Isolation,identification, and function of the Dufour gland secretion ofXylocopa virginica texana (Hymenoptera: Anthophoridae)

The Dufour's gland secretion ofXylocopa virginica texana possesses short-term repellency for conspecifics when applied to passion flowers. This secretion contains a number of straight-chain hydrocarbons. The two major components are the methyl esters of palmitic and myristic acid. A mixture of the two esters and two of the available hydrocarbons were as effective as the Dufour's gland extract in eliciting a response in females to the passion flower,Passiflora incarnata, to which the extract was applied.Approved as TA13387 by the Director, Texas Agricultural Experiment Station and conducted in cooperation with the USDA. Supported in part by NSF-DEB-76-03963.     

率直、快速、驱动力强劲——Golden Sound Vacuum Tube Pre Vacuum Tube Mono Amplifier 200

说起Golden Sound这个品牌，对于国内的发烧友来说，它是一个非常陌生的名字。而实际上，Golden Sound早年是以代工音响线材而闻名的。由于自身具备线材的生产技术，后来就干脆以Golden Sound作为品牌推出各种各样的音响线材。当中，Golden Sound所生产的高规格HDMI线材更是得到了视频发烧友们的肯定。不过，Golden Sound除了生产线才之外，在近年还生产音箱以及放大器，而且其价格一点儿也不便宜。     

WiMAX：策划通向全球宽带移动性的新途径

介绍了WiMAX在试验、实际部署、频谱分配等方面的最新成果，在固定或移动，WiMAX方面的机会，分析了WiMAX正在进行中的部署及遇到的挑战以及测试和测量的重要性。     

全新Delta，“驾势”登场——试听Classé CDP-102CD／DVD播放机

Classé公司在1980年成立于加拿大法语区的魁北克省蒙特利尔，中文译名“驾势”（“驾势”一词源自粤语，大概意思是威风，猛）。初期是以生产音频放大器为主，设计的目的是将音响重播出来的声音能和现场的距离拉近。     

速度与厚度兼备——Audioquest(线圣)Colordo(科罗拉多)平衡式音频信号线

自从上期介绍过AQ的HDMI音视频连接线后,读者兴致很浓。我们这次不妨将视线转移到Hi-Fi发烧友感兴趣的发烧线材上,就为大家带来AQ的另一款发烧级音频信号线——Colordo(科罗拉多)。相信每一位音响发烧友都听过"换线等于换器材"这句话了,而通过这句话可以看出线材在一套音响系统里面是多么重要的一部分。自从一些著名品牌,包括AQ开启发烧线材理念后并经过多年的发展,各品牌线材无论在导体的材质、绞合方式、屏蔽、避震以及焊接等方面都作出大幅的改良,使线材从音响附件慢慢地被列为音响器材的一部分。     

重现模拟魅力感受音乐神韵——Amari(阿玛尼)LP-200黑胶唱盘

黑胶唱片,俗称LP,这种以模拟方式来记录声音信号的媒体出现至今已经长达半个世纪之多了。在黑胶唱片的发展过程中,曾带动整个音响业制造出不少高级的黑胶唱盘系统。例如:英国的Nottingham、SME、Linn,德国的Thorens,瑞士的Goldmund,美国的Rockport Technology以及以使用气浮技术而著称的瑞典Forsell等品牌,都是HI-END音响界中的耀眼明星。即使面对CD、SACD、DVD-Audio等现今数码音乐光盘的普及状态下,黑胶唱片仍然以其独特的"模拟味道"以及优秀的音乐表现能力而成为相当一部分发烧友的至爱。而且黑胶唱片的制造工艺比较复杂,能有效地减少盗版制品的产生。综合以上种种情况,一些厂商最近纷纷推出高级黑胶唱盘系统以满足喜欢模拟声音的发烧友,Amari(阿玛尼)LP-200就是其中之一。     

体现Hi-End精粹尽显高贵品位——Marantz (马兰士) SA-11S1/SC-11S1/SM-11S1 Hi-Fi音响系统

Model 7 9、CD63SE、Project T—1、VP11S1……相信涉足音响领域的发烧友们都会知道这些型号的影音器材均出自日本音响制造名厂Marantz(马兰士)。从过往的模拟LP年代到现今高清数字时代,Marantz都推出了相应的产品来面向市场(?)至今天,Marantz的产品已经发展得相当多元化,而且产品的覆盖面很广,既能满足到高端音响发烧友的需要,又能照顾到普罗大众的消费群体,因而让它能化当今风云变幻的影音市场中依然站在时代的前列而屹立不倒。由于Marantz是以生产Hi-Fi音响起家的公司,在推出AV产品之余,Hi-Fi音响产品的生产从未间断过,而SA-11S11SACD机、SC-11S1前级放大器以SM-11S1功率放人器就是新推出的一套定位于高端系列的Hi-Fi音响组合。     

Development and validation of an analytical method for total amitraz in fruit and honey with quantification by gas chromatography-mass spectrometry

The EU maximum residue limit (MRL) definition for amitraz is 'the sum of amitraz plus all its metabolites containing the 2,4-aniline moiety, expressed as amitraz'. A rapid and sensitive method has been developed and validated in-house for the determination of total amitraz in pears, strawberries, oranges and honey. Samples were hydrolysed (under acidic followed by alkaline conditions) to convert amitraz to 2,4-dimethyaniline, which was then partitioned into 2,2,4-trimethylpentane prior to quantification by gas chromatography-mass spectrometry. The method was validated at 0.02 and 0.1 mg kg^-1 amitraz (well below MRL requirements) with a lowest calibrated level (LCL) for 2,4-dimethylaniline of 0.002 mg kg^-1 (equivalent to 0.0024 mg kg^-1 amitraz). A single partition step yielded recoveries of ∼60% (with % CV values in the range 3.3-8.2), which is satisfactory for screening purposes. A second partition increased recoveries by 10-20%, making the method suitable for the quantification of residues.