Sur un cas de variabilité chez Sphaeropsis sapinea

A case of variability in Sphaero sis sapinea . Two isolates (type I and type II) of Sphaeropsis sqinea were isolated from the co lar of a declining Cedrus deo daa in the South of France. Cultural characteristics on PDA and MEA as well as conidial dimensions were compared with those of types A and B of S. sapinea described to occur in North America. Type II was similar to type A in respect to cultural aspects and growth but distinctly different in conidial dimensions. Slower growing type I was similar to type B. However, type I grew faster on PDA, had smaller conidia and lacked microconidia. Single-conidia isolates obtained from the four types showed stability of these characteristics.     

磁处理对大豆中大豆异黄酮的作用

采用不同磁场强度不同时间处理大豆萌发种子,通过分光光度计法测量大豆异黄酮的含量。研究结果表明：磁场可以改变大豆中大豆异黄酮的含量,在不同的磁场及处理时间条件下,大豆中大豆异黄酮的含量不同。其中150mT处理1h,100mT处理1．5h的大豆中大豆异黄酮含量最大,相比对照分别增加了9．3％,11．8％。该实验结果发现,磁场强度与处理时间的乘积为150mT·h时,大豆异黄酮含量最高。     

A nine-year study of successful breeding in a Bonelli’s eagle population in southeast Spain: a basis for conservation

We analyse the factors influencing breeding success in a healthy population of Bonelli’s eagle (Hieraaetus fasciatus) from south-east Spain, a raptor that has suffered a serious decline in Europe. Between 18 and 33 pairs were annually monitored during the period 1994-2002. Several factors that may affect four breeding parameters were studied, namely human presence, vegetation, relief, climatic factors, intra- and inter-specific relationships, diet, prey abundance, nest building, adult mortality and age of reproduction. A consistently high breeding success was registered during the study period (productivity=1.43, SD=0.11), which was probably the result of high adult survival, adequate prey availability and mild weather conditions. However, a certain vulnerability to the presence of golden eagles (Aquila chrysaetos) and to human disturbance was observed. One interesting result was the reduced survival of young chicks on north-facing cliffs owing to colder conditions, which may partially explain the decline of the Bonelli’s eagle populations along its European distribution limits. We discuss the role of this healthy subpopulation in an Iberian metapopulation context, and propose that the potential interference of golden eagles should be taken into account when designing management strategies for Bonelli’s eagles. Finally, we pinpoint some conservation priorities and the importance of reducing the main causes of adult mortality (i.e. shooting and electrocution) to assure successful reproduction and survival of this species.     

基于内边缘场电容效应的树干/枝水分传感器研究

茎秆水分与茎流速率是解析植物茎秆内水分传输的2个重要参数。设计了一种基于内边缘场电容效应的树干/枝水分传感器。采用有机溶液试剂法与枝条冻融法分别对传感器做了性能测试试验,证实了传感器在相对介电常数16.8~81变化范围内具有很好的线性关系(R2=0.977 2),并从冻融-干湿等价性能看,传感器反应灵敏度满足测量要求。利用枝条脱水法得到了传感器参考标定曲线,决定系数为0.992 2。温室环境下的盆栽苹果树试验证实了该传感器既可无损观测树干细胞昼夜间的充放水过程,还可感测亏水树干内膨压崩溃与恢复过程。     

次生盐渍土垂向剖面斥水性及其与理化性质关系

为探求土壤剖面斥水性的变化规律及其与土壤水盐含量、pH值的关系,在新疆新垦膜下滴灌棉田以10 cm×10 cm和5cm×5cm的网格等间距采集两个土壤剖面样品,对剖面土壤的斥水性、含水率、含盐量和pH值了进行经典统计、地学统计和相关性分析。结果表明：次生盐渍土剖面斥水性呈中等程度变异,空间自相关性中等偏弱;土壤斥水性在40cm深度附近时最强,在大于80cm深度的土层斥水特征不明显;在0~40cm深度土层,含水率与土壤斥水性正相关,在40~80cm深度与斥水性负相关;含盐量除在0~10cm的表层与斥水性正相关外,在其余土层均为负相关; pH值与斥水性之间多为正相关。     

Assessing Silicon Availability in Soils of Rice-Growing Lowlands and Neighboring Uplands in Benin and Nigeria

Silicon(Si) is known as a beneficial nutrient in the cultivation of rice, playing a key role in photosynthesis enhancement, lodging resistance and tolerance to various environmental stress. The present study aimed to examine available Si content in both lowland soils(n = 29) and neighboring upland soils(n = 21) collected from Benin and Nigeria and to evaluate the validity of the assessment results through a pot experiment. Our results revealed that the acetate-buffer method predicted Si concentration in rice straw at the harvest stage(R~2 = 0.68, P < 0.01) better than the anaerobic-incubation method(R2 = 0.31, P > 0.05), and 76% of the uplands and 38% of the lowlands were deficient(< 50 mg/kg) in acetate-buffer soluble Si. These findings suggest that the Si-deficiency soils prevail across the study area, making rice plants starved for Si and prone to environmental stress.     

Biodiversity and Dynamics of Planthoppers and Their Natural Enemies in Rice Fields with Different Nitrogen Regimes

Biodiversity both theoretically and practically has relevance in addressing many problems of contemporary agriculture and allows the formation of functional groups that drive key ecosystem processes [1]. One of the most important processes in agroecosystems is pest regulation, because biodiversity is related closely to host-plant resistance, pest management attributes, natural biological control agents and their impacts, and stability as the ecological basis for pest management [2-3]. On one h…     

磁场影响GOD催化活性的初步探讨

本文成功地研制了ＰＶＣ葡萄糖氧化酶（ＧＯＤ）柱，用流动装置和Ｉ电极探讨了磁场对ＧＯＤ活性的影响：密闭条件下磁化，ＧＯＤ活性有所降低，敞开条件下则活性有所增强，并对其结果进行了初步探讨。     

深厚砂砾石地基墙幕结合防渗体系搭接长度优化研究

目前深厚砂砾石地基墙幕结合防渗体系普遍采用10m的经验搭接长度,针对搭接长度在设计中偏于保守的现状,结合新疆下坂地水利枢纽工程,采用了有限元数值模拟计算和归一化处理的方法,在防渗体系不同深度布置尺寸和搭接长度的情况下,建立有限元数值计算模型,对防渗墙的受力和位移进行研究分析,计算分析出新疆下坂地墙幕结合防渗体系优化搭接长度度值,并总结出墙幕优化搭接长随防渗墙修建深度的变化规律,为深厚砂砾石地基墙幕结合防渗体系的设计和施工提供一定的参考。     

基于场地分析的城市滨水绿地景观设计--以哈尔滨市马家沟任家桥-和兴桥段为例

以哈尔滨市马家沟的一段滨水绿地的景观设计为例,从场地性分析入手,提出现代城市滨水绿地规划设计的思路和策略.