PREPARATION AND MOLECULAR-STRUCTURE OF METHYLBIS(TERT-BUTYLCYCLOPENTADIENYL)NEODYMIUM AND METHYLBIS(TERT-BUTYLCYCLOPENTADIENYL)GADOLINIUM

Bis(t-butylcyclopentadienyl)lanthanide chloride (Ln = Nd or Gd) reacts with one equivalent of methyllithium in ether/tetrahydrofuran to give the complex [(C5H4tBu)2LnCH3]2 (Ln = Nd or Gd). The structure of [(C5H4tBu)2NdCH3]2 has been determined by X-ray analysis. The crystals are monoclinic of space group Cm with a = 9.538(2), b = 23.298(4), c = 9.505(3) angstrom, beta = 119.53(2)-degrees, V = 1828.0(7) angstrom 3, D(calc.) = 1.458 g/cm3 and Z = 2 for the dimer. The two (C5H4tBu)2Nd units in the dimer are connected by asymmetrical methyl bridges with independent Nd-C bond lengths of 2.70(2) and 2.53(2) angstrom and Nd-C-Nd angles of 94.7(9) and 87.3(6)-degrees.

四氟化铀结晶水的测定

本文叙述了测定四氟化铀结晶水的重量分析方法。这种方法简便、可靠、快速。从实验结果可见,作为一种常规分析方法,用此法测量四氟化铀和四氟化钍等的结晶水是可行的。

New life cycles of Porphyra katadae var. hemiphylla in culture

Porphyra katadae Miura var. hemiphylla Tseng et T. J. Chang, a species distributed around the Liaodong and Shandong Peninsulas of China, produces gametophytes from late winter to early spring. These are monoecious with male and female reproductive tissues in distinct halves or sectors. Vegetative tissues from sectors expected to differentiate into sexual tissue were cultured in the laboratory. Male and female reproductive organs, as well as conchocelis and blades, were differentiated from these tissues. The male and female reproductive tissues were in patches and mixed on the cultured tissue pieces. This was quite different from the wild-type sectored individuals. The F-1 conchospore germlings also produced monospores, carposporangia, spermatangia and conchocelis. These carposporangia and spermatangia were in patches and were mixed on the F-1 fronds. The results imply that P. katadae var. hemiphylla is possibly sex-differentiated rather than sex-determined. This is the first report of such a dimorphic life history in the genus Porphyra.

Morphological and genetic study of Prorocentrum donghaiense Lu from the East China Sea, and comparison with some related Prorocentrum species

In this paper, the detailed morphology of Prorocentrum donghaiense Lu from both field samples and cultures was examined, and a taxonomic comparison was made between P donghaiense and some related Prorocentrum spp. using morphological and molecular data and other published information. There were distinct differences among these species in morphological characteristics that historically have been presented as conservative features. The discrepancies extended beyond that of individual variations within the same species due to environmental factors. Therefore, these morphological features may not be conservative but, rather, polymorphic depending on environmental conditions. Based on this analysis, we suggest that the high-biomass bloom-forming species in the East China Sea, previously reported as Prorocentrum dentatum Stein, is P donghaiense Lu. The species reported from the East China Sea and Japanese and Korean waters appear to be the same species. Molecular data also suggest that P. dentatum (CCMP1517) and P. donghaiense are genetically identical. Therefore, the geographic distribution of P. donghaiense may be much wider than expected. (C) 2004 Elsevier B.V. All rights reserved.

Metabolic characteristics of sea cucumber Apostichopus japonicus (Selenka) during aestivation

Metabolic characteristics of the sea cucumber Aposticholpus japonicus (Selenka) during aestivation were studied in the laboratory. The effects of water temperature on oxygen consumption rate (OCR) and ammonia-N excretion rate (AER) in A. japonicus were determined by the Winkler and Hypobromite methods, respectively. Mature (large, 148.5 +/- 15.4 g, medium 69.3 +/- 6.9 g) and immature (small, 21.2 +/- 4.7 g) individuals aestivated at water temperatures of 20 and 25 degrees C, respectively. The metabolic characteristics of mature individuals were different from immature individuals during this period. The OCR of mature sea cucumbers peaked at 20 degrees C, and then dropped significantly at higher temperatures, whereas the OCR of the immature animals continued to increase slightly, even beyond the aestivation temperature. The AER of mature individuals peaked at 20 T, while that of the immature animals peaked at 25 degrees C. The relationships between dry weight (DW) and absolute oxygen consumption (R) and absolute ammonia-N excretion (N) could be described by the regression equation R or N=aW(b). With the exception of 15 degrees C, the O/N ratios (calculated in atomic equivalents) of large size sea cucumbers was close to 20 across the temperatures used in this study, indicating that their energy Source was a combination of lipid and protein. Oil the other hand, apart from small individuals maintained at 10 degrees C, the O/N ratios of the medium and small sea Cucumbers were close to 10, indicating that protein was their major energy source. The O/N ratios in all size groups remained unchanged after aestivation was initiated. (c) 2005 Elsevier B.V. All rights reserved.

肯塔基草地早熟禾愈伤组织的诱导及再生体系的建立

以肯塔基草地早熟禾成熟种子为外植体,研究了影响愈伤组织诱导、分化以及再生苗生根、移栽的主要因素,建立了肯塔基草地早熟禾高频再生体系.结果表明,在MS培养基上,低浓度的BA(0.1mg/L)配合2,4-D(3.0 mg/L)诱导肯塔基草地早熟禾种子出愈率达到74.9士7.35%;0.1mg/L 2,4-D在SH培养基上诱导愈伤组织分化成芽,分化率平均每块愈伤可达8.1土0.36个芽;最适生根条件为1/2MS+1.0mg/L NAA.

HPLC法测定獐牙菜及其近缘植物中4种有效成分的含量

目的:建立反相高效液相色谱法同时测定獐牙菜及其近缘植物中番木鳖酸、獐牙菜苦苷、龙胆苦苷、芒果苷的含量。方法:采用ZORBAX SB—C18(250 mm×4.6mm,5μm)色谱柱,以流动相甲醇和水(含0.04%磷酸)的比例在0-24 min内由22:78至38:62线性梯度洗脱,流速1 mL•min～1,检测波长254 nm,柱温30℃。结果:4种成分均达到基线分离,番木鳖酸、獐牙菜苦苷、龙胆苦苷、芒果苷的线性范围分别为0.05—6.25μg(r=0.9999),0.0095—2.9 μg(r=0.9998),0.0486—2.56μg(r=0.9999),0.0056—2.8μg(r=0.9998);回收率为102%(RSD=4.4%),97.7%(RSD=4.3%),99.5%(RSD=3.5%),103%(RSD=1.1%)。结论:方法测定快速,结果准确、可靠。

组织中去甲肾上腺素的荧光测定法

本文研究了去甲肾上腺素荧光分光光度测定方法。测定范围在10～100 ng 则与荧光值呈良好线性关系, λex/ λem= 410 nm/505 nm , 回收率为91.68%～ 96.64% , 标准偏差平均为6.1% (n = 10) 。本法具有准确、简便、快速等特点。

龙胆属的系统发育分析

本文运用支序分类的原理和方法,对龙胆科龙胆属的属下等级进行了重新归类和系统发育分析。龙胆属是一个单系群,以3项近裔共性为归类依据。性状分析作了性状同源性分析和性状极性分析。性状极化主要以外类群比较、性状相关性及染色体资料为依据,其它方法,如生物重演律原则、地理递进原则以及孢粉形态等也被结合使用。分析结果,双蝴蝶属和蔓龙胆属被选择为外类群,71个性状被选择作为建立数据矩阵的基本资料。使用PAUP程序对矩阵进行了运算,得到4个最简约的谱系分支图,它们均具一致性系数0.637,支序长度为160步,f-比值范围为0.179～0.189,其中具最低f-比值的图被选作为类群归类和讨论亲缘关系的基础。在支序图上龙胆属归为15个组;其中5个组又划分为系,共包括23个系,其余组为单型组,故共有33个属下类群。一个严格的一致性谱系分支图总结了所有的一致点,从而支持了支序分析的结果。

河西走廊棘豆毒草中的硒及其与牲畜中毒关系研究

河西走廊地区草原生态环境,棘豆等毒草泛滥成灾,导致大量牲畜中毒死亡。棘豆毒草导致的牲畜中毒症状与历史上马可波罗记载的古代肃州牲畜毒草中毒症状及其相似。为了确定马可波罗所记载的肃州牲畜毒草中毒是否与硒有关,本项研究对河西走廊地区主要草原畜牧区肃南县草原发育的棘豆属植物及其土壤中的硒进行了测定,测定结果表明:土壤硒含量平均值为0.205±0.173mg/kg,与世界平均土壤硒含量相近。棘豆属植物小花棘豆根、茎叶的硒平均含量分别为0.112±0.038mg/kg(0.052～0.174mg/kg),0.102±0.027mg/kg(0.066～0.158 mg/kg);黄花棘豆全株硒平均含量为0.066±0.009mg/kg(0.058～0.078mg/kg),种子硒:0.107mg/kg。可见该区棘豆属毒草硒含量远低于能导致一般动物中毒的3mg/kg植物硒含量。根据肃南县棘豆毒草发育的地理位置、牲畜中毒症状调查及其硒含量测定的结果,本文认为马可波罗所记载的中国西部肃州牲畜毒草中毒是棘豆属毒草中毒,其主要毒素成分不是硒。

云南中甸雪鸡坪和普朗斑岩铜矿容矿斑岩的地球化学特征

国家自然科学基金面上项目(40372049)；国家基础研究规划“973”项目(2002CB412605)