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1.
Previous work showed that females of the European tarnished plant bug, Lygus rugulipennis Poppius (Heteroptera: Miridae), produced three chemicals, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal, and that these were suspected to be components of the female sex pheromone. In field experiments, traps baited with blends of these chemicals dispensed from polyethylene vials and sachets failed to catch significant numbers of males. Here, we report more recent field experiments in which the chemicals were released from glass microcapillary tubes. A blend of hexyl butyrate and (E)-4-oxo-2-hexenal was significantly attractive to male L. rugulipennis. In addition, whereas the mixture of all three components attracted fewer L. rugulipennis males, this tertiary blend captured significantly greater numbers of males of the congeneric species Lygus pratensis than the binary mixture. The possible reasons for the success of the microcapillaries compared with other dispensers are discussed.  相似文献   
2.
Atomic force microscopy (AFM) has been used to study the surface of chocolate as well as the progress of chocolate bloom over time. Fresh chocolate was found to be relatively smooth but with deep holes. These could be pipes leading deep down into the body of the chocolate, perhaps reaching the filling. After storage for a few weeks, we observed the growth of small drops around these holes. With increasing time, these drops became larger and more structured. After further storage, a crystalline structure and bloom were revealed. These results suggest that bloom growth in pralines is a two-phase process, with drops initially forming on the surface and then bloom crystals nucleating and growing from them. Further, we deduced pipes leading down into the center of the chocolate through which the migration of filling fats can preferentially occur.  相似文献   
3.
Generating the medial surface for a general boundary representation model raises several difficulties. Problems might emerge from the complexity of the resulting equations, singularities caused by unforeseen relative boundary element positions and orientations, etc. The majority of the current algorithms are based on the topology of the boundary representation model and produce wireframes composed of straight lines regardless of the real medial surfaces. Many of the solids used in engineering can be represented by extrusions, delimited by a cross-section and an extrusion distance. This paper develops a fast and efficient method for creating the facetted approximations of the medial surfaces of extrusions generated by sweeping along the normal direction to the generating cross-section.
P. XirouchakisEmail:
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4.
音箱市场中占有率最多的英国音箱由于声音温和动听,往往是许多音响玩家心目中的首选,甚至非英国音箱不听的音响迷也大有人在。Tannoy我想不用多做介绍,许多人都应该知道它是一家来自英国的音箱制造老厂。1926年成立于伦敦的Tannoy早期是以制作销售音响电器用品起家,1940年开始Tannoy开始着手研发同轴单元,并极力发展多款音响专用的功率放大器,而第一个由Tannoy所推出的全音域同轴单元LSU-HF-15于1947年正式上市。延至今日,Tannoy曾推出像是Prestige、Westminster Royal等铭器作品,到现在都还是许多老一辈音响迷赞誉有加的音箱。随着影音多声道的演变发展,  相似文献   
5.
In software development, testers often focus on functional testing to validate implemented programs against their specifications. In safety-critical software development, testers are also required to show that tests exercise, or cover, the structure and logic of the implementation. To achieve different types of logic coverage, various program artifacts such as decisions and conditions are required to be exercised during testing. Use of model checking for structural test generation has been proposed by several researchers. The limited application to models used in practice and the state space explosion can, however, impact model checking and hence the process of deriving tests for logic coverage. Thus, there is a need to validate these approaches against relevant industrial systems such that more knowledge is built on how to efficiently use them in practice. In this paper, we present a tool-supported approach to handle software written in the Function Block Diagram language such that logic coverage criteria can be formalized and used by a model checker to automatically generate tests. To this end, we conducted a study based on industrial use-case scenarios from Bombardier Transportation AB, showing how our toolbox CompleteTest can be applied to generate tests in software systems used in the safety-critical domain. To evaluate the approach, we applied the toolbox to 157 programs and found that it is efficient in terms of time required to generate tests that satisfy logic coverage and scales well for most of the programs.  相似文献   
6.
烈焰 《大众硬件》2002,(1):53-53
本人的电脑近来一直很正常,那天在网上上闲逛,发现自己显卡新的超频工具,于是将工具下载下来对显卡大超特超。我的显卡是小影霸TNT2 M64,超频以后跑3DMark 2001测试,分数明显增加了好多,心里不禁一阵狂喜,我已经榨干了显卡的最后一滴“油水”?然而麻烦也随之而来,每次运行1个半小时左右的《极品飞车5》以后,系统就出现“罢工”现象,凭经验应该是某一部位散热不良造成的。  相似文献   
7.
Destaillats F  Angers P 《Lipids》2002,37(5):527-532
In this paper, an alternative base-catalyzed methodology for the facile derivatization in mild conditions of lipid TAG prior to FA analysis is proposed. Reagents were prepared by proton exchange between potassium tert-butoxide and either ethanol, n-propanol, n-butanol, or 2-methoxyethanol and used for the synthesis, at 40°C for 15 min, of the corresponding derivatives, which were directly analyzed by GC. This methodology can be used on a routine basis and has been applied to standard and complex natural lipid samples. Tripalmitin was used to determine optimal reaction conditions; and bovine milk fat, containing C4 to C22 acids, and celery (Apium graveolens) seed oil, characterized by a high level of petroselinic acid, were comparatively analyzed as their ethyl, n-propyl, n-butyl, and 2-methoxyethyl esters.  相似文献   
8.
A comparative analysis of methods for calculating digital holograms based on discrete transformations for various types of objects is presented. Qualitative results of synthesis and reconstruction of holograms are obtained, as well as examples of the realization of some of the types of holograms considered. The quality of digital hologram recovery is estimated by calculation of signal-tonoise ratio (SNR) and root-mean-square error (RMSE).  相似文献   
9.
N2O emissions from a fertilized humid grassland near Cork, Ireland were continuously measured during 2003 using an eddy covariance system. For most of the year emissions were close to zero and 60% of the emissions occurred in eight major events of 2–20 days’ duration. Two hundred and seven kg ha−1 of synthetic N and 130 kg ha−1 organic N were applied over the year and the total measured annual N2O emission was 11.6 kg N ha−1. The flux data were used to test the prediction of N2O emissions by the DNDC (DeNitrification – DeComposition) model. The model predicted total emissions of 15.4 kg N ha−1, 32 % more than the observed emissions. On this basis the model was further used to simulate (a) background (non-anthropogenic) N2O emissions and (b) the effect on N2O emissions of future climate perturbations based on the Hadley Center model output of the IS92a scenario for Ireland. DNDC predicts 1.7 kg N ha−1 year−1 of background N2O emissions, accounting for 15% of the observed emissions. Climate shifts will increase total annual modeled N2O emissions from 15.4 kg N ha−1 to 22.4 kg N ha−1 if current levels of N applications are maintained, or to 21.2 kg N ha−1 if synthetic N applications are reduced to 170 kg N ha−1 to comply with recent EU water quality legislation. Thus the projected increase in N2O emissions due to climate change is far larger than the decrease expected from reduced fertilizer applications.  相似文献   
10.
A number of bioactive ceramics have been researched since the development of Bioglass in the 1970s. Fluorapatite mullite has been developed from the dental glass-ceramics used for more general hard tissue replacement. Being brittle in nature, glass-ceramics are currently used mainly as coatings. This paper shows that fluorapatite glass LG112 can be used as a sputtered glass coating on roughened surfaces of Ti6Al4V for possible future use for medical implants. An AFM was used to measure the roughness of the surface before and after coating to determine the change in the topography due to the coating process as this greatly affects cell attachment. The sputter coating partially filled in the artificially roughened surface, changing the prepared topography. Osteoblasts have been successfully grown on the surface of these coatings, showing biocompatibility with bone tissue and therefore potential use in hard tissue repair.  相似文献   
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