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The boundedness for commutators of maximal hypersingular integrals with rough kernels

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Science China Mathematics 2013年第4期56卷 707-728页

作者： CHEN YanPing DING Yong li ran Department of Applied Mathematics University of Science and Technology Beijing School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems(BNU) Ministry of Education

In this paper,we prove that the commutators of maximal hypersingular integrals with rough kernels are bounded from the Sobolev space Lpγ(Rn) to the Lebesgue space Lp(Rn),which is a substantial improvement and an exte... 详细信息

关键词： commutator maximal hypersingular integrals rough kernel BMO sobolev space

Biocompatible Zr-Al-Fe bulk metallic glasses with large plasticity

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Science China(Physics,Mechanics & Astronomy) 2012年第9期55卷 1664-1669页

作者： HUA NengBin li ran WANG JianFeng ZHANG Tao Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beihang University Beijing 100191 China Department of Materials Science and Engineering Fujian University of Technology Fuzhou 350108 China

In the present study,high-zirconium ternary Zr-Al-Fe bulk metallic glasses(BMGs) with low Young's modulus and good plasticity were ***75 Al7.5 Fe17.5 BMG exhibits a low Young's modulus of 70 GPa and high Poisson's ratio of *** plasticity was demonstrated under both compression and bending conditions for the ***,the alloys show high corrosion resistance in phosphate buffered *** combination of desirable mechanical and chemical properties implies potential for biomedical applications.

关键词： bulk metallic glass mechanical properties elastic modulus corrosion behavior biomedical application

Analysis of the wide area differential correction for BeiDou global satellite navigation system

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Research in Astronomy and Astrophysics 2018年第11期18卷 17-28页

作者： ran li Yue-ling Cao Xiao-Gong Hu Cheng-Pan Tang Shan-Shi Zhou Xin Meng li liu ran-ran Su Zhi-Qiao Chang Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Shanghai Key Laboratory of Space Navigation and Position Techniques Shanghai 200030China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China Beijing Global Information Application and Development Center Beijing 100094China

The regional BeiDou Satellite System, or BDS2, broadcasts a differential correction as Equivalent Satellite Clock Correction to correct both orbit and satellite clock errors. For the global BDS, or BDS3, satellite orbit and clock corrections conforming with RTCA standards will be broadcast to authorized users. The hybrid constellation and regional monitoring network pose challenges for the high precision separation of orbit and satellite clock corrections. Three correction models of kinematic,dynamic and Two-way Satellite Time Frequency Transfer(TWSTFT)-based dynamic were studied to estimate the satellite orbit and clock corrections. The correction accuracy of the three models is compared and analyzed based on the BDS observation data. Results show that the accuracies(root mean square, RMS) of dual-frequency real-time positioning for the three models are about 1.76 m, 1.78 m and 2.08 m respectively, which are comparable with the performance of WAAS and EGNOS. With dynamic corrections, the precision of Precise Point Positioning(PPP) experiments may reach about 23 cm after convergence.

关键词： celestial mechanics methods: data analysis space vehicles

Growth rate,catalase and superoxide dismutase activities in rock carp(Procypris rabaudi Tchang) exposed to supersaturated total dissolved gas

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第11期12卷 909-914页

作者： Xiao-qing liU Ke-feng li Jun DU Jia li ran li State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China Fisheries Institute Sichuan Academy of Agricultural Sciences Chengdu 611731 China

Total dissolved gas supersaturation(TDGS) appears when the pressures of gases in a solution exceed the barometric *** is often caused by flood discharge at *** may lead to gas bubble disease(GBD) for fish and biochemical responses of selected fish and other aquatic *** purpose of this study was to determine the impact of long-term TDGS levels on the growth and biochemical responses of rock carp(Procypris rabaudi Tchang) dwelling in the upper reaches of the Yangtze ***-year-old rock carp were exposed to TDGS levels at 100%,104%,108%,112%,and 116% for 42 *** were taken every 7 d after the start of the trial in order to determine catalase(CAT) and superoxide dismutase(SOD) activities in gill and muscle *** were taken at Days 0 and 42 of exposure to determine growth *** effect was found on growth rate in all treatment *** and CAT activities varied in different tissues,according to time of exposure and TDGS *** biochemical response of fish exposed to TDGS was more obvious in gill tissue than in muscle *** of SOD and CAT activities in different tissues offer important information about the effect of TDGS on the rare fish in the Yangtze River,and may help evaluate the risk to the aquatic eco-environment and aquatic ecosystem in the downstream of the Yangtze River.

关键词： Total dissolved gas supersaturation (TDGS) Rock carp (Procypris rabaudi Tchang) Growth rate Catalase Superoxide dismutase

A New Route to the Interpretation of Hopf Invariant

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Communications in Theoretical Physics 2008年第7期50卷 53-58页

作者： REN Ji-Rong li ran DUAN Yi-Shi Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

We discuss an object from algebraic topology,Hopf invariant,and reinterpret it in terms of the φ-mappingtopological current *** main purpose of this paper is to present a new theoretical framework,which can directlygive the relationship between Hopf invariant and the linking numbers of the higher dimensional submanifolds of Euclideanspace R^(2n-1).For the sake of this purpose we introduce a topological tensor current,which can naturally deduce the(n-1)-dimensional topological defect in R^(2n-1) *** these (n-1)-dimensional topological defects are closed orientedsubmanifolds of R^(2n-1),they are just the (n-1)-dimensional *** linking number of these knots is well *** the inner structure of the topological tensor current,the relationship between Hopf invariant and the linkingnumbers of the higher-dimensional knots can be constructed.

关键词： Hopf invariant higher-dimensional knot linking number

Vortex lines and Monopoles in Electrically Conducting Plasmas

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Communications in Theoretical Physics 2009年第2期51卷 335-340页

作者： WANG Ji-Biao REN Ji-Rong li ran Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

Based on the φ-mapping topological current theory and the decomposition of gauge potential theory, the vortex lines and the monopoles in electrically conducting plasmas are studied. It is pointed out that these two topological structures respectively inhere in two-dimensional and three-dimensional topological currents, which can be derived from the same topological term n^→·（Эin^→×Эjn^→）, and both these topological structures axe characterized by the φ-mapping topological numbers-Hopf indices and Brouwer degrees. Furthermore, the spatial bifurcation of vortex lines and the generation and annihilation of monopoles are also discussed. At last, we point out that the Hopf invaxiant is a proper topological invaxiant to describe the knotted solitons.

关键词： plasma vortex line monopole

Breeding ecology of ground tits in northeastern Tibetan plateau, with special reference to cooperative breeding system

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Current Zoology 2011年第6期57卷 751-757页

作者： Xin LU ran HUO Yang li Wenbo liAO Chen WANG Department of Zoology College of Life Sciences Wuhan University Wuhan 430072 China

Data on breeding ecology of a color-band marked population of the ground tit Parus humilis were collected in north Qinghai on the Tibetan plateau, during 2008 and 2009. In spring the birds excavated 0.8-3.2 m long nesting burrows under the ground. First-egg laying occurred between late April and late June during which a pair produced one brood. Incubation was done by female alone for 15-16 days and nestling-feeding by both sexes and helpers in any for 23-25 days. Average brood size at fledging was 5.8 （＋ 1.4 SD, 3-8） and all the 27 observed nesting attempts fledged at least one young. At the population level, brood sex ratio did not differ from 1：1. The birds are a territory-living resident, with annual resight rates being 48% （22 of 46） in adult breeders and 10% （7 of 67） in yearlings. Pairs were socially monogamous, of which 23% （9 of 40） contained one and some- times two male helpers, most likely being philopatric sons of the breeders. The formation of cooperative groups is similar to the population in central Tibet but differs from that in south Guansu where breeding ground tits exhibit a high level of annual turnover

关键词： Burrow-nesting Cooperative breeding life history Parus humilis Tibetan plateau

Two-phase smooth particle hydrodynamics modeling of air-water interface in aerated flows

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Science China(Technological Sciences) 2017年第3期60卷 479-490页

作者： YANG HuiXia li ran liN PengZhi WAN Hang FENG JingJie College of Civil Engineering Guizhou University State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

Abstracted/indexed in：Science Citation Index,Science Citation Index Expanded（SciSearch）,Journal Citation Reports/Science Edition,SCOPUS,INSPEC,Zentralblatt Math,Chemical Abstracts Service（CAS）,Google Scholar,CSA,Academic OneFile,Current Contents/Engineering,Computing and Technology,Earthquake Engineering Abstracts,EI-Compendex,Gale,OCLC,SCImago,Summon by ProQuest Supervised by Chinese Academy of Sciences

关键词： aerated flow dam break density difference hydraulic jump interface smoothed particle hydrodynamics

Characterization of carboxylesterase PxαE8 and its role in multi-insecticide resistance in Plutella xylostella(L.)

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Journal of Integrative Agriculture 2022年第6期21卷 1713-1721页

作者： li ran SUN Xi liANG Pei GAO Xi-wu Department of Entomology China Agricultural UniversityBeijing 100193P.R.China

Carboxylesterase(CarE)was considered as important phase-I detoxifying enzymes which participated in detoxification of different types of ***-regulation of CarE genes has been proved playing a major role in insecticide resistance in many pest insects,but its involvement in resistance to insecticides in Plutella xylostella has been rarely *** this study,a CarE cDNA named PxαE8 was identified in ***,which has an open reading frame of 1599 nucleotides and putatively encodes 532 amino *** investigation of spatial expression profiles of PxαE8 revealed that it was expressed in all developmental stages,especially in larvae and *** body part/tissue-specific expression profiles showed that the PxαE8 mainly expressed in fat body,malpighian tubule and hemolymph of ***,the relative expression of PxαE8 in two multi-resistant field populations,Hainan(HN)and Guangdong(GD)populations,was found 24.4-and 15.5-fold higher than that in susceptible population,*** of PxαE8 by RNA interference dramatically increased the mortalities of larvae of HN population treated with LC_(50) of beta-cypermethrin and phoxim by 25.3 and 18.3%,*** results suggested that up-regulation of PxαE8 was involved in resistance to both beta-cypermethrin and phoxim in ***,which shed light on further understanding of molecular mechanisms of multi-insecticide-resistance in *** and other pest insects.

关键词： Plutella xylostella carboxylesterase insecticide resistance beta-cypermethrin phoxim