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Coefficients of earth pressure at rest in thick and deep soils

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Mining Science and Technology 2009年第2期19卷 252-255页

作者： tian qiu-hong XU Zhi-wei ZHOU Guo-qing ZHAO Xiao-dong HU Kun State Key Laboratory for Geomechanics ＆ Deep Underground Engineering School of Architecture and Civil Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

The effect of test methods and stress paths on the experimental value of the coefficient of earth pressure at rest, K0, was investigated under high pressures. The results indicate that the rigid pressure chamber and flexible lateral confining pressure medium method gives a stress ratio at the initial stage that is not the real K0. Moreover, K0 increases during the loading process becoming greater at high pressures. In the unloading process, however, K0 increases only at the initial stage but decreases thereafter. In addition, the incremental magnitude definition, K0=dσ3/dσ1, gives higher values than the total magnitude definition, K0=σ3/σ1, under loading. This is also true during initial stages of unloading. The experiment results also indicate that earth pressure at rest in deep and thick soils can be estimated by a power function of axial and confining pressures. It is necessary to choose the appropriate Kn to avoid some accidents.

关键词： experimental research earth pressure at rest loading and unloading paths thick and deep soils

"Nonlinear" characteristics of the static earth pressure coefficient in thick alluvium

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Mining Science and Technology 2009年第1期19卷 129-132页

作者： XU Zhi-wei ZENG Kai-hua WEI Zhou LIU Zhi-qiang ZHAO Xiao-dong tian qiu-hong State Key Laboratory for Geomechanics ＆ Deep Underground Engineering School of Architecture and Civil Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China Nanchang Institute of Technology Nanchang Jiangxi 330099 China Jiangsu tiandi Steel Structure Work Engineering Group Co. Ltd. Xuzhou Jiangsu 221006 China

Exact calculations of the static earth pressure from a thick alluvium require accurate/Co values. These calculations influence the sinking cost and the safety of the freezing method. The static earth pressure coefficient （K0） of thick and deep soil was analyzed using laboratory tests. The results show that the static earth pressure coefficient of thick and deep soils is nonlinear and different from that of superficial soils. The constant of superficial soils is usually invariant and the total stress or incremental stress definitions used in traditional geo-meehanics give the same value. The influence of load increments when calculating for superficial soil is ignored. The difference in values of K0 for thick alluvium defimed by the total stress or the incremental stress methods is over 10%. The effects of the thick alluvium on K0 should be considered during the design of frozen shaft projects. Such things as the frozen shaft thickness and the excavated section height should be chosen to assure the rationality of the design and to avoid potential faults and accidents.

关键词： thick alluvium static earth pressure coefficient nonlinear analysis

Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： Yan Liu qiu Tang Xin-Cheng tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in *** improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

Exogeneous metal ions as therapeutic agents in cardiovascular disease and their delivery strategies

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Regenerative Biomaterials 2024年第2期3卷 1-16页

作者： Xiaoqian hong Geer tian Yang Zhu Tanchen Ren Department of Cardiology of the Second Affliated Hospital and State Key Laboratory of Transvascular Implantation Devices Cardiovascular Key Laboratory of Zhejiang ProvinceZhejiang University School of MedicineHangzhou 310o09China Binjiang Institute of Zhejiang University Hangzhou 310053China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Metal ions participate in many metabolic processes in the human body,and their homeostasis is crucial for *** cardiovascular diseases(CVDs),the equilibriums of metal ions are frequently interrupted,which are related to a variety of disturbances of physiological processes leading to abnormal cardiac *** supplement of metal ions has the potential to work as therapeutic strategies for the treatment of *** with other therapeutic drugs,metal ions possess broad availability,good stability and safety and diverse drug delivery *** delivery strategies of metal ions are important to exert their ther-apeutic effects and reduce the potential toxic side effects for cardiovascular applications,which are also receiving increasing *** local delivery strategies for metal ions based on various biomaterials are constantly being *** this review,we comprehensively summarized the positive roles of metal ions in the treatment of cVDs from three aspects:protecting cells from oxidative stress,inducing angiogenesis,and adjusting the functions of ion *** addition,we introduced the transferability of metal ions in vascular reconstruction and cardiac tissue repair,as well as the currently available engineered strategies for the precise delivery of metal ions,such as integrated with nanoparticles,hydrogels and scaffolds.

关键词： metal ions cardiovascular disease tissue engineering oxidative stress angiogenesis ion channel

Efficacy comparison of fruquintinib,regorafenib monotherapy or plus programmed death-1 inhibitors for microsatellite stable metastatic colorectal cancer

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2449-2462页

作者： tian-Qi An Hui qiu Quan-Bo Zhou hong Zong Shuang Hu Yu-Gui Lian Rui-Hua Zhao Department of Oncology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000Henan ProvinceChina Department of Hepato-Pancreato-Biliary Surgery Peking University Cancer Hospital and InstituteBeijing 100000China Department of Colorectal Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000Henan ProvinceChina

BACKGROUND Regorafenib(R)and fruquintinib(F)are the standard third-line regimens for colorectal cancer(CRC)according to the National Comprehensive Cancer Network guidelines,but both have limited *** phase 2 trials have indicated that R or F combined with immune checkpoint inhibitors can reverse immunosuppression and achieve promising efficacy for microsatellite stable or proficient mismatch repair(MSS/pMMR)*** to the lack of studies comparing the efficacy between F,R,F plus programmed death-1(PD-1)inhibitor,and R plus PD-1 inhibitors(RP),it is still unclear whether the combination therapy is more effective than *** To provide critical evidence for selecting the appropriate drugs for MSS/pMMR metastatic CRC(mCRC)patients in clinical *** A total of 2639 CRC patients were enrolled from January 2018 to September 2022 in our hospital,and 313 MSS/pMMR mCRC patients were finally *** A total of 313 eligible patients were divided into F(n=70),R(n=67),F plus PD-1 inhibitor(FP)(n=95)and RP(n=81)*** key clinical characteristics were well balanced among the *** median progression-free survival(PFS)of the F,R,FP,and RP groups was 3.5 months,3.6 months,4.9 months,and 3.0 months,*** median overall survival(OS)was 14.6 months,15.7 months,16.7 months,and 14.1 *** FP regimen had an improved disease control rate(DCR)(P=0.044)and 6-month PFS(P=0.014)and exhibited a better trend in PFS(P=0.057)compared with F,and it was also significantly better in PFS than RP(P=0.030).RP did not confer a significant survival benefit;instead,the R group had a trend toward greater benefit with OS(P=0.080)compared with *** significant differences were observed between the R and F groups in PFS or OS(P>0.05).CONCLUSION FP is superior to F in achieving 6-month PFS and DCR,while RP is not better than *** has an improved PFS and 6-month PFS compared with RP,but F and R had similar clinical ***,FP may be a

关键词： Colorectal cancer Fruquintinib Regorafenib Programmed death-1 inhibitor Real-world

Review on laser directed energy deposited aluminum alloys

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International Journal of Extreme Manufacturing 2024年第2期6卷 84-131页

作者： tian-Shu Liu Peng Chen Feng qiu hong-Yu Yang Nicholas Tan Yew Jin Youxiang Chew Di Wang Ruidi Li Qi-Chuan Jiang Chaolin Tan Singapore Institute of Manufacturing Technology(SIMTech) Agency for ScienceTechnology and Research(A∗STAR)5 Cleantech LoopSingapore 636732Singapore State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130025People’s Republic of China Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and EngineeringJilin UniversityChangchun 130025People’s Republic of China School of Mechanical&Automotive Engineering South China University of TechnologyGuangzhou 510640People’s Republic of China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083People’s Republic of China

Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al *** a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and ***,LDED Al alloys are highly challenging due to their inherent poor printability(*** laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al *** porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al *** parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al *** underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are *** benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are *** review aims to provide a critical and in-depth evaluation of current progress in LDED Al *** opportunities and perspectives in LDED high-performance Al alloys are also outlined.

关键词： additive manufacturing laser directed energy deposition(LDED) aluminum alloys printability aluminum matrix composite auxiliary fields mechanical properties

Impact of Mo/Ni alloying on microstructural modulation and low-temperature toughness of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第7期31卷 1746-1762页

作者： Wei Liu hong-li Zhao Bing-xing Wang Yong tian State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

The high-strength low-alloy steel plates with varying Ni/Mo contents were manufactured using the thermos-mechanical control *** investigation was conducted to explore the effect of Ni/Mo microalloying on microstructure evolution and mechanical properties of the *** results revealed that the increase in Ni content from 1 to 2 wt.%reduced the transition temperature of ferrite and the growth range of ferritic grain was narrowed,which promoted grain *** optimized combination of grain size,high-angle grain boundaries(HAGBs),and martensite-austenite(M-A)islands parameter contributed to the excellent impact toughness of S1 steel at-100℃(impact absorbed energy of 218.2 J at-100℃).As the Mo increases from 0 to 2 wt.%,the matrix structure changes from multiphase structure to granular bainite,which increases the average effective grain size to~4.62 pm and reduces HAGBs proportion to~36.22%.With these changes,the low-temperature impact toughness of S3 steel is *** addition,based on the analysis of the characteristics of crack propagation path,it was found that M-A islands with low content(~2.21%)and small size(~1.76 pm)significantly retarded crack propagation,and the fracture model of M-A islands with different morphologies was further ***,correlation between behaviour of delamination and toughness was further analysed by observing delamination size and impact energy parameters.

关键词： High-strength low-alloy steel Microstructural regulation Ni addition Mo addition Crack propagation Low-temperature toughness

Energy beam-based direct and assisted polishing techniques for diamond:A review

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International Journal of Extreme Manufacturing 2024年第1期6卷 93-124页

作者： Zhuo Li Feng Jiang Zhengyi Jiang Zige tian tian qiu Tao Zhang qiuling Wen Xizhao Lu Jing Lu Hui Huang Institute of Manufacturing Engineering Huaqiao UniversityXiamen 361021People’s Republic of China School of Mechanical MaterialsMechatronic and Biomedical EngineeringUniversity of WollongongWollongongNSW 2522Australia College of Mechanical Engineering and Automation Huaqiao UniversityXiamen 361021People’s Republic of China State Key Laboratory of High Performance Tools Huaqiao UniversityXiamen 361021People’s Republic of China

Diamond is a highly valuable material with diverse industrial applications,particularly in the fields of semiconductor,optics,and high-power ***,its high hardness and chemical stability make it difficult to realize high-efficiency and ultra-low damage machining of *** address these challenges,several polishing methods have been developed for both single crystal diamond(SCD)and polycrystalline diamond(PCD),including mechanical,chemical,laser,and ion beam processing *** this review,the characteristics and application scope of various polishing technologies for SCD and PCD are ***,various energy beam-based direct and assisted polishing technologies,such as laser polishing,ion beam polishing,plasma-assisted polishing,and laser-assisted polishing,are *** current research progress,material removal mechanism,and infuencing factors of each polishing technology are *** some of these methods can achieve high material removal rates or reduce surface roughness,no single method can meet all the ***,the future development prospects and application directions of different polishing technologies are presented.

关键词： single crystal diamond polycrystalline diamond energy beam polishing technology material removal mechanism influencing factors

Drought-Tolerant Rice at Molecular Breeding Eras:An Emerging Reality

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Rice science 2024年第2期31卷 179-189页

作者： ZHU Chengqi YE Yuxuan qiu tian HUANG Yafan YING Jifeng SHEN Zhicheng Institute of Insect Sciences Zhejiang UniversityHangzhou 310058China Performance Plants Inc. 1287 Gardiners RoadKingstonOntario K7P 3J6Canada China National Rice Research Institute Hangzhou 310006China

Rice(Oryza sativa L.)stands as the most significantly influential food crop in the developing world,with its total production and yield stability affected by environmental *** stress impacts about 45%of the world’s rice area,affecting plants at molecular,biochemical,physiological,and phenotypic *** conventional breeding method,predominantly employing single pedigree selection,has been widely utilized in breeding numerous drought-tolerant rice varieties since the Green *** rapid progress in plant molecular biology,hundreds of drought-tolerant QTLs/genes have been identified and tested in rice crops under both indoor and field *** genes have been introgressed into elite germplasm to develop commercially accepted drought-tolerant varieties,resulting in the development of several drought-tolerant rice varieties through marker-assisted selection and genetically engineered *** review provides up-to-date information on proof-of-concept genes and breeding methods in the molecular breeding era,offering guidance for rice breeders to develop drought-tolerant rice varieties.

关键词： conventional breeding drought stress drought tolerant rice genetic engineering marker-assisted selection breeding