Sex pheromone components of male <Emphasis Type="Italic">Tirathaba mundella</Emphasis> (Lepidoptera: Pyralidae)

Summary. During peak calling activity by male oil palm bunch moths, Tirathaba mundella Walker (Lepidoptera: Pyralidae), their hairpencils, wings or entire body were extracted in hexane. Gas chromatographic-electroantennographic detection (GC-EAD) analyses of hair pencil extracts revealed four compounds that consistently elicited responses from female antennae. The NMR spectrum of isolated compound 1, and mass spectra and retention indices of compounds 1–4 suggested that they were (3S,6S)-2,2,6-trimethyl-6-vinyl-tetrahydro-pyran-3-ol (1), 4-hydroxy-3-methoxy-benzaldehyde (2, vanillin), 6,10,14-trimethyl-2-pentadecanone (3), and 6,10,14-trimethyl-2-pentadecanol (4). Comparative GC and GC-MS analyses of hair pencils extract and synthetic standards confirmed these structural assignments. Moreover, comparative chromatography of synthetic and hairpencil-isolated 1 on a Cyclodex-B column (which separated the four stereoisomers with baseline resolution) revealed that male T. mundella produce the SS-stereoisomer (SS-1). In field cage bioassay experiments in Palembang, Indonesia, synthetic SS-1 and vanillin in combination, but not singly, attracted female T. mundella. SS-1 plus vanillin were as effective as male T. mundella in attracting females. Compounds 3 and 4 did not enhance the blend's attractiveness. Received October 11 2002; accepted March 14, 2003. R1D=" Correspondence to: Gerhard Gries, email: gries@sfu.ca     

Dynamics of Turbulence in Low-Speed Oscillating Bottom-Boundary Layers of Stratified Basins

This paper focuses on the impact of an oscillating low-speed current on the structure and dynamics of the bottom-boundary layer (BBL) in a small stratified basin. A set of high-resolution current profile measurements in combination with temperature-microstructure measurements were collected during a complete cycle of the internal oscillation (`seiching') in the BBL of Lake Alpnach, Switzerland. It was found that even a relatively long seiching period of 24 hours significantly changed the form of the near-bottom current profiles as well as the dynamics of the turbulent dissipation rate compared to the steady-state law-of-the-wall. A logarithmic fit to the measured current profiles starting at a distance of 0.5 m above the sediment led to inconsistent estimates of both friction velocity and roughness length. Moreover, a phase lag between the current and the turbulent dissipation of 1.5 hours and a persistent maximum in the current profile at a height of 2.5 to 3 m above the sediment were observed. The experimental findings were compared to the results of a k- turbulence model and showed good agreement in general. Specifically, the inconsistent logarithmic fitting results and the observed phase lag were reproduced well by the model.     

焙烧温度对N掺杂TiO2催化剂催化性能的影响

以Ti（SO4）2为钛源、碳酸氢铵为氮源,采用均匀沉淀法制得水合沉淀物,在N2保护下对水合沉淀物进行程序升温处理,制得了不同焙烧温度的N掺杂TiO2可见光响应催化剂.以三硝基间苯二酚为目标降解物,研究了所制备微粒在可见光区及紫外光区的光催化活性.对所制备的催化剂采用X射线衍射、热重-差热分析、傅立叶变换红外光谱和紫外-可见漫反射光谱对催化剂进行表征,研究改性催化剂的晶相结构、热稳定性、表面结构和光谱特征.结果表明：N-掺杂TiO2的可见光催化活性显著提高,焙烧温度为300℃时可见光催化活性最为优异,在不降低紫外段催化能力的同时,催化剂的吸收带边红移至468nm.     

Prenatal diagnosis of ring chromosome 6

An amniocentesis was performed on a gravida 1, para 0 23-year-old female because of high maternal serum alpha-fetoprotein and nuchal thickening/cystic mass apparent on the fetal ultrasound. Detailed ultrasound examination revealed multiple anomalies including brain abnormalities. The fetus was found to have a mosaic female karyotype: 45,XX, - 6/46,XX,r(6) (p25q27) (62 per cent:38 per cent). This is the first report of a prenatally diagnosed case of ring chromosome 6.     

民国初年灾荒史研究综述

自民国迄今,一些政治家、思想家及学者分别从自然科学角度和社会历史角度对民国初年灾荒史予以诠释,依时间而言主要集中于20世纪80年代以后,依内容而言又呈现出一种多元化的态势。其间,虽然取得了一定的成就,诸如积累了一些资料、研究内容多样化等,但仍存在着一些不足。     

The prenatal determination of glucose-6-phosphatase activity by fetal liver biopsy

Two fetuses at risk for glucose-6-phosphatase deficiency had in utero liver biopsies. Analysis of each showed this enzyme activity to be in the normal range and the pregnancies continued. Neither child has any clinical or metabolic evidence of glucose-6-phosphatase deficiency.     

中国水污染防治40年回顾与展望

改革开放40多年来,我国水污染防治工作取得巨大成效。本文通过回顾我国水污染防治发展历程和总结不同阶段我国流域水污染防治工作特点,提出了面向2035年水生态环境保护的管理建议,以期为2035年美丽中国水环境建设提供参考。     

介质阻挡放电协同Bi2WO6/天然赤铁矿降解乙酸乙酯

为强化DBD（介质阻挡放电）技术对VOCs（挥发性有机物）的处理效果,采用溶胶凝胶法制备Bi₂WO₆/NH（NH为天然赤铁矿）复合催化剂,并利用DBD协同催化剂降解EA（ethyl acetate,乙酸乙酯）.采用XRD（X射线衍射）仪、BET（比表面积及孔径）分析仪、SEM（扫描电子显微镜）分析仪对催化剂进行表征,对比分析DBD、DBD/Bi₂WO₆（DBD协同Bi₂WO₆）、DBD/NH（DBD协同NH）及DBD/Bi₂WO₆/NH（DBD协同Bi₂WO₆/NH复合催化剂）4个体系中EA去除率和能量产率随输入功率、初始ρ（EA）及气体停留时间的变化情况,同时探究输入功率和催化剂对ρ（O₃）及矿化率的影响,并对降解产物进行分析.结果表明:①在不同工艺参数条件下,EA去除率和能量产率均表现为DBD/Bi₂WO₆/NH体系> DBD/NH体系> DBD/Bi₂WO₆体系> DBD体系.②EA去除率随输入功率的升高和气体停留时间的延长而增加,随初始ρ（EA）的升高而降低;但能量产率随输入功率的升高和气体停留时间的延长而降低,随初始ρ（EA）的升高而增加.③在输入功率为84 W、初始ρ（EA）为0.40 mg/L、气体流量为1.0 m3/h的条件下,相较于DBD体系,DBD/Bi₂WO₆/NH体系中EA去除率和矿化率分别提高了19.16%和14.44%,而ρ（O₃）降低了74.47%.④DBD降解EA的最终产物主要为CO₂、H₂O及微量的CH₄、CH₃CH₂OH及CH₃COOH等小分子有机化合物.研究显示,DBD协同Bi₂WO₆/NH复合催化剂能够高效去除EA.      

基于人因可靠性的间歇装置SIL分析与改进

IEC 61508和IEC 61511等标准针对连续工艺装置提出了安全仪表系统安全完整性等级评估方法。但对于间歇装置的SIL评估，受人因因素影响水平并未明确，且没有提出相应计算模型。以某六氟磷酸锂间歇生产装置典型SIS为例，采用HAZOP结合LOPA方法对其进行风险分析，在明确间歇生产装置存在人员中毒、窒息及燃烧爆炸风险的基础上，确定并验证其安全仪表系统的SIL，再依据间歇生产装置人工依赖性高，即部分安全仪表系统未接入自动联锁且需人工手动触发的特点，建立人因可靠性模型，来分析人因可靠性对安全仪表系统SIL的影响，并进行改进研究。研究结果表明:人因因素对安全仪表系统SIL有显著影响；可通过改变SIS元件冗余结构、测试策略并结合改进人因管理措施来提高SIL。