联结基对磺酸盐型双子表面活性剂的界面张力和起泡性能的影响

合成了一系列具有支状疏水链的新型磺酸盐型双子表面活性剂D2Cn(D为疏水基仲辛基,C为联结基中亚甲基,n=2,4,6,8),考察了联结基对其表面活性的影响。结果表明,D2Cn系列双子表面活性剂溶液的临界表面张力γCMC与临界胶束浓度CMC值均随联结基长度的增加而增大;辽河原油加入D2Cn系列双子表面活性剂溶液后的油-水界面张力随着联结基团长度的增加先增加后降低。D2Cn系列双子表面活性剂具有良好的泡沫性能,随着联结基长度的增加,初始起泡体积降低,泡沫半衰期先增加后降低;随着温度的增加,泡沫半衰期显著下降,初始起泡体积先增加后降低。

Structure of the Bovine ACAD8 Gene and the Association of Its Polymorphism with the Production Traits

Acyl-coenzyme A dehydrogenases （ACAD） are a family of nuclear-coded, mitochondrial flavoenzymes that catalyze the alpha, and beta-dehydrogenation of fatty acids. The eighth member of this family, ACAD8 catalyzes the valine catabolism. In this study, the bovine ACAD8 full-length mRNA and genomic DNA sequence were obtained and its gene structure was determined through alignment of the genomic DNA sequence to the mRNA sequence. The mRNA sequence consisted of a 1,251 bp open reading frame （ORF） flanked by a 37 bp 5＇-untranslated region （UTR） and a 444 bp 3＇-UTR; and its full-length genomic DNA sequence was 13,814 bp in length and included 11 exons and 10 introns. One A-G single nucleotide polymorphism （SNP） was revealed at nucleotide 13,408 （GenBank accession No. DQ435445） in the bovine ACAD8 gene by sequencing the polymerase chain reaction （PCR） products of 6 randomly selected individuals from the sample population. Different genotypes were determined by restriction fragment length polymorphism （RFLP）. The association analysis of this SNP in bovine ACAD8 with production traits in 178 unrelated steers from 5 breeds showed that it had a significant effect on the daily gain and the beef tenderness （P〈0.05）. Cattle with the G allele grew more rapidly and the beef they produced was more tender than those with the A allele. Thus, this SNP of the bovine ACAD8 gene can be used as an indicator to improve the growth rate and the beef tenderness.

Ultrathin 3D radial tandem‐junction photocathode with a high onset potential of 1.15 V for solar hydrogen production

Combining a progressive tandem junction design with a unique Si nanowire(SiNW)framework paves the way for the development of high‐onset‐potential photocathodes and enhancement of solar hydrogen production.Herein,a radial tandem junction(RTJ)thin film water‐splitting photo‐cathode has been demonstrated experimentally for the first time.The photocathode is directly fab‐ricated on vapor‐liquid‐solid‐grown SiNWs and consists of two radially stacked p‐i‐n junctions,featuring hydrogenated amorphous silicon(a‐Si:H)as the outer absorber layer,which absorbs short wavelengths,and hydrogenated amorphous silicon germanium(a‐SiGe:H)as the inner layer,which absorbs long wavelengths.The randomly distributed SiNW framework enables highly efficient light‐trapping,which facilitates the use of very thin absorber layers of a‐Si:H(~50 nm)and a‐SiGe:H(~40 nm).In a neutral electrolyte(pH=7),the three‐dimensional(3D)RTJ photocathode delivers a high photocurrent onset of 1.15 V vs.the reversible hydrogen electrode(RHE),accompanied by a photocurrent of 2.98 mA/cm^(2) at 0 V vs.RHE,and an overall applied‐bias photon‐to‐current effi‐ciency of 1.72%.These results emphasize the promising role of 3D radial tandem technology in developing a new generation of durable,low‐cost,high‐onset‐potential photocathodes capable of large‐scale implementation。

ANALYSIS OF GROUP MULTIUSER DETECTION BASED ON COALITION GAME THEORY

Coalition game theory is introduced to investigate the performance,fairness and stability of decorrelating group multiuser detection receiver,not only from the perspective of individual nodes,but also various coalitions and the whole system as well. Firstly,to derive how the system scale with coalition size,a stochastic model with transferable payoffs (stochastic TU-model) is provided. Secondly,to find the most preferred coalition structures from the view point of individual nodes,a model with Non-Transferable payoffs (NTU-model) is presented. Theoretical analysis and simulation results suggest that stochasticaly the grand coalition is payoff maximizing for the system as a whole,while individual nodes with good-conditioned channels may prefer local "win-win coalitions".

Epigenetic modification regulates both expression of tumor-associated genes and cell cycle progressing in human colon cancer cell lines: Colo-320 and SW1116

The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.

Top Limit Characteristics of New Type Cascade PC on the Basis of Homogeneous Semiconductor

A new type homogeneous planar PC （photoelectric converter） on the basis of multijunction semiconductor n＋-p-p＋-n＋-p-p＋-...-n＋-p-p＋ structure has been investigated. The entire structure is a cascade PC consisting of a number of elements of the structure--single PCs connected in series and illuminated by light that has consistently passed through the previous semiconductor layers. The theory of converter of both monochromatic and solar radiation has been developed and the limiting values of their photoelectric and power characteristics have been determined, including the optimal thickness and number of single PCs layered on a base PC, their spectral sensitivity, current-voltage characteristics and efficiency. The open-circuit voltage grows practically linearly with the number of elements in the cascade. The top efficiency limit for a certain optimal elements number reaches its maximum that exceeds considerably that of the base PC, especially in the range of low collecting coefficient of charge carriers in the base PC.

Synthesis and Crystal Structure of N,N'-Diphenyl-3, 6-diethyl-1,4-dihydro-s-tetrazine-1,4-dicarbonamide

The crystal structure of the title compound N,N-bisphenyl-3,6-diethyl-1,4- dihydro-s-tetrazine-1,4-dicarbonamide (C20H22N6O2, Mr = 378.44) has been prepared and determi- ned by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pbca with a = 16.287(2), b = 11.347(4), c = 20.975(4) ? V = 3876.4(16) ?, Z = 8, Dc = 1.297 g/cm3, F(000) = 1600, m = 0.088 mm-1, MoKa radiation (l = 0.71073 ?. The structure was refined to R = 0.0337 and wR = 0.1038 for 1952 observed reflections with I > 2s(I). X-ray diffraction analysis reveals that two amide groups are located at the 1 and 4 positions, and the tetrazine ring itself shows a boat conformation.

Coordination Triangular Prism of Bisilver Complex with Triply-bridged of Bis(diphenylphosphino)amine

The binuclear complex [Ag2(m-Ph2PNHPPh2)3](ClO4)2CH2Cl2CH3OH (Ph2PNHP- Ph2 = bis(diphenylphosphino)amine) was prepared from the reaction of AgClO4 with bis- (diphenylphosphino)amine in equimolar ratio through self-assembly. The coordination cation affords a triply-bridging [Ag2L3]-type coordination moiety. The silver atom is in a trigonal planar environment with P3 coordination chromophore. The complex (C74H69Cl4N3O9P6Ag2) crystallizes in monoclinic, space group Cc with a = 18.3738(1), b = 20.0207(4), c = 20.5422(4) ? b = 95.829(1), V = 7517.5(2) 3, Z = 4, Mr = 1687.68, Dc = 1.491 g/cm3, F(000) = 3432, m = 0.848 mm-1, the final R = 0.0460 and wR = 0.0935 for 7005 observed reflections with I > 2s(I).

Crystal Structure of Chlorinate (N,N-1,3-Dibenzyl-benzimidazole) Hydrate

The structure of the title compound consisting of N,N-1,3-dibenzyl-benzimidazole ion, Cl- anion and hydrate was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with a = 9.320(2), b = 9.850(2), c = 11.510(2) ? = 68.75(3), = 80.57(3), = 70.20(3)? C21H19ClN2H2O, Mr = 352.85, V = 925.6(3) 3, Z = 2, Dc = 1.266 g/cm3, F(000) = 372, = 0.217 mm-1, R = 0.0452 and wR = 0.1372. The total reflections were 3462 and 3244 (Rint = 0.0206) were independent, of which 1666 were observed with I > 2s(I). The planes of benzyl group are nearly perpendicular to each other. The water molecules with Cl-anions and C(8) atom are involved in hydrogen bonds and interactions, and - stacking interaction exists obviously between the adjacent phenyl and imidazole rings. The title complex forms a three-dimensional network throughout the structure through these hydrogen bonds and interactions.

Synthesis and Characterization of New Palladium（ll） Complexes Containing 4,5-dimethyl-2,2＇-bipyridine： X-ray Crystal Structure of Bis（4-methyl pyrdine）-4,5- dimethyl-2,2＇-bipyridine palladium （11） Perchlorate

New heteroleptic and homoleptic complexes of the type[Pd（4,5-dmbipy）C12], [Pd（4,5-dmbipy）L2], and [Pd（4,5-dimebipy）2]2＋ （L = Pyridine or 4-methylpyridine（4-picoline）, bipy = 2,2＇-bipyridine, and 4,5-dimebipy = 4,5-dimethyl-2,2＇-bipyridine） were synthesized and characterized by IH NMR and elemental analysis. The crystal structure of bis（4-methylpyridine）-4,5- dimethyl-2,2＇-bipyridinepalladium（II）perchlorate [Pd（4,5-dmbipy）（4-pic）2]（CIO4）2 was also determined by single crystal X-ray diffraction. This complex crystallized in the triclinic crystal system and space group PI with a = 9.562 （2）, b = 11.326 （4）, c = 15.0120 （10） A°; α = 70.940°, β= 77.60 （2）, γ= 67.86 （2） and z = 4. The Pd （II） in square planar environment showed a small distortion towards tetrahedral through one coordinated bipyridine ring twisting with respect to the other.

Helix-sense-selective radical polymerization of bulky styrenic monomers: chiral induction and liquid crystallinity

Eight chiral vinylterphenyl monomers, （＋）-2,5-bis{4＇-[（S）-1＂-methylpropyloxy]phenyl}styrene （Ia）, （＋）-2,5-bis{4＇-[（S）-2＂- methylbutyloxy]phenyl}styrene （Ib）, （＋）-2,5-bis{4＇-[（S）-3＂-methylpentyloxy]phenyl}styrene （Ic）, （＋）-2,5-bis{4＇-[（S）-4＂- methylhexyloxy]phenyl}styrene （Id）, （-）-2,5-bis{4＇-[（R）-1＂-methylpropyloxy]phenyl}styrene （le）, （＋）-2-/4＇-[（S）-l＂-methyl- propyloxy]phenyl}-5-{4＇-[（R）-1＂-methylpropyloxy]phenyl}styrene （Ⅱa）, （-）-2-{4＇-[（R）-1＂-methylpropyloxy]phenyl}-5-{4＇- [（S）- 1 ＂-methylpropyloxy]phenyl } styrene （lib）, and （＋）-2- { 4＇-[（S）-2＂-methylbutyloxy]phenyl }-5- { 4＇-[（S）- 1＂-methylpropyl- oxy]phenyl}styrene （Ⅲ）, were synthesized and radically polymerized. These molecules were designed to further understand long-range chirality transfer in radical polymerization and to possibly tune the chiroptical properties of the polymers by varying the spatial configuration, position, and various combination of the stereogenic centers at the ends ofp-terphenyl pendants. The resultant polymers adopted helical conformations with a predominant screw sense. When the stereogenic centers ran away from the terphenyl group as in Ⅰb-d, the corresponding polymers changed the direction of optical rotation in an alternative way and showed no obvious stereomutation upon annealing in tetrahydrofuran. The two stereogenic centers of Ⅱa, Ⅱb, and Ⅲ acted concertedly in chiral induction, whereas those of la and Ie played a counteractive role. The five polymers derived from Ⅰa, Ⅰe, Ⅱa, Ⅱb, and Ⅲ underwent stereomutation when annealed in tetrahydrofuran. The polymers PIa-e had good thermal stability and high glass transition temperatures （Tgs）. They generated liquid crystalline phases at above Tgs that could be kept upon cooling, with the exception of Pie. This result was consistent with the extended helical structures.