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Acta Mathematicae Applicatae Sinica 2015年第1期31卷 131-138页

作者： pan-yu WU Zeng-jing CHEN qilu Securities Institute for Financial Studies Shandong University School of Mathematics Shandong University

In this paper, we first study a property about the generator g of Backward Stochastic Differential Equation （BSDE） when the price of contingent claims can be represented by a multidimensional BSDE in the no-arbitrage financial market. Furthermore, motivated by the behavior of agents in finance market, we introduce a new total order q on Rn and obtain a necessary and sufficient condition for comparison theorem of multidimensional BSDEs under this order. We also give some further results for q

关键词： backward stochastic differential equation comparison theorem viability property

Pregnancy and fetal outcomes of chronic hepatitis C mothers with viremia in China

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World Journal of Gastroenterology 2022年第34期28卷 5023-5035页

作者： Calvin q pan Bao-Shen Zhu Jian-Ping Xu Jian-Xia Li Li-Juan Sun Hong-Xia Tian Xi-Hong Zhang Su-Wen Li Er-Hei Dai Center for Liver Diseases Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Division of Gastroenterology and Hepatology Department of MedicineNYU Langone HealthNYU School of MedicineFlushingNY 11355United States Department of Obstetrics and Gynecology The Fifth Hospital of ShijiazhuangHebei Medical UniversityShijiazhuang 050021Hebei ProvinceChina School of Public Health North China University of Science and TechnologyTangshan 063210Hebei ProvinceChina Division of Liver Disease Department of MedicineThe Fifth Hospital of ShijiazhuangHebei Medical UniversityShijiazhuang 050021Hebei ProvinceChina

BACkGROUND Data that assess maternal and infant outcomes in hepatitis C virus(HCV)-infected mothers are *** To investigate the frequency of complications and the associated risk *** We performed a cohort study to compare pregnancy and fetal outcomes of HCVviremic mothers with those of healthy *** factors were analyzed with logistic *** Among 112 consecutive HCV antibody-positive mothers screened,we enrolled 79 viremic *** randomly selected 115 healthy mothers from the birth registry as the *** to healthy mothers,HCV mothers had a significantly higher frequency of anemia[2.6%(3/115)vs 19.0%(15/79),Pquired caesarian section[27.8%(32/115)vs 48.1%(38/79),P=0.004],and nuchal cords[9.6%(11/115)vs 34.2%(27/79),Pkely to suffer anemia[adjusted odds ratio(OR):18.1,95%confidence interval(CI):4.3-76.6],require caesarian sections(adjusted OR:2.6,95%CI:1.4-4.9),and have nuchal cords(adjusted OR:5.6,95%CI:2.4-13.0).Their neonates were also more likely to have smaller head circumferences(adjusted OR:2.1,95%CI:1.1-4.3)and lower birth weights than the average(≤3250 gms)with an adjusted OR of 2.2(95%CI:1.2-4.0).The vertical transmission rate was 1%in HCV-infected *** Maternal HCV infections may associate with pregnancy and obstetric *** demonstrated a previously unreported association between maternal HCV viremia and a smaller neonatal head circumference,suggesting fetal growth restriction.

关键词： Hepatitis C virus viremia Mother-to-child transmission Pregnancy complications Maternal health Infant hepatitis C virus infection

A Two-point Method for Multiaxial Fatigue Life Prediction

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Acta Mechanica Solida Sinica 2022年第2期35卷 316-327页

作者： Jianhui Liu Xuemei pan Youtang Li Xiaochuang Chen School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050China Lanzhou Jinchuan Advanced Materials Technology Co. Ltd.Lanzhou 730101China

Fatigue fracture is one of the most common failure modes of engineering compo-nents,and the combined action of geometrie discontinuity and multiaxial loading is more likely to cause severe fatigue damage of *** work focuses on the fatigue behavior of U-notched q345 steel specimens with differen t notch sizes under proportional cyclic ***,based on the concept of strain energy,the calculation method of critical plane is given and the equivalent stress of the specified path on the critical plane is extracted to char-acterize the equivalent stress distribution state and the stress gradient ***,based on the high stress volume method and theory of critical distance,a simple method for determining the critical distance is given considering the contribution of stress at the dangerous point and the critical *** addition,based on the idea of stress-distance normalization,a new stress gradient impact factor is defined and a new method for predicting the multiaxial fatigue life of notched specimens is *** prediction results of the proposed model,the local stress-strain method and the point method of theory of critical distance are compared with the experimental *** comparisons show that the prediction results of the proposed model are closer to experimentai life,and the calculation accuracy is higher.

关键词： Multiaxial fatigue Stress gradient Life prediction Critical distance method Local stress-strain method

Nondestructive Testing and Characterization of Residual Stress Field Using an Ultrasonic Method

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 365-371页

作者： SONG Wentao XU Chunguang pan qinxue SONG Jianfeng School of Mechanical Engineering Beijing Institute of Technology School of Mechanical Engineering Shijiazhuang Tiedao University

To address the difficulty in testing and calibrating the stress gradient in the depth direction of mechanical components, a new technology of nondestructive testing and characterization of the residual stress gradient field by ultrasonic method is proposed based on acoustoelasticity theory. By carrying out theoretical analysis, the sensitivity coefficients of different types of ultrasonic are obtained by taking the low carbon steel（12%C） as a research object. By fixing the interval distance between sending and receiving transducers, the mathematical expressions of the change of stress and the variation of time are established. To design one sending-one receiving and oblique incidence ultrasonic detection probes, according to Snell law, the critically refracted longitudinal wave（LCR wave） is excited at a certain depth of the fixed distance of the tested components. Then, the relationship between the depth of LCR wave detection and the center frequency of the probe in q235 steel is obtained through experimental study. To detect the stress gradient in the depth direction, a stress gradient LCR wave detection model is established, through which the stress gradient formula is derived by the relationship between center frequency and detecting depth. A C-shaped stress specimen of q235 steel is designed to conduct stress loading tests, and the stress is measured with the five group probes at different center frequencies. The accuracy of ultrasonic testing is verified by X-ray stress analyzer. The stress value of each specific depth is calculated using the stress gradient formula. Accordingly, the ultrasonic characterization of residual stress field is realized. Characterization results show that the stress gradient distribution is consistent with the simulation in ANSYS. The new technology can be widely applied in the detection of the residual stress gradient field caused by mechanical processing, such as welding and shot peening.

关键词： ultrasonic nondestructive testing acoustoelasticity theory residual stress field stress gradient ultrasonic characterization

TWO WEIGHT CHARACTERIZATIONS FOR THE MULTILINEAR LOCAL MAXIMAL OPERATORS

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Acta Mathematica Scientia 2021年第2期41卷 596-608页

作者： Yali pan qingying XUE College of Mathematics and Computer Science Zhejiang Normal UniversityJinhua 321004China Department of Mathematics School of InformationHuaibei Normal UniversityHuaibei 235000China School of Mathematical Sciences Beijing Normal UniversityLaboratory of Mathematics and Complex SystemsMinistry of EducationBeijing 100875China

Let 0<β<1 andΩbe a proper open and non-empty subset of R^(n).In this paper,the object of our investigation is the multilinear local maximal operator Mβ,defined by M_(β)((f))(x)=sup_(q(∈)xq∈Fβ)Π_(i=1)^m1/|q|∫_... 详细信息

Let 0q(∈)xq∈Fβ)Π_(i=1)^m1/|q|∫_(q)|f_(i)(y_(i))|dy_(i),where F_(β)={q(x,l):x∈Ω,lq=q(x,l)is denoted as a cube with sides parallel to the axes,and x and l denote its center and half its side ***-weight characterizations for the multilinear local maximal operator M_(β)are obtained.A formulation of the Carleson embedding theorem in the multilinear setting is proved.

关键词： Multilinear local maximal operators A_((p,q))^(β)weights two-weight inequalities

Topsoil organic carbon mineralization and CO_2 evolution of three paddy soils from South China and the temperature dependence

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Journal of Environmental Sciences 2007年第3期19卷 319-326页

作者： ZHANG Xu-hui LI Lian-qing pan Gen-xing Institute of Resources Ecosystem and Environment of Agriculture Nanjing Agricultural University Nanjing 210095 China.

Carbon mineralization and its response to climatic warming have been receiving global attention for the last decade. Although the virtual influence of temperature effect is still in great debate, little is known on the mineralization of organic carbon （SOC） of paddy soils of China under warming. SOC mineralization of three major types of China＇s paddy soils is studied through laboratory incubation for 114 d under soil moisture regime of 70% water holding capacity at 20℃ and 25℃ respectively. The carbon that mineralized as CO2 evolved was measured every day in the first 32 d and every two days in the following days. Carbon mineralized during the 114 d incubation ranged from 3.51 to 9.22 mg CO2-C/gC at 20℃ and from 4.24 to 11.35 mg CO2-C/gC at 25℃ respectively; and a mineralizable C pool in the range of 0.24 to 0.59 gC/kg, varying with different soils. The whole course of C mineralization in the 114 d incubation could be divided into three stages of varying rates, representing the three subpools of the total mineralizable C： very actively mineralized C at 1-23 d, actively tnineralized C at 24--74 d and a slowly mineralized pool with low and more or less stabilized C mineralization rate at 75-114 d. The calculated q10 values ranged from 1.0 to 2.4, varying with the soil types and N status. Neither the total SOC pool nor the labile C pool could account for the total mineralization potential of the soils studied, despite a well correlation of labile C with the shortly and actively mineralized C, which were shown in sensitive response to soil warming. However, the portion of microbial C pool and the soil C/N ratio controlled the C mineralization and the temperature dependence. Therefore, C sequestration may not result in an increase of C mineralization proportionally. The relative control of C bioavailability and microbial metabolic activity on C mineralization with respect to stabilization of sequestered C in the paddy soils of China is to be further studied.

关键词： C mineralization carbon pool laboratory incubation paddy soil soil warming

Deep Reinforcement Learning-Based URLLC-Aware Task Offloading in Collaborative Vehicular Networks

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China Communications 2021年第7期18卷 134-146页

作者： Chao pan Zhao Wang Zhenyu Zhou Xincheng Ren Hebei key Laboratory of Power Internet of Things Technology North China Electric Power UniversityBeijing102206Baoding071003HebeiChina Shaanxi key Laboratory of Intelligent Processing for Big Energy Data Yanan UniversityYanan 716000China

Collaborative vehicular networks is a key enabler to meet the stringent ultra-reliable and lowlatency communications(URLLC)requirements.A user vehicle(UV)dynamically optimizes task offloading by exploiting its collaborations with edge servers and vehicular fog servers(VFSs).However,the optimization of task offloading in highly dynamic collaborative vehicular networks faces several challenges such as URLLC guaranteeing,incomplete information,and dimensionality *** this paper,we first characterize URLLC in terms of queuing delay bound violation and high-order statistics of excess ***,a Deep Reinforcement lEarning-based URLLCAware task offloading algorithM named DREAM is proposed to maximize the throughput of the UVs while satisfying the URLLC constraints in a besteffort *** with existing task offloading algorithms,DREAM achieves superior performance in throughput,queuing delay,and URLLC.

关键词： collaborative vehicular networks task of-floading URLLC awareness deep q-learning

Toughening additive manufactured Zr-based bulk metallic glass composites by martensite phase transformation

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Journal of Materials Science & Technology 2024年第3期170卷 95-102页

作者： Pengcheng Zhang Cheng Zhang Jie pan Di Ouyang Lin Liu State key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Additive manufacturing technology based on laser powder bed fusion(LPBF)offers a novel approach for fabricating bulk metallic glass(BMG)products without restriction in size and ***,the BMGs prepared by LPBF usually suffered from less plasticity and poorer fracture toughness as compared to their cast counterparts due to partial crystallization in heat-affected zones(HAZs).Since crystallization in HAZs is hard to avoid completely in LPBF BMGs,it is desirable to design a suitable alloy system,in which only ductile crystalline phase,instead of brittle intermetallics,is formed in *** unique structure could effectively increase the toughness/plasticity of the LPBF *** achieve this goal,a quaternary BMG system with a composition of Zr_(47.5)Cu_(45.5)Al_(5)Co_(2)is adopted and subjected to *** is found that nearly a single phase of B_(2)-ZrCu is precipitated in HAZs,while a fully amorphous phase is formed in molten pools(MPs).This B_(2)phase reinforced BMG composite exhibits excellent mechanical properties with enhanced plasticity and ***,it is easy to modulate the mechanical properties by altering the amount of the B_(2)phase via adjusting the laser energy ***,the best combination of strength,plasticity,and notch toughness is obtained in the BMG composite containing 27.4%B_(2)phase and 72.6%amorphous phase,which exhibits yield strength(σ_(s))of 1423 MPa,plastic strain(ε_(p))of 4.65%,and notch toughness(k_(q))of 53.9 MPa m 1/***,a notable strain-hardening is also *** improvement of plasticity/toughness and appearance of strain-hardening behavior are mainly due to the martensite phase transformation from the B_(2)phase to the Cm phase during plastic deformation(i.e.,the phase transformation-induced plasticity effect).The current work provides a guide for making advanced BMGs and BMG composites by additive manufacturing.

关键词： Laser powder bed fusion Bulk metallic glass composites Phase transformation-induced plasticity Deformation mechanism

Prophylactic effect of kudingcha polyphenols on oxazolone induced colitis through its antioxidant capacities

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Food Science and Human Wellness 2018年第3期7卷 209-214页

作者： Xingyao Long Yanni pan Xin Zhao Chongqing Collaborative Innovation Center for Functional Food Chongqing University of EducationChongqing 400067PR China College of Food Science Southwest UniversityChongqing 400715PR China School of Biological and Chemical Engineering Chongqing University of EducationChongqing 400067PR China

This research the preventive effect of kudingcha polyphenols(kp)on colitis based on animal *** mice divided into four groups,including normal group,model group,low-concentration kp(LkP)group and high-concentration kp(HkP)group,and they all smeared and given 0.15 mL 1%oxazolone solution by lavage to induce BALB/c mice ***,colon weight/length ratio,serum levels of cytokines,related antioxidant activities of colon tissues such,and the mRNA *** experimental results show that kP can significantly(pqPCR assay show that kp can significantly increase(pkit,SCF and decrease the expression of IL-8,CXCR2 in mice colon tissues with *** has a good preventive effect on colitis,and high concentration of PT has better preventive effect.

关键词： kudingcha polyphenols Oxazolone Antioxidant Colitis mRNA expression