Symmetry energy and isovector giant dipole resonance in finite nuclei

We study the relationship between the properties of the isovector giant dipole resonance of finite nuclei and the symmetry energy in the framework of the relativistic mean field theory with six different parameter sets of nonlinear effective Lagrangian. A strong linear correlation of excited energies of the dipole resonance in finite nuclei and symmetry energy at and below the saturation density is found. This linear correlation leads to the symmetry energy at the saturation density at the interval 33.0MeV <= S(po) <= 37.0 MeV. The comparison to the present experimental data in the soft dipole mode of (132) Sn constrains approximately the symmetry energy at p = 0.1 fm(-3) at the interval 21.2MeV similar to 22.5 MeV. It is proposed that a precise measurement of the soft dipole mode in neutron rich nuclei could set up an important constraint on the equation of state for asymmetric nuclear matter.

1,2,4-三氯苯胁迫对萌发大豆种子中活性氧的影响

以盆栽法研究了不同浓度 1,2 ,4 三氯苯 (TCB)胁迫对萌发大豆种子中活性氧代谢的影响 .结果表明 ,10 0～ 30 0 μg·g-1TCB胁迫初期 (1～ 3天 )促使萌发大豆种子呼吸强度升高及其峰值提前出现 ,超氧阴离子自由基 (O2 - )及过氧化氢 (H2 O2 )的积累显著增加 ,同时伴随丙二醛 (MDA)含量升高 ,显示发生膜脂质过氧化作用 .TCB胁迫 1～ 6天使活性氧清除酶功能紊乱 ,其中过氧化物酶 (POD)活性升高 ,超氧化物岐化酶 (SOD)活性开始上升后转为下降 .在萌发大豆种子受TCB胁迫伤害过程中 ,活性氧代谢失衡造成的膜脂质过氧化将起着重要作用 .

不同方法计算湿地松林生物量的比较

利用实测值建模法、估计值建模法和平均标准木法计算中国科学院千烟洲试验站湿地松(Pi-nus elliotii)人工林各器官生物量和总地上生物量,并与利用文献中的湿地松相对生长方程计算的结果进行比较。结果表明,枝条基径与该枝条叶生物量及总生物量之间存在显著的相关关系;不同方法计算的总地上生物量存在一定的差别,其中实测值建模法和估计值建模法的计算结果最接近,分别为7.9×104和8.0×104kg.hm-2,利用平均标准木法得到的生物量偏低,为7.41×104kg.hm-2;3种方法得到的各器官生物量差别较大,尤其是叶生物量,利用实测值建模法的计算结果为8450 kg.hm-2,估计值建模法和平均标准木法的计算结果分别为6 580和1.0×104kg.hm-2,其中平均标准木法的计算结果因取样的不同而有所差异;直接利用他人建立的相对生长方程计算的生物量与以上3种方法计算结果相比差异较大,使用时须谨慎。计算总地上生物量时,实测值建模法是最可靠的方法,估计值建模法在一定程度上可以代替实测值建模法。

长白山阔叶红松林主要树种光合作用的光响应曲线

以叶片光合作用观测资料为基础,利用直角双曲线与非直角双曲线两种方法对长白山阔叶红松林的主要建群树种红松(Pinuskoraiensis)、紫椴(Tiliaamurensis)、蒙古栎(Quercusmongolica)、水曲柳(Fraxinusmandshurica)光合作用的光响应曲线进行了拟合.结果表明,两种方法拟合结果不同,直角双曲线方法简单,但非直角双曲线的拟合结果更符合生理意义.由直角双曲线拟合得出4个树种的初始量子效率α、最大净光合作用速率Pmax以及暗呼吸Rd大于非直角双曲线的拟合结果,而光补偿点Lcp随树种不同而有差异.两种方法得出4个树种的α、Rd大小顺序相同,分别是α为水曲柳>紫椴>蒙古栎>红松;Rd为水曲柳>蒙古栎>紫椴>红松,但由两种方法得出的Pmax、Lcp值大小顺序有差异.

松果采摘对种子库及动物影响的探讨

根据食物链原理和动物与生境密切的关系,探讨了松果采摘对长白山自然保护区动物的影响.认为松果采摘后,一方面松籽没有动物帮助搬运,使红松不能正常天然更新,影响了红松林生态系统正常演替而破坏了动物生境;另一方面使得保护区内以松籽为主要食物来源的动物因缺少食物而发生数量变化,致使食物链遭受破坏,从而导致红松林中动物分布发生变化.

下辽河平原农业生态系统不同施肥制度的土壤养分收支

本试验是在潮棕壤上进行了 10年的定位试验 .研究了在养分循环再利用的基础上采取不同施肥制度下作物养分移出量 ,并结合施肥量计算出土壤中N、P、K养分收支 .结果表明 ,在保持农业系统养分循环再利用的基础上 ,根据养分供给力设计化肥施用量 ,不仅可实现作物高产 ,而且可平衡土壤养分收支 ,避免土壤中肥料养分过剩 (主要是N)进入环境 .并揭示了我国在 2 0世纪 70年代以前大面积农田土壤缺P和 80年代农田土壤大面积缺K的原因 .

Fabrication of metalloporphyrin-polyoxometalyte hybrid film by layer-by-layer method and its catalysis for dioxygen reduction

Through layer-by-layer method [tetrakis(N-methylpyridyl)porphyrinato] cobalt (CoTMPyP) and polyoxometalyte were alternately deposited on 4-aminobenzoic acid (4-ABA) modified glassy carbon electrode. The resulting organic-inorganic hybrid films were characterized by cyclic voltammetry (CV), UV/visible absorption spectroscopy, and atomic force microscopy (AFM). It was proved that the multilayer films are uniform and stable. CoTMPyP-containing multilayer films exhibit remarkable electrocatalytic activity for the reduction of O-2. Rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry confirm that P2W18/CoTMPyP multilayer films can catalyze the four-electron almost reduction of O-2 to water in pH > 4.0 buffer solution, while SiW12/CoTMPyP multilayer films catalyze about two-electron reduction of O-2 to H2O2 in pH 1 - 6 buffer solutions. The kinetic constants for O-2 reduction were comparatively investigated at P2W18/CoTMPyP and SiW12/CoTMPyP multilayer films electrodes.

Synthesis and crystal structure of 3-methoxycarbonylethyltin tetrachlorides anion

The anion of MeO2CCH2CH2SnCl4 - was obtained by decomposing the yellow solution of MeO2CCH2CH2SnCl3.(2-OHC6H4CH=NC6H5) by standing for 15 days, which is the product of 3-methoxy-carbonylethyltin trichlorides with Schiff base (2-OHC6H4CH=NC6H5). The title compound was characterized by elemental analysis, IR. H-1 NMR,C-13 NMR and X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P2cn, a=7.852(2), b=12.236(1),c=16.952(4)Adegrees, V=1628.7 Angstrom(3), Z=4, D-c=1.79g/cm(3) F(000)=860, mu=22.2cm(-1), R=0.0449, Rw=0.0382. The title compound exists as a discrete molecule, and the tin atom attains a distorted octahedral geometry via the coordination of intramolecular carbonyl oxygen and chloride ion. The coordination number of tin atom is 6.

3-(四氯化锡)-丙酸甲酯阴离子的合成及晶体结构

在用酯基锡MeO2CCH2CH2SnCl3合成配合物MeO2CCH2CH2SnCl3·(2-OHC6H4CH=NC6H5)时,其配合物的甲苯溶液放置培养单晶时(放置十天以上)会发生分解生成配合物MeO2CCH2CH2SnCl4—·H+。研究了标题化合物的合成反应,用元素分析、IR、NMR对配合物进行了表征,并测定了晶体结构。为正交晶系,空间群为P2cn, a=7.852(2), b=12.236(1), c=16.952(4) ? V=1628.7?, Z=4, Dc=1.79g/cm3, F(000)= 860,m=22.2cm—1(Mo),R=0.0449, Rw=0.0382。标题化合物的空间构型为畸变的八面体构型,中心锡原子的配位数为6。

STUDY ON POLYANILINE FILM WITH HIGH-DENSITY AND HIGH MECHANICAL STRENGTH

Free-standing film of polyaniline with excellent mechanical and electrical properties has been successfully prepared by using the solution-casting method. The results show that its tensile strength, Young's modulus and elongation at break are about 87.9 MPa, 1563.9 MPa and 10.2%, respectively. It is essential that the soluble polyaniline should be appropriately treated in some suitable organic solvents before making a free-standing film. Films having lustrous, smooth surface, high density and good flexibili...

高性能聚苯胺自支撑膜

本文通过对可溶性聚苯胺(PAn)的特殊处理及成膜工艺的改造,采用溶液浇铸法,首次成功地制备出力学和电学性能均较好的大面积聚苯胺自支撑膜(HSPAn膜).研究结果表明,HSPAn膜的抗张强度、杨氏模量和伸长率分别为87.9MPa,1563.9MPa和10.2％;该膜具有金属光泽、较高的致密性和较好的韧性。分子尺寸较小的质子酸(如HCl,HClO_4,等)可有效掺杂HSPAn膜,使其电导率可达到导电型PAn粉末的数量级。有效掺杂的HSPAn膜均可轻度拉伸(断裂伸长率大于40.0％),拉伸膜的电导率可高达36.7s/cm。本征和掺杂的HSPAn膜均具有良好的环境稳定性,空气中放置数月后,其强度和电导率基本不变。

Molecular cloning and expression of a Relish gene in Chinese mitten crab Eriocheir sinensis

P>NF-kappa B is a B-cell specific transcription factor that plays crucial roles in inflammation, immunity, apoptosis, development and differentiation. In the present study, a novel NF-kappa B-like transcription factor Relish was cloned from Chinese mitten crab Eriocheir sinensis (designated as EsRelish) by rapid amplification of cDNA ends (RACE) technique based on expressed sequence tag (EST). The full-length cDNA of EsRelish was of 5034 bp, consisting of a 5' untranslated region (UTR) of 57 bp, a 3' UTR of 1335 bp with two mRNA instability motifs (ATTTA), a polyadenylation signal sequence (AATAAA) and a poly (A) tail, and an open reading frame (ORF) of 3645 bp encoding a polypeptide of 1214 amino acids with a calculated molecular mass of 134.8 kDa and a theoretical isoelectric point of 5.26. There were a typical Rel homology domain (RHD), two nuclear localization signal (NLS) sequences (KR), an inhibitor kappa B (I kappa B)-like domain with six ankyrin repeats, a PEST region and a death domain in the deduced amino acid sequence of EsRelish. Conserved domain, higher similarity with other Rel/NF-kappa Bs and phylogenetic analysis suggested that EsRelish was a member of the NF-kappa B family. Quantitative real-time RT-PCR was employed to detect the mRNA transcripts of EsRelish in different tissues and its temporal expression in hemocytes of E. sinensis challenged with Pichia methanolica and Listonella anguillarum. The EsRelish mRNA was found to be constitutively expressed in a wide range of tissues. It could be mainly detected in the hemocytes, gonad and hepatopancreas, and less degree in the gill, muscle and heart. The expression level of EsRelish mRNA in hemocytes was up-regulated from at 3, 6, 9 and 12 h after P. methanolica challenge. In L. anguillarum challenge, it was up-regulated at 9, 12 and 24 h. The results collectively indicated that EsRelish was potentially involved in the immune response against fungus and bacteria.