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HEAT KERNEL ON RICCI SHRINKERS(II)

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Acta Mathematica Scientia 2024年第5期44卷 1639-1695页

作者： yu LI Bing WANG Institute of Geometry and Physics University of Science and Technology of ChinaHefei230026China Hefei National Laboratory Hefei230088China

This paper is the sequel to our study of heat kernel on Ricci shrinkers[29].In this paper,we improve many estimates in[29]and extend the recent progress of Bamler[2].In particular,we drop the compactness and curvature boundedness assumptions and show that the theory of F-convergence holds naturally on any Ricci flows induced by Ricci shrinkers.

关键词： Ricci flow Ricci shrinker heat kernel

Fracture geometry and breakdown pressure of radial borehole fracturing in multiple layers

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Petroleum Science 2024年第1期21卷 430-444页

作者： yu-Ning Yong Zhao-Quan Guo Shou-Ceng Tian Lu-Yao Ma Tian-yu Wang Mao Sheng National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Beijing Petroleum Machinery Company Limited CNPC Engineering Technology R&D Company LimitedBeijing102206China Smart Energy Co. LtdChina Xiongan GroupXiong’an New Area071000HebeiChina

Radial borehole fracturing that combines radial boreholes with hydraulic fracturing is anticipated to improve the output of tight oil and gas *** paper aims to investigate fracture propagation and pressure characteristics of radial borehole fracturing in multiple layers.A series of laboratory experiments with artificial rock samples(395 mm×395 mm×395 mm)was conducted using a true triaxial fracturing *** crucial factors corresponding to the vertical distance of adjacent radial borehole layers(vertical distance),the azimuth and diameter of the radial borehole are *** results show that radial borehole fracturing in multiple layers generates diverse fracture *** types of fractures are identified based on the connectivity between hydraulic fractures and radial *** vertical distance significantly influences fracture propagation perpendicular to the radial borehole *** increase in the vertical distance impedes fracture connection across multiple radial borehole layers and reduces the fracture propagation distance along the radial borehole *** azimuth also influences fracture propagation along the radial borehole *** the azimuth reduces the guiding ability of radial boreholes,which makes the fracture quickly curve to the maximum horizontal stress *** breakdown pressure correlates with diverse fracture geometries *** the fractures connect multi-layer radial boreholes,increasing the vertical distance decreases the breakdown *** the azimuth and increasing the diameter also decrease the breakdown *** extrusion force exists between the adjacent fractures generated in radial boreholes in multiple rows,which plays a crucial role in enhancing the guiding ability of radial boreholes and results in higher breakdown *** research provides valuable theoretical insights for the field application of radial borehole fracturing technology in tight oil and g

关键词： Multi-layer radial boreholes Hydraulic fracturing Fracture propagation Pressure characteristic

Investigating impacts of different building contents on the post-earthquake evacuation time using an agent-based model with considering turning behavior

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 939-955页

作者： Bao yu School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China Sanya Science and Education Innovation Park of Wuhan University of Technology Sanya 572025China

Accurate assessment of crowd evacuation inside the post-earthquake environment is critical from many perspectives,but this issue receives much less attention compared to the seismic losses of structural and non-structural *** could be attributed to the fact that post-earthquake evacuation analysis is complex due to the interaction between human behavior and the actual built environment induced by different building *** study attempts to tackle this problem by investigating the impacts of different building contents on post-earthquake evacuation time by using an agent-based model that considers turning *** this end,the agent-based model is first described,including:properties of the agent-based model with turning behavior,key aspects in its formulation considering different evacuation stages,and influence of different building contents(namely,debris from partition walls and ceiling systems,and various types of equipment)on the agent’s ***,a school building is used as a benchmark problem to validate the model without earthquake,and the findings indicate that the agent-based model can match the real safety drill results reasonably *** the validation,the school building is subsequently designed in accordance with modern seismic design codes,and the influence of debris and equipment on post-earthquake evacuation time is quantitatively studied using a suite of pulse-type ground motions as *** on this case study,recommendations are made for structural and architectural designers in an effort to reduce the potential evacuation ***,debris induced by partition walls or ceiling systems should be controlled as it has the greatest impact on the total evacuation time.

关键词： seismic fragility evacuation agent-based model route choice built environment

Hybrid ionic thermoelectric and photocatalytic materials(i-TEPC):a new choice for energy harvesting

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Science China Chemistry 2024年第7期67卷 2127-2129页

作者： Qikai Li Mao yu Weishu Liu Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

Ionic thermoelectric(i-TE)material is a kind of new functional material that can convert heat energy into electric energy,which is of great significance for renewable energy technologies and sustainable development[1].The fundamental constitution of i-TE material mainly comprises an electrolyte matrix,ion providers and redox pairs.

关键词： energy harvesting convert

Challenges and strategies of chlorine inhibition in anode systems for seawater electrolysis

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Science China Chemistry 2024年第10期67卷 3198-3208页

作者： Chuqiang Huang Zhouzhou Wang Shaojun Cheng yunpeng Liu Binglu Deng Shaoyi Xu Luo yu Ying yu School of Materials Science and Hydrogen Energy Foshan UniversityFoshan 528000China Institute of Nanoscience and Nanotechnology College of Physical Science and TechnologyCentral China Normal UniversityWuhan 430079China Department of Physics and Texas Center for Superconductivity at the University of Houston(TcSUH) University of HoustonHoustonTX 77204USA Laboratory of Solar Fuel Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430074China

Seawater electrolysis for green hydrogen production is one of the key technologies for achieving carbon ***,in anode systems,the chloride ions(Cl^(-))in seawater will trigger an undesired chlorine evolution reaction(CER)that competes with an oxygen evolution reaction(OER),resulting in inferior OER activity and ***,the corrosive Cl^(-)and its derivative products will corrode anodes during seawater electrolysis,leading to poor ***,great efforts have been devoted to developing efficient strategies for chlorine inhibition to improve the activity,selectivity,and stability of anode ***,focusing on chlorine inhibition,we present a mini review to comprehensively and concisely summarize the recent progress in anode systems for boosting seawater *** particular,two strategies of physical and chemical regulation to inhibit Cl^(-)are summarized in some representative ***,some challenges and future opportunities in anode systems for seawater electrolysis are *** mini review aims to shed light on designing highly efficient anode materials for seawater electrolysis.

关键词： seawater electrolysis anode systems chlorine inhibition physical regulation chemical regulation

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Biomimetic chitin hydrogel via chemical transformation

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Nano Research 2024年第2期17卷 771-777页

作者： Rui-Rui Liu Qian-Qian Shi yu-Feng Meng Yong Zhou Li-Bo Mao Shu-Hong yu Division of Nanomaterials&Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China College&Hospital of Stomatology Key Laboratory of Oral Diseases Research of Anhui ProvinceAnhui Medical UniversityHefei 230032China Department of Dental Implantology College&Hospital of StomatologyAnhui Medical UniversityHefei 230032China

Chitin hydrogel has been recognized as a promising material for various biomedical applications because of its biocompatibility and ***,the fabrication of strong chitin hydrogel remains a big challenge because of the insolubility of chitin in many solvents and the reduced chain length of chitin regenerated from *** herein introduce the fabrication of chitin hydrogel with biomimetic structure through the chemical transformation of chitosan,which is a water-soluble deacetylated derivative of *** reacetylation of the amino group in chitosan endows the obtained chitin hydrogel with outstanding resistance to swelling,degradation,extreme temperature and pH conditions,and organic *** chitin hydrogel has excellent mechanical properties while retaining a high water content(more than 95 wt.%).It also shows excellent antifouling performance that it resists the adhesion of proteins,bacteria,blood,and ***,as the initial chitosan solution can be feasibly frozen and templated by ice crystals,the chitin hydrogel structure can be either nacre-like or wood-like depending on the freezing method of the precursory chitosan *** to these anisotropic structures,such chitin hydrogel can exhibit anisotropic mechanics and mass transfer *** current work provides a rational strategy to fabricate chitin hydrogels and paves the way for its practical applications as a superior biomedical material.

关键词： chitin hydrogel biomimetic structure chemical stability mechanical strength antifouling

Gastric cancer immunotherapy:A scientometric and clinical trial review

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World Journal of Gastroenterology 2024年第2期30卷 196-198页

作者： Qian-Cheng Du Xin-yu Wang Hua yu Thoracic Surgery Shanghai Xuhui Central HospitalShanghai 200031China Thyroid Breast and Vascular SurgeryShanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of General Surgery Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China

This letter is intended to arouse your interest in a recent review of comprehensive scientometrics and clinical trials on immunotherapy for gastric cancer(GC).Our study reviews recent advances in immunotherapy in the field of GC and highlights its new prospects as a treatment for *** research reveals China’s leadership in this field,as well as new therapeutic strategies such as immune checkpoint inhibitors,cellular immunotherapy,and *** combined findings highlight the potential of immunotherapy to improve survival and quality of life in patients with stomach *** believe that this study will provide important guidance for the future direction of the GC treatment field.

关键词： Gastric cancer Immunotherapy Bibliometrics Comment Therapeutic strategies

A Note on Gradient Estimates for Elliptic Equations with Discontinuous Coefficients

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 1-10页

作者： yu PENG Xiandong SUN Huichun ZHANG Department of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China.

The authors will use a method in metric geometry to show an L^(P)-estimate for gradient of the weak solutions to elliptic equations with discontinuous coefficients,even the BMO semi-norms of the coefficients are not *... 详细信息

关键词： L^(p)-Estimate Elliptic equation Discontinuous coefficients

A resonant high-pressure microsensor based on a composite pressure-sensitive mechanism of diaphragm bending and volume compression

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Microsystems & Nanoengineering 2024年第2期10卷 57-66页

作者： Pan Qian Zongze yu Jie yu yulan Lu Bo Xie Jian Chen Deyong Chen Junbo Wang The State Key Laboratory of Transducer Technology Aerospace Information Research InstituteChinese Academy of SciencesBeijing100190China The School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing100049China

In this paper,a composite pressure-sensitive mechanism combining diaphragm bending and volume compression was developed for resonant pressure microsensors to achieve high-pressure measurements with excellent *** composite mechanism was explained,and the sensor structure was designed based on theoretical analysis and finite element *** all-silicon resonant high-pressure microsensor with multiple miniaturized cavities and dual resonators was developed,where dual resonators positioned in two resonant cavities with suitably different widths are used to perform opposite characteristics in pressure and the same characteristics at different temperatures,which can improve pressure sensitivities and realize temperature self-compensation by differential frequency *** microsensor was fabricated by microfabrication,and the experimental results showed that the sensor had an accuracy of±0.015%full scale(FS)in a pressure range of 0.1~100 MPa and a temperature range of−10~50℃.The pressure sensitivity of the differential frequency was 261.10 Hz/MPa(~2523 ppm/MPa)at a temperature of 20℃,and the temperature sensitivities of the dual resonators were−1.54 Hz/℃(~−14.5 ppm/℃)and−1.57 Hz/℃(~−15.6 ppm/℃)at a pressure of 2 *** differential output had an outstanding stability within±0.02 Hz under constant temperature and ***,this research provides a convenient solution for high-pressure measurements because of its advantages,namely,large range,excellent accuracy and stability.

关键词： stability resonant bending