Study on the Luminescent Properties and Structure of Yb-Implanted InP (Yb)

用离子注入法配合优化退火新技术制成了一种高效发光材料InP（yb）；用高灵敏度激光光谱仪测量了该材料的发光特性（Pl），并研究了离子注入和退火过程中发光特性的变化，对Pl谱峰作出辨认；用X射线衍射谱（XdS）测量分析晶格结构和注入损伤（缺陷）；研究了原材料的掺杂（Sn）对发光特性的影响；较深入地探讨了该材料的发光机制，并用一改进rE发光中心模型阐明该材料的激发发光过程。A new eFFicient luminescent material of rare earth Yb doped InP(Yb)was prepared by ion implanted method accompanied by a new optimal annealingthchnigue.The Photoluminescent (PL) properties of the material and the peak.changes of PL spectra of InP (Yb) crystals during RE (Yb) implantation and annealing processes have been studied by high discriminative laser spectrome ter.The structure and implanted damage(deFects)of these crystals have been analyzed systematically by X-ray diFFractional spectra (XDS) and PL.The luminescent mechanism of the material has been investigated deeply.And these results have been interpreted by a improved model of rare earth luminescent center

NMR Studies on Interactions between Diperoxovanadate Complex and 3-Substituted Pyridines

为探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/LNaCl溶液),应用多核(1H、13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(简写为dpV)与3-取代吡啶的相互作用,并首次报道了一些物种的NMR化学位移.dpV与有机配体的反应性从强到弱的顺序为:吡啶>烟酸根>烟酸甲酰胺≈烟酸甲酯,这说明吡啶环上取代基影响反应平衡.竞争配位导致一系列新的6配位的过氧钒物种生成.密度泛函计算结果合理地解释了实验结果,并表明溶剂化效应在反应中起重要作用.To understand the substituting group effects of organic ligands on the reaction equilibrium, the interactions between a diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]- (abbr. dpV) and a series of 3-substituted pyridines in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data were given for the first time. The reactivity among the 3-substituted pyridines towards dpV takes the order of pyridine>nicotinate>N-methyl nicotinamide≈ methyl nicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O2)2L]n- (L=3-substituted pyridines, n=1 or 2). The results of density func-tional calculations provided a reasonable explanation of the relative reactivity of the 3-substituted pyridines. Solvation effects play an important role in these reactions.国家自然科学基金(Nos.20772027,20803020);; 973子课题(No.2003CB716005);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 湖南省教育厅青年项目(No.06B028);; 固体表面物理化学国家重点实验室资助项目;; 湖南科技大学博士基金(No.E-55107)资助项

NMR Studies on Interactions between Diperoxovanadate and Imidazole-like Ligands

为探讨咪唑环上取代基团对反应平衡的影响,在模拟生理条件(0.15 mol·L~(-1)NaCl溶液)下,应用多核(~1H、~(13)C和~(51)V)、扩散排序谱(DOSY)以及变温NMR等谱学技术研究双过氧钒配合物NH_4[OV(O_2)_2{2-(2'-Pyri-dine)- [midazole}]·4H_2O(简写为bpV(Imi-Py))和咪唑类配体(咪唑、2-甲基-咪唑、4-甲基-咪唑和组氨酸)的相互作用,其从强到弱的顺序为咪唑≈4-甲基-咪唑>2-甲基-咪唑>组氨酸.研究结果表明,咪唑环上取代基团空间位阻对反应平衡产生较大影响,同时竞争配位的结果导致新的6配位过氧物种[OV(O_2)_2L]~-(L为咪唑类配体)的生成,当配体为4-甲基-咪唑和组氨酸时,生成的则是一对异构体.To understand the substituting effects of imidazole ring on the reaction equilibrium,the interactions between diperoxovanadate complex NH_4[OV(O_2)_2{2-(2'-Pyridine)-Imidazole}]·4H_2O (abbr.bpV(Imi-Py)) and a series of imidazole-like ligands (imidazole,2-methyl-imidazole,4-methyl-imidazole,and histidine) in solution were explored using multinuclear (~1H,~(13)C,and ~(51)V) magnetic resonance,diffusion ordered spectroscopy (DOSY),and variable temperature NMR in 0.15 mol·L~(-1) NaCl ionic medium for mimicking the physiological conditions.The experimental results indicated that the activities of bpV(Imi-Py) and organic ligands were as follows:imidazole≈4-methyl-imidazole>2-methyl- imidazole>histidine.The stedc effect of the organic ligands affects the reaction equilibrium.At the same time,new six- coordinated peroxovanadate species [OV(O_2)_2L]-(L=imidazole-like ligands) were formed due to the competitive coordination between 2-(2'-pyridyl)-imidazole and the imidazole-like ligands.When the ligand was 4-methyl- imidazole or histidine,a pair of isomers was formed.国家自然科学基金(20772027);; 973子课题(2003CB716005);; 湖南省自然科学基金(06JJ30004);; 中国博士后科学基金(20070410805);; 湖南省教育厅青年项目(068028);; 卫生部(福建省)卫生教育联合攻关计划(3502220051027);; 厦门市重大疾病攻关研究基金(Wkj2005-2-019);; 固体表面物理化学国家重点实验室开放基金和湖南科技大学博士基金(E55107)资

A male-specific expression gene, encodes a novel anionic antimicrobial peptide, scygonadin, in Scylla serrata

【英文摘要】Scygonadin is a novel antimicrobial peptide, which was originally isolated from the seminal plasma of the mud crab, Scylla serrata. Based on the partial 20-residue NH2-terminal sequence of the peptide, H-Gly-Gln-Ala-Leu-Asn-Lys-Leu-Met-Pro-Lys-Ile-Val-Ser-Ala-Ile-Ile-Tyr-Met-Val-Gly-OH, scygonadin was cloned from the gonads of S. serrata using a degenerated reverse transcriptase (RT)-PCR and rapid amplification of cDNA ends (RACE). The full-length cDNA sequence contains an open reading frame of 539 bases (excluding polyA) with a coding capacity of 126 amino acids, which constitutes a putative NH2-terminal signal sequence (1–24) and a mature peptide (25–126). Analysis of the genomic DNA sequence revealed that scygonadin consists of 2300 bp containing two introns (1569 and 120 bp) and three exons (187, 131 and 218 bp) and this sequence is different from any other reported antimicrobial peptide. The theoretical pI of the mature peptide is 6.09, which suggests that it is an anionic molecule. The sex and tissue-specific expression of the scygonadin gene was revealed using RT-PCR and Northern-blot analysis of multiple tissues of S. serrata males and females and this demonstrated that the scygonadin gene was predominantly expressed in the male reproductive tract of S. serrata and was restricted to the ejaculatory duct. This suggests that scygonadin might be one of the antibacterial peptides responsible for protection of the male crab reproductive tract from invading pathogenic microorganisms, so as to maintain a sterile environment leading to successful fertilization

The Listed Companies' Liabilities Behavior, Shareholders' Wealth and Stock Market Effect

本文就上市公司举债对股东财富的影响及股市效应进行了理论分析和实证检验 ,发现中国上市公司举债所产生的效应恰恰与西方国家相反 ,即借款比率与股票风险 β存在负相关关系。进一步的分析发现 ,借款负债对企业经营业绩和股东财富的波动有稳定的作用 ,但随着公司的业绩水平和市场竞争能力的变化 ,这种稳定作用的显著程度也不相同。This paper investigates into the effects of the listed companies' liabilities behavior on their shareholders' wealth,and then examines this by empirical method.The investigation finds that company's liabilities ratio negatively interrelates with stock risk β,that is contrary to the western researches.Further study reveals that,when the market economy was in prosperous position,the shareholders' wealth which should have been increased from high debt,was restrained by the increased managers moral hazards and agent costs caused by the administrative and unrational behavior of company's raising money from bank,and that when the market economy was in depression liability may provide incentive on managers in a certain extent,and holds back the descent of shareholders' wealth because of high debt.So,raising money from banks may stabilize the fluctuation of company's earnings and shareholders' wealth,but the degree of stabilization varies from the listed company's operational power and its competitive power.教育部人文社会科学重点研究基地重大项目阶段性成

广西柳州市九头村一号汉墓

离广西柳州市区东南约3公里的九头村西,有三座残存封土的古墓,文物普查编号为M1、M2、M3。1982年冬,我馆对一号墓进行了清理。此墓残存封土高约1.5、直径约10米,为带墓道的长方形竖穴土坑墓。墓向为110度。斜坡式墓道,宽2.1米,倾斜31度。墓室东西长6.3、南北宽4、深3米。墓内两侧有两条纵沟,长4.8、宽O.2、深O.15米(图一)。墓壁经夯打,墓内填入黄红色土。葬具及骨架已腐朽,仅在墓室后部发现部分棺木痕迹。墓室两侧的纵沟可能是垫棺椁的

柳州市郊东汉墓

为配合农田基本建设,本馆人员于1983年10月,在市东南郊九头山东北面发掘了一座东汉初年墓(图一)。现将发掘收获报告如下。该墓残存封土高约1.4米,直径约10.5米。为长方竖穴土坑墓,墓向125°。有两个墓室,相距3.2米。墓室 A:位于北侧,长5.5、宽3.5、深2米,墓内两侧有两条垫棺枕木沟,长4.7、宽0.3、深0.2米,斜坡墓道倾度20°(图二);墓室 B:位于南侧,长5、宽2.6、深1.8米,墓内两条垫棺枕木沟长4.3、宽0.2、深0.15米,斜坡墓道倾度20°(图三)。

高速列车齿轮传动系统黏滑振动特性分析

为了分析黏滑振动时高速列车齿轮传动系统的扭转振动,考虑高速列车齿轮系统的时变啮合刚度和齿轮啮合误差,建立高速列车齿轮传动参数振动模型,分析了轮轨蠕滑率变化引起的齿轮传动系统扭转自激振动特性。结果表明,时变啮合刚度是齿轮传动系统发生谐波振动的主要原因,当蠕滑率超过最佳蠕滑率时,传动系统发生自激振动,系统响应出现稳定的极限环运动,自激振动不会改变系统振动主频,但使参数谐波振动更加明显,从而导致系统振动更为剧烈

Large Shareholders' Equity Collateral,Assets Expropriation,and Earnings Management

【中文摘要】本文首先建立了一个模型，分析了大股东在作股权质押决策时如何在控制权与现金流权之间权衡，并提出大股东质押股权的可能性与股权集中度正相关、与股价被高估的程度正相关的假设，随后的实证研究验证了根据理论模型推导结果提出的假 设。本文随后分析了大股东质押股权的行为后果。实证研究表明，如果上市公司的终极控制人是国有企业或政府机构，大股东质押股权并不必然导致盈余管理或资金侵占。当上市公司的终极控制人为非国有实体或个人时，盈余管理和资金侵占都可能是大股东股权质押的行为后果。本文的结论对相关部门加强对大股东股权质押行为的监管、改善金融生态环境具有借鉴意义。 【Abstract】In this paper we develop a model to analyze whether large shareholders make decisions on equity collateral by trading off between control rights and cash flow rights. We find that the higher the levels of ownership concentration and stock overpricing are, the more likely it is for large shareholders to collateralize their equity holdings. The subsequent empirical analysis supports the model’s prediction. We also analyze large shareholders’ subsequent behavior after they collateralize their equity holdings. During the world economic crisis, large shareholders face the risks of being not able to repay ther loans and losing ther right for equity collateral.. Large shareholders may use two strategies to ease their repayment pressure： raise the stock price through earnings management and then raise capital through re-collateralizing ther equity holdings; expropriate assets from other listed firms they control. Empirical analysis shows that if a state-owned enterprise or government agency ultimately controls the listed company, large share holders’ equity collateral choice does not necessarily lead to earnings management or assets expropriation. In contrast, when a non-state-owned entity or an individual ultimately controls the listed company, large shareholders’ equity collaterals are likely to lead to earnings management and assets expropriation. Our conclusions can used by policy makers to strengthen the regulations of large shareholders’ equity collateral behavior and to improve the efficiency of the capital market in China

Synthesis and Herbicidal Activities of Bifunctional Acetic Acid Ester Derivatives of Monoterpene Oxabicyclodiol

以（3R,4R）-4,7,7-三甲基-6-氧杂二环[3,2,1]辛烷-3,4-二醇（1）和乙酰氯（2）为原料,经＂一锅法＂制得混合物Ⅰ;Ⅰ经分离纯化得4个新型的双官能单萜氧杂二环二醇乙酸酯类衍生物（3a-3d）,其结构经1H NMR,13C NMR,FT-IR和HR-MS表征。考察了物料比r[n（2）∶n（1）]和反应时间对3a-3d相对浓度的影响。结果表明,在反应条件[1 5 mmol,r=7,回流反应7 h]下,3a-3d的相对浓度分别为21.6%,15.6%,37.9%和24.9%;在反应条件[1 5 mmol,r=4,回流反应7 h]下,3a-3d的相对浓度分别为50.7%,36.6%,7.84%和4.86%。用培养皿法测试了1和3a-3d的除草活性。实验结果表明,1和3a-3d均能显著抑制一年生黑麦草胚根与胚芽生长;在用药浓度为5 mmol·L-1时,1和3a-3d对根长抑制率分别为55.1%,86.0%,84.2%,91.3%和97.5%;对芽长抑制率分别为55.1%,76.5%,92.8%,94.8%和98.4%。Four novel acetic acid ester derivatives（3a-3d） were synthesized by the reaction of （3R, 4R） -4,7,7-trimethyl-6-oxabicyclo [ 3.2.1 ] octane-3,4-diol （ 1 ） with acetyl chloride （2） by one-pot method and then purified. The structures were characterized by 1H NMR, 13C NMR, FF-IR and HR-MS. Effects of material ratio { r[ n（2） ： n（1） ] } and reaction time on the relative concentration of 3a -3d were investigated. The resluts showed that the relative concentration of 3a - 3d were 21.6%, 15.6%, 37.9% and 24.9% under the condition of 1 5 mmol, r=7 and reflux for7 h. The relative concentra- tion of3a -3d were 55.1%, 86.0%, 84.2%, 91.3% and 97.5% under the condition of 1 5 mmol, r =4 and reflux for 7 h. The herbicidal activities of 1 and 3a -3d were tested by dish dipping method. The results showed that 1 and 3a - 3d exhibited obvious inhibition activities against the growth of annual ryegrass root and shoot. The inhibition rate of 1 and 3a - 3d against root growth at 55 mmol·L^-1 were 55.1%, 86.0%, 84.2%, 91.3% and 97.5%, respectively. The inhibition rate of 1 and 3a -3d against shoot elongation at 5 mmol ·L^-1 were 55.1%, 76.5%, 92.8%, 94.8% and 98.4%, respectively.国家自然科学基金资助项目(31460174);广西省自然科学基金资助项目(2011GXNSFA018057);广西省科学研究与技术开发计划资助项目(1348006-10