近年我国高效电池发展简况

近年来,电池技术有了很大发展,从铅酸电池——镍镉电池——镍氢电池,又发展到锂离子电池,能量密度提高了２～３倍,容量效率提高了１倍多,自放电率降低到较低水平。然而,能量密度始终不尽人意,它已成为制约太阳能利用、电动汽车等多项技术发展的瓶颈。研究、开发出...     

飞机维护模拟器发动机系统仿真模型研究

飞机维护训练模拟器至关重要一部分就是发动机系统模型.本文将主要研究对象即飞机地勤维护模拟器发动机系统,对发动机工作过程进行模块化分析和仿真模型研究.     

钻井工人护目镜佩戴的智能识别

工人未按规定佩戴护目镜的行为,在石油生产过程中存在着极大的安全隐患,而传统的监控设施又无法对该行为进行实时、准确的监察。为了解决这一安全隐患,文章提出了基于YOLOv4检测模型的护目镜佩戴识别技术,能够解决传统监控系统容易误报、漏报、报警反应时间长等问题,实现了更加及时、准确地获取监控信息,为钻井工人的安全提供了保障,并且能够在一定的程度上降低公司营运的成本。     

国有企业监管的国际比较及启示--国资委与国有企业的关系探讨

对比分析了德国、法国、英国等国外国有企业监管模式,通过借鉴国外经验,探讨了我国政府监管机构———国资委与国有企业的关系等问题。     

泸州老窖启动第三次创业

2013年酒类销售收入达到100亿,这是泸州老窖第三次创业的直接目标,而启动第三次创业更深层次的目的,则是要让泸州老窖无论是产品、营销,还是团队,都获得质的变化。     

永醇酒业的星级酒店策略

在许多进口酒商看来,星级酒店进入门槛高、竞争激烈、回报低。但是永醇酒业却以价格优势和专业服务,用五年的时间慢慢耕耘,最终从星级酒店中获得丰厚的回报。     

多晶硅微型电极阵列的研制

讨论了pn结对制作硅微电极阵列的局限性,提出了一种在沟道侧壁制作多晶硅电极阵列的设计和制作方法.实验结果表明,利用该方法研制的微电极阵列不仅克服了pn结的影响,能够为MEMS芯片器件提供所需的工作电压,而且也为一些小型化电极的设计及研制提供了新的思路和方法.     

Aspergillus spp., distribution, population composition and ochratoxin A production in wine producing vineyards in Greece

Vineyard surveys of 11 wine producing grape cultivars, were carried out in sixteen vineyards, in five winemaking regions in Greece, during 2002 and 2003. The occurrence of various Aspergillus spp. in bunches of berries at setting, veraison and ripening at harvest time was investigated. Aspergillus niger aggregate and A. carbonarius were predominantly isolated from sampled berries. Although the prevailing Aspergillus spp. isolates belonged to A. niger aggregate, isolates of A. carbonarius were the most efficient ochratoxin A (OTA) producers. Of 50 tested isolates of A. carbonarius 42% produced amounts of OTA, exceeding 25 ppb, while none of the 85 isolates of A. niger aggregate tested produced above 16 ppb.     

Filter for biomedical imaging and image processing

Image filtering techniques have numerous potential applications in biomedical imaging and image processing. The design of filters largely depends on the a priori, knowledge about the type of noise corrupting the image. This makes the standard filters application specific. Widely used filters such as average, Gaussian, and Wiener reduce noisy artifacts by smoothing. However, this operation normally results in smoothing of the edges as well. On the other hand, sharpening filters enhance the high-frequency details, making the image nonsmooth. An integrated general approach to design a finite impulse response filter based on Hebbian learning is proposed for optimal image filtering. This algorithm exploits the interpixel correlation by updating the filter coefficients using Hebbian learning. The algorithm is made iterative for achieving efficient learning from the neighborhood pixels. This algorithm performs optimal smoothing of the noisy image by preserving high-frequency as well as low-frequency features. Evaluation results show that the proposed finite impulse response filter is robust under various noise distributions such as Gaussian noise, salt-and-pepper noise, and speckle noise. Furthermore, the proposed approach does not require any a priori knowledge about the type of noise. The number of unknown parameters is few, and most of these parameters are adaptively obtained from the processed image. The proposed filter is successfully applied for image reconstruction in a positron emission tomography imaging modality. The images reconstructed by the proposed algorithm are found to be superior in quality compared with those reconstructed by existing PET image reconstruction methodologies.     

Gene expression profiles of Spo11-/- mouse testes with spermatocytes arrested in meiotic prophase I

Spo11, a meiosis-specific protein, introduces double-strand breaks on chromosomal DNA and initiates meiotic recombination in a wide variety of organisms. Mouse null Spo11 spermatocytes fail to synapse chromosomes and progress beyond the zygotene stage of meiosis. We analyzed gene expression profiles in Spo11(-/ -)adult and juvenile wild-type testis to describe genes expressed before and after the meiotic arrest resulting from the knocking out of Spo11. These genes were characterized using the Gene Ontology data base. To focus on genes involved in meiosis, we performed comparative gene expression analysis of Spo11(-/ -)and wild-type testes from 15-day mice, when spermatocytes have just entered pachytene. We found that the knockout of Spo11 causes dramatic changes in the level of expression of genes that participate in meiotic recombination (Hop2, Brca2, Mnd1, FancG) and in the meiotic checkpoint (cyclin B2, Cks2), but does not affect genes encoding protein components of the synaptonemal complex. Finally, we discovered unknown genes that are affected by the disruption of the Spo11 gene and therefore may be specifically involved in meiosis and spermatogenesis.