hydroxymethylfurfural conversion and 90.3%2,5-dihydroxymethylfuran *** density functional theory calculation revealed that the synergistic effect between Pd0and Pd2+in Pd/g—C_(3)N_(4)—300 system could boost the adsorption of the substrate and the dissociation of *** this work,we highlight the important correlation between metal oxidation state and catalytic activity,which provides valuable insights for the rational design of precious metal catalysts for hydrogenation reactions.

关键词： Pd/g-C_(3)N_(4) Selective hydrogenation 5-hydroxymethylfurfural 2,5-dihydroxymethylfuran Oxidation state

An Innovative Coupled Common-Node Discrete Element Method-Smoothed Particle Hydrodynamics Model Developed with LS-DYNA and Its Applications

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第3期38卷 467-482页

作者： SHEN Zhong-xiang WANG Wen-qing XU cheng-yue LUO Jia-xin LIU Ren-wei School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China

In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SPH)method is developed using LS-DYNA *** DEM and SPH are established on the same node to create common-node DEM-SPH particles,allowing for fluid–structure *** simulations of various scenarios,including water entry of a rigid sphere,dam-break propagation over wet beds,impact on an ice plate floating on water and ice accumulation on offshore structures,are *** interaction between DS particles and SPH fluid and the crack generation mechanism and expansion characteristics of the ice plate under the interaction of structure and fluid are also *** results are compared with available data to verify the proposed coupling ***,the simulation results demonstrated that controlling the cutoff pressure of internal SPH particles could effectively control particle splashing during ice crushing failure.

关键词： common-node DEM-SPH fluid-structure interaction discrete element method smoothed particle hydrodynamics

Neuroelectrophysiological characteristics of Hirayama disease： report of 14 cases

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2012年第14期125卷 2440-2443页

作者： GUO Xiu-ming QIN xin-yue HUANG cheng Department of Neurology First Affiliated Hospital ChongqingMedical University Chongqing 400016 China

Background Hirayama disease is a juvenile muscular atrophy of the distal upper extremities and affects mainly young males. The present study aimed to investigate the neuroelectrophysiological characteristics of Hirayama disease. Methods We retrospectively analyzed the neural conduction velocity （NCV） parameters and needle-electrode electromyograms （EMG） of 14 patients with Hirayama disease. According to the clinical features of the patients, NCV was performed on affected upper-limb including median nerves and ulnar nerves, while EMG was selectively performed on upper and lower extremities, sternocleidomast and thoracic paraspinal muscles. Results The median nerves of all affected upper limbs of patients with Hirayama disease had normal conduction velocities and compound motor action potentials （CMAPs）. The ulnar nerves of all affected upper limbs also had normal conduction velocities. Of the 16 measured ulnar nerves of the affected upper limbs, eight had normal CMAPS, while the other eight showed CMAPs below the normal value by 〉20%. All patients had neurogenic injury on the affected side in muscles innervated by anterior horn cells at the lower cervical region （C7-8, T1）. Four patients had unilateral upper-limb muscle neurogenic injury on the affected side. Seven patients had bilateral upper-limb muscle neurogenic injury, while only two patients experienced bilateral upper-limb muscle atrophy / weakness. The other three patients showed extensive neurogenic injury （unilateral upper-limb muscle atrophy/weakness in one patient, bilateral symptoms in the other two patients）. Conclusions Electromyographic examination showed that the majority of Hirayama disease patients exhibited characteristic segmental injury in the anterior horn of the lower cervical region, while a few patients exhibited extensive neurogenic injury. These data suggest that the actual influence of Hirayama disease may be more extensive than indicated by the clinical presentations.

关键词： Hirayama disease, neuroelectrophysiology neurological injury

Analysis of acupoint massage combined with touch on relieving anxiety and pain in patients with oral implant surgery

在线全文

学校读者我要写书评

暂无评论

World Journal of Psychiatry 2024年第4期14卷 533-540页

作者： Jin-Hong Qu cheng-cheng Shou xin He Qin Wang yue-Xia Fang Department of Stomatology Hangzhou Lin'an Traditional Chinese Medicine HospitalHangzhou 311300Zhejiang ProvinceChina Department of Software R&D Hangzhou Broadlink Technology CoLtd.Hangzhou 311300Zhejiang ProvinceChina Department of Stomatology Hangzhou Red Cross HospitalHangzhou 310003Zhejiang ProvinceChina Department of Cardiovascular Hangzhou Lin'an Traditional Chinese Medicine HospitalHangzhou 311300Zhejiang ProvinceChina Department of Traditional Chinese Medicine Development Hangzhou Lin'an Traditional Chinese Medicine HospitalHangzhou 311300Zhejiang ProvinceChina

BACKGROUND Oral implant surgery is an effective procedure for artificial implants in missing tooth areas under local *** patients under local anesthesia are conscious during this procedure,compared with general anesthesia-related operations,they are more likely to experience negative emotions,such as anxiety and *** emotional reactions result in shivering and chills in the limbs,leading to poor doctor-patient cooperation and even avoidance of *** traditional Chinese medicine,it is believed that acupoint massage regulates blood and Qi,dredge menstruation,and relieve pain,which is beneficial for patients’emotional adjustment;however,there are few related clinical *** To observe the changes in anxiety and pain in patients with oral implant after acupoint massage combined with touch *** One hundred patients undergoing oral implantation in our hospital between May 2020 and May 2023 were randomly divided into control and study groups,according to a random number table,with 50 patients in each *** control group received routine intervention,and the study group received acupoint massage combined with touch on the basis of the control ***[assessed using the Modified Dental Anxiety Scale(MDAS)],pain severity,blood pressure,heart rate,and satisfaction were compared between the two *** Before intervention,the difference in MDAS score between the two groups was not significant(P>0.05),while after the intervention,the MDAS scores decreased in both groups compared with those before the intervention(P0.05).The systolic and d

关键词： Oral implant Acupoint massage Touch Anxiety Degree of pain