用兆欧表测霓虹灯管的好坏

对于霓虹灯管的好坏判断,在业余情况下,若没有测试霓虹灯管的专用仪器是无法判断的。笔者经实践发现,利用1000V兆欧表（电工称摇表）能顺利地实测出霓虹灯管的好坏,具体测法如下;     

Pollutant emissions from gasoline combustion. 1. Dependence on fuel structural functionalities

To study the formation of air pollutants and soot precursors (e.g., acetylene, 1,3-butadiene, benzene, and higher aromatics) from aliphatic and aromatic fractions of gasoline fuels, the Utah Surrogate Mechanisms is extended to include submechanisms of gasoline surrogate compounds using a set of mechanism generation techniques. The mechanism yields very good predictions of species concentrations in premixed flames of n-heptane, isooctane, benzene, cyclohexane, olefins, oxygenates, and gasoline using a 23-component surrogate formulation. The 1,3-butadiene emission comes mainly from minor fuel fractions of olefins and cyclohexane. The benzene formation potential of gasoline components shows the following trends as functions of (i) chemical class: n-paraffins < isoparaffins < olefins < naphthalenes < alkylbenzenes < cycloparaffins < toluene; (ii) carbon number: n-butane < n-pentane < n-hexane; and (iii) branching: n-hexane < isohexane < 2,2,4-trimethylpentane < 2,2,3,3-tetramethylbutane. In contrast, fuel structure is not the main factor in determining acetylene formation. Therefore, matching the benzene formation potential of the surrogate fuel to that produced by the real fuel should have priority when selecting candidate surrogate components for combustion simulations.     

农药残留检测对独立、第三方实验室的需求

诺安检测服务有限公司是中国第一家世界级独立于政府、研究机构．行业协会、贸易协会及任何可能利益相关者的食品检测实验室。公司成立于2003年。一直致力于为需要质量数据来评估和评断其食品质量安全的种植、生产、采购、销售企业或品牌提供优质的检测、食品链咨询和培训服务,通过提供全方位,个性化的解决方案帮助客户提高其产品或服务的价值。主要检测服务：农药残留、兽药残留、微生物、重金属、食品添加剂、营养标签等。     

Stochastic dynamic output feedback stabilization of uncertain stochastic state-delayed systems

This paper addresses the problem of stochastic dynamic output feedback (SDOF) stabilization for a class of stochastic continuous-time state-delayed systems with norm-bounded nonlinear uncertainties. The aim is to design a linear, delayless, and SDOF control for all admissible uncertainties. The designed control ensures stochastically exponentially stability in the mean square, independent of the deterministic time delay. Using the Finsler's lemma, the necessary and sufficient conditions for the existence of such a control are proposed in terms of certain linear matrix inequalities. These results are illustrated with a simple example to demonstrate the applicability of the proposed design approach.     

Fluorescence microscopy: established and emerging methods, experimental strategies, and applications in immunology

Cutting-edge biophysical technologies including total internal reflection fluorescence microscopy, single molecule fluorescence, single channel opening events, fluorescence resonance energy transfer, high-speed exposures, two-photon imaging, fluorescence lifetime imaging, and other tools are becoming increasingly important in immunology as they link molecular events to cellular physiology, a key goal of modern immunology. The primary concern in all forms of microscopy is the generation of contrast; for fluorescence microscopy contrast can be thought of as the difference in intensity between the cell and background, the signal-to-noise ratio. High information-content images can be formed by enhancing the signal, suppressing the noise, or both. As improved tools, such as ICCD and EMCCD cameras, become available for fluorescence imaging in molecular and cellular immunology, it is important to optimize other aspects of the imaging system. Numerous practical strategies to enhance fluorescence microscopy experiments are reviewed. The use of instrumentation such as light traps, cameras, objectives, improved fluorescent labels, and image filtration routines applicable to low light level experiments are discussed. New methodologies providing resolution well beyond that given by the Rayleigh criterion are outlined. Ongoing and future developments in fluorescence microscopy instrumentation and technique are reviewed. This review is intended to address situations where the signal is weak, which is important for emerging techniques stressing super-resolution or live cell dynamics, but is less important for conventional applications such as indirect immunofluorescence. This review provides a broad integrative discussion of fluorescence microscopy with selected applications in immunology.     

Comparison of inflammatory microRNA expression in healthy and periodontitis tissues

MicroRNAs (miRNAs) are short RNA molecules that negatively regulate gene expression primarily by degrading target mRNA or inhibit the translation of protein product. Recently, many reports have shown the altered miRNA expression in various diseases. However, there are no reports on miRNA expression related to periodontitis. Thus, this study aimed to compare the miRNAs differentially expressed in healthy and chronic periodontitis tissues and to determine the miRNAs closely associated with chronic periodontitis. To find out the miRNAs differentially induced in healthy and chronic periodontitis tissues, miRNA microarray was carried out and the expression of miRNAs was confirmed by real-time PCR. According to miRNA microarray analyses, six miRNA genes, let-7a, let-7c, miR-130a, miR301a, miR-520d, and miR-548a, were up-regulated more than 8 fold compared to the healthy gingiva. The expression of twenty-two miRNAs was increased more than 4 fold. Among these miRNAs, eight miRNAs which are known to be closely related to inflammation were selected. Six of these miRNA genes, miR-181b, miR-19b, miR-23a, miR-30a, miR-let7a, and miR-301a, were amplified successfully and increased much more in periodontitis gingivae than in healthy ones. In summary, this study indicate that six miRNAs up-regulated in periodontitis gingiva may play a key role in chronic periodontitis.     

Atmospheric correction of ocean color imagery: use of the junge power-law aerosol size distribution with variable refractive index to handle aerosol absorption

When strongly absorbing aerosols are present in the atmosphere, the usual two-step procedure of processing ocean color data-(1) atmospheric correction to provide the water-leaving reflectance (rho(w)), followed by (2) relating rho(w) to the water constituents-fails and simultaneous estimation of the ocean and aerosol optical properties is necessary. We explore the efficacy of using a simple model of the aerosol-a Junge power-law size distribution consisting of homogeneous spheres with arbitrary refractive index-in a nonlinear optimization procedure for estimating the relevant oceanic and atmospheric parameters for case 1 waters. Using simulated test data generated from more realistic aerosol size distributions (sums of log-normally distributed components with different compositions), we show that the ocean's pigment concentration (C) can be retrieved with good accuracy in the presence of weakly or strongly absorbing aerosols. However, because of significant differences in the scattering phase functions for the test and power-law distributions, large error is possible in the estimate of the aerosol optical thickness. The positive result for C suggests that the detailed shape of the aerosol-scattering phase function is not relevant to the atmospheric correction of ocean color sensors. The relevant parameters are the aerosol single-scattering albedo and the spectral variation of the aerosol optical depth. We argue that the assumption of aerosol sphericity should not restrict the validity of the algorithm and suggest an avenue for including colored aerosols, e.g., wind-blown dust, in the procedure. A significant advantage of the new approach is that realistic multicomponent aerosol models are not required for the retrieval of C.     

Remote sensing of ocean color: assessment of water-leaving radiance bidirectional effects on atmospheric diffuse transmittance

Two factors influence the diffuse transmittance (t) of water-leaving radiance (L(w)) to the top of the atmosphere: the angular distribution of upwelling radiance beneath the sea surface (L(u)) and the concentration and optical properties of aerosols in the atmosphere. We examine these factors and (1) show that the error in L(w) that is induced by assuming L(u) is uniform (i.e., in treating the subsurface reflectance by the water body as Lambertian) is significant in comparison with the other errors expected in L(w) only at low phytoplankton concentration and then only in the blue region of the spectrum; (2) show that when radiance ratios are used in biophysical algorithms the effect of the uniform- L (u) approximation is even smaller; and (3) provide an avenue for introducing accurate computation of the uniform L(u) diffuse transmittance into atmospheric correction algorithms. In an Appendix the reciprocity principle is derived for a medium in which the refractive index is a continuous function of position.     

利勃海尔在bauma 2004上的展示

利勃海尔LTM1400／1型全路面起重机具有卓越的操控性、优异的起重能力。后桥独立转向、全电子监控、先进的吊车控制系统、数据总线系统、全自动伸缩臂系统，大大增强了起重机的操控性、工作效率和安全性，使其更进一步满足石化、电建，设备租赁以及其他行业客户的需求。在德国bauma展会上，赢得很高的赞誉。