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Progress in organocatalytic asymmetric (4+3) cycloadditions for the enantioselective construction of seven-membered rings

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Science China Chemistry 2023年第4期66卷 966-992页

作者： Wei Tan Jia-Yi Zhang cong-hui Gao Feng Shi Research Center of Chiral Functional Heterocycles School of Chemistry and Materials ScienceJiangsu Normal UniversityXuzhou 221116China School of Petrochemical Engineering Changzhou UniversityChangzhou 213164China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

Chiral seven-membered ring systems such as seven-membered carbocycles and heterocycles are widely found in natural products and ***,the catalytic enantioselective construction of such frameworks has evoked considerable interest in the field of *** the various approaches,organocatalytic asymmetric(4+3)cycloadditions are highly effective for the enantioselective construction of seven-membered *** the past two decades,substantial efforts have been devoted to this field and chemists have developed various organocatalytic asymmetric(4+3)*** review summarizes the progress in organocatalytic asymmetric(4+3)cycloadditions from 2003 to early 2022 and provides insights into challenging issues faced in this research field,enabling the future development of this field.

关键词： organocatalysis (4+3)cycloaddition seven-membered rings four-atom building blocks

Dynamics of a Reaction-diffusion-ODE System in a Heterogeneous Media

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 275-301页

作者： cong-hui ZHANG Hai-feng ZHANG Mei-rong ZHANG School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this *** first show that there exist both continuous and discontinuous stationary *** a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate *** addition,we demonstrate the influences of the diffusion coefficient on stationary *** results we obtained are based on the super-/sub-solution method and the generalized mountain pass ***,some numerical simulations are given to illustrate the theoretical results.

关键词： reaction-diffusion-ODE system discontinuous stationary solutions stability asymptotic behavior monotone solutions

Landslide dynamic process and parameter sensitivity analysis by discrete element method: the case of Turnoff Creek rock avalanche

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Journal of Mountain Science 2020年第7期17卷 1581-1595页

作者： an hui-cong Ouyang Chao-jun Zhao Chuan Zhao Wei Key Laboratory of Mountain Hazards and Earth Surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing100101China University of Chinese Academy of Sciences Beijing100049China Sichuan Academy of Water Conservancy Chengdu610072China

The great diversity and complexity of geological hazards in terms of flowing materials,environment,triggering mechanisms and physical processes during the flow bring great difficulties to the numerical parameter selection for the discrete element *** order to identity the significance of individual parameters on the landslides dynamic process and provide valuable contribution to the runout analysis of similar landslide,the dynamic process and associated microscopic mechanism of the Turnoff Creek rock avalanche in Canada are *** present numerical results are compared with the field survey data and the results of depth-integrated continuum *** final deposit range matches well with the field survey *** is illustrated that the discrete element method is robust and feasible to capture the dynamic characteristics of large rock avalanche over a complex ***,a new method to assess the landslide hazard level based on the discrete element method is *** to the parameter sensitivity analysis,it is demonstrated that the basal friction coefficient and bond strength are essential to the final deposit while rolling coefficient and restitution coefficient have little effects on it.

关键词： Discrete element method Contact model Numerical modeling Rock avalanche Geological hazard assessment Parameter analysis

Determination of mechanical properties of pure zirconium processed by surface severe plastic deformation through nanoindentation

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Rare Metals 2019年第9期38卷 824-831页

作者： Yao-Mian Wang Wei Zhuang Huan-Ping Yang cong-hui Zhang School of Metallurgical Engineering Xi’an University of Architecture and Technology

Commercially pure zirconium was processed by the surface mechanical attrition treatment(SMAT),and the microstructure observation showed that a gradient structure was *** measurements were taken to obtain the load-displacement curves at different depths below the treated *** dimensional analysis,the local yield stress,hardness,strain hardening exponent,and elastic modulus at the corresponding depths were *** results showed that the yield stress and hardness varied with depth,while the strain hardening exponent and elastic modulus were approximately *** finite element method was used to simulate nanoindentation at different depths below the treated surface to verify the derivation of the local elastic-plastic constitutive *** curves were computed for the treated samples through the rule of mixtures,and they agreed well with the experimental *** analysis showed that the surface and subsurface hardening layers as well as the transition layer shared a high load applied to the samples,even though their volume fraction was small.

关键词： Mechanical property Severe plastic deformation Gradient microstructure Nanoindentation Finite element method

Mechanical properties of electroformed copper layers with gradient microstructure

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International Journal of Minerals,Metallurgy and Materials 2010年第1期17卷 69-74页

作者： Qiang Liao Li-qun Zhu hui-cong Liu Wei-ping Li School of Materials Science and Engineering Beihang University Beij ing 100191 China

The electroformed copper layer with gradient microstructure was prepared using the ultrasonic technique. The microstructure of the electroformed copper layer was observed by using an optical microscope （OM） and a scanning electron microscope （SEM）. The preferred orientations of the layer were characterized by X-ray diffraction （XRD）. The mechanical properties were evaluated with a Vicker＇s hardness tester and a tensile tester. It is found the gradient microstructure consists of two main parts： the outer part （faraway substrate） with columnar crystals and the inner part （nearby substrate） with equiaxed grains. The Cu-（220） preferred orientation increases with the increasing thickness of the copper layer. The test results show that the microhardness of the electroformed copper layer decreases with increasing grain size along the growth direction and presents a gradient distribution. The tensile strength of the outer part of the electroformed copper layer is higher than that of the inner part but at the cost of ductility. Meanwhile, the integral mechanical properties of the electroformed copper with gradient microstrucmre are significantly improved in comparison with the pure copper deposit.

关键词： electroforming copper layer gradient rnicrostructure mechanical properties preferred orientation

T-cell immunoglobulin mucin molecule-3, transformation growth factor β, and chemokine-12 and the prognostic status of diffuse large B-cell lymphoma

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World Journal of Clinical Cases 2022年第32期10卷 11804-11811页

作者： Hao Wu hui-cong Sun Gui-Fang Ouyang Department of Hematology Ningbo First HospitalNingbo Clinical Research Center for Hematologic MalignanciesNingbo 315010Zhejiang ProvinceChina Department of Adult Internal Medicine Ningbo Women and Children's HospitalNingbo 315012Zhejiang ProvinceChina

BACKGROUND The effects of T-cell immunoglobulin mucin molecule-3(Tim-3),transforming growth factor β(TGF-β),and chemokine-12(CXCL12) expression on the prognosis of patients with diffuse large B-cell lymphoma(DLBCL) have not been *** To examine the correlation between Tim-3,TGF-β and CXCL12 expression and DLBCL *** Lymph node tissues of 97 patients with DLBCL and 93 normal-response hyperplastic lymph node tissues treated from January 2017 to May 2019 were selected as the DLBCL and control groups,*** expression of Tim-3,TGF-β,and CXCL12 was detected *** were followed up for 3 years,and progression-free survival was *** mult-ifactorial analysis was performed to analyze the risk factors for poor *** The positive expression rates of Tim-3,TGF-β,and CXCL12 were higher in DLBCL tissues than in non-cancerous(control) tissues(P < 0.05).One-year postsurgery,the positive expression rates of Tim-3,TGF-β,and CXCL12 were higher in patients with effective treatment than in those with ineffective treatment(P < 0.05).The 3-year progression-free survival of 97 patients with DLBCL was 67.01%(65/97).Univariate analysis revealed that clinical stage,bone marrow infiltration,International Prognostic Index(IPI) score,Tim-3 positivity,TGF-β positivity,and CXCL12 positivity were associated with poor prognosis(P < 0.05).Multivariate Cox regression analysis demonstrated that clinical stage Ⅲ–Ⅳ,bone marrow infiltration,mediate-to-high-risk IPI scores,Tim-3 positivity,TGF-β positivity,and CXCL12 positivity were independent risk factors affecting prognosis(P < 0.05).CONCLUSION DLBCL tissues exhibit high positive expression of Tim-3,TGF-β,and CXCL12,and a high expression of all three indicates a poor prognosis.

关键词： T-cell immunoglobulin mucin molecule-3 Transforming growth factorβ Chemokine-12 Diffuse large B-cell lymphoma

Commentary on “Transurethral seminal vesiculoscopy for recurrent hemospermia: experience from 419 cases”

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Asian Journal of Andrology 2020年第2期22卷 227-228页

作者： Kun Pang Bing-Zheng Dong cong-hui Han Department of Urology Xuzhou Central HospitalXuzhou Clinical College Affiliated to Xuzhou Medical UniversityXuzhou 221009China

Dear Editor,We have read the article by Chen et al.1 with great *** reported the effect of transurethral seminal vesiculoscopy(TSV)for the treatment of recurrent hemospermia,and they concluded that TSV was an effective and safe procedure in the management of seminal tract disorders.1 TSV is an endoscopic technique that has developed rapidly in recent *** it is a relatively simple procedure and does not change the normal anatomical structures of seminal vesicles,this technique is becoming an alternative for the diagnosis and treatment of seminal vesicle and seminal tract diseases.

关键词： TSV treatment recurrent

Rock characteristics and dynamic fragmentation process of the 2018 Daanshan rockslide in Beijing,China

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Journal of Mountain Science 2023年第2期20卷 448-465页

作者： FAN Tian-zhen an hui-cong OUYANG Chao-jun WANG Dong-po State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China Key laboratory of Mountain Hazards and Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

This study investigated the failure mechanism associated with the rock mass structure and the dynamic fragmentation process of blocky rocks of the 2018 Daanshan rockslide that occurred on 11 August,*** was found that the initially collapsed rock of this rockslide was partitioned along the unconformity and strata *** analyzed how the unique rock mass structure,coupled with the road cut and the antecedent rainfall,jointly resulted in its *** on the rock types and geological structures,the initial stratified configuration of a discrete element model was setup to reveal the influences of the local *** numerical model was divided into three *** 1 is the basalt of the Nandaling Formation,the normal and shear stiffnesses of the basalt particles are set as 80 MPa and 40 *** 2 and 3 are the sandstones interbedded with mudstone and sandstone of the Shihezi Formation,and the normal and shear stiffnesses of these parts were set as 6 MPa and 10 MPa,*** dynamic process of the rockslide,particularly the rock fragmentation process,was numerically analyzed using a 3D discrete element *** numerical results were compared with real-time videos and field *** results show that the rock fragmentation and the final deposition range match well with the real disaster phenomenon,and the calculation accuracy of the rockslide reaches 82.41%.Moreover,a parameter sensitivity analysis was conducted,and classical uniform models under different bonding forces were established;the stratified model can better restore the true state of the fragmentation,movement,and deposition processes of ***,for complicated rocks with significant differences in lithology,clarifying the rock mass stratigraphy is essential for an accurate reconstruction of the dynamic process of rockslides.

关键词： Discrete element method Rockslide Stratified model Numerical modeling Fragmentation Daanshan rockslide

Synthesis and Potential Application of Novel C_(2)-Symmetrical Bis(ferrocenyl)P2N Ligand

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Chinese Chemical Letters 2003年第11期14卷 1113-1115页

作者： Xiang Ping HU hui Lin CHEN hui cong DAI Xin Quan HU Zhuo ZHENG Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023

A novel chiral bis(ferrocenyl) P2N ligand 1 with C2-symmetry was synthesized through a four-step procedure from (R)-N,N-dimethyl-1-ferrocenylethylamine. In a model reaction of Pd-catalyzed allylic alkylation of 1,3-d... 详细信息

关键词： Synthesis C_(2)-symmetry bis(ferrocenyl) P2N ligand Pd-catalyzed allylic alkylation.