Half-sandwich metal diselenolate complexes Cp#M(NO)(SePh)(2) (M = Mo or W; Cp# = Cp or MeCp) as ligands. Synthesis of selenolate-bridged heterobimetallic compounds

The reactions of half-sandwich diselenolate Mo and W complexes (CpM)-M-#(NO)(SePh)(2) (M = Mo; Cp-# = Cp' (1a), MeCp (1b); M = W; Cp-# = Cp' (1c)) with (Norb)Mo(CO)(4), Ni(COD)(2) and Fe(CO)(5) have been investigated. Treatment of (1a), (1b) and (1c) with (Norb)Mo(CO)(4) in PhMe gave the bimetallic complexes: Cp'Mo(NO)(mu -SePh)(2)Mo(CO)(4) (2a), MeCpMo(NO)(mu -SePh)(2)Mo(CO)(4) (2b) and Cp'W(NO)(mu -SePh)(2)Mo(CO)(4) (2c) in moderate yields. Irradiation of (1a) and (1c) in the presence of Fe(CO)(5) gave heterobimetallic complexes Cp'Mo(CO)(mu -SePh)(2)Fe(CO)(3) (3a) and Cp'W(NO)(mu -SePh)(2)Fe(CO)(3) (3c). Ni(COD)(2) reacts with two equivalents of (1a), (1b) and (1c) to give [Cp'Mo(NO)(mu -SePh)(2)](2)Ni (4a), [MeCpMo(NO)(mu -SePh)(2)](2)Ni (4b) and [Cp'W(NO)(mu -SePh)(2)](2)Ni (4c) in good yields. The new heterobimetallic complexes were characterized by i.r., H-1-n.m.r., C-13-n.m.r. and EI-MS spectroscopy.

Luminescent properties of Gd3PO7 : Eu in UV/VUV region

The luminescent properties of Gd3PO7:Eu were investigated in W and VUV regions. This phosphor has such strong emissions around 618.5 nn under UV excitation, especially around 209nn, that it has a better colour saturation than that of Y2O3:Eu. It could be a new potential red phosphor for lamp and other applications with W-excitation source or even for displaying devices. In the VUV excitation spectrum of Eu3+ emissions, energy absorptions by Gd3+, Gd-O and PO43- have been observed, on which it can be inferred that there are three kinds of energy transferring processes to Eu-3(+) ions. The energy absorptions of Gd3+, Gd-O and PO43- are induced by 4f --> 4f transitions, a bandgap transition of Gd3PO7 and intramolecular (2t(2) --> 2a, 3t(2)) transition, respectively. The energy transfer efficiency of the PO43- intramolecular transition is lower compared with that of the bandgap transition (Gd-O).

叔丁基取代的环戊二烯基钛、锆、铪二氯化物的合成及催化乙烯聚合

(tBuC5H4 ) 2 MCl2 (M =Ti(1a) ,Zr(1b) ,Hf(1c) )和 (tBu2 C5H3 ) 2 MCl2 (M =Ti(2a) ,Zr(2b) ,Hf(2c) )可以通过单叔丁基环戊二烯基锂或双叔丁基环戊二烯基锂与MCl4 (M =Ti,Zr,Hf)在四氢呋喃中反应制备得到 ,用IR、1H NMR和EI MS对这些化合物进行了表征 .采用X光单晶结构分析测定了 (tBuC5H4 ) 2 HfCl2 的晶体结构 .六个化合物均具有一定的催化乙烯聚合活性

用于核磁共振波谱仪三调探头电路的设计

本文叙述了用于核磁共振谱仪的单线圈三调谐探头电路的设计。单线圈三调谐探头电路同时提供三个通道不同频率信号的发射和接收,氢(~1H)通道,碳(~13C)通道,氘通道三调谐电路如图1所示.氢通道的等效电路如图2a所示,碳通道等效电路如图2b所示,氘(~2D)

KMgF_3:Eu~(2+)中电荷补偿的途径

KMgF_3,立方钙钛矿结构,空间群O_h~1。原胞内F~-位于面心,Mg~(2+)位于体心,K~+占据顶角。Mg-F间距约为2A,Mg~(2+)为六配位,K-F间距的为2.8A,K~+为十二配位。KMgF_3晶体光学透明区域宽(200～1000nm),掺入稀土离子Eu~(2+)会观察到Eu~(2+)的f→f跃迁尖峰发射,峰值位于360nm附近,KMgF_3:Eu~(2+)是短波可见固体激光晶体的候备材料。Eu~(2+)占据KMgF_3中十二配位的K~+格位,产生杂质缺陷Eu_k。形成的K~+空位通常以晶格间隙中的F~-完成电荷补偿。

Chinikomycins A and B: Isolation, structure elucidation, and biological activity of novel antibiotics from a marine Streptomyces sp isolate M045

In our screening of marine Streptomycetes for bioactive principles, two novel antitumor antibiotics designated as chinikomycins A (2a) and B (2b) were isolated together with manumycin A (1), and their structures were elucidated by a detailed interpretation of their spectra. Chinikomycins A (2a) and B (2b) are chlorine-containing aromatized manumycin derivatives of the type 64-pABA-2 with an unusual para orientation of the side chains. They exhibited antitumor activity against different human cancer cell lines, but were inactive in antiviral, antimicrobial, and phytotoxicity tests.

The dominant Ulva strain of the 2008 green algal bloom in the Yellow Sea was not detected in the coastal waters of Qingdao in the following winter

The region of Qingdao, China, experienced the world's largest green tide from May to July 2008. More than one million tons of fresh algal biomass of the green alga Ulva prolifera was harvested, while more was suspected to have sunk to the bottom. The original source of this seaweed was suspected to be from the south as revealed by satellite images. The floating biomass drifted with the water current northward and flourished in nearshore waters around Qingdao. However, direct biological evidence for "seed" source is lacking. It is still unclear whether this alga could survive the Qingdao local coastal environment and pose future danger of potential blooming. Systematic and seasonal sampling of waters in the intertidal zone at six collection sites along the Qingdao coast was conducted from December 2008 to April 2009. Forty-eight water samples were analyzed. From these, nine different morphotypes of Ulva were grown in the laboratory under standard temperature and light regimes. Growth of Ulva was observed in all water samples. However, molecular phylogenetic analyses revealed that the dominant U. prolifera strain of the 2008 bloom was absent in all the water-derived cultures during the sampling period. These results provide evidence that the dominant bloom-forming alga was unlikely able to survive the coastal waters (the minimal surface water temperature in February is 2A degrees C) in winter conditions in Qingdao, even though all the sampling locations were heavily covered by this alga in June 2008.

Bifurcation of Pacific North Equatorial Current at the surface

The grid altimetry data between 1993 and 2006 near the Philippines were analyzed by the method of Empirical Orthogonal Function (EOF) to study the variation of bifurcation of the North Equatorial Current at the surface of the Pacific. The relatively short-term signals with periods of about 6 months, 4 months, 3 months and 2 months are found besides seasonal and interannual variations mentioned in previous studies. Local wind stress curl plays an important role in controlling variation of bifurcation latitude except in the interannual timescale. The bifurcation latitude is about 13.3A degrees N in annual mean state and it lies at the northernmost position (14.0A degrees N) in January, at the southernmost position (12.5A degrees N) in July. The amplitude of variation of bifurcation latitude in a year is 1.5A degrees, which can mainly be explained as the contributions of the signals with periods of about 1 year (1.2A degrees) and 0.5 year (0.3A degrees).

An N-shape thermal front in the western South Yellow Sea in winter

An N-shape thermal front in the western South Yellow Sea (YS) in winter was detected using Advanced Very High Resolution Radiation (AVHRR) Sea Surface Temperature data and in-situ observations with a merged front-detecting method. The front, which exists from late October through early March, consists of western and eastern wings extending roughly along the northeast-southwest isobaths with a southeastward middle segment across the 20-50 m isobaths. There are north and south inflexions connecting the middle segment with the western and eastern wings, respectively. The middle segment gradually moves southwestward from November through February with its length increasing from 62 km to 107 km and the southern inflexion moving from 36.2A degrees N to 35.3A degrees N. A cold tongue is found to coexist with the N-shape front, and is carried by the coastal jet penetrating southward from the tip of the Shandong Peninsula into the western South YS as revealed by a numerical simulation. After departing from the coast, the jet flows as an anti-cyclonic recirculation below 10 m depth, trapping warmer water originally carried by the compensating Yellow Sea Warm Current (YSWC). A northwestward flowing branch of the YSWC is also found on the lowest level south of the front. The N-shape front initially forms between the cold tongue and warm water involved in the subsurface anti-cyclonical recirculation and extends upwards to the surface through vertical advection and mixing. Correlation analyses reveal that northerly and easterly winds tend to be favorable to the formation and extension of the N-shape front probably through strengthening of the coastal jet and shifting the YSWC pathway eastward, respectively.

An approach to prediction of the South China Sea summer monsoon onset

In the present paper, correlation between the South China Sea summer monsoon (SCSSM) onset and heat content in the upper layer of the warm pool in the western Pacific Ocean is examined using the Scripps Institution of Oceanography dataset for the period of 1955-1998 and an approach to prediction the SCSSM onset is proposed. Correlation showes that there exists interdecadal variability of the SCSSM onset demarcated by 1970 with the largest correlation coefficient in the area west of the center of the warm pool rather than near its centers, implying certain effect from other factors involved besides ENSO. As the correlation is poor for the period before 1970, the heat content anomaly of the warm pool after 1970 is used to indicate early or late onset of the SCSSM beforehand. An ideal representative area (1A degrees x1A degrees) for the warm pool heat content was determined with its center at 3A degrees N/138A degrees E. The nearest TAO (TAO-Tropical Atmosphere Ocean-array) mooring to the center is at 2A degrees N/137A degrees E, and chosen to calculate the heat content for prediction. It is suggested that the TAO mooring at 2A degrees N/137A degrees E could be used to predict the SCSSM onset with the heat content in the upper layer, if the correlation between the SCSSM onset and the heat content of the warm pool runs like that of after 1970. On the other hand, if the situation does like the one before 1970, the representative station is determined at 13A degrees S/74A degrees E with relatively poor correlation, meaning that the warm pool in the western Pacific Ocean plays more important role in the SCSSM onset than the Indian Ocean.

渤海近代沉积物的古地磁与古环境研究

本论文的主要实验测量工作可分为古地磁学与地球化学二大部分。在古地磁学方面。对JX91-2A（168），JX91-2B（80），JX91-3A（66）和JX91-3B（137）共451个样品进行了天然剩磁（NRM）及交变退磁测量，还进行了磁化率及磁化率各向异性的测量。对JX91-2A，JX91-2B和JX91-3A开展了岩石磁学研究，测量了非粘滞性剩磁（ARM），等温剩磁（ARM），饱和等温剩磁（FIRM）以及个别样品的FIRM衰减曲线，对JX91-3B求出了中间破坏强度（MDF）。在地球化学方面，对JX91-2A（79），JX91-3B（67），JX91-3m(50)和JX91-4G（27）共223个样品进行了X光萤光（XRF）分析。包括10种主要元素及21种向量元素，以及X光衍射（XRD）分析。还对JX91-2A进行了有机碳、微体古生物学及稳定碳氧同位素分析；对JX-91-3B进行了~（210）Pb 测量。另外还对此四岩芯测定了含水量及粒度分布等。所有实验数据都用计算机进行了分析处理，并做了广泛的多学科综合对比研究。在充分借鉴前人成果的基础上，本论文就以下四个方面的问题得到了一点新的认识。一、渤海黄河口外的浊流系统及浅水浊流沉积。这一浊流系统的存在具有多方面的证据。二、渤海沉积物的高精度年代学。对于渤海中央盆地沉积物主要采用了全新世以来的海平面变化曲线及古地磁场强度曲线确定年代，定出JX91-2A底部年代为距今8，500年。三、古地磁记录改正方法及渤海地区古地磁长期变样本曲线的建立。四、渤海古环境综合分析及黄河全新世以来的河道变迁。

八株海洋微生物次级代谢产物的研究

本论文选取4株胶州湾海洋放线菌和4株条斑紫菜丝状体相关丝状真菌，进行了次级代谢产物的分离纯化与鉴定，共得到78个单体化合物，其中10个为新颖结构。对部分纯化合物进行了抑菌，抗肿瘤活性测试，并对菌株进行了菌种鉴定。具体结果如下： 从胶州湾放线菌M491，M097，M361和M353得到40个单体化合物，其中6个为新颖结构化合物。从M491分离到14个单体化合物，包括2个新结构倍半萜15-hydroxy-T-muurolol (1a)和11,15-dihydroxy-T-muurolol (1b)，2个首次报道的微生物来源的倍半萜T-muurolol (2b)和3α-hydroxy-T-muurolol (2c)，2个新颖结构大环内酯chalcomycin C (7)和chalcomycin D (8)。制备了3-oxo-T-muurolol (2a)单晶体，纠正了前人发表的错误结构。从M353分离得到10个化合物，包括2个新颖倍半萜5-hydroxy-epi-isozizaene (28)和5,14-dihydroxy-isozizaene (30)。自M097和M361分别分离得到12个，4个已知结构化合物。 从健康条斑紫菜丝状体分离得到了12株真菌。从优势附生菌N5分离得到了12个化合物，包括phenylacetic acid (42)，p-hydroxyphenylethyl alcohol (43)和L-β-phenyllactic acid (49)等广谱抗生素和紫菜生长调节剂。 对分离自白斑病条斑紫菜丝状体真菌N27，EF8，GA4进行了次级代谢产物研究，分离得到38个单体化合物。从GA4分离得到了16个化合物，4个为新结构化合物，包括1个酰脲类化合物hualyzin (62)和3个phenalenone族新化合物7-methyl isonorherqueinone (69)，7,8-dimethyl atrovenetin (70)和8-methyl-deoxyherqueinone (73)。从真菌N27和EF8分别分离得到12个和2个已知结构化合物。 采用MTT法，对37株人体肿瘤细胞株活性表明：chalcomycin C (7)和chalcomycin D (8)具有非常强的细胞毒活性，其平均IC50分别为0.027 μg/mL和0.007 μg/mL。7,8-Dimethyl atrovenetin (71)和8-methyl deoxyherqueinone (73)具有中等细胞毒活性，其平均IC50分别为5.1 μg/mL和0.7 μg/mL。 此外，本文首次报道了几个已知化合物的细胞毒活性，分别是chalcomycin （0.015 μg/mL），kalamycin (0.06 µg/mL)，(+)-homononactic acid（1.9 µg/mL），(+)-nonactic acid（2.3 µg/mL），griseoviridin（3.9 µg/mL），cyclo（L-Trp-L-Phe）（3.3 µg/mL），WIN 64821（5.8 µg/mL）和3,5-dihydroxy-2-methyl-4-pyrone（3.3 µg/mL）。 菌种鉴定结果表明：M353归属链霉菌，GA4，N27归属青霉属，EF8归属曲霉属，N5为枝孢霉属。

唐古特大黄五个居群的核型

报道了唐古特大黄（Rheum tanguticum）5个居群的染色体数目和核型,结果如下：大武、柯曲、达卡三个居群均为2n=2x=22=2sm＋20m;吉卡居群为2n=2x=22=20m＋2M;松潘居群为2n=2x=22=2sm＋18m＋2M。大武,柯曲和吉卡居群核型类型属于1A型,达卡和松潘居群属于2A型。Q型聚类分析结果表明,5个居群在核型上存在一定分化,这可能是由不同的生境造成的。

高寒草甸土壤有机碳储量和CO2通量

选择青藏高原东北隅海北站区的4种高寒草甸土壤进行高分辨率采样，测定土壤有机碳及其^14C信号；应用^14C示踪技术探讨高寒草甸土壤有机碳更新周期和CO2通量．研究得出海北站高寒草甸生态系统土壤有机碳储量在22．12×10^4～30．75×10^4kgC•hm^-2之间，平均为26．86×10^4kgC•hm^2．高寒草甸土壤有机碳的更新周期从表层的45～73a随深度增加到数百年甚至数千年或更长．高寒草甸生态系统土壤呼吸的CO2通量变化于103．24—254．93gC•m^-2•a^-1之间，平均为191．23gC•m^-2•a^-1．土壤有机质分解产生的CO2通量变化于73．3～181gC•m^-2•a^-1之间．矮嵩草草甸土壤30％以上的有机碳贮存在土壤表层（0～10cm）的活动碳库中，土壤有机质更新产生的CO2占整个剖面有机质更新产生的CO2通量的72．8％～81．23％．响应于全球变暖，青藏高原高寒草甸生态系统土壤有机碳的储量、流量、归宿变化等问题有待进一步研究．

国产6种点地梅属植物的核型及其系统学意义

报道了点地梅属6种12个居群的染色体数目和核型。它们的染色体数目（2n）、核型公式（KF）、染色体相对长度组成（CRL）、核型不对称性系数（A. sK％）和核型类型（KT）分别为：点地梅在南京的2个居群都是2n=2x=20，KF=18m+2sm, CRL=2L+6M_2+10M_1+2S，核型KT属于1A型，但核型不对称性系数As. K％分别是55.04％和56.71％；北点地梅在内蒙古锡林郭勒和白音锡勒居群的2n=2x=20，KF分别为16m+2sm+2st+1b和16m+2sm+2st+4b，染色体相对长度组成分别是14M_2+4M_1+2S+1b和12M_2+6M_1+2S+4b，核型不对称性系数As. K％分别是57.65％和58.86％，属2A型和2B型；高原点地梅在青海玛沁县昌马河居群和兴海县温泉居群都是2n=2x=20，KF=10m+8sm+2st。但相对长度组成分别为12M_2+8M_1和4L+6M_2+6M_1+4S, As. K％分别是60.35％和62.57％，属2A型和2B型；雅江点地梅在青海玛多县巴颜喀拉山居群和大通县达坡山居群分别为2n=4x=40和20n=6x=60，KF=36m+2sm+2st和KF=46m+10sm+4st+2b, CRL=2l+20M_2+14M_1+4S和GRL=6L+30M_2+16M_1+8S+2b, As.K％分别为55.62％和58.31％，核型均属于2B；巴颜喀拉山北坡的鳞叶点地梅2n=40、60、80。西藏点地梅青湖居群中有2种细胞型：①2n=2x=24, KF=12m+6sm+6st+4b, CRL=6L+2M_2+8M_1+4S+4b, As. K％＝65.74％，核型属2B；②2n=2x=22,KF=14m+4sm(2SAT)+4st, CRL=4L+6M_2+8M_1(2SAT)+4S,As. K％=63.40％，核型也属于2B。西宁西山湾居群也有2种细胞型；①2n=3x=36, KF=36m,CRL=4L+12M_2+20M_1, As. K％=54.82％，核型属1A；②2n=3x=33,KF=33m, CRL=3L+12M_2+18M_1,As. K％=52.11％，核型属1A。点地梅属的染色体原始基数可能是x=10，在种间或种内观察到有3种核型变化：染色体非整倍性变化、多倍化和核型不对称性变化。将2倍体居群的核型和不对称性进行比较，可以看出点地梅是较对称的核型。因此，在研究的种中应是比较原始的类群。北点地梅的核型不对称性和进化程度高于点地梅而低于高原点地梅和西藏点地梅。染色体多倍化的雅江点地梅、鳞叶点地梅和西藏点地梅等在核型上也许是最进化的类群。