植物病害化学防治概念的演变

预测植物病害化学防治的未来,任何人似乎都很有信心。然而,现在在探索新的杀菌剂研究中所有效进行的工作,都是在计划新的研究战略,希望从中能产生下一代的防治措施。发现、开发和登记新的农药品种所需的漫长时间和巨大费用,迫使工业界采取稳健的研究开发模式,它对新产品的成功率具有显著的影响力,因此任何时候,试验方法或程序只能作细微的变化,所以说新农药发现的原则的变化几乎是不可理解和预知的。     

一种结构新颖的热交换器

<正> 最近,笔者研制了一种结构新颖的热交换器。这种热交换器可在很大程度上克服常规热交换设备所存在的两个不足之处,即换热表面的污染和密封垫圈的泄漏。新的换热器采用了新的结构和新的流体运动模式,相比现有的其他各种换热设备,它能向使用单位提供更多的便利。 在常规换热器使用过程中,被加热或冷     

冠带层新平台技术

子午线轮胎出现不久，就采用钢丝带束层代替了纤维带束层，这对于实现子午线轮胎提高使用寿命和改善操纵性能的潜能是必要的。     

Progress and recent trend in MILD combustion

Moderate or intense low oxygen dilution(MILD)combustion plays a significant role in the mitigation of combustion-generated pollutants and greenhouse gases whilst meeting thermal efficiency needs.However,due to the lack of the fundamental knowledge on this combustion,there is a misconception that MILD combustion should be established by high preheating of the air,which has limited its application.Our research and development on this combustion has been performed for several years. We have found that the requ...     

高浓度二氧化硫以工业用氧在沸腾层转化器氧化

使用工业用氧焙烧铜精矿和黄铁矿精矿可得到高浓度二氧化硫(50%—90%SO_2)的炉气。在接触法硫酸生产中用氧来氧化,过程可增强3—7倍,并直接制得100%SO_3和65%发烟硫酸。在固定层转化器进行此过程,对于从触媒层排出热和在过剩氧很小时氧化二氧化硫,都有一定的困难。而且设备体积大,管理和操作复杂。至于循环法仅适于处理洁净的SO_2和O_2(不少于99%)。     

Nonstationary filtering of transmission tomograms in high photon counting noise

The algorithm presented here for nonstationary constrained least-squares filtering deals with the transmission photon counting noise problem in the presence of limited dosages and highly nonhomogeneous fields. This technique consists of a design for a set of nonstationary filters, tuned to local noise autocorrelation functions in the reconstructed image. Estimates of noise properties can be taken from object detection information. The approach yields improvement in the tradeoff between noise levels and resolution of the image by exchanging artifacts for less colored noise, which is more easily overcome by the viewer.     

小型轧机的铸造轧辊

1.前言在上个世纪末,轧辊制造工艺还不很完善,材质为简单的普通铸铁。辊身在冷型中铸造,而辊颈在砂模中铸造,见图1.在冷型中的部分由于具有较高的冷却速度可以得到富碳化物的辊身表面;在砂型中的部分由     

抽水蓄能机组设计经验

抽水蓄能电站机组的设计必须保证高峰负荷运行的高可用性和可靠性。在过去50多年间。阿尔斯通公司为提升机组运行性能、效率和可靠性,不断改进其设计。深入研究了阿尔斯通公司设计和安装可逆式抽水蓄能电站的经验。     

俄罗斯兴建基斯罗古布斯卡亚潮汐电站的经验

以基斯罗古布斯卡亚（Kislogubskaya）潮汐电站为例,综述了俄罗斯潮汐电站的发展历程。从修建该电站所采用的建筑材料、建筑方法以及发电机组的选型等方面,对过去40多年的运行经验进行了总结。     

Cytotoxicity of aggregated fullerene C60 particles on CHO and MDCK cells

The cytotoxicity of fullerene C60 particles on two mammalian cell lines, i.e. the Chinese hamster ovary (CHO) cells and the Madin-Darby canine kidney (MDCK) cells, has been investigated. Although innate fullerene particles have a very low solubility in deionized (DI) water, these particles can be dissolved in the tetrahydrofuran (THF) solvent at a great value. Further, the dissolved fullerene particles in the THF solvent could be extracted into a DI water solution at a significantly increased solubility. The formation of fullerene particle aggregates is believed to be the cause of the increased solubility. Results presented here show that once the concentration of the fullerene aggregates reaches a certain level, the cells start to die. The lethal dosage LD50, which is defined as the lowest fullerene concentration that results in a 50% cell death within 24 h, has been determined. Furthermore, the percentage of cell mortality increased with increasing fullerene concentration and incubation time yielding a negative effect on cell viability. These results, illustrated by atomic force microscopy (AFM), dynamic light scattering (DLS) and other microscopic techniques, will help to better understand the side effects of fullerene particles in mammalian cells.