Bacillus pallidus sp nov., isolated from forest soil

A Gram-positive bacterium, designated strain CW 7(T), was isolated from forest soil in Anhui Province, south-east China. Cells were strictly aerobic, motile with peritrichous flagella and rod-shaped. The strain grew optimally at 30-37 degrees C and pH 7.0-8.0. The major fatty acids of strain CW 7(T) were anteiso-C-15:0, iso-C-15:0 and anteiso-C-17:0. The predominant menaquinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The G + C content of the genomic DNA was 42.3 mol%. Phylogenetic analysis indicated that strain CW 7(T) belonged to a monophyletic cluster within the genus Bacillus and showed 16S rRNA gene sequence similarities of less than 96.5% to recognized species of the genus Bacillus. The results of the polyphasic taxonomic study, including phenotypic, chemotaxonomic and phylogenetic analyses, showed that strain CW 7(T) represents a novel species of the genus Bacillus, for which the name Bacillus pallidus sp. nov. is proposed. The type strain is CW 7(T) (=KCTC 13200(T)=CCTCC AB 207188(T)=LMG 24451(T)).

蛋白质含量不同的饲料对树qu氮平衡的影响

五组成长期的树qu, 分别喂从以蛋白质含量为10%、15%、20%、25%和30%的 配合饲料,为时15d。统计学分析各组日均氮沉积量和沉积率差异极为显著(P<0.01) 。表明树qu饲料中蛋白质的含量以25%较为合适。按采食量折算生长树qu每日每千克体重应进食52.0—62.0克蛋白质。图2表9参9

Microsatellite diversity and population genetic structure of redfin culter (Culter erythropterus) in fragmented lakes of the Yangtze River

Redfin culter (Culter erythropterus) is a small lethic freshwater fish and widely distributed in the adjacent lakes of the Yangtze River of China. Five microsatellite loci were applied to investigate the genetic variation and population structure of redfin culter from seven lakes in the middle-and-lower reaches of the Yangtze River. The gene diversity was high among the populations (H > 0.9), the average number of alleles among seven populations was low with a range from 2.00 to 3.87. The mean observed (H-O) and expected (H-E) heterozygosity ranged from 0.111 to 0.419 and from 0.162 to 0.750, respectively. Significant deviations from Hardy-Weinberg Equilibrium expectation were found in 50% of the total locus-population combination tests in which heterozygote deficits were apparent. The analysis of molecular variance (AMOVA) indicated that the percentage of variance among and within these populations were 6.18 and 93.82, respectively. The Fst values (0.062, P < 0.001) among studied populations indicated that there were significant genetic differentiations among redfin culture populations from the scattered lakes with different connections to the Yangtze River. These results are useful for the evaluation and conservation of small freshwater fishes. The factors that may be involved in low intra-population polymorphism and the pattern of the population genetic structure of redfin culter from the Yangtze River were discussed.

Improvement of Ge self-organized quantum dots by use of Sb surfactant

A Sb-mediated growth technique is developed to deposit Ge quantum dots (QDs) of small size, high density, and foe of dislocations. These QDs were grown at low growth temperature by molecular beam epitaxy. The photoluminescence and absorption properties of these Ge QDs suggest an indirect-to-direct conversion, which is in good agreement with a theoretical calculation. (C) 1998 American Institute of Physics. [S0003-6951(98)00420-3].

太阳能空气饱和蒸馏器的试验研究

研究得到了太阳能空气饱和蒸馏器在稳态情况下和不同海水加热温度下的蒸发速度实验式:lgD=7.062+3.446t_0海水加热温度是影响淡水产量的主要因素，以46.2℃为转折，超过此温度，蒸发速度急促增加。液-气两相重量流量比(W/G)，必须与海水加热温度相适应。温度较高，(W/G)值也应较大，这样才能最大限度地提高产水量和降低产水的耗热量。当t_0=96℃时，(W/G)_(最佳)=12;当(W/G)=11时，t_(0最佳)=90℃。在一般太阳辐射条件下，t_0=60℃，(W/G)=1.67—3.0时，热耗值最低。过多地通入空气是空气饱和蒸馏器动力消耗较大的重要原因。在适当工况下进行操作，所需空气量较小。这样，不但产水量高、热耗值低、系统阻力减少，而且能耗大幅度降低。 模拟试验表明:太阳能空气饱和蒸馏器在太阳辐射日总量4500〔千卡/米~2〕时，每平方米集热器面积，每日可产淡水5—7公斤，所需翅片冷凝器换热面积为0.21〔米~2/时·公斤淡水〕。

抗菌不锈钢抗菌性能和机理初步研究

由于近年来有害微生物的肆虐和人们防病抗菌意识的增强，社会对各种新型抗菌材料的需求越来越迫切。抗菌不锈钢是一种兼具良好机械和抗菌性能的新型功能材料，具有广泛的应用前景。开发和推广抗菌不锈钢，具有重要的经济和社会意义。 本文以中科院金属研究所研制的两种抗菌不锈钢为研究对象，对其抗菌性能和抗菌机理进行了研究，以期为抗菌不锈钢的深入研发和推广提供理论依据。 本文获得了如下主要结论： 1．采用覆膜法研究了抗菌不锈钢的抗菌广谱性，铁素体和奥氏体抗菌不锈钢对供试的17株菌（除产气肠杆菌外），均显示了较强的杀灭作用，证明其具有抗菌广谱性。两种材料对非孢子（或芽孢）产生菌的杀灭作用强于孢子（或芽孢）产生菌。但是，两种材料对产气肠杆菌均无杀灭作用。 2．考察了铁素体和奥氏体的杀菌率随时间和菌浓度的变化情况。两种材料分别在作用3h时和9h时，对菌体浓度为1×107CFU/mL的大肠杆菌（ATCC25922）的杀菌率均达到99.5%。对菌体浓度≤1×107CFU/mL的大肠杆菌在24h内均可全部杀灭。 3．随打磨次数的增加，抗菌率没有变化，表明打磨不影响铁素体和奥氏体抗菌不锈钢的抗菌性能；抗菌率不受温度的影响，0～37℃之间，未观察到抗菌率受温度变化的明显影响。 4．从抗菌不锈钢中溶出的铜在杀菌过程中可能起重要作用。铁素体和奥氏体抗菌不锈钢与添加了终浓度为1mmol/L的EDTA的菌液作用后，杀菌率分别降为46.8%和38.8%，因为EDTA络合了溶液中的金属离子，间接表明铜离子在杀菌过程中起重要作用。 5．两种抗菌不锈钢中O2-的产生速率分别为0.117 nmol•min-1•g-1和0.107nmol•min-1•g-1，显著高于普通不锈钢（0.062 nmol•min-1•g-1）。细胞膜不饱和脂肪酸过氧化的终产物丙二醛含量分别为1.96 nmol/g和1.93 nmol/g。显著高于普通对照的1.08 nmol/g，表明存在脂肪酸被氧化的现象。这些结果为抗菌过程中存在O2-的氧化杀菌作用提供了间接证据。 6．通过透射电镜和原子力显微镜观察，与抗菌不锈钢作用后的细胞外形多发生变化，细胞壁和细胞膜破裂，细胞内容物漏出，有的菌体完全溶解为碎片，显示两种不锈钢对细胞膜和细胞壁形态的显著影响。随作用时间延长，菌液中钾离子浓度亦显著升高，在3h时，分别达到2.57mg/L和2.79mg/L（普通对照为1.61mg/L）。 7．在巯基氧化实验中，添加终浓度为5 mmol/L的L-cys，作用8h，铁素体的抗菌率降为11.1%,薄层层析结果显示，半胱氨酸可能被氧化成胱氨酸，表明抗菌不锈钢可能对还原性酶具有氧化作用。 8．提取与抗菌不锈钢作用后菌的DNA，凝胶电泳观察并未出现smear现象。表明在本实验条件下尚不能检测到抗菌不锈钢对细菌遗传物质的氧化切割作用。 关键词： 抗菌材料 抗菌不锈钢 抗菌性能 抗菌机理 O2-

碳离子局部照射对荷瘤小鼠存活时间和血常规的影响

目的观察碳离子局部照射对荷瘤小鼠存活时间和血常规的影响。方法将30只荷瘤小鼠随机均分为3组(0、1、24Gy组),用碳离子单次局部照射小鼠右后肢,分别在第0、7、14天计数外周血白细胞和血小板数,并记录小鼠生存时间。结果各组动物存活时间无显著性差异。照射后白细胞数都逐步升高,但与对照组(0Gy组)相比无显著性差异;除24Gy组第14天时血小板数显著升高外(P=0.032,F=4.062),照射后各组血小板数无明显变化。结论碳离子局部照射小鼠右后肢对动物存活天数和血常规无显著影响。

混凝土薄壳球形水窖结构的优化设计

分析球形水窖空间结构的应力分布情况并进行几何尺寸优化,避免建设者根据经验来确定球形水窖的厚度、构造及混凝土标号,以节省建窖材料,同时防止应力不足而发生破坏。【方法】利用基于ANSYS平台新开发的窖体有限元分析软件,对实际中窖壁厚度为4和11 cm的混凝土薄壳球形水窖进行空间结构应力分析,同时以水窖耗材量最小为目标函数,以许用应力和变形量为约束条件,对其进行几何尺寸优化。【结果】计算得出窖壁厚度为4和11 cm的水窖最大拉应力分别为1 380.00和447.31 kPa,最大压应力分别为5 153.20和1 896.70 kPa;优化出空窖不利工况下容积为20,30和40 m3的球形水窖窖壁最佳厚度,即栗钙土地区分别为0.051,0.061和0.065m,黄土地区分别为0.050,0.059和0.062 m。【结论】经软件优化计算后的球形水窖结构,既能满足强度和刚度的要求,同时也最大限度地节约了材料用量;利用新开发的窖体结构优化分析软件,能够对球形水窖进行空间应力分析与结构优化,可以作为球形水窖设计软件。

油松水源保护林人工诱导更新与定向恢复机理

以油松水源保护林为对象,进行人工诱导更新与定向恢复机理研究。结果表明,在郁闭林分内油松更新苗密度平均为5 375株.hm-2,更新苗年龄为1~2年,而在人工Gap“效应岛”样地内,更新苗密度平均为17 062.5株.hm-2,其中1~2年、3~4年、5~6年生更新苗分别占73.44%,13.97%和12.59%;生长季光照强度在0、1.5和2.0 m三个不同高度梯度上,在Gap内部的平均值分别为289.0×100、542.0×100和589.0×100 lux,在对照林分内分别为139.0×100、146.0×100和246.0×100lux;从夏季观测到的空气温度平均值日变化分析,在白天Gap内的温度高于郁闭林分内部,温差可差2~3℃,在夜间Gap内的温度低于郁闭林分内,温差可差0.5~1℃;在白天6:00~11:00,人工Gap“效应岛”内空气湿度明显低于郁闭林分内,在其它时间段大致相当;对于同一层次土壤而言,Gap内的土壤温度明显高于郁闭林分内且变化幅度大,在0、10和20 cm三个梯度上Gap与郁闭林分相比土壤温度最大差值分别可达10、5和2℃;0~10、10~20和20~30 cm三个层次平均土壤含水量在Gap内分别为16.9%1、5.1%和12.3%,在郁闭林分内分别为14.6%、12.5%和9.9%。总体上比较二者的光照强度、空气温度、空气湿度、土壤温度、土壤水分等有显著差异,因此人工Gap“效应岛”的创建是诱导其内部微环境因子变化的基础,也是油松水源保护林定向恢复更新的机理之所在。

Syntheses and crystalline structures of clusters Co-3(CO)(7)(mu(3)-S)(mu, eta(2)-SCNR2)

Through the reaction of Co-2(CO)(8) with four thiuram [R2NC(S)S](2), four new sulfur-capped trinuclear cobalt carbonyl clusters Co-3 (CO)(7) (mu(3)-S) (mu, eta(2)-S* C* NR2) ( I : R = Me; I : R = Et; II : R = i-Pr; IV : NR= -N [GRAPHICS] were prepared and characterized by elementary analysis, IR,H-1 NMR and MS spectroscopy. The crystal structure of the cluster Co-3(CO)(7)(mu(3)-S)[mu, eta(2)-S*C*N (i-Pr)(2)]( III) was determined by X-ray single crystal diffraction method. The crystal of m is monoclinic, belonging to space group P2(1)/n, and the cell parameters are as follows: a = 1, 145 2(2) nm, b = 1. 502 8(3) nm, c = 1, 214 4(2) nmj alpha = 90 degrees, beta = 92, 15(3)degrees, gamma = 90 degrees; V = 2. 088 5(7) nm(3) , Z = 4, F (000) = 1 096, D-c = 1. 747 mg . m(-3), mu = 2. 588 mm(-1), R=0. 040 7, R-w=0. 062 4, The structural analysis shows that cluster II has a pyrimidal Co3S framework and contains a heterocylic bridging bidentate ligand [mu, eta(2)-S* C* N (i-Pr)(2)] linked to the Co2 and Co3 atoms of the cluster by a cobalt-carbon and a cobalt-sulfur bond respectively.

Synthesis, structure characterization and transesterification of the complexes of beta-alkoxycarbonylethyltin trichlorides

Thirteen title complexes ROCOCH2CH2SnCl3 . L(R = C(1 similar to 5)alkyl;L = DBSO,HMPA) were synthesized and characterized by elemental analysis, IR,H-1 NMR. The crystal structure of n -PrOCOCH2CH2SnCl3 . DBSO was determined by the X-ray diffraction analysis. The crystal belongs to orthorhombic system,space group P2(1)2(1)2(1) with a = 1.062, b = 1.427, c = 1.635nm; Z = 4. The complex exists as a discrete molecule, and the tin atom attains a distorted octahedral geometry via the coordination of intramolecular carbonyl oxygen and the Lewis base donor atom. The transesterification of CH3OCOCH2CH2SnCl3 . L with alcohol was studied, and the intramolecular Lewis acid catalytic mechanism was suggested.

β-烷氧羰基乙基三氯化锡配合物的合成、结构表征及酯交换反应

合成了13个标题化合物POCOCH_2CH_2SnCl_3·L(R=C_(1～5)烷基;L=DBSO,HMPA),通过元素分析、IR和~1H NMR进行了表征.n-PrOCOCH_2CH_2SnCl_3·DBSO的晶体结构分析表明,该晶体属正交晶系;空间群P2_12_12_1;a=1.062,b=1.427,c=1.635nm;Z=4.该化合物为含有分子内碳基配位和Lewis碱配体配位的具有畸变八面体构型的单分子有机锡化合物.研究了CH_3OCOCH_2CH_2SnCl_3·L和醇的酯交换反应,提出了分子内Lewis酸催化的反应机理.

STUDIES ON OLEFIN-COORDINATING TRANSITION-METAL CARBENE COMPLEXES .20. SYNTHESIS OF 1,3-CYCLOHEXADIENE(DICARBONYL) [ETHOXY(ARYL)-CARBENE]IRON COMPLEXES AND THEIR PHOSPHINE ADDUCTS - CRYSTAL-STRUCTURE OF C6H8(CO)2FEC(OC2H5)C6H4CH3-O

Reaction of 1,3-cyclohexadiene(tricarbonyl)iron (1) with ortho-substituted aryllithium reagents ArLi (Ar=o-CH3C6H4, o-CH3OC6H4, o-CF3C6H4) in ether at low temperature, and subsequent alkylation of the acylmetalates formed with Et3OBF4 in aqueous solution at 0-degrees-C or in CH2Cl2 at -60-degrees-C gave the 1,3-cyclohexadiene(dicarbonyl)[ethoxy(aryl)carbene]iron complexes (eta4-C6H8)(CO)2FeC(OC2H5)Ar (3, Ar = o-CH3C6H4; 4, Ar = o-CH3OC6H4), and the isomerized product (eta3-C6H8)(CO)2FeC(OC2H5)C6H4CF3-o (5), respectively, among which the structure of 3 has been established by an X-ray diffraction study. Complex 3 is monoclinic, space group P2(1) with a = 8.118(4), b = 7.367(4), c = 14.002(6) angstrom, beta = 104.09(3)-degrees, V = 812.2(6) angstrom3, Z = 2, D(c) = 1.39 g cm-3, R = 0.056, and R(w) = 0.062 for 976 observed reflections. Complexes 3 and 5 were converted into the chelated allyliron phosphine adducts(eta3-C6H8)(CO)2(PR31)FeC(OC2H5)Ar (6, Ar = o-CH3C6H4, R1 = Ph; 7, Ar = o-CH3C6H4, R1 = OPh; 9, Ar = o-CF3C6H4, R1 = Ph), by reaction with phosphines in petroleum ether at low temperatures.

STRUCTURE OF THIAMINE BROMIDE SESQUIHYDRATE

3-[(4-Amino-2-methyl-5-pyrimidinyl)-methyl]-5-hydroxyethyl-4-methylthiazolium bromide sesquihydrate, C12H17N4OS+.Br-.1.5H2O, M(r) = 372.28, monoclinic, P2(1)/a, a = 11.676 (2), b = 24.819(7), c = 12.344 (3) angstrom, beta = 113.74(2)-degrees, V= 3274 (1) angstrom3 , Z = 8, D(x) = 1.51 g cm-3 (Mo Kalpha) = 0.71069 angstrom, mu = 26.2 cm-1, F(000) = 1528, T 293 K, R = 0.062 for 2720 observed reflections. Both the independent thiamine molecules A and B in the asymmetric unit adopt the common F conformation. A bromide anion is held by four neighbouring thiamine molecules through C(2)-H...Br hydrogen bonds and Br ... thiazolium-ring electrostatic interactions. Another bromide anion (or a water molecule) bridges the pyrimidine and thiazolium moieties of molecule A (or B) through a hydrogen bond with the amino group and an electrostatic interaction with the thiazolium ring.