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A new Early Cretaceous lizard with well-preserved scale impressions from western Liaoning, china

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Progress in Natural Science:Materials International 2005年第2期15卷 67-73页

作者： JI Shu’an*(school of Earth and Space sciences, Peking university, Beijing 100871, china) school of Earth and Space sciences Peking University Beijing 100871 China

A new small lizard, Liaoningolacerta brevirostra gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning is described in detail. The new specimen was preserved not only by the skeleton, but also by the exceptionally clear scale impressions. This lizard can be included within the taxon Scleroglossa based on its 26 or more presacrals, cruciform interclavicle with a large anterior process, moderately elongated pubis, and slightly notched distal end of tibia. The scales vary evidently in size and shape at different parts of body: small and rhomboid ventral scales, tiny and round limb scales, and large and longitudinally rectangular caudal scales that constitute the caudal whorls. This new finding provides us with more information on the lepidosis of the Mesozoic lizards.

关键词： new genus Squamata skeleton lepidosis Early Cretaceous western Liaoning

On Riemann-Finsler geometry

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Chinese Science Bulletin 1998年第6期43卷 447-450页

作者： MO Xiaohuan school of Mathematical sciences, Peking university, Beijing 100871, china school of Mathematical sciences Peking University Beijing China

The history of Finsler geometry is reviewed and briefly recent development in Finsler geometry and its application is completed systematically. Furthermore, an interesting open problem has been proposed in this field.

关键词： Finsler space Chern connection Hilbert form Minkowski potential projective sphere bundle.

Virus rejection with two model human enteric viruses in membrane bioreactor system

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Science china Chemistry 2007年第3期50卷 397-404页

作者： ZHENG Xiang1,2 & LIU JunXin1 1 Research Center for Eco-Environmental sciences, Chinese Academy of sciences, Beijing 100085, china 2.school of Environment & Natural Resources, Renmin university of china, Beijing 100872, china 1. Research Center for Eco-Environmental sciences Chinese Academy of Sciences Beijing 100085 China 2. school of Environment & Natural Resources Renmin University of China Beijing 100872 China

A membrane bioreactor (MBR) with gravity drain was tested for virus rejection with two coliphages, T4 and f2, which were used as surrogates for human enteric viruses. Virus rejection was investigated by PVDF and PP membrane modules, with the pore sizes of 0.22 and 0.1 μm, respectively. In tap water system, 2.1 lg rejection of coliphage T4 could be achieved by PVDF membrane compared with complete rejection by PP membrane, while for coliphage f2 with smaller diameter, 0.3―0.5 lg rejection of the influent virus was removed by the two membranes. In domestic wastewater system, cake layer and gel layer on the membrane surface changed the cut-off size of the membrane so that there was no significant difference between PP and PVDF for each coliphage. The removal ratios of coliphage T4 and f2 in the MBR were more than 5.5 and 3.0 lg, respectively. Compared with 5.5 lg removal for virus T4 in the MBR system, only 2.1 lg (96.8%―99.9%) removal rate was observed in the conventional activated sludge system with the influent virus concentration fluctuating from 1830 to 57000 PFU/mL. Only 0.8%―22% virus removal was the effect of adsorption to activated sludge, which showed a decreasing tendency with the retention time, while 75%―98% was the effect of virus inactivation by microbial activity. It indicated that the major mechanism of virus removal was not the transfer of viruses from the water phase to the sludge phase but inactivation in the biological treatment process.

关键词： MBR model virus enteric virus inactivation

The evolution and morphological stability of a spherical crystal

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Science china(Technological sciences) 2008年第3期51卷 225-243页

作者： CHEN MingWen1,2, WANG ZiDong2 & XU JianJun3,4 1 school of Applied sciences, university of Science and Technology Beijing, Beijing 100083, china 2.school of Materials Science and Engineering, university of Science and Technology Beijing, Beijing 100083, china 3 school of Mathematical sciences, Nankai university, Tianjin 300071, china 4 Department of Mathematics and Statistics, McGill university, Montreal H3A 2K6, Canada 1. school of Applied sciences University of Science and Technology Beijing Beijing 100083 China 2. school of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China 3. school of Mathematical sciences Nankai University Tianjin 300071 China 4. Department of Mathematics and Statistics McGill University Montreal H3A 2K6 Canada

The growth model of a spherical crystal in the undercooled melt including the surface energy, interfacial kinetics and convective flow is established. The effect of the convective flow induced by a small far field flow on the evolution and morphological stability of the interface of the spherical crystal is studied. The interface shape of the spherical crystal, which is affected by the far field flow, and the dispersion relation of the growth rate of amplitude of the perturbed interface are derived. It is shown that the convection induced by the far field flow makes the interface of the growing spherical crystal further grow in the upstream direction of the far field flow and inhibit growth in the downstream direction; the interface of the decaying spherical crystal further decays in the upstream direction and inhibits decay in the downstream direction. The theoretical result suggests that both the growth of the sphere in the upstream direction and the decay of the sphere in the downstream direction make the spherical crystal tend to evolve into an oval; the morphological stability of the interface depends on a certain radius R c such that the spherical crystal is unstable when its radius is greater than R c and stable when its radius is less than R c . The surface energy and interfacial kinetics have strong stabilizing effects on the growth of the spherical crystal. In the meantime interfacial kinetics is a table factor of the interface when the interface of the sphere is growing; it is an unstable factor of the interface when the interface is decaying.

关键词： solid-liquid interface spherical crystal convective flow crystal growth morphological stability

Progress in studies on the DEK protein and its involvement in cellular apoptosis

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Science china(life sciences) 2009年第7期52卷 637-642页

作者： HUA Ying,HU HongGang & PENG XiangLei College of life sciences and Bioengineering,school of Science,Beijing Jiaotong university,Beijing 100044,china College of life sciences and Bioengineering School of Science Beijing Jiaotong University Beijing 100044 China

DEK protein is an ubiquitous phosphorylated nuclear *** binding of DEK to DNA could change the topology of DNA and then affect the gene activity of the underlying DNA *** is speculated that there might be some potential relationship between the stress reaction of cells and DEK *** phosphorylation status of DEK protein is altered during death-receptor-mediated cell *** phosphorylation and poly(ADP-ribosyl)ation could promote the release of DEK from apoptotic nuclei to extracellular environment,and in this case DEK becomes a potential autoantigen of some autoimmune *** available evidence powerfully suggests that DEK protein is closely relevant to *** overexpression of DEK protein has dual function in cell apoptosis,in terms of inhibiting or triggering cell apoptosis.

关键词： DEK cell apoptosis phosphorylation poly(ADP-ribosyl)ation p53 caspase

cDNA cloning,sequence analysis,and recombinant expression of akitonin beta,a C-type lectin-like protein from Agkistrodon acutus

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Acta Pharmacologica Sinica 2004年第03期25卷 118-123页

作者： Xiang-dong ZHA1,2,Jing LIU1,Kang-sen XU3 1 school of life Science,university of Science and Technology,Hefei 230026 school of life Science,Anhui university,2 Hefei 230039 National Institute for Control of Pharmaceuticals and Biological Products,Beijing 100050,china 3 school of life Science University of Science and Technology school of life Science Anhui University National Institute for Control of Pharmaceuticals and Biological Products Beijing 100050 China

AIM: To clone the cDNA of a new member of snake venom C-type lectin-like proteins, to study its structure- function relationships and to achieve its recombinant production. METHODS: PCR primers were designed based on the homology and cDNA was amplified by RT-PCR using total RNA from snake venom gland as the template. The PCR products were cloned into the plasmid pGEM-T and sequenced. The deduced protein sequence was analyzed with some bioinformatic programs. A recombinant expression plasmid was constructed using pBAD- TOPO as vector and transformed into *** TOP10 competent cells. RESULTS: A novel cDNA sequence encod- ing akitonin β was found and accepted by GenBank (accession number AF387100). Akitonin β consists of a typical carbohydrate recognition domain (CRD) of C-type lectins, and it is homologous with other snake venom C-type lectin-like proteins. It was predicted to be a platelet antagonist. Upon induction with arabinose rAkitonin β express- ing in E coli was achieved at a high level (superior to 150 mg/L). The recombinant fusion protein exhibited inhibitory activities on rat platelet aggregation in vitro. CONCLUSION: A new member of snake venom C-type lectin-like proteins was discovered and characterized, and an efficient recombinant expression system was estab- lished for its production.

关键词： snake venoms cDNA akitonin C-type lectin-like proteins recombinant proteins structure- activity relationship

Hausdorff dimension of Julia set of a polynomial with a Siegel disk

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Science china Mathematics 2006年第9期49卷 1284-1296页

作者： SHEN Liang LMAM, school of Mathematical sciences, Peking university, Beijing 100871, china LMAM School of Mathematical Sciences Peking University Beijing 100871 China

Let f(z) = e2πiθz(1+z/d)d,θ∈R\Q be a polynomial. Ifθis an irrational number of bounded type, it is easy to see that f(z) has a Siegel disk centered at 0. In this paper, we will show that the Hausdorff dimension o... 详细信息

关键词： Hausdorff dimension Siegel disk porous set

Predictive control and scheduling codesign in network control systems

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控制理论与应用（英文版） 2010年第2期8卷 239-244页

作者： Qing SHEN 1 , 2 , Weihua GUI 2 , Ying XIONG 2 , Chunhua YANG 2 (1.school of Basic Education for Officers, National university of Defense Technology, Changsha Hunan 410003, china 2.school of Information Science and Engineering, Central South university, Changsha Hunan 410083, china) school of Basic Education for Officers National University of Defense Technology Changsha Hunan China school of Information Science and Engineering Central South University Changsha Hunan China

A codesign approach combining predictive control compensation and network scheduling is presented in this paper to overcome the adverse influences of stochastic time delays and packet losses encountered in network-based real-time control systems. The state estimation and control prediction compensation algorithms are used for the random network delays in the feedback and forward channels, and the stability criteria are analyzed. The proper sampling rate is given with network scheduling to meet the desired system performance, while the network-induced delay is tolerated. Simulations show that the codesign approach works well with the bounded network delay.

关键词： Network control system Prediction Scheduling Stability

Global Existence of Classical Solutions for Some Oldroyd-B Model via the Incompressible Limit

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Chinese Annals of Mathematics,Series B 2006年第5期27卷 565-580页

作者： Zhen LEI school of Mathematical sciences, Fudan university, Shanghai 200433, china school of Mathematics and Statistics, Northeast Normal university, Changchun 130024, china. school of Mathematical sciences Fudan University Shanghai 200433 China school of Mathematics Statistics Northeast Normal University Changchun 130024 China

In this paper, we prove local and global existence of classical solutions for a system of equations concerning an incompressible viscoelastic fluid of Oldroyd-B type via the incompressible limit when the initial data ... 详细信息

关键词： Incompressible limit Global existence Oldroyd model