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Acta Mathematica Sinica,English Series 2017年第8期33卷 1083-1106页

作者： jiao chen School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

The main purpose of this paper is to establish the HSrmander-Mihlin type theorem for Fourier multipliers with optimal smoothness on k-parameter Hardy Spaces for k≥ 3 using the multi- parameter Littlewood-Paley theory. For the sake of convenience and simplicity, we only consider the case k 3, and the method works for all the cases k ≥ 3： Tmf（x1,x2,x3） =1/（（2π）＋n1＋n2＋n3） ∫ R n1×R n2×R n3 m（ξ）f（ξ）e 2π ix.ξ dξ. where x = （x1,x2,x3） ∈ Rn1 × Rn2 × R n3 and ξ = （ξ1,ξ2,ξ3） ∈ R n1 × Rn2 ×R n3. One of our main results is the following： Assume that m（ξ） is a function on Rn1＋n2＋n3 satisfying sup j,k,l ∈Z ｜｜mj,k,l｜｜ W（s1,s2,s3）〈∞ with si 〉 ni（1/p-1/2） for 1 ≤ i ≤ 3. Then Tm is bounded from HP（R n1 × R n2 ×R n3） to HP（R n1 ×R n2 × R n3） for all 0 〈 p ≤ 1 and ｜｜Tm｜｜ Hp→Hp≤ sup j,k,l∈Z ｜｜mj,k,l｜｜ W（s1,s2,s3） Moreover, the smoothness assumption on sl for 1 ≤ i ≤ 3 is optimal. Here we have used the notations mj,k,l （ξ）= m（2 j ξ1,2 k ξ2, 2 l ξ3） ψ（ξ1） ψ（ξ2） ψ（ξ3） and ψ（ξi） is a suitable cut-off function on R ni for 1 ≤ i ≤ 3, and W（s1,s2,s3） is a three-parameter Sobolev space on R n × R n2 × Rn 3. Because the Fefferman criterion breaks down in three parameters or more, we consider the Lp boundedness of the Littlewood-Paley square function of T mf to establish its boundedness on the multi-parameter Hardy spaces.

关键词： Hormander multiplier minimal smoothness condition Littlewood-Paley's inequality,multi-parameter Hardy Hp spaces multi-parameter Sobolev spaces

Hormander Type Multipliers on Anisotropic Hardy Spaces

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Acta Mathematica Sinica,English Series 2019年第11期35卷 1841-1853页

作者： jiao chen Liang HUANG School of Mathematical Sciences Chongqing Normal UniversityChongqing 401131P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

The main purpose of this paper is to establish, using the Littlewood–Paley–Stein theory(in particular, the Littlewood–Paley–Stein square functions), a Calderón–Torchinsky type theorem for the following Fourier multipliers on anisotropic Hardy spaces Hp(Rn;A) associated with expensive dilation A:■Our main Theorem is the following: Assume that m(ξ) is a function on Rn satisfying ■with s > ζ--1(1/p-1/2). Then Tm is bounded from Hp(Rn;A) to Hp(Rn;A) for all 0 < p ≤ 1 and ■where A* denotes the transpose of A. Here we have used the notations mj(ξ) = m(A*jξ)φ(ξ) and φ(ξ) is a suitable cut-off function on Rn, and Ws(A*) is an anisotropic Sobolev space associated with expansive dilation A* on Rn.

关键词： Hormander multiplier Littlewood-Paley’s inequality anisotropic Hardy space anisotropic Sobolev spaces

The construction of shale rock physics model and brittleness prediction for high-porosity shale gas-bearing reservoir

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Petroleum Science 2020年第3期17卷 658-670页

作者： Xin-Peng Pan Guang-Zhi Zhang jiao-jiao chen School of Geoscience and Info-Physics Central South UniversityChangsha 410082HunanChina School of Geoscience China University of Petroleum(East China)Qingdao 266580ShandongChina

Due to the huge differences between the unconventional shale and conventional sand reservoirs in many aspects such as the types and the characteristics of minerals,matrix pores and fluids,the construction of shale rock physics model is significant for the exploration and development of shale *** make a better characterization of shale gas-bearing reservoirs,we first propose a new but more suitable rock physics model to characterize the *** then use a well A to demonstrate the feasibility and reliability of the proposed rock physics model of shale gas-bearing ***,we propose a new brittleness indicator for the high-porosity and organic-rich shale gas-bearing *** on the parameter analysis using the constructed rock physics model,we finally compare the new brittleness indicator with the commonly used Young’s modulus in the content of quartz and organic matter,the matrix porosity,and the types of filled *** also propose a new shale brittleness index by integrating the proposed new brittleness indicator and the Poisson’s *** on real data sets demonstrate that the new brittleness indicator and index are more sensitive than the commonly used Young’s modulus and brittleness index for the high-porosity and high-brittleness shale gas-bearing reservoirs.

关键词： Shale gas Rock physics model Brittleness prediction

The effects of Ca and Mn on the microstructure,texture and mechanical properties of Mg-4 Zn alloy

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Journal of Magnesium and Alloys 2021年第3期9卷 1084-1097页

作者： Chunquan Liu Xianhua chen jiao chen Andrej Atrens Fusheng Pan International Joint Laboratory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400045China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScihencesShenyang 110016China School of Mechanical and Mining Engineering The University of QueenslandSt Lucia Qld 4072Australia

The microstructural evolution,texture and mechanical properties of nine Mg-4Zn-xCa-yMn alloys(x=0.3,0.6,1.0;y=0.2,0.3,0.7 wt.%)were investigated *** with Ca and Mn refined the grains of the extruded sheets and increased the unDRX *** could be the heterogeneous nucleation site of Ca2Mg6Zn3 phase because of a good atom matching at the orientation relationship of(211)_(Mn)//(1211)_(Ca2Mg6Zn3),(251)_(Mn)//〈1103〉_(Ca2Mg6Zn3).The traditional texture weakening effect of Ca was strongly decreased for the simultaneously addition of *** increasing Ca and Mn concentration,the strength increased and ductility ***-4Zn-0.6Ca-0.7Mn exhibited a good combination of ultimate tensile strength(320 MPa),yield strength(286 MPa)and elongation(16%).A model of strengthening indicated that grain boundary strengthening and precipitate strengthening made a large contribution to the strength of *** addition,the dynamic recrystallization,texture modification and the strengthening effect from different parts also have been analyzed in detail.

关键词： Mg-Zn-Ca-Mn alloy Texture Dynamic recrystallization Particle-stimulated nucleation Mechanical properties

Secular Changes of Stature in Rural Children and Adolescents in China, 1985-2010

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Biomedical and Environmental Sciences 2014年第8期27卷 573-581页

作者： chen Tian jiao JI cheng Ye Institute of Child and Adolescent Health School of Public Health Peking University Health Science Center

Objective To analyze and assess secular change in stature in rural children and adolescents in China from 1985 to 2010. Methods Data were obtained from the 6 rounds of the Chinese National Survey on Student＇s Constitution and Health. The subjects enrolled in the study were children and adolescents aged 7-18 years in rural areas of provincial capitals. Results An overall positive secular trend in stature occurred in rural areas of provincial capitals in China from 1985 to 2010. The overall average increase rates were 3.1 and 2.4 cm/decade for boys and girls, respectively. The total body height increases for grown up boys and girls were 3.6 and 2.3 cm and the increase rates were 1.4 and 0.9 cm/decade, respectively. There were differences in body height increase among eastern, central and western regions. The average body height of the children or adolescents in eastern region was highest, followed by central region and western region. The overall increase rates in central region were highest among the three regions. The difference between eastern/central region and western region was obvious. 〈br〉 Conclusion Positive secular trend in stature of children or adolescents has occurred in rural area of China, and rural boys and girls showed a great potential for continuous growth. More attention should be paid to the differences in children＇s body height between western region and eastern/central region.

关键词： Secular change Stature Rural population Regional difference Child and adolescent

Secular Change in Stature of Urban Chinese Children and Adolescents, 1985-2010

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Biomedical and Environmental Sciences 2013年第1期26卷 13-22页

作者： chen Tian jiao JI cheng Ye Institute of Child and Adolescent Health School of Public HealthPeking University Health Science Center

Objective Research evidence shows a secular trend in Chinese physical growth in recent *** aim of this study was to analyze and assess changes in stature of children and adolescents during the 25 years from 1985‐2010,using national *** Data came from successive cycles of the Chinese National Survey on Students＇ Constitution and Health（CNSSCH）.Subjects were 7‐ to 18‐year‐old children and *** An overall positive secular trend occurred in urban China during 1985‐*** overall average rates of increment were 2.4 and 1.7 cm/decade for boys and girls,*** increases in adult stature for boys and girls were 2.6 and 1.7 cm,yielding rates of 1.0 and 0.7 cm/decade,*** with different socioeconomic levels had different characteristic *** stature increases in big cities were larger than those in moderate and small cities,and boys and girls in moderate and small cities showed greater potential for growth in *** An overall positive secular growth trend was associated with socioeconomic progress and differed with area socioeconomic *** policies and strategies should be developed based on increased stature,and should continue narrowing the inequity between different socioeconomic populations.

关键词： Secular change Stature Growth Socioeconomic disparity Children and adolescents

A Reverse Auction Framework for Hybrid Access in Femtocell Network

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Journal of Computer Science & Technology 2017年第6期32卷 1250-1264页

作者： Yan-jiao chen Xiao-Yan Yin Jin Zhang State Key Laboratory of Software Engineering School of Computer Wuhan University Wuhan 430072 China School of Information Science and Technology Northwest University Xi'an 710127 China Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen 518055 China

In the two-tier macro-femto heterogeneous network, hybrid access is regarded as the most ideal access con- trol approach to mitigating macro-femto cross-tier interference and enhancing overall network performance. However, the implementation of hybrid access is hindered by a lack of incentive market mechanism to motivate private femtocell owners to offer access permissions to macro users. In this paper, we propose a reverse auction framework for access permission transaction between a macrocell operator and multiple femtocell owners to promote hybrid access. Our goal is to maximize social welfare while guaranteeing the truthfulness of the auction. Since the coverage of multiple femtocells may overlap, we partition each cell to adjust the granularity of access permission availability. We first propose a Vickery-Clarke-Grove （VCG）-based mechanism, which costs the least among all auction mechanisms that produce maximum social welfare. As the VCG mechanism is too time-consuming, we propose two alternative truthful mechanisms, namely, generalized second- price and suboptimal mechanism. We further extend the auction framework to the scenario where femtocell owners have heterogeneous valuations for access permissions in different locations.

关键词： femtocell hybrid access reverse auction

A nanostructured Ni/T-Nb_(2)O_(5)@carbon nanofibers as a long-life anode material for lithium-ion batteries

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Rare Metals 2021年第2期40卷 374-382页

作者： Si-Ru He Jian-Peng Zou Li-Bao chen Yue-jiao chen State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

In this work,nickel/T-Nb_(2)O_(5)nanoparticles encapsulated in mesoporous carbon nanofibers(denoted as Ni/T-Nb_(2)O_(5)@CNFs)are successfully prepared through a simple electrospinning route and succedent heating *** presence of Ni in carbon nanofibers is beneficial for enhancing the electronic conductivity and the initial Coulombic ***/T-Nb_(2)O_(5)nanoparticles are homogeneously incorporated in carbon nanofibers to form a nanocomposite system,which provides effective buffering during the lithiation/delithiation process for cycling *** Ni/TNb_(2)O_(5)@CNFs show high surface area(26.321 m^(2)·g^(-1))and mesoporous microstructure,resulting in higher capacity and excellent rate *** Ni/T-Nb_(2)O_(5)@CNFs exhibit a remarkable capacity of 437 mAh·g^(-1)at a current density of0.5 A·g^(-1)after 230 cycles and a capacity of 173 mAh·g^(-1)at a current density up to 10.0 A·g^(-1)after 1400 *** work indicates that nickel/T-Nb_(2)O_(5)nanoparticles encapsulated in carbon nanofibers can be a promising candidate for anode material in high-power LIBs.

关键词： Electrospinning Nickel T-Nb_(2)O_(5) Nanofiber anode Lithium-ion batteries

Nonfunctional bladder paraganglioma misdiagnosed as hemangioma:A case report

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World Journal of Clinical Cases 2022年第15期10卷 4929-4934页

作者： jiao chen Han-Feng Yang Department of Obstetrics and Gynecology Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina Department of Radiology Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina

BACKGROUND Paraganglioma of the urinary bladder(PUB)is a nonepithelial tumor of the bladder that is also known as bladder *** incidence of nonfunctional paraganglioma of the urinary bladder is rare in clinical *** SUMMARY A case of nonfunctional paraganglioma of the urinary bladder diagnosed and treated in our hospital is reported herein.A 2.5 cm×2.1 cm moderate-echo mass protruding into the right anterior wall of the bladder was incidentally found during transvaginal color Doppler ultrasound *** on a contrastenhanced computed tomography scan of the bladder,the right anterior wall of the bladder was considered to present a *** patient underwent laparoscopic partial resection of the bladder wall in our hospital,and pathological results showed paraganglioma of the *** present,we have followed up with the patient for half a year,and there has been no recurrence of the *** The imaging patterns of PUB and bladder hemangioma are *** clinical practice,the possibility of PUB should be considered for a single wide-based isoechoic mass in the bladder,especially functional PUB may cause some adverse effects during surgery.

关键词： Bladder tumor Paraganglioma Diagnosis and treatment methods Case report

Ga-based liquid metal as an extreme pressure lubricant for steel-ceramic pairs

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Science China(Technological Sciences) 2022年第5期65卷 1107-1115页

作者： YANG DongSheng chen WenYuan chen jiao SUN QiChun TAN Hui chenG Jun State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China

Extreme pressure lubrication is a crucial engineering problem for many mechanical ***,an extraordinary and novel functional material,Ga-based liquid metal(GLM),is found to be a promising extreme pressure lubricant for steel-ceramic sliding pairs and bears applied load above 1500 N.A Ga-rich metallic tribofilm forms on the frictional interface during sliding,providing good lubricity and bearing *** addition,the lubrication performance of GLM strongly depends on its composition and the contacting *** Ga-In-Sn alloy has superior lubrication to binary Ga-In *** lubrication is more effective on the interfaces of AISI52100/Si_(3)N_(4)than on those of AISI52100/SiC sliding pairs.

关键词： liquid metal sliding wear tribochemistry boundary lubrication