河北木兰围场油松年轮生态学的初步研究

运用树木年轮气候学方法,研究了河北木兰围场油松的生长与气候要素之间的关系.结果表明:油松生长对环境变化十分敏感,以早材最为敏感.5、6月气温与油松生长存在显著的负相关关系;6月的降水和相对湿度对油松早材的生长有促进作用,上年9月到翌年9月的降水对油松生长有更强的促进作用;12月到翌年3月的相对湿度对油松晚材生长的促进作用较干旱和全轮显著;油松的生长与大尺度气候波动存在一定的相关性.1951—2006年间,围场地区增温明显.随气温的升高,油松生长对温度和降水的敏感性下降,且有向相反方向转变的趋势.百年尺度上5—6月平均气温的重建值与观测值差异较大,说明当地油松的宽度生长对气候因子变化的敏感性波动较大.

辽东次生林区主要阔叶林型叶面积指数季节动态

蒙古栎(Quercus mongolica)、花曲柳(Fraxinus rhynchophulla)和胡桃楸(Juglans mandshurica)林是我国东北天然次生林区具有代表性的主要林型。本研究以该3种林型为对象,利用数码相机外带鱼眼镜头获得3种林型的半球面影像,再利用专用软件Gap Light Analyzer处理分析获得了叶面积指数、林冠孔隙度和林下光照因子等参数。结果表明,3种林型的叶面积指数变化总体趋势是一致的,均呈先上升再下降的单峰曲线,蒙古栎林和胡桃楸林都是在7月中旬或8月中旬达到最大峰值,花曲柳林是在8月中旬或9月中旬达到最大峰值;3种林型冠层孔隙度的变化总体趋势也是一致的,呈先下降再上升的单峰曲线,不同样地峰值出现的时间也不同,最低峰值在6、7、8、9月中旬均有出现;通过对不同月份的叶面积指数、林下散射光、林下直射光的变异系数分析表明,7—9月叶面积指数的空间格局是影响林下散射光空间分布的主要因素。叶面积指数与林冠孔隙度呈指数相关。

辽宁植烟土壤pH值状况及其与烟叶主要品质指标的相关分析

以辽宁省7个植烟县为对象,采集了154个土壤和中部烟叶样品,在测定土壤pH值的基础上,测定烟叶中的烟碱含量、还原糖含量、总糖含量以及氮钾含量。通过数理统计的方法分析了土壤pH值与烟叶内在质量指标之间的关系,结果表明:辽宁烟区植烟土壤的pH值大多比较适合烟叶生长,但是仍有12%的植烟土壤pH值过高或过低,需要进行改良。土壤pH值与烟叶总氮含量、烟碱含量、钾含量两两之间均呈显著或极显著的曲线相关关系,即当土壤pH值从4.0变化到6.5时土壤pH值与烟碱含量之间为负效应关系,当土壤pH值从6.5变化到9.0时土壤pH值与烟碱含量之间为正效应关系,土壤pH值与总氮含量、钾含量、总糖含量之间为负效应关系。

辽西地区水分亏缺与树木生长关系

利用修正的Thornthwaite最大蒸发力公式,计算了辽西地区不同市的水分亏缺量。各市最大潜在蒸发散计算结果是:朝阳1180.6 mm,锦州1146.0 mm,葫芦岛1140.1 mm,阜新1030.3 mm;水分亏缺量计算结果为:朝阳-658.3 mm,锦州-538.4 mill,葫芦岛-544.8 mm,阜新-626.9 mm。利用美国spss数理统计软件计算了油松与蒙古栎的胸径连年生长量和对应的各年1—12月份的月均温、月降雨量、平均相对湿度的回归关系,表明油松生长与温度紧密,蒙古栎生长与水分关系紧密。

乌丹地区文冠果生物学特性及物候观测

通过野外定枝追踪,对乌丹地区文冠果年生长周期的物候、生殖过程进行连续观测,研究了文冠果的果实生长进程与有效积温的关系、数量动态和落花落果率.结果表明:文冠果物候变化与有效积温之间存在极显著的线性函数关系;雄花花丝的伸长和花药的开裂在时间上具有先后性;文冠果果实生长发育过程中经历3次落果,授粉率为26.4,落花率达73.6,落果率可达92.9,落花、落果现象十分严重;6月上中旬果实的纵径生长较快,6月中下旬果实横径生长较快,纵横径比可达2.17;个体间物候有一定的差异,不利于文冠果异株授粉和授粉率的提高.

Assembly of Seven Supramolecular Compounds with p-Sulfonatocalix[6]arene

Seven supramolecular compounds comprising p-sulfonatocalix[6]arene and transition metals, {[Cu(Imz)-(phen)(H2O)](4)[C6AS]}center dot 10H(2)O (1), {[Cu(Imz)(2)(phen)](2)[Cu(Imz)(phen)(H2O)(2)](2)[C6AS]}center dot 13.3H(2)O (2), {[M(phen)(2)(H2O)]-[(M(phen)(2)](2)[C6AS]}center dot nH(2)O (3 and 4) (3: M = Co and n = 29.6; 4: M = Zn and n = 29.9), {[Cu(phen)(2)](4)[C6AS]}(2)center dot 13H(2)O (5), [H3O](2)[Co(phen)(3)](2)[C6AS]center dot 10.7H(2)O(6), and [Cu(phen)(2)(H2O)](2){[Cu(phen)(2)](2)[C6AS]}center dot 8H(2)O(7)(phen = 1,10-phenanthroline, C6AS = p-sulfonatocalix[6]arene, Imz = imidazole), have been synthesized by a hydrothermal method and structurally characterized by IR spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA), and single crystal X-ray diffraction.

Enhanced affinochromism of polydiacetylene monolayer in response to bacteria by incorporating US nano-crystallites

By incorporating bio-specific receptors, such as p-10,12-pentacosadiyne-1-N-(3,6,9-trioxaundecylamide)-alpha-D-mannopyranoside (MPDA), into 10,12-pentacosadiyonic acid (PDA) monolayer, the MPDA/PDA monolayer underwent affinochromatic transition in response to the bacteria binding to the receptor. Here, we described a new method to study the membrane/macromolececular interaction between Escherichia coli (E coli) and mannose and its relative affinochromism by modifying MPDA/PDA with CdS nano-crystallites (MPDA/PDA-CdS). CdS not only triggered the strong tropism of the bacteria but also reduced the rigidity of the MPDA/PDA backbone, resulting in the enhanced affinochromism. This discovery might be of significance in basic biophysical studies of membrane/macromolececular and designing novel biosensor.

Chemiluminescence determination of trace ascorbic acid with chromium (VI)-H2O2-luminol system

A new chemiluminescence(CL) system for the determination of ascorbic acid has been established. By the fast reduction reaction between chromium(VI) and ascorbic acid, chromium(M was generated to react with luminol and hydrogen peroxide in alkaline aqueous solution and hydrogen peroxide to produce CL. The CL emission intensity was correlated with ascorbic acid concentration in the range 8.0 x 10(-9) to 1.6 x 10(-4) mol/L, and the detection limit was 8.0 x 10(-9) mol/L ascorbic acid. The relative standard deviation (n = 11) for 1.0 x 10(-6) mol/L ascorbic acid is 0.9%. The method has been applied to the determination of ascorbic acid in vitamin C tablets with satisfactory results.

Ceramic carbon/polypyrrole materials for the construction of bienzymatic amperometric biosensor for glucose

A novel amperometric glucose biosensor was constructed by electrochemical formation of a polypyrrole (PPy) membrane in the presence of glucose oxidase (GOD) on the surface of a horseradish peroxidase (HRP) modified ferrocenecarboxylic acid (FCA) mediated sol-gel derived ceramic carbon electrode. The amperometric detection of glucose was carried out at +0.16 V (vs. SCE) in 0.1 mol/L phosphate buffer solution (pH 6.9) with a linear response range between 8.0x10(-5) and 1.3x10(-3) mol/L of glucose. The biosensor showed a good suppression of interference and a negligible deviation in the amperometric detection.

Phase identification in a series of liquid crystalline TPP polyethers and copolyethers having highly ordered mesophase structures. 6. Structure changes from smectic to columnar phases in a series of copolyethers containing odd and even numbers of methylene units in equal molar composition

A series of liquid crystalline copolyethers has been synthesized from 1-(4-hydroxy-4'-biphenyl)-2-(4-hydroxyphenyl)propane and different alpha,omega-dibromoalkanes [coTPP(n/m)]. In this report, coTPPs having n = 5, 7, 9, 11 and m = 12 are studied, which represent copolyethers having both varying odd number and a fixed even number of methylene units. The compositions were fixed at an equal molar ratio (50/50). These coTPPs(nlm) show multiple phase transitions during cooling and heating in differential scanning calorimetry experiments. The undercooling dependence of these transitions is found to be small, indicating that these transitions are close to equilibrium, Although the coTPPs possess a high-temperature nematic (N) phase, the periodicity order along the chain direction is increasingly disturbed when the length of the odd-numbered methylene units decreases from n 11 to 5. in the coTPPs(5/12, 7/12, and 9/12), wide-angle X-ray diffraction experiments at different temperatures show that, shortly after the N phase formation during cooling, the lateral molecular packing improves toward a hexagonal lattice, as evidenced by a gradual narrowing of the scattering halo. This process represents the possible existence of an exotic N phase, which serves as a precursor to the columnar (Phi(H)) phase. A further decrease in temperature leads to a (PH phase having a long-range ordered, two-dimensional hexagonal lattice. In coTPP(11/12), the phase structures are categorized as highly ordered and tilted, smectic and smectic crystal phases, similar to homoTPPs, such as the smectic F (S-F) and smectic crystal G (SCG) phases. An interesting observation is found for coTPP(9/12), wherein a structural change from the high-temperature Phi(H) phase to the low-temperature S-F phase occurs. It can be proven that, upon heating, the well-defined layer structure disappears and the lateral packing remains hexagonal. The overall structural differences in this series of coTPPs between those of the columnar and highly ordered smectic phases are related to the disorders introduced into the layer structure by the dissimilarity of the methylene unit lengths in the comonomers.

Synthesis, properties and crystal structure of charge-transfer salt (DBTTF)(6)HSiMo12O40H2O

Charge-transfer salt (DBTTF)(6)HSiMo(12)O(40)4H(2)O was synthesized by electrocrystallization and characterized by IR spectrum and electronic spectrum. Its magnetic property, conductivity and crystal structure were determined. The title compound consists of heteropoly anions, water molecules and DBTTF columns which are formed by repeated arrangement of tetramer (DBTTF), in the direction of 15 degrees to the a axis in the tunnel constituted by the anions and other type of DBTTF. The title compound is paramagnetic and semiconducting. (C) 1998 Elsevier Science Ltd. All rights reserved.

In-situ synthesis of terbium complex with salicylic acid in silica matrix by a two-step sol-gel process

A process for in situ synthesis of terbium complex with salicylic acid by a two-step sol-gel method in silica matrix has been proposed. The luminescence properties of the silica gels codoped with terbium and salicylic acid have also been discussed with respect to that of the gel doped with terbium and that of pure terbium complex with salicylic acid.

Probing lanthanide ions binding on tRNA(Phe) by H-1 NMR

The structure of phenylalanine transfer ribonucleic acid (tRNA(Phe)) in solution was explored by H-1 NMR spectroscopy to evaluate the effect of lanthanide ion on the structural and conformational change. It was found that La3+ ions possess specific effects on the imino proton region of the H-1 NMR spectra for yeast tRNA(Phe). The dependence of the imino proton spectra of yeast tRNA(Phe) as a function of La3+ concentration was examined, and the results suggest that the tertiary base pair G(15). C-48, which is located in the terminal in the augmented dihydrouridine helix (D-helix), was markedly affected by La3+ (shifted to downfield by as much as 0.35). Base pair U-8. A(14) in yeast tRNA(Phe), which are stacked on G(15). C-48, was also affected by added La3+ when 1 similar to 2 Mg2+ were also present. Another imino proton that may be affected by La3+ in yeast tRNA(Phe) is that of the tertiary base pair G(19). C-56. The assignment of this resonance in yeast tRNA(Phe) is tentative since it is located in the region of highly overlapping resonances beween 12.6 and 12.2. This base pair helps to anchor the D-loop to the T Psi C loop. The binding of La3+ caused conformational change of tRNA, which is responsible for shifts to upfield or downfield in H-1 NMR spectra.

Synthesis and characterization of aromatic liquid crystalline poly(ester-imide)s derived from an imidodicarboxylic acid

A new class of liquid crystalline poly(ester-imide)s was synthesized by melt polycondensation. The basic physical properties of the resulting polymers were investigated by differential scanning calorimetry (d.s.c.), wide-angle X-ray diffraction (WAXD), polarized light microscopy, scanning electron microscopy (SEM), thermogravimetric analysis (t.g.a.), and rheological and mechanical testing. All of these poly(ester-imide)s were amorphous, as reflected by the results obtained from the WAXD and d.s.c. studies. Characterization and comparison of these poly(ester-imide)s with the corresponding polyesters suggested that the introduction of imide groups into the polyester chain is favourable for the formation of liquid crystalline phases. These results, together with the rheological studies, suggested that there existed a form of strong inter- or intramolecular electron donor-acceptor interaction which played a significant role in the liquid crystalline properties of the poly(ester-imide)s. The polymer products thus obtained exhibited good mechanical properties, with flexural strengths and moduli as high as 174 MPa and 6.9 GPa, respectively. The morphology of the fracture surfaces of extruded rod samples showed a sheet-like structure which consisted of ribbons and fibres oriented along the flow direction. The glass transition temperatures and thermal stabilities of the polymers were improved by the incorporation of imide groups. Copyright (C) 1996 Elsevier Science Ltd.

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.