检索结果-南通市图书馆

Atomic-Scale Insights into Damage Mechanisms of GGr15 Bearing Steel Under Cyclic Shear Fatigue

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7期37卷 1265-1278页

作者： Qiao-Sheng Xia Dong-Peng Hua Qing Zhou Ye-Ran Shi Xiang-Tao Deng Kai-Ju Lu hai-feng wang Xiu-Bing Liang Zhao-Dong wang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an710072China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Defense Innovation Institute Academy of Military ScienceBeijing100071China

Alternating shear stress is a critical factor in the accumulation of damage during rolling contact fatigue,severely limiting the service life of ***,the specific mechanisms responsible for the cyclic shear fatigue damage in bearing steel have not been fully *** the mechanical response and microstructural evolution of a model GGr15 bearing steel under cyclic shear loading are investigated through the implementation of molecular dynamics *** samples undergo 30 cycles under three different loading conditions with strains of 6.2%,9.2%,and 12.2%,*** findings indicate that severe cyclic shear deformation results in early cyclic softening and significant accumulation of plastic damage in the bearing ***,samples subjected to higher strain-controlled loading exhibit higher plastic strain energy and shorter fatigue ***,strain localization is identified as the predominant damage mechanism in cyclic shear fatigue of the bearing steel,which accumulates and ultimately results in fatigue ***,simulation results also revealed the microstructural reasons for the strain localization(e.g.,BCC phase transformation into FCC and HCP phase),which well explained the formation of white etching *** study provides fresh atomic-scale insights into the mechanisms of cyclic shear fatigue damage in bearing steels.

关键词： Cyclic shear fatigue Molecular dynamic simulation Bearing steels Plastic damage accumulation

Developing a diagnostic model for predicting prostate cancer: a retrospective study based on Chinese multicenter clinical 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

Asian Journal of Andrology 2024年第1期26卷 34-40页

作者： Chang-Ming wang Lei Yuan Xue-Han Liu Shu-Qiu Chen hai-feng wang Qi-Fei Dong Bin Zhang Ming-Shuo Huang Zhi-Yong Zhang Jun Xiao Tao Tao Department of Urology The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Radiology The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Core Facility Center for Medical Sciences The First Affiliated Hospital of USTcDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Urology Affiliated Zhongda Hospital of Southeast UniversityNanjing 210009China Department of Urology Shanghai East HospitalTongji University School of MedicineShanghai 200120China Department of Urology Shanghai Changhai HospitalSecond Military Medical UniversityShanghai 200000China Department of Urology Affiliated Anhui Provincial Hospital of Anhui Medical UniversityHefei 230001China

The overdiagnosis of prostate cancer(PCa)caused by nonspecific elevation serum prostate-specific antigen(PSA)and the overtreatment of indolent PCa have become a global problem that needs to be solved *** aimed to construct a prediction model and provide a risk stratification system to reduce unnecessary *** this retrospective study,clinical data of 1807 patients from three Chinese hospitals were *** final model was built using stepwise logistic regression *** apparent performance of the model was assessed by receiver operating characteristic curves,calibration plots,and decision curve ***,a risk stratification system of clinically significant prostate cancer(csPCa)was created,and diagnosis-free survival analyses were *** multivariable screening and evaluation of the diagnostic performances,a final diagnostic model comprised of the PSA density and Prostate Imaging-Reporting and Data System(PI-RADS)score was *** validation in the development cohort and two external cohorts showed excellent discrimination and ***,we created a risk stratification system using risk thresholds of 0.05 and 0.60 as the cut-off *** follow-up results indicated that the diagnosis-free survival rate for csPCa at 12 months and 24 months postoperatively was 99.7%and 99.4%,respectively,for patients with a risk threshold below O.05 after the initial negative prostate biopsy,which was significantly better than patients with higher *** diagnostic model and risk stratification system can achieve a personalized risk calculation of *** provides a standardized tool for Chinese patients and physicians when considering thenecessity of prostatebiopsy.

关键词： nomogram prostate biopsy prostate cancer Prostate Imaging-Reporting and Data System prostate-specific antigen density

Insight into the photoexcitation effect on the catalytic activation of H_(2) and C-H bonds on TiO_(2)(110)surface

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 2022年第10期33卷 4705-4709页

作者： Min Zhou hai-feng wang Key Laboratory for Advanced Materials Centre for Computational Chemistry and Research Institute of Industrial CatalysisEast China University of Science and TechnologyShanghai 200237China

Semiconductor photocatalysis holds great promise for breaking the inert chemical bonds under mild condition;however,the photoexcitation-induced modulation mechanism has not been well understood at the atomic ***,by performing the DFT+U calculations,we quantitatively compare H_(2) activation on rutile TiO_(2)(110)under thermo-versus photo-catalytic *** is found that H2 dissociation prefers to occur via the heterolytic cleavage mode in thermocatalysis,but changes to the homolytic cleavage mode and gets evidently promoted in the presence of photoexcited hole(h^(+)).The origin can be ascribed to the generation of highly oxidative lattice O-radical(O_(br)^(·−))with a localized unoccupied O-2p *** importantly,we identify that this photo-induced promotion effect can be practicable to another kind of important chemical bond,i.e.,C-H bond in light hydrocarbons including alkane,alkene and aromatics;an exception is the C(sp^(1))-H in alkyne(HC≡CH),which encounters inhibition effect from *** quantitative analysis,the origins behind these results are attributed to the interplay between two factors:C-H bond energy(E_(bond))and the *** to the relatively high E_(bond) and acidity,it favors the C(sp^(1))-H bond to proceed with the heterolytic cleavage mode in both thermo-and photo-catalysis,and the photoexcited O_(br)^(·−)is adverse to receiving the transferred *** contrast,for the other hydrocarbons with moderate/low E_(bond),the O_(br)^(·−)would enable to change their activation mode to a more favored homolytic one and evidently decrease the C-H activation *** work may provide a general picture for understanding the photocatalytic R-H(R=H,C)bond activation over the semiconductor catalyst.

关键词： Density functional theory calculation Photocatalysis H_(2)activation C-H bond activation TiO_(2)

Schemes for Generating Different Nonlinear Schrodinger Integrable Equations and Their Some Properties

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2022年第3期38卷 579-600页

作者： Yu-feng ZHANG hai-feng wang Na BAI School of Mathematics China University of Mining and TechnologyXuzhou 221116China School of Computer Science and Technology China University of Mining and TechnologyXuzhou 221116China

In the paper,we want to derive a few of nonlinear Schrodinger equations with various formats and investigate their properties,such as symmetries,single soliton solutions,multi-soliton solutions,and so *** of all,we propose an efficient and straightforward scheme for generating nonisospectral integrable hierarchies of evolution equations for which a generalized nonisospectral integrable Schrodinger hierarchy(briefly GNISH)singles out,from which we get a derivative nonlinear Schrodinger equation,a generalized nonlocal Schrodinger integrable system and furthermore we investigate the symmetries and conserved qualities of the ***,we apply the dbar method to obtain a generalized nonlinear Schr?dinger-Maxwell-Bloch(GNLS-MB)equation and its hierarchy by introducing a generalized Zakhrov-Shabat spectral problem,whose soliton solutions and gauge transformations are obtained.

关键词： nonisospectral integrable hierarchy Schroodinger equation symmetry

First principles study of Fenton reaction catalyzed by FeOCl:reaction mechanism and location of active site

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2019年第8期38卷 783-792页

作者： Xuan-Xuan Ji hai-feng wang Pei-Jun Hu Key Laboratory for Advanced Materials Research Institute of Industrial Catalysis and Centre for Computational Chemistry School of Chemical and Molecular Engineering East China University of Science and Technology Shanghai 200237 China School of Chemistry and Chemical Engineering The Queen’s University of Belfast Belfast BT9 5AZ UK

Fe-based solid catalysts in promoting Fenton reaction to generate ·OH radical has drawn much attention,and interestingly,FeOCl was reported to have superior activity compared with the traditional Fe2 O3 ***,the mechanism of Fenton reaction on FeOCl and the origin of high activity remain ***,by virtue of DFT+ U calculations,the H2 O2 decomposition and conversion mechanism on FeOCl(100)surface were systematically *** is found that on clean FeOCl(100)surface,the exposed[Fe^3+-Fe^3+]sites can hardly break O-O bond of H2 O2 into OH groups,but instead H2 O2 tends to dehydrogenate by the surface lattice O,resulting in a series of side reactions and final conversion into O2,while the left H atoms gradually saturate the surface lattice O and reduce Fe^3+ into Fe^2+.On fully H-covered FeOCl(100),H2O2 can efficiently dissociate at[Fe^2+-Fe^2+]sites into two OH,but OH binds with Fe^2+ so strongly that it cannot desorb as OH radical as easily as that on Fe^3+.Interestingly,FeOCl(100)tends to be partially protonated in the real acid solution,which,along with H2 O2 dehydrogenation,results in the formation of active unit [Fe^2+-Fe^3+].On[Fe^2+-Fe^3+]unit,H2 O2 can easily break its O-O bond and OH at Fe3+ can desorb as OH radical,while the other OH at Fe^2+ couples with the surface H into H2O and finish the catalytic *** comparison,Fe2 O3(012)cannot provide enough [Fe^2+-Fe^3+] active units due to the relative difficulty in H2 O2 dehydrogenation,which accounts for its inferior catalytic efficiency for Fenton reaction.

关键词： Fenton reaction FeOCl Density functional theory H2O2 Active site

Migration of harmful elements in municipal sludge under hightemperature oxidation conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第9期30卷 1701-1713页

作者： Xiao-dong Ping hai-feng wang feng wang Xin-yu Wan Zhi-wei An Jian-lei Pan State Key Laboratory of Advanced Steel Processes and Products Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China Department of Science and Technology Development China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China Production and Equipment Department Chengde Jianlong Special Steel Co.Ltd.Chengde 067200HebeiChina Technology Department Chengde Jianlong Special Steel Co.Ltd.Chengde 067200HebeiChina

Municipal sludge is produced in large amounts and is difficult to *** is the most direct and thorough treatment *** order to study the feasibility of sintering for municipal sludge treatment,the municipal sludge reforming process was studied under high-temperature oxidation *** results showed that the sludge reforming process could be divided into four stages:the precipitation and evaporation of adsorbed water,the precipitation and combustion of the volatile,the combustion of the residual volatile and solid carbon,and the decomposition of salts and the melting of *** increase in the heating rate resulted in more intense sludge combustion and improved the sludge reaction capacity and combustion *** burning at 1300℃,Si,Ca,Mg,Al,K,Na,and Cu formed new phases and entered the slag.75%of P remained in the slag.80%of the S formed SO_(2) and entered the flue *** formed gaseous chlorides like HCl upon combustion and entered the flue *** sintering is a feasible method for treating municipal sludge,care must be taken to limit the amount of P that ends up in the ore.

关键词： Municipal sludge Oxidizing atmosphere Mini-sintering Reforming process Element migration

Growth of solidified shell in bloom continuous casting mold of hypo-peritectic steel based on a FeS tracer method

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 Iron and Steel Research International 2020年第7期27卷 782-787页

作者： Da-peng Li Hua-zhang Wu hai-feng wang Hong Li State Key Laboratory of Advanced Steel Processing and Products Central Iron and Steel Research InstituteBeijing 100081China Benxi Iron&Steel Group Co. Ltd.Benxi 117021LiaoningChina State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

Solidification behavior in the mold region plays an important role in production efficiency and steel *** investigate shell growth within a mold,the sulfur prints of the entire shell thickness profile the meniscus to 100 mm below the mold were obtainedadding FeS tracer into molten steel during bloom continuous casting of hypo-peritectic *** law of shell thickness evolution along mold height and circumference was *** results show that there are three weak regions of solidification,which are in the mold upper part,in the mold lower part,and just below mold exit,possibly resulting periodic fluctuation of air gap between the shell and the mold,the impingement of melt jets on the solidification front,and the decreasing cooling intensity,*** solidification point along casting direction appears at approximately 35 mm below the ***,the solidified shell thickness in the inner side of the mold is a little larger than that in the outer side,and the former and the latter reach 25.5 and 24.3 mm at the mold exit,*** non-uniform shell growth in the inner side of the bloom is provided,while shell thicknesses in the narrow face and the outer side follow relatively regular *** of the mold,the thinnest shells on the transverse section exist in the regions of 60–90 mm and 40–70 mm the corners of the inner and outer sides,respectively,i.e.,the of-corners.

关键词： Continuous casting Mold Hypo-peritectic steel Solidified shell Sulfur print

The fractions of post-binary-interaction stars and evolved blue straggler stars on the red giant branch of globular clusters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2021年第9期21卷 101-110页

作者： Dan-Dan Wei Bo wang hai-Liang Chen hai-feng wang Xiao-Bo Gong Dong-Dong Liu Deng-Kai Jiang Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of ScienceKunming 650216China University of Chinese Academy of Science Beijing 100049China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China South-Western Institute for Astronomy Research Yunnan UniversityKunming 650500China LAMOST

The red giant branch(RGB)of globular clusters(GCs)is home to some exotic stars,which may provide clues on the formation of multiple stellar populations in *** is well known that binary interactions are responsible for many exotic ***,it is important to understand what fraction of stars on the RGB of GCs is the result of binary *** this paper,we performed a binary population synthesis study to track the number of post-binary-interaction(post-BI)stars that appear on the RGB,with particular emphasis on the evolved blue straggler stars(E-BSSs).Assuming an initial binary fraction of nearly 50%,we find that about half of the objects on the RGB(called giants)underwent the binary interactions,and that E-BSSs account for around 10%of the giants in our standard *** also compare the properties of post-BI giants that evolved from different *** find that the initial orbital period and mass ratio distributions significantly affect the fraction of post-BI *** results imply that the non-standard stars from binary interactions provide a non-negligible contribution to the RGB stars in GCs,which should be considered in future investigations of the origin of multiple stellar populations.

关键词： blue stragglers stars:chemically peculiar globular clusters:general binaries:general

Synthesis of 2,5-disubstituted tetrahydrofurans from organozinc halides and lactones

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第5期21卷 511-514页

作者： Dan feng Huang hai feng wang Chang Ming Xu Teng Niu Yu Lai Hu College of Chemistry and Chemical Engineering Northwest Normal UniversityLanzhou 730070China

2,5-Disubstituted tetrahydrofurans were obtained from lactones and organozinc halides in moderate to high yield in the presence of Lewis acids.

关键词： Organozinc halides Lactones Lactols 2,5-Disubstituted tetrahydrofurans Lewis acid