白冠长尾雉等鸟类感染大肠杆菌的诊治

通过对患病白冠长尾雉、红腹锦鸡、褐马鸡等观赏鸟类临床观察、剖检,并结合病原微生物分离培养、革兰氏染色镜检以及生化试验鉴定,初步诊断为大肠杆菌病.本次病例表明,不同品种观赏鸟类间可以相互感染大肠杆菌病,通过对症治疗,可以有效控制病情.     

竹叶片氮含量高光谱估测方法对比研究

为实现快速无损检测竹叶片氮含量,采用波长范围为350~2500nm的地物光谱仪获取竹叶片光谱数据,以金镶玉竹叶片为样本,对其进行高光谱分析。将高光谱原始反射率及其一阶微分、对数一阶微分和二阶微分值,与化学法测量的竹叶片氮含量值进行了相关性分析,分别获得了不同微分变化下的特征波段;基于微分变换后的高光谱反射率数据,分别采用二元线性回归、多元逐步回归、偏最小二乘回归和基于主成分分析的BP神经网络方法,建立了4种金镶玉竹叶片的氮含量高光谱估测模型。对比4种估测模型的校验结果表明,在光谱反射率的对数一阶微分变换下,采用拓扑结构为6-10-1的基于主成分分析的BP神经网络估测模型,校验环节决定系数为0.838,均方根误差RMSE为0.0452,具备较好的竹叶片氮含量估测效果。     

大熊猫主食竹研究进展

(西南大学资源环境学院,重庆 400716)     

毛栓菌27-1漆酶对酚酸类化合物降解的效能分析

探究毛栓菌27-1漆酶对酚酸类化合物的降解效能,为竹林地酚酸类自毒物质降解提供依据.采用超高效液相色谱检测法,通过测定菌液处理后酚酸含量变化,研究毛栓菌27-1漆酶对10种酚酸类化合物的降解特性.结果 表明,毛栓菌27-1漆酶能完全降解酚酸类化合物中的香草酸、咖啡酸和芥子酸;丁香酸、阿魏酸和龙胆酸的降解效果一般,降解率...     

毛竹切削力的研究

为合理制定竹材切削工艺,节约切削动力,该文利用传感器技术及信号分析技术,经切削实验研究了毛竹不同切面、密度、含水率等物理性质及刀具前角、切削量与切削速度等切削参数对切削力的影响.结果表明,由于竹黄部位维管束分布较疏,所需主切削力较小;竹青部位维管束分布密集,主切削力较大.端面切削主切削力最大,纵向切削力次之,横向切削力最小;竹材密度对切削力有明显影响,且呈正相关关系.随着含水率的增大,竹材韧性增加,所需主切削力增加;当含水率超过30%之后,主切削力随含水率的进一步增加而缓慢降低.刀具前角对主切削力的影响较为显著,随刀具前角的增大,所需主切削力明显减小.主切削力与切削量呈正相关关系.切削速度对切削力的影响不大.      

国内12种常见龙船花属观赏植物鉴别与分类检索

针对目前国内对龙船花属(Ixora L.)观赏植物存在名称混乱、辨识困难的问题,通过比对植物标本、图鉴和文献资料,对12种(含变种和品种)常见龙船花属观赏植物进行了正名,归纳总结了识别要点;并以花和叶的形态、色彩及大小为基础,编制检索表。     

园林植物化感作用研究现状与问题探讨

化感作用已成为园林植物相互关系研究的热点和焦点之一。从化感作用的概念、争论焦点、研究方法、化感物质的成分及作用机制等方面系统地总结了国内外园林植物化感作用的研究成果,指出现阶段研究存在的6个方面问题并进行了分析讨论:①科学文献少,经验材料多,研究不够深入;②研究对象尚待明确,应更多基于指导实践的目的,选择实际中人工配置频繁的观赏种及品种进行研究;③化感作用的证实缺乏说服力,应区分化感作用与其他植物应激机制,注重研究化感在整个植物相互关系中的作用和地位;④实验室和自然环境之间的差异导致说服力降低,建议将实验室研究与自然环境模拟实验相结合来进行研究;⑤化感作用物质的报道少;⑥化感物质的作用机制研究不够深入,应深入研究园林植物化感作用的机理及一般规律,以指导园林植物配置。参56     

Recent developments and improvements in ornamental fish packaging systems for air transport

Current ornamental fish packaging systems are characterized by very high fish loading densities and high metabolic wastes in the transport water after shipment. They focus mainly on management of the quality of transport water. Recent studies using the guppy as a model fish showed that post‐shipment mortality could be reduced through enhancement of the stress resistance of the fish, and hence emphases should also be placed on the preparation of the fish for transport and recovery of the fish after shipment. Farmers can contribute significantly by applying nutritional prophylaxis before harvesting. Exporters may use the salinity stress test to identify fish lots of good quality for transport, apply health prophylaxis to eradicate parasites and optimize other techniques such as starvation of the fish or addition of salt to the transport water to enhance the stress resistance of the fish. Importers may adopt proper acclimation procedure and allow fish to recover in low salinity water to reduce post‐shipment mortality. As the main bulk of post‐shipment mortality is stress‐mediated and occurs during the 1‐week recovery period, the industry should consider revising the basis of the current warranty system for their customers, from death on arrival to cumulative mortality at 7 days post shipment (or death after 7 days, DA7), in order to cut down fish losses after shipment.     

日本金竹文化论

日本的金竹文化鲜明体现在古代战争、传统节日、文学等方面,具有历史悠久、内涵深刻、表现广泛等特点。近代以后金竹文化低迷,但仍然是日本竹文化中最具神圣文化内涵的部分。     

Feeding strategies for striped blenny Meiacanthus grammistes larvae

Rotifers and Artemia salina nauplii are the most widely used live prey for newly hatched larvae, but they do not always promote optimal survival and growth. Alternative food sources such as copepods, which bypass these inadequacies and promote adequate growth, are needed and they are viewed with considerable interest by the scientific community. The aim of the present study was to test two different diets [rotifers and A. salina nauplii (group A) and a mixture (group B) of rotifers/Tisbe spp. copepods and A. salina nauplii/copepods] during the larval rearing of the striped blenny Meiacanthus grammistes. The analysis of the survival rate, size (total length and wet weight) and metamorphosis time during the larval phase of this species showed that Tisbe spp. administration can significantly improve larval survival and growth and also reduce the metamorphosis time. The results obtained are related to the fatty acid content of the live prey used and are essential in order to improve the captive production of M. grammistes through a closed system and, in turn, to preserve natural stocks.