4种不同生境的蟹类金属硫蛋白cDNA的克隆与比较

利用Carcinus maenas金属硫蛋白氨基酸序列资料，用全简并引物从鳃组织总RNA中扩增并克隆了首个甲壳类金属硫蛋白cDNA片段序列，3'-RACE获得了其编码区全长cDNA。之后，用部分简并的引物扩增并克隆了其它3种国内常见蟹类的金属硫蛋白cDNA编码区全长序列。序列分析结果表明，几种蟹的金属硫蛋白cDNA序列存在差异，推知的氨基酸序列也不完全相同，比较不同蟹的cDNA和氨基酸序列数据不能证明不同生态环境对金属硫蛋白的分子进化起重要作用。图4表1参15     

Restrictive dermopathy and fetal behaviour

We report three siblings from consecutive pregnancies affected with restrictive dermopathy (RD). During the second pregnancy, fetal behavioural development and growth were studied extensively using ultrasound at 1–4 week intervals. Dramatic and sudden changes occurred in fetal body movements and growth but not until the end of the second trimester of pregnancy. Prominent at that time were prolonged periods of fetal quiescence and very low heart rate variability, together with abnormally executed body movements of short duration. Retarded femoral development and jerky abrupt fetal body movements (abnormal movement quality) were already present in the early second trimester of pregnancy. Facial anomalies emerged despite the presence of fetal mouth movements. The clinical features of RD were only partly explained by present knowledge of skin development and the fetal akinesia deformation sequence hypothesis. Quantitative assessment of fetal movements proved to be a poor early marker for antenatal diagnosis of this disorder. Copyright © 2001 John Wiley & Sons, Ltd.     

Hunting Increases Dispersal Limitation in the Tree Carapa procera, a Nontimber Forest Product

Abstract:  The sustainability of seed extraction from natural populations has been questioned recently. Increased recruitment failure under intense seed harvesting suggests that seed extraction intensifies source limitation. Nevertheless, areas where more seeds are collected tend to also have more intense hunting of seed-dispersing animals. We studied whether such hunting, by limiting disperser activity, could cause quantitative dispersal limitation, especially for large crops and for crops in years of high seed abundance. In each of four Carapa procera (Meliaceae) populations in French Guiana and Surinam, two with hunting and two without, we compared seed fate for individual trees varying in crop size in years of high and low population-level seed abundance. Carapa seeds are a nontimber forest product and depend on dispersal by scatter-hoarding rodents for survival and seedling establishment. Hunting negatively affected the proportion of seeds dispersed and caused greater numbers of seeds to germinate or be infested by moths below parent trees, where they would likely die. Hunting of seed-dispersing animals disproportionally affected large seed crops, but we found no additional effect of population-level seed abundance on dispersal rates. Consistently lower rates of seed dispersal, especially for large seed crops, may translate to lower levels of seedling recruitment under hunting. Our results therefore suggest that the subsistence hunting that usually accompanies seed collection is at the cost of seed dispersal and may contribute to recruitment failure of these nontimber forest products. Seed extraction from natural populations may affect seedling recruitment less if accompanied by measures adequately incorporating and protecting seed dispersers.     

联合改良剂对桉树吸收重金属的作用——以矿区土壤中Cd、Zn和Cu为例

通过5种矿区土壤的盆栽试验,研究了联合改良剂对桉树部分生理指标、根中Cd、Zn和Cu的含量、以及土壤中Cd、Zn和Cu的BCR提取形态的影响,探讨了其对矿区土壤还林的作用.结果表明,与对照相比,施用改良剂后桉树的生物量和叶绿素含量的增幅分别为-7.6%~158.8%和-0.7%~23.1%,丙二醛含量的降幅为2.6%~37.9%,其中部分处理的生物量和丙二醛含量的变化达到显著水平（P<0.05）;土壤中有效态Cd、Zn和Cu的含量分别下降12.5%~63.8%、1.6%~54.7%和16.2%~57.6%,桉树根中Cd、Zn和Cu的含量分别下降3.1%~56.6%、-1.5%~21.3%和9.3%~50.1%.土壤对桉树根中Cd、Zn和Cu的含量有显著影响（P<0.05）,改良剂的配比或施用量无显著影响（P>0.05）,但在5种矿区土壤中G3降低桉树根中Cu含量的效果优于G1和G2;在重金属含量最高的2种土壤中,G1降低桉树根中Cd和Zn含量的效果优于G2和G3.研究表明施用联合改良剂能降低桉树对重金属的吸收,有利于矿区土壤的还林.     

铝合金的实验室盐雾试验腐蚀行为图像特征提取

目的提取铝合金材料在盐雾箱试验中可以表征腐蚀程度的表面形貌图像特征量。方法首先,对采集于表面化学清洗过的试样原始图像进行图像增强等预处理,突出腐蚀部位;其次,基于数字图像处理的分形和小波分解方法提取出分形维数和小波能量特征值。结果与以质量损失量为基础的腐蚀深度特征值进行相关性对比,基于图像分析的特征提取法的准确度和精度比较高。结论该方法可以应用于对试样的腐蚀程度进行定性和定量分析,判断并预测试样的腐蚀速度。     

石墨炉原子吸收光谱法测定海河下游水中痕量镉

原子吸收光谱法直接测定高盐水中痕量镉时，有很大背景吸收和误差。本文采用络合—萃取技术使共存元素与待测元素分离，既消除了基体干扰，又达到了富集作用，使测定结果准确可靠。     

超临界二氧化碳萃取－GC／MS测定土壤中的多环芳烃

本文开发了一种采用超临界二氧化碳萃取土壤中多环芳烃、不须经过纯化步骤，直接可用于ＧＣ／ＭＳ分析的简便、高效的方法。本实验中超临界革取的流体是二氧化碳，改善剂是５％的二氯甲烷／甲醇，萃取温度为１２０℃、压力为３４ＭＰａ。ＧＣ／ＭＳ分析时除了采用外标外，还加入了６种同位素ＰＡＨｓ内标以校正各段ＰＡＨｓ的响应因子。采用本方法成功地测定了我国未开垦森林土壤中的ＰＡＨｓ。     

膜、柱串联固相萃取-高效液相色谱法测定水中多环芳烃(PAHs)的研究

建立了用膜-柱串联固相萃取(SPE)技术,甲醇和水作为流动相进行梯度洗脱,紫外和荧光检测器串联的高效液相色谱法(HPLC)分析水中EPA优先监控的16种PAHs的方法.     

毛细柱气相色谱法测定废水中的三氯乙醛

讨论了用毛细柱气相色谱法测定废水中三氯乙醛的方法。该方法用(2+1)石油醚-乙醚萃取废水中的三氯乙醛,方法的相对标准偏差4.9％,回收率91.2％～101.1％,最低检出限4×10~(-2)ng。     

Determination of organophosphorus pesticides and related compounds in water samples by membrane extraction and gas chromatography

A membrane extraction-gas chromatography method was developed fordetermination of organophosphorus pesticides and related compounds including methamidophos, DDVP, dimethoate, methyl parathion, parathion, thiophosphoric acid trimethyl ester, and thiophosphoramidic acid dimethyl ester in water samples. In thismethod, surface-modified acetic cellulose membranes were used to extract the target analytes in water samples, the extracted analytes were back-extracted into a small amount of methanol, andgas chromatography with pulsed flame photometric detector (GC-PFPD) was used to determine the concentrations of targetanalytes in the extracts. The recoveries obtained for thetarget analytes spiked into the water samples ranged from 66to 94%. The method detection limit for each target analyte was 0.05 g L^-1. The method developed in this study had shown the advantages of being cheap, simple, fast, and reliable. It had been used successfully to determine the concentrations of target analytes in river water samples.