Synthetic studies on optically active Schiff-base ligands derived from condensation of 2-hydroxyacetophenone and chiral diamines

Three optically active Schiff-base ligands have been prepared by condensation of 2-hydroxyacetophenone with (IR,2R)-(-)-1,2-diaminocyclohexane, (1S,2S)-(-)1,2-diphenylethylenediamine or R-(+)-2,2'-diamino-1,1'-binaphthalene, respectively. The products have been characterized by their IR, H-1- and C-13-NMR spectra.

A collinear light-emitting diode-induced fluorescence detector for capillary electrophoresis

A novel fluorescence detector based on collinear scheme using a brightness light-emitting diode emitting at 470 nm as excitation source is described. The detector is assembled by all-solid-state optical-electronic components and Coupled with capillary electrophoresis using on-column detection mode. Fluorescein isothiocyanate (FITC) and FITC-labeled amino acids and small molecule peptide as test analyte were used to evaluate the detector. The concentration limit of detection for FITC-labeled phenylalanine was 10 nM at a signal-to-noise ratio (S/N) of 3. The system exhibited good linear responses in the range of 1 x 10(-7) to 2 x 10(-5) M (R-2 = 0.999). (c) 2004 Elsevier B.V. All rights reserved.

Oscillatory instability of Rayleigh-Marangoni-Bénard convection in two-layer liquid systems

The oscillatory behaviour of the Rayleigh-Marangoni-Bénard convective instability (R-M-B instability) regarding two combinations of two-layer fluid systems has been investigated theoretically and numerically. For the two-layer system of Silicone oil (10cSt) over Fluorinert (FC70), both linear instability analysis and 2D numerical simulation show that the instability of the system depends strongly on the depth ratio Hr = H1/H2 of the two-layer liquid. The oscillatory regime at the onset of R-M-B convection enlarges with reducing Γ = Ra/Ma values. In the two-layer system of Silicone oil (2cSt) over water, it loses its stability and onsets to steady convection at first, then the steady convection bifurcates to oscillatory convection with increasing Rayleigh number Ra. This behaviour was found through numerical simulation above the onset of steady convection in the case of r = 2.9, ε=(Ra-Ruc)/Rac = 1.0, and Hr = 0.5. Our findings are different from the previous study of the Rayleigh-Benard instability and show the strong effects of the thermocapillary force at the interface on the time-dependent oscillations at or after the onset of convection. We propose a secondary oscillatory instability mechanism to explain the experimental observation of Degen et al. [Phys. Rev. E, 57 (1998), 6647-6659].

解不可压缩流体力学问题的降阶法Ⅲ、二阶有限元格式

在本系列文章里,我们提出一种新的求解不可压缩流体力学问题的有限元方法——降阶法。这种算法是通过寻找零散度空间V~h的一组简单的基函数从而对原来的混合有限元问题降阶来实现的。本文对于一人类解Ω(?)R~2上的NavierStokes方程的有限元格式(包括一些二阶格式和[4]中讨论的一阶格式)给出了空间V~h的基函数。最后给出几个算例。

Dy^3＋掺杂Ge-Ga-Se硫系玻璃的性质(英文)

实验制备了Dy^3+掺杂Ge-Ga—Se系统硫系玻璃样品，测试了玻璃的密度、显微硬度、可见-红外透射光谱、荧光光谱以及荧光寿命。根据玻璃的密度计算了玻璃的摩尔体积以及致密度。讨论了玻璃的这些性能随系统平均配位数的变化关系。实验结果表明：该系统中配位数大于2．67的玻璃在1．3μm具有较好的发光性能，荧光寿命在440-530μs之间，当玻璃组成位于化学门槛即平均配位数为2．73时玻璃的发光强度最强。

迷迭香（Rosmarinus officinalis L.）精油和抗氧化剂的研究

本文应用植物引种驯化，栽培学及植物化学的理论方法对引入我国的迷迭香（Rosmarinus officinalisL．）精油和抗氧化剂进行了研究．主要结果如下; 1、昆明地区的生态气候条件最适宜迷迭香生长。南京地区局部良好环境也能满足迷迭香正常生长需要。北京地区在保护栽培的情况下,迷迭香才能够安全越冬。 2、用GC-MS和GC-IR鉴定了迷迭香精油的23种成分。不同采收期精油成分含量变化有3种类型，即似单峰曲线，似8曲线和w曲线。一年生与二年生苗在精油成分含量上略有差异。与主要栽培国相比，我国不同引种地精油成分化学类型各具特点，北京地区α—蒎稀（31.58%）含量很高，南京地区富含樟脑（14.86%）乙酸龙脑酯（7.97%）和龙脑（6.90%）含量也相对较高，昆明地区则是α—蒎稀（24.32%）和1.8—桉叶油素（24.43%）含量并重。 乙酸龙脑酯含量的高低对精油香气质量优劣起关键作用。北京地区雨季来临收获（7月初）精油香气质量最好。南京地区，11月初精油香气质量也属优质。本实验未能得到高质量的昆明地区精油。 3、从迷迭香蒸油残渣中分离得到三种抗氧化成分，迷迭香酚( Rosrmanol)、鼠尾草酚(Carnosol)和迷迭香双醛（R0smadial），并用质谱，核磁做了鉴定．硫氰铁酸法、TBA法、AOM法检测了三种成分的抗氧化效能．Rosmanol对多双键不饱和脂肪酸抗氧化效果显著,Carnosol和BHT在不同双键脂肪酸中抗氧化效果稳定，Rosmadial的抗氧化效果则随不饱和双键数目的增加而降低。在猪油中，抗氧化效能的强度顺序为Rosmanol >carnosol>BR>Rosmadial。 抗氧化物质在植株体内是不断积累的。不同引种地迷选香抗氧化效能的强弱差异表现为昆明>北京>南京。 迷迭香的正己烷，两酮提取物抗氧化效能都是随着添加量的增加而增强、丙酮提取物的抗氧化效能优于正己烷提取物。 对迷迭香抗氧化剂提取工艺做了探讨，得到R-1，R—2，R-3三种小试样品，R-2，R-3的抗氧化效果优于BHT．B—l接近于BET。

全球变化下中国东北样带植物多样性梯度分析及气候-NDVI-植被的关系研究

中国东北样带（NorthEast China Transect, NECT）是位于中纬度温带以降水量作为主要驱动因素的陆地样带。本文的工作以此作为研究平台，利用生态信息系统（Ecological Information System, EIS）以及Microsoft Excel 7.0软件包建立了样带的地理数据库和植物多样性数据库，包括气候数据库、植被数据库、遥感数据库和内蒙内C_4植物数据库以及样带内生态系统特征数据库。在此基础上，主要研究了以下四个方面的内容： 1. 利用Holdridge的生命地带方法对NECT内的生物群区进行了划分。 主要是确定了生物群区间过渡带的位置与宽度，并预测了在全球变化三种模式下NECT内生物群区，尤其是过渡带的变化图景。湿度升高2 ℃后，过渡带的面积都呈扩大化的趋势。森林区对于降水量的变化反应很敏感。荒漠灌丛（即荒漠草原类型）由于其水热条件处于样带内较极端类型，因而对于全球气候变化反应也比较敏感。 2. 研究了NECT内的α、β多样性以及包括生活型、水分生态型、区系地理成分等在内的植物群落特征多样性的梯度变化规律。 研究了样带内的多样性梯度，提出了在样带内存在的α多样性测度问题以及β多样性沿样带的变化规律：样带内由东到西，β多样性逐渐升高，群落内物种被替代的速率变慢;两种植被类型边界上的两个样地之间的相似程度由东到西呈上升趋势;同一类型群落之间的物种周转率比不同类型群落间的物种周转率相对要低。同时将各个环境因子与α、β多样性作了回归分析，找出样带内决定α、β多样性的主要环境因子指标。 样带内沿43.5°N一线附近植物群落的生活型共有17类，水分生态型8类，区系地理成分包括17类，以此为基础分析了群落特征沿样带的变化规律。并探讨了生活型分布的历史地理原因。 3. 对样带气候－NDVI间的关系以及植被－NDVI的关系进行了探讨。 利用来自气象卫星的遥感数据一归一化植被指数（NDVI），和数值化后的样带1:100万植被图进行叠加，找到NECT内每种植被类型对应的NDVI值。样带内共有植被类型147种，反映在NDVI变化上的植被类型有106类。其中，自然植被101种。 影响年均NDVI分布的因子主要有经度、辐射日照百分率及7月温度，与经度呈正相关，与辐射日照时数及7月温度呈负相关。回归方程如下： NDVI = -220.426 + 3.273Lon - 80.338Ratio - 1.962T_7 (R~2 = 0.9714, F = 521.52, p < 0.001) 4. 研究了NECT内的光合功能型。 主要包括内蒙古地区的C_4植物及其生态地理特性。揭标C_4植物的分类群特性、生活型、水分生态型与区系地理成分等生态学特性。C_4植物分布的科属极其集中。C_4光合型为维管植物某些分类群（科、属、种）的特性，为它们固有的遗传特性。推断C_4起源于草本的某些科属。C_4植物为喜热、耐旱的类群。世界种、泛热带种、泛地中海种C_4植物较集中。 样带内的C_3、C_4功能型及其与环境因子的相关性。样带内C_4和C_3光合型植物组成比例由东到西表现出两高两低的趋势。分布主要与年均温和降水量呈显著相关。 提出了一种新的C_3、C_4鉴别方法。即根据野外测定的光合数据建立了C_3、C_4的判别模型： f_1(x) = -1.5493 + 0.1427Pn + 0.1035Tr + 0.3768ΔT + 0.1000Gs f_2(x) = -15.6142 + 1.0542Pn - 0.2503Tr - 0.2957ΔT + 0.6491Gs 最后，综合7个GCMs模型（GFDL，GISS，LLNL，MPI，OSU，UKMOH，UKMOL）的输出结果，利用此结果和本文建立的回归模型，模拟了样带内生物多样性的窨分布格局，并预测了末来全球变化下归一化植被指数NDVI的空间分布格局的变化。

内蒙古典型草原群落SPAC系统水运动的观测与仿真

草原不仅是陆地生态系统重要的一种类型，而且是人类赖以生存的畜牧业基地。由于草原多处于半干旱区，所以研究草原生态系统的水循环、水利用非常重要。本文对我国内蒙古草原区一个典型的群落－羊草群落的水分运动特征进行了定位观测，并在对这些观测结果进行分析的基础上，对土壤－植物－大气连续体（Soil-Plant-Atomosphere Continuum, SPAC）内的水流运动过程进行了仿真。 气孔是草原生态系统SPAC水流运动中最大的阻力项，是制约SPAC内水流通量的“瓶颈”，因此要想对该系统进行仿真首先必须建立精确的气孔导度（阻力）模型。根据1998～1999观测，羊草气孔导度主要受0～40cm土壤含水量的影响，在日的时间尺度上，用普通的线性回归模型对日均气孔导度就可以实现精确的预测，R~2可以达到96％，但是在小时的时间尺度上，仅用0～40cm土壤含水量是不够的，必须同时考虑其它环境因子的作用、构建具有一定机理基础的模型才能达到较为理想的模拟精度。现有的具有机理性质的气孔导度模型大致可以分为“Jarvis-类”和“BWB模型”（或“光合－导度”模型）。但是它们都没有充分考虑土壤水分因素对气孔导度的重要作用，所以这不符和草原区的实际情况。本文构建了一个考虑土壤水分因素的气孔导度模型，并分析了环境因素之间的互作对气孔导度的影响程度，最后这个模型被应用到了SPAC系统能量平衡和蒸散过程的模拟中去。 在降水量正常的情况下，例如1999年（年降水量344mm），羊草群落的显热通量明显高于潜热通量;在特别干旱的情况下，例如 1997年（年降水量仅280mm左右），白天甚至可能出现潜热的逆向传递;但是在湿润的年份，例如1998年（年降水量507mm），潜热通量却与显热通量相当。 在模拟植物蒸腾和群落的蒸散时需要分析叶片和冠层能量平衡，此时，往往需要简化处理，为了使这种简化更符合实际情况，所以根据羊草叶片红外辐射温度的实测结果，对羊草叶片上的能量平衡进行了分析。结果表明，太阳短波辐射对叶片能量总收入的贡献率小于30％，而来自地表和天空的长波辐射却古总收入的约74％。叶片的热辐射为双向，占叶片能量总支出的约90％。显热与潜热交换的总和才占叶片能量总支出的10％，而且在所测的时间点上两者的平均值相近，各占5％左右。在能量平衡的各分量中，长波辐射部分表现为净支出，因而可以假设短波辐射为叶片的唯一能量来源。此时，热辐射消耗其中的59％，显热潜热消耗40.1％。 将冠层分成上中下三层，分别模拟了这三层叶片以及土壤表面的能量平衡动态。与实测的各层红外辐射温度进行了对比，发现模型预测的冠层温度值与实测值的相关性良好，但是对中下层叶片温度的预测偏低。对土壤表面温度的模拟效果不好。 由于1998年降水量很大，根据蒸渗仪的观测，2m土体出现了渗漏。渗漏的出现，使得生长季末0～2m土壤贮水量与生长季初相比不但没有增加，反而减少。由于渗漏使得80～120cm土层内的粗细交界面得以贯通，该层对其上层土壤水头的蓄持能力下降，所以在1999年即使降雨强度不大也会造成渗漏的再次发生，这使得1999年生长季各月份水分平衡表现为较大的净支出。因此，实现SPAC水流成功模拟应该考虑土壤质地的成层性，以及渗漏的问题。 根据1998年波文比、涡度相关和蒸发渗漏仪联合实验的结果，对三种方法监测内蒙古草原群落蒸散的适用性进行了分析。三种仪器逐时、逐日蒸散回归关系极显著（P＝0.000），但是涡度相关的测量值往往低于其它两者。分析认为蒸发渗漏仪在逐日或者更长的取样时间间隔上能够达到足够的精度，适合于作为长期监测内蒙古草原群落蒸散量的工具，但是，由于受风压等随机因素的影响，不适用于逐时或逐分的测量。波文比在无对流逆温的天气里可以精确地测定逐刻和逐时的潜热通量，适合于作为短期的监测工具，但在更复杂的气象条件下波动幅度较涡度相关大。涡度相关法能在较复杂的天气条件下稳定地反映逐刻、逐时和逐日的潜热通量变化。但是，在内蒙古草原区现实的野外条件下，涡度相关法尚难以作为长期蒸散监测的工具。 除了对上述三,种观测方法进行比对外，还有波文比与Penman-Moteith公式、涡度相关法与Penman-Moteith公式对蒸散的监测进行了对比，发现Penman-Monteith公式在1998和1999年都低估了蒸散。分析认为，对总蒸散的低估可能来自对土表蒸发的低估。 本文最后还对SPAC系统水流各部分的模拟进行了整合，希望得到一个对整个系统的水流循环进行动态仿真的模型。

Habitat degradation of Rhinopithecus bieti in Yunnan, China

Black-and-white snub-nosed monkeys (Rhinopithecus bieti) are endemic to the Trans-Himalayas in Northwest Yunnan and Southeast Tibet between the upper Yangtze and Mekong Rivers. Based on field surveys and previous reports, we identified the dark-coniferous forest, the mixed coniferous and broadleaf forest, and oak patches as suitable habitats (SH) for the monkeys. Summer grazing lands (SGL), which were made by local people cutting and burning the dark-coniferous forest at the high altitude belt, replaced SH. To have a general view of the status of the SH in Yunnan, we estimated the areas of SH and SGL from satellite images in 1997, and compared with areas estimated from aerial photo-based maps (ca. 1958). The work resulted in: 1) the area of SH was 4,169 km(2) in 1997; 2) SGL was 1,923 km(2); 3) during the past 40 years, the area of SH decreased by 31% (1,887 km(2)), and SGL increased by 204% (1,291 km(2)); and 4) the mean size of forest patches decreased from 15.6 to 5.4 km(2). In addition, the area of SGL is positively correlated to local human population (R-2 greater than or equal to0.53), implying that the reduction and fragmentation of habitat for Rhinopithecus bieti is a result of population growth of humans, who mostly employ traditional modes of production. Only 11 monkey groups remained in the changing habitat. Considering that forests at lower elevation were also encroached upon by farmlands in a similar way, the forest ecosystem is highly threatened. The destruction will continue unless there is a change in the mode of production in the region.

鳡鱼仔稚鱼耳石的标记和其日轮的确证

用茜素络合物对鳡鱼仔鱼进行了浸泡标记,耳石上能检测到橘红色荧光标记环。100mg/L茜素络合物溶液的标记效果较差;120mg/L和150mg/L溶液浸泡后微耳石的标记率很高,矢耳石和星耳石的标记率低。标记后耳石上的生长轮数与饲养天数间呈一一对应关系,相关方程为:N=0.2663+0.9276D(n=68,r~2=0.9664)。方程的斜率0.9276与1无显著差异,证明生长轮确系日轮。鱼体长与微耳石、矢耳石及星耳石的直径间呈显著的线性关系,相关方程为:BL=66.8723LD+2.7064(n=73,r~

Forecasting Daily Chlorophyll a Concentration during the Spring Phytoplankton Bloom Period in Xiangxi Bay of the Three-Gorges Reservoir by Means of a Recurrent Artificial Neural Network

A recurrent artificial neural network was used for 0-and 7-days-ahead forecasting of daily spring phytoplankton bloom dynamics in Xiangxi Bay of Three-Gorges Reservoir with meteorological, hydrological, and limnological parameters as input variables. Daily data from the depth of 0.5 m was used to train the model, and data from the depth of 2.0 m was used to validate the calibrated model. The trained model achieved reasonable accuracy in predicting the daily dynamics of chlorophyll a both in 0-and 7-days-ahead forecasting. In 0-day-ahead forecasting, the R-2 values of observed and predicted data were 0.85 for training and 0.89 for validating. In 7-days-ahead forecasting, the R-2 values of training and validating were 0.68 and 0.66, respectively. Sensitivity analysis indicated that most ecological relationships between chlorophyll a and input environmental variables in 0-and 7-days-ahead models were reasonable. In the 0-day model, Secchi depth, water temperature, and dissolved silicate were the most important factors influencing the daily dynamics of chlorophyll a. And in 7-days-ahead predicting model, chlorophyll a was sensitive to most environmental variables except water level, DO, and NH3N.

A high throughput Nile red method for quantitative measurement of neutral lipids in microalgae

Isolation of high neutral lipid-containing microalgae is key to the commercial success of microalgae-based biofuel production. The Nile red fluorescence method has been successfully applied to the determination of lipids in certain microalgae, but has been unsuccessful in many others, particularly those with thick, rigid cell walls that prevent the penetration of the fluorescence dye. The conventional "one sample at a time" method was also time-consuming. In this study, the solvent dimethyl sulfoxide (DMSO) was introduced to microalgal samples as the stain carrier at an elevated temperature. The cellular neutral lipids were determined and quantified using a 96-well plate on a fluorescence spectrophotometer with an excitation wavelength of 530 nm and an emission wavelength of 575 run. An optimized procedure yielded a high correlation coefficient (R-2 = 0.998) with the lipid standard triolein and repeated measurements of replicates. Application of the improved method to several green algal strains gave very reproducible results with relative standard errors of 8.5%, 3.9% and 8.6%, 4.5% for repeatability and reproducibility at two concentration levels (2.0 mu g/mL and 20 mu g/mL), respectively. Moreover, the detection and quantification limits of the improved Nile red staining method were 0.8 mu g/mL and 2.0 mu g/mL for the neutral lipid standard triolein, respectively. The modified method and a conventional gravimetric determination method provided similar results on replicate samples. The 96-well plate-based Nile red method can be used as a high throughput technique for rapid screening of a broader spectrum of naturally-occurring and genetically-modified algal strains and mutants for high neutral lipid/oil production. (C) 2009 Published by Elsevier B.V.

Validation of a method of estimating age, modelling growth, and describing the age composition of Coilia mystus from the Yangtze Estuary, China

A collection of 577 Coilia mystus was made during April 2006 and 2007 from China's Yangtze Estuary to estimate the age structure and growth patterns of the population. Examination of sectioned sagittal otoliths revealed a periodic straight/curved growth pattern. The straight zone was from April to November, and the curved zone from October to May, indicating annual periodicity. Annual periodicity was also verified by margin zone analysis. The shift from a curved-zone to the next straight-zone stanza was defined as an annulus. The fish from which the otoliths were taken were 0-5 years old. The von Bertalanffy growth function was fitted to standard length (LS)-at-age data as L-S = 215.16 (1 - e(-0.53(t+0.30))) (n = 577, r(2) = 0.81, p < 0.05). The mature females included five age classes, ages 1 and 2 accounting for 74.3% of the population. The mature males included fish aged 1 and 2, those at age 1 accounting for 86.4% of the population. Mean length was smaller, and annual growth less, for mature males than for females of comparable age. The study demonstrated that the Yangtze population of C. mystus consists of more age classes than previously thought and that the age structure of the population needs to be considered in management decisions.

Determination of the surface area of common carp, Cyprinus carpio L.

A wrap method adaptation combined with AutoCAD2005 and Scion Image for Windows were used to determine the surface area of a fish. Compared with the corresponding r(2) and F of many models, the most accurate formula: S = 752.15W(0.675) (r(2) = 0.999, F = 18362.94, P < 0.0001) for estimating the surface area of common carp was obtained. Similarly, the fin formula: S = 1834.12W(0.708) (r(2) = 0.992, F = 2690.47, P < 0.0001) was also obtained for the same purpose. It was proven that these two formulae gave good estimates of surface and fin areas of four strains of common carp: Yellow-river carp, fancy carp, mirror carp and Xingguo red carp.

A novel chemiluminescent immunoassay for microcystin (MC) detection based on gold nanoparticles label and its application to MC analysis in aquatic environmental samples

A novel chemiluminescent immunoassay method based on gold nanoparticles was developed for the detection of microcystins (MCs). The immunoassay included three main steps: indirect competitive immunoreaction, oxidative dissolution of gold nanoparticles, and indirect determination for MCs with Au3+-catalysed luminol chemiluminesent system. The method has a wide working range (0.05-10 mu g L-1, r(2) = 0.9914), the limit of detection was determined to be 0.024 mu g L-1, which is much lower than the World Health Organization's proposed guidelines (1 mu g L-1) for drinking-water. The proposed method was applied to MC analysis in natural water and fish tissue samples, and most results in the proposed method were in agreement with the conventional indirect competitive enzyme-linked immunosorbent assay method, which indicated that the new chemiluminescent immunoassay was sensitive, reliable, and suitable for MC analysis in natural water and fish tissue samples.