线性空间L(V,W)理论的再研究

给出了 L(V,W)的一般基。证明了 L(V,V* )中同一线性变换关于两对对偶基的矩阵是合同的。

A General Study of the Number of Assembly Configurations for Multi-Circuit Planar Linkages

This paper presents a general approach for determining the configuration number for any linkage: A kinematic cham (KC) can be divided into some basic kinematic chains (BKCs) and driving joints; there are only 33 kinds of BKCs with υ =1-4 independent loop, containing only R (revolute) joints and their configuration numbers are given; the configuration number of a KC equals to the multiplication of the configuration numbers of BKCs contained in the KC.

Structural insights into a novel histone demethylase PHF8

Dynamic regulation of histone methylation/demethylation plays an important role during development. Mutations and truncations in human plant homeodomain （PHD） finger protein 8 （PHF8） are associated with X-linked mental retardation and facial anomalies, such as a long face, broad nasal tip, cleft lip/cleft palate and large hands, yet its molecular function and structural basis remain unclear. Here, we report the crystal structures of the catalytic core of PHF8 with or without α-ketoglutarate （α-KG） at high resolution. Biochemical and structural studies reveal that PHF8 is a novel histone demethylase specific for di- and mono-methylated histone H3 lysine 9 （H3K9me2/1）, but not for H3K9me3. Our analyses also reveal how human PHF8 discriminates between methylation states and achieves sequence specificity for methylated H3K9. The in vitro demethylation assay also showed that the F279S mutant observed in clinical patients possesses no demethylation activity, suggesting that loss of enzymatic activity is crucial for pathogenesis of PHF8 patients. Taken together, these results will shed light on the molecular mechanism underlying PHF8-associated developmental and neurological diseases.

Isozyme Analysis of Spotted Halibut Verasper variegatus Temminck et Schlegel

To investigate the tissue-specificities of isozymes and the genetic structureof wild spotted halibut ( Verasper variegatus) population, horizontal starch gel electrophoresiswas performed on 45 individuals collected in part of the Yellow Sea. The performances of 17 isozymesin 8 kinds of tissues or organs were screened preliminarily in a TC-7.0 buffer system. The resultsshowed that the screened isozymes displayed remarkable tissue-specificities. Finally, 14 enzymes(AAT, ADH, EST, OPI, G3PDH, IDHP, LAP, LDH, MDH, MPI, PGDH, PGM, SDH and SOD) and 4 kinds of tissues(eye, skeleton muscle, liver and heart) were selected for genetic analysis. Fourteen isozymes areencoded by 20 loci, and 9 of them are polymorphic. The polymorphic loci are AAT-1~*, GPI-2~*,G3PDH~*, IDHP-1~*, LDH~*, MPI~*, PGM-1~*. PGM-2~* and SDH~*, and the proportion of polymorphic lociis 0.4500 (P_(0.99)) ? The mean values of observed and expected heterozygosities are 0.0278and 0.0265, respectively and the average effective number of alleles is 1.0675.

Normal Orthodox Semigroups with Inverse Transversals

A normal orthodox semigroup is an orthodox semigroup whose idempotent elements form a normal band. We deal with congruences on a normal orthodox semigroup with an inverse transversal. A structure theorem for such semigroup is obtained. Munn(1966) gave a fundamental inverse semigroup. Following Munn's idea, we give a fundamental normal orthodox semigroup with an inverse transversal.

Synthesis of 3-O-Benzoyl-1 ,2-O-isopropylidene-a-D-allofuranose and Its Dimesylated Derivative

Diisopropylidenated α-D-glucofuranose （1） was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose （ 3）. The yield of 3 increased by 8% than that with only oxidated product as reduction substrate. Benzoylated derivative of 3 was selectively nydrolyzed and dimesylated to synthesize 3-O-benzoyl-1 .2- O- isopropylidene-α-D-allofuranose （ 5 ） and its dimesylated derivative respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by ^1H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81.8%. Oxidation. reduction and other procedures were practical and had application potential.

The study on the evolution of real estate industry based on the theory of self-organization

Based on some basic principles of self-organization theory including dissipation structure and synergy,the author analyzes the condition,dynamic and evolving route of the self-organization evolution of the real estate industry,and builds synergetic evolution model,calculates out the order parameter of the real estate industry. The paper supplies new methods and tools for further research of real estate industry and contributes to reference of the government for its direction of macro-control.

The Automorphism Groups of Complete Lie Algebras with Commutative Nilpotent Radical

The automorphism groups of finite-dimensional complete Lie algebras withcommutative nilpotent radical over complex field C are given.

Knockdown of OsHox33, a member of the class III homeodomain-leucine zipper gene family, accelerates leaf senescence in rice

The class III homeodomain-leucine zipper(HD-Zip III)gene family plays important roles in plant growth and development,including regulation of apical embryo patterning,embryonic shoot meristem formation,leaf polarity,vascular development,and meristem function,with a particularly crucial function in leaf development.Although HD-Zip III members are highly conserved in land plants,previous studies,such as genetic analyses based on multiple mutants in Arabidopsis and other plants,suggest that various HD-Zip III family genes have evolved with distinct functions and pleiotropic effects on plant growth and development.In this study,we analyzed a HD-Zip III member,OsHox33,and demonstrated that it plays an important role in age-dependent leaf senescence in rice.We constructed two specific RNAi vectors derived from the 5′-end region and 3′-UTR of OsHox33 to knockdown its expression.Transgenic plants harboring either RNAi construct displayed similar phenotypes of precocious leaf senescence symptoms,suggesting that knockdown of OsHox33 accelerates leaf senescence in rice.pOsHox33::GUS fusion expression and RT-PCR revealed that OsHox33 is highly expressed in young organs,especially in young meristems such as shoot apical meristems,intercalary meristems,and young callus.In addition,real-time PCR indicated that OsHox33 was more highly expressed in young leaves than in old leaves.To further investigate OsHox33 function,we analyzed chloroplast ultrastructure in different-aged leaves of RNAi plants,and found that OsHox33 knockdown accelerated chloroplast degradation,which is consistent with RNAi phenotypes.Finally,real-time PCR studies showed that OsHox33 can regulate the expression of GS1 and GS2,two senescence-associated genes.Taken together,the work presented here provides new insights into the function of HD-Zip III members in plants.

THE FUNDAMENTAL GROUP OF THE AUTOMORPHISM GROUP OF A NONCOMMUTATIVE TORUS THE FUNDAMENTAL GROUP OF THE AUTOMORPHISM GROUP OF A NONCOMMUTATIVE TORUS

Assume that each completely irrational noncommutative torus is realized as an inductive limit of circle algebras, and that for a completely irrational noncommutative torus Aω of rank m there are a completely irrational noncommutative torus Aρ of rank m and a positive integer d such that tr（Aω） = tr（Aρ）. It is proved that the set of all C*-algebras of sections of locally trivial C*-algebra bundles over S2 with fibres Aω. has a group structure, denoted by π1（Aut（Aω.））, which is isomorphic to Z if d > 1 and {0} if d > 1. Let Bcd be a cd-homogeneous C*-algebra over S2 x T2 of which no non-trivial matrix algebra can be factored out. The spherical noncommutative torns Sρcd is defined by twisting C*（T2 x Zm-2） in Bcd C* （Z（m-2）） by a totally skew multiplier ρ on T2 x Z（m-2）. It is shown that Sρcd Mp∞ is isomorphic to C（S2） C* （T2 x Zm-2, ρ） Mcd（C） Mp∞ if and only if the set of prime factors of cd is a subset of the set of prime factors of p.

Structural basis for the recognition of RNA polymerase II C-terminal domain by CREPT and p15RS

CREPT and p15RS are two recently identified homologous proteins that regulate cell proliferation in an opposite way and are closely related to human cancer development. Both CREPT and pl5RS consist of an N-terminal RPR domain and a C-terminal domain with high sequence homology. The transcription enhancement by CREPT is attributed to its interaction with RNA polymerase II （Pol II）. Here we provide biochemical and structural evidence to support and extend this molecular mechanism. Through fluorescence polarization analysis, we show that the RPR domains of CREPT and pl5RS （CREPT-RPR and pI5RS-RPR） bind to different Pol II C-terminal domain （CTD） phosphoisoforms with similar affinity and specificity. We also determined the crystal structure of pl5RS-RPR. Sequence and structural comparisons with RPR domain of Rttl03, a homolog of CREPT and p l5RS in yeast, reveal structural basis for the similar binding profile of CREPT-RPR and p 15RS-RPR with Pol II CTD. We also determined the crystal structure of the C-terminal domain of CREPT （CREPT-CTD）, which is a long rod-like dimer and each monomer adopts a coiled-coil structure. We propose that dimerization through the C-terminal domain enhances the binding strength between CREPT or pl5RS with Pol II by increasing binding avidity. Our results collectively reveal the respective roles of N-terminal RPR domain and C-terminal domain of CREPT and pl5RS in recognizing RNA Pol II.

Cobalt(Ⅱ) coordination polymers built on isomeric dipyridyl triazole ligands with pyromellitic acid:Synthesis,characterization and their effects on the thermal decomposition of ammonium perchlorate

Three new cobalt（II） coordination compounds, [Co（3,3＇-Hbpt）2（H2pm）（H20）2]＇2H20 （1）, [Co（4,4＇-Hbpt）（pm）0.5（H20）]＇3H20 （2） and [Co（3,4＇-Hbpt）（pm）0.5（H20）3]＇2H20 （3） （3,3＇-Hbpt = 3,5-bis（3-pyridyl）-lH-1,2,4-triazole; 4,4＇-bpt = 3,5-bis（4-pyridyl）- 1H-1,2,4-triazole, 3,4＇-Hbpt = 3-（3-pyridyl）-5-（4＇-pyridyl）-lH-1,2,4-triazole and Hapm = pyromellitic acid） have been synthe- sized by hydrothermal reactions. Single-crystal X-ray diffraction reveals that compound 1 has a one-dimensional （1D） chain network, 2 exhibits a four-connected three-dimensional （3D） structure with 1D open channels encapsulated by water molecules, while 3 displays a regular two-dimensional （2D） architecture connected through 1D metal helical chains. In addition, the effi- cacy of compounds 1-3 as additives to promote the thermal decomposition of ammonium perchlorate （AP） is explored by dif- ferential scanning calorimetry （DSC）.

The isomorphic realization of nondegenerate solvable Lie algebras of maximal rank based on Kac-Moody algebras

In this paper,based on Kac-Moody algebra,the isomorphic realization of nondegenerate solvable Lie algebras of maximal rank is given,which in turn revels the closed connections between nondegenerate solvable Lie algebras and Kac-Moody algebras,resulting in some new worthy topics in this area.

Predicting hiCE inhibitors based upon pharmacophore models derived from the receptor and its ligands

Human intestinal carboxyl esterase （hiCE） is a drug target for ameliorating irinotecan-induced diarrhea. By reducing irinotecan- induced diarrhea, hiCE inhibitors can improve the anti-cancer efficacy of irinotecan. To find effective hiCE inhibitors, a new virtual screening protocol that combines pharmacophore models derived from the hiCE structure and its ligands has been pro- posed. The hiCE structure has been constructed through homology techniques using hCESI＇s crystal structure. The hiCE structure was optimized via molecular dynamics simulations with the most known active hiCE inhibitors docked into the structure. An optimized pharmacophore, derived from the receptor, was then generated. A ligand-based pharmacophore was also generated from a larger set of known hiCE inhibitors. The final hiCE inhibitor predictions were based upon the virtual screening hits from both ligand-based and receptor-based pharmacophore models. The hit rates from the ligand-based and receptor-based pharmacophore models are 88% and 86%, respectively. The final hit rate is 94%. The two models are highly consistent with one another （85%）. This proves that both models are reliable.

Integrated research methods in watershed science

We discuss the concepts, research methods, and infrastructure of watershed science. A watershed is a basic unit and possesses all of the complexities of the land surface system, thereby making it the best unit for practicing Earth system science. Watershed science is an Earth system science practiced on a watershed scale, and it has developed rapidly over the previous two decades. The goal of watershed science is to understand and predict the behavior of complex watershed systems and support the sustainable development of watersheds. However, watershed science confronts the difficulties of understanding complex systems, achieving scale transformation, and simulating the co-evolution of the human-nature system. These difficulties are fundamentally methodological challenges. Therefore, we discuss the research methods of watershed science, which include the self-organized complex system method, the upscaling method dominated by statistical mechanics, Darwinian approaches based on selection and evolutionary principles, hydro-economic and eco-economic methods that emphasize the human-nature system co-evolution, and meta-synthesis for addressing unstructured problems. These approaches together can create a bridge between holism and reductionism and work as a group of operational methods to combine hard and soft integrations and capture all aspects of both natural and human systems. These methods will contribute to the maturation of watershed science and to a methodology that can be used throughout land-surface systems science.

Effect of metal centres and substituents on the structure and optoelectronic properties of diarylethene compounds:A theoretical study

Diarylethene derivatives are a class of fascinating photochromic materials because of their open and closed isomers with different absorption spectra and many other characteristics.To reveal the detailed structure and optoelectronic properties as well as the effect of metal centres and substituents on them,a systematic study on a series of diarylethene derivatives and their Re(I),Pt(II),and Ir(III) complexes was performed via theoretical calculation.The optimized geometries,electronic properties,frontier molecular orbitals,ionization potentials,electron affinities,reorganization energies,and absorption spectra for both of their open-and closed-isomers have been calculated and analyzed.Metal-coordination and substituents exhibit great influence on the photophysical,charge-injection and-transporting characteristics.In addition,the binding of F-with the boron atom of dimesitylboryl group through Lewis acid/base interactions also induces great changes of structural,photophysical and electronic properties for these diarylethene derivatives,and consequently the compound with the substituent of dimesitylboryl group can be used as selective near-infrared phosphorescent F-probe.