Synthesis and structural characterization of V(IV) and V(V) containing mixed-valence heteropolytungstogermanates

V(IV) and V(V) containing mixed-valence heteropolytungstogermanates have been prepared by controlled potential reduction of corresponding GeW9V3O407-, their electronic spectra have been recorded. The ESR spectra of one-electron-reduced anions in solution at 340K consist of more than 40 equally spaced lines, showing that the three VO6 octahedra in both alpha- and beta-forms are corner-shaped and one of the bridging oxygen atoms is protonated at pH 4.7.

Direct visualization of collapse process of porphyrin monolayers and porphyrin exclusion for mixed monolayers at the air-water interface

The collapse process of porphyrin monolayers at the air-water interface was studied by Brewster angle microscopy and by compression-recompression isotherms. It was found that the start of collapse observed by BAM is accordant with that measured by compression-recompression isotherms. The behavior of mixed monolayers was studied also and the results showed that porphyrin islands were excluded from mixed monolayers at 35mN/m.

Bilayer formation of two chiral ferroelectric liquid crystal molecules at the air-water interface

The bilayer formation behavior of two chiral ferroelectric liquid crystal molecules at the air-water interface was studied.

Single-chain single crystals of gutta-percha

Single-chain single crystals of gutta-percha have been observed by transmission electron microscopy of atomizer-sprayed particles deposited from a very dilute solution in chloroform onto a carbon film which had a filter paper wetted with ethanol in contact with its under side. Selected-area electron diffraction patterns of crystals having no definite crystal profiles showed that the crystals were of the low-melting crystalline form and that the chain segments in the single crystals were standing up from the substrate during crystallization. In cases of single crystals showing sharply defined crystal profiles, electron diffraction patterns showed that they were neither of the low-melting form nor the high-melting form. The structure of this new crystalline modification needs further studies.

A method to identify the collapse of monolayers at the air-water interface

The collapse behaviour of phthalocyanine monolayers at the air-water interface was studied by means of compression-expansion isotherms. Measurements of two cycles of compression-expansion isotherms of copper tetrakis (4'-benzyloxy-4-phenylsulfonylphenoxy) phthalocyanine showed that the difference in the area per molecule at target pressure between the first cycle and the second cycle was dependent on the target pressure. This difference was used to identify the collapse of monolayers at the air-water interface. The transfer behaviour of monolayers at the air-water interface onto a substrate at different target pressures was also studied.

Mass spectrometric evidence for the generation of benzyne from benzoyl peroxide in thermolysis

Benzoyl peroxide gave rise to benzoic acid (at m/z 122) in its electron impact mass spectrum, and its perdeuterated counterpart produced perdeuterobenzoic acid, C6D5CO2D, at m/z 128 under the same conditions, An intramolecular hydrogen abstraction is proposed for the formation of benzoic acid from the peroxide in thermolysis. As a result of this reaction, benzyne would be generated simultaneously. Anthracene was employed to trap any of the reactive intermediate benzyne. Collision-induced dissociation of the ion of m/z 254 from the mixture of benzoyl peroxide and anthracene indicated that triptycene was obtained by the trapping reaction, therefore confirming that benzyne is generated from benzoyl peroxide in thermolysis.

有机磷化合物的质谱研究 Ⅲ.O-乙基-N-异丙基(取代硫脲基)硫代磷酰胺酯

本文对新合成的19个O-乙基-N-异丙基(取代硫脲基)硫代磷酰胺醋进行了质谱研究。讨论了P—N键的断裂,包括简单断裂和重排反应、失HS·反应及硫脲N上不同取代基的影响等问题。在亚稳态测定和高分辨精确质量测量的基础上得到了这类化合物的断裂规律和质谱特征。

Four viral proteins of white spot syndrome virus (WSSV) that attach to shrimp cell membranes

White spot syndrome virus (WSSV) is a major shrimp pathogen that has a widespread negative affect on shrimp production in Asia and the Americas. It is known that WSSV infects shrimp cells through viral attachment proteins (VAP) that bind with shrimp cell receptors. However, the identity of both WSSV VAP and shrimp cell receptors remains unclear. We used digoxigenin (DIG)labeled shrimp hemocyte and gill cell membranes to bind to WSSV proteins immobilized on nitrocellulose membranes, and 4 putative WSSV VAP (37 kDa, 39 kDa and 2 above 97 kDa) were identified. Mass spectrometric analysis identified the 37 kDa putative VAP as the product of WSSV gene VP281.

海洋中天然高分子有机物来源、结构物片以及碎屑小生境非平衡态现象的研究

海洋高分子有机物在水生态系统中具有很重要的作用。以生化稳定性为特征的腐植质能促进生物细胞的呼吸和营养盐吸收；腐化过程使生化反应的中部分生物转化为相对的物质从而增加生态系统中有机物的稳定性；腐植质还参与液－液、液－固和气－液界面过程对许多微量元素的生物地球化学循环有很大的影响。论文首次用GDX－102树脂从硅藻代谢产物和分解产物中分离提取腐植质（EHS、DHS）以及乙醇可溶物（EES、DES）。用~1H-NMR、IR和紫外光进行结构分析并同海水腐蚀植质（HS）和乙醇可溶物（ES）进行比较。在测定~3H-NMR谱时，样品先在加有NaOD和D_2O溶液中溶解50天，结果得到结构信息十分丰富的谱图。HSEHS和DHS经碱水解后，许多小分子（如甲酸、甲醇、醋酸等）从大分子网络中释放出来，在~1H-NMR谱中出现许多离散尖峰，反映了它们前体物质的相似性。HS、EHS、和DHS都含有较多的高支链烷烃、碳水化合物和氨基酸结构及少量的芳烃和杂环化合物。另外，EHS和DHS中含有许多活性基团如腈基（可能是蛋白质、核本和卟啉的分解产物）、参键等，说明其仍处于腐植化过程中。结果表明，浮游植物分解产物和代谢产物是海水植质的重要来源。~1-NMR和IR谱表明，ES、EES和DES结构差别较大。ES和DES含有大量高支链烷烃（可能来源于藻类中的类脂化合物），而在EES中烷烃含量相对很少。ES、EES和DES具有不同类型的羰基（IR谱上的吸收峰分另为1720cm~(-1)、1750cm~(-1)、1680cm~(-1)）；另外，三者与氧、氮相连的α－碳上的质子类型也有很大不同。EES的低含量高支链烷烃（高支链烷结构不易被细菌降解）以及DES中含有复杂的降解产物组份表明它们潜在的不稳定性。海洋环境中广泛存在着松散的絮状聚合物－－海洋雪。海洋雪是光合作用过程和营养盐循环的重要场所，作为大洋中特殊微环境－－碎屑小生境具有和周围水体明显不同的生化性质，如有很高的新陈代谢活性，在海洋的物质、能量流动中起着重要作用。实验研究了碎小生境演分过程中特殊营养盐迁移过程和脱氢酶活性的变化，认为碎聚合物表面不仅有微生物群落的演替，而且存在非平衡过程的连续变化。当碎表面有机物氧化，O_2被消耗碳出现氧化还原电位梯度时，在时间分布上NO_3~-、SO_4~(2-)、CO_3~(2-) 可分别成为缺微区代谢过程的最终电子受体。而碎小生境氧化还原电位梯度的存在使一些要求不同氧化还原势的过程紧靠在一起进行，即在碎屑表面分布上存在不同的电子最终受体。具有特殊性质的碎屑小生境允许一些在周围水体中不能进行或受抑制的特殊营养盐迁移过程（如固氮、硝化、反硝化、氨化甚至发酵）在碎屑表面进行。对于碎屑小生境非平衡态过程的改变，作为一种适应，微生群落重新调节新陈代谢，在分叉点附近，脱氢酶活性增大。因此，碎屑小生境是一个时空有序的半封闭结构。论文还对碎屑小生境的涨落和稳定性机制作了探讨。

合成孔径雷达提取海面风、浪信息研究

传统海洋测量方法例如岸基观测站、船只和浮标等方式只能对海面进行单点观测，存在很多不足之处：观测点少，只能获得有限的点的资料，无法得到大范围的海面信息；费用较高，无法大范围的密集观测；传统方法受天气影响较大，无法长时间的连续观测；星载合成孔径雷达能全天候、全天时、高分辨率对海面成像，能实现多波段、多极化、多视角得观测海面，提供大范围、高精度的实时动态海面信息。同时，这种全天候、全天时和高分辨率观测海洋的优势是可见光和红外传感器所没有的。总之研究如何从SAR影像中有效地获取海面信息具有重要的科学和实用意义。 自从1978年Seasat卫星发射以来SAR图像就广泛的应用于海洋要素的反演如海面风场、波高、平均周期。其中对海面风场的反演研究的最多，一般的方法是首先对SAR图像进行快速傅立叶变换得到SAR图像谱，通过图像谱的峰值信息能够得到具有180°模糊的风向，利用SAR图像的条纹或者浮标等外部信息来消除180°模糊确定风向，其次把风向和图像的正交后向散射截面数值(NRCS)带入经验函数CMOD4通过迭代计算得到风速。这种方法得到的海面风场需要外部信息的辅助，不利于大范围的业务化的反演海面风场。因此本文试图直接通过SAR图像来反演海面风场而不利用其他外部信息的帮助。2002年3月1日发射的ENVISAT卫星所获得的ASAR图像具有不同于ERS系列的SAR图像的新特点：不同入射角的情况下获得ASAR图片、双极化数据以及可以获得更宽的带幅的图像。双极化数据可以同时地提供同极化和交错极化的影像，两种极化的数据能够增加分辨目标的能力和提供目标更多的信息，这方面的优势也使得利用双极化的数据来消除SAR图像反演风场中的180º模糊问题提供了可能。本文推导了利用双极化的ASAR图像反演海面风场的新函数，该函数是在同极化和交错极化函数的基础上推导出来的，有效的消除了只用一副ASAR图片反演风场所固有的180º模糊现象。风速和风向的反演结果与Quikscat数据之间的均方根误差分别为0.53 m/s和2.21º。该方法与传统方法的比较可以看出新方法与浮标数据以及Quikscat数据符合的更好。 利用SAR图像来反演海浪的波高也是一个研究的比较多的领域。比较传统的方法是由SAR图像得到的海浪谱计算出波高，目前国际上比较流行的SAR图像反演海浪谱的模式有两种：一种是Hasselmann（1991）提出的在Max－Planck Institute（MPI）发展起来的方法，Hasselmann（1996）进行了改进和完善。另一种是Mastenbroek和de Valk（2000）提出的半参数化反演方法。这两种方法的最主要的缺点就是需要引进外部信息(WAM模式结果或者散射计的风的信息)来消除图像所固有的180°方向模糊问题。而本文应用的经验函数方法(CWAVE)不需要引进任何外部信息而直接得到海浪的重要参数－有效波高(Hs)，输入该经验函数的参数主要有：波模式图像的雷达截面、图像方差以及由SAR谱得到的20个参数。这些参数的选择是通过逐步回归方法进行筛选的。CWAVE经验函数的系数是通过6000幅全球分布的ERS-2波模式的图像谱拟合同时同地点的WAM模式结果得到的。利用CWAVE经验函数反演了1998年9月到2000年11月两年多的全球接近一百万的ERS-2 SAR图像的有效波高，利用NOAA浮标数据对反演结果进行了验证，他们之间的相关系数为0.83, 均方根误差为0.61m，偏差为0.02 m；反演结果也与欧洲中长期预报中心(ECMWF)的ERA-40有效波高资料和高度计资料进行了比较，结果表明该方法是通过SAR图像反演Hs的一种有效方法。 SAR的反演结果也应用于有效波高的非线性统计分布的研究。结合动力学和随机统计学原理推导了海面高度、波高和有效波高的非线性统计分布，同时利用了NOAA浮标数据、华师大的波高数据以及SAR的有效波高数据分别对推导出的非线性统计分布函数进行了检验。 SAR的结果也用来反演新的风浪成长关系： ，与已有的风浪成长关系的比较表明该成长关系与已有的结果比较一致。

Effects of body size and water temperature on food consumption and growth in the sea cucumber Apostichopus japonicus (Selenka) with special reference to aestivation

To investigate the effects of body size and water temperature on feeding and growth in the sea cucumber Apostichopus japonicus (Selenka), the maximum rate of food consumption in terms of energy (C-maxe; J day(-1)) and the specific growth rate in terms of energy (SGRe; % day(-1)) in animals of three body sizes (mean +/- SE) - large (134.0 +/- 3.5 g), medium (73.6 +/- 2.2 g) and small (36.5 +/- 1.2 g) - were determined at water temperatures of 10, 15, 20, 25 and 30 degrees C. Maximum rate of food consumption in terms of energy increased and SGRe decreased with increasing body weight at 10, 15 and 20 degrees C. This trend, however, was not apparent at 25 and 30 degrees C, which could be influenced by aestivation. High water temperatures (above 20 degrees C) were disadvantageous to feeding and growth of this animal; SGRe of A. japonicus during aestivation was negative. The optimum temperatures for food consumption and for growth were similar and were between 14 and 15 degrees C, and body size seemed to have a slight effect on the optimal temperature for food consumption or growth. Because aestivation of A. japonicus was temperature dependent, the present paper also documented the threshold temperatures to aestivation as indicated by feeding cessation. Deduced from daily food consumption of individuals, the threshold temperature to aestivation for large and medium animals (73.3-139.3 g) was 24.5-25.5 degrees C, while that for small animals (28.9-40.7 g) was between 25.5 and 30.5 degrees C. These values are higher than previous reports; differences in sign of aestivation, experimental condition and dwelling district of test animals could be the reasons.

Biological activity of a red-tide alga - A-tamarense under co-cultured condition with bacteria

The relationship between Alexandrium tamarense (Lebour) Balech, one of red-tide alga, and two strains of marine bacteria, Bacillius megaterium(S-7) and B. halmapulus(S-10) isolated from Xiamen Western Sea, was investigated by evaluating the growth state of A. tamarense and the variation of P-glucosidase activity in co-culture system. The results showed the growth and multiplication of the alga were related with the concentration, genus speciality of the bacteria, and growth stage of the alga itself. The growth of A. tamarense was obviously inhibited by S7 and S, at high concentration. Either inhibition or promotion contributed much more clearly in earlier than in later stage of the growth of the alga. Furthermore, there was a roughly similar variation trend of the activity of extra-cellular enzyme, beta-glucosidase, in the water of the separately co-cultured bacteria S-7 and S-10 with the alga. The beta-glucosidase activity (beta-GlcA) rapidly increased during the later algal growth accompanying the increase of the lysis of the alga cells. The obvious inhibition of A. tamarense by marine bacteria at high concentration and evident increase of beta-GlcA in co-colture system would help us in better understanding the relationship between red-tide alga and bacteria, and also enlightened us the possible use of bacteria in the bio-control of red-tide.

Studies on mass summer mortality of cultured zhikong scallops (Chlamys farreri Jones et Preston) in China

Mass mortalities of cultured zhikong scallops (Chlamys farreri) have occurred each summer in most culture areas of northern China since 1996. Among the hypothesized causes are high culture density, infectious disease and genetic inbreeding. To investigate these potential agents, C. farreri were deployed at three densities (low, medium and high) at three sites (Jiaonan, Penglai and Yantai) in the summer of 2000. Scallops were sampled for survival, growth and histopathology before, during and after a mortality episode. Most of the mortality occurred in July and August, during and toward the later part of the spawning season, when water temperature reached 23-26 degrees C. Final cumulative mortalities reached 85% to 90% at all three sites. Scallops in the medium and high densities had higher initial death rates than did those at the low density. High densities also inhibited growth. Ciliates from the genus Trichodina, larvae of various organisms and anomalous secretions were observed in sections of the gill cavity, with highest prevalence during and at the end of the mortality period. Prokaryotic inclusion bodies were found in the soft tissues, but their prevalence was low and apparently without correlation with mortalities. Genetic analysis with random amplified polymorphic DNA markers showed slightly lower heterozygosity in the cultured stocks (0.301) than in the wild stocks (0.331). It is possible that the mortalities are caused by a combination of several factors such as stress associated with reproduction, high temperature, overcrowding and poor circulation in the growout cages, opportunistic invaders or pathogens, and possibly inbreeding. (c) 2005 Elsevier B.V. All rights reserved.

Growth characters and photosynthetic capacity of Gracilaria lemaneiformis as a biofilter in a shellfish farming area in Sanggou Bay, China

Experiments on growth characters and ecological functions of the macroalgae Gracilaria lemaneiformis, collected from south China, were conducted in polyculture areas of kelp and filter-feeding bivalve in Sanggou Bay in Weihai City, Shandong, in north China from May 2002 to May 2003. The results of 116 days cultivation showed that the average wet weight of alga increased 89 times from 0.1 to 8.9 kg rope(-1), with an average specific growth rate ( based on wet weight) of 3.95% per day. The most favorable water layer for its growth was 1.0 - 1.8 m below the surface in July and August, with an average specific growth rate of 8.2% per day in 30-day experiments. Photosynthetic activity changed seasonally, with an average of 7.3 mg O-2 g dw(-1) h(-1). The maximum rate (14.4 mg O-2 g dw(-1) h(-1)) was recorded in July, or 19.3 mg CO2 g dw(-1) h(-1), while the minimum (0.40 mg CO2 g dw(-1) h(-1)) was in April. This study indicated that the culture of G. lemaneiformis is an effective way to improve water quality where scallops are cultivated intensively.