下贝氏体碳化物源的高温电镜观察

在JEM-1000超高压透射电镜高温台中对40CrMnSiMoV钢310℃等温所得下贝氏体进行定点动态观察的结果表明,原先无碳化物的贝氏体铁素体内,在高于等温转变温度经一定时间回火后,析出了典型下贝氏体碳化物。这说明下贝氏体铁素体是过饱和碳的。奥氏体中也可析出碳化物,但不具备下贝氏体碳化物的典型特征。     

Al-Si合金的细化与Ti偏析的研究

研究了不同处理时间、不同位置对Ti偏析及细化效果的影响。结果表明，保温4h，A1—5Ti-1B的细化效果达到最佳。Ti在铸件顶端和底部的偏析程度不一样，在底部偏析更为严重，这主要是由于Ti在浇注过程中聚集的结果。     

钢中贝氏体长大方式的TEM研究

利用ＴＥＭ考察了钢中贝氏体铁素体／奥氏体相界面台阶结构及奥氏体精细结构。用ＴＥＭ温台发现在贝氏体增厚过程中新形成的贝氏体中存在奥氏体预存孪晶；在贝氏体铁素体／奥氏体相界面存在台阶结构，但台阶阶面可对应于母相奥氏体中孪晶面或层错面，表明台阶的阶面为共格的滑移界面。因而贝氏体铁素体／奥氏体相界面可通过界面台阶沿面缺陷进行保守滑移，贝氏体长大具有滑移切变特征。根据实验结果提出了贝氏体二次层错切变模型及组织形貌示意图。     

粒状贝氏体组织的疲劳性能

本文研究了粒状贝氏体组织的低周疲劳性能、冲击疲劳性能及旋转弯曲疲劳性能.结果表明:在等抗拉强度下,粒状贝氏体的低周疲劳性能与冲击疲劳性能均优于回火马氏体组织.且随粒状贝氏体含量增加,冲击疲劳寿命相应提高.粒状贝氏体中的(M-A)岛对疲劳裂纹扩展有阻碍作用,对提高疲劳寿命有利.在等强度下,粒状贝氏体的旋转弯曲疲劳性能和回火马氏体组织相当,疲劳极限(Sf)与屈服强度(σy)和断裂强度(S_K)的关系为: S_f=4.651+0.1411(σ_y+S_K)     

钢中贝氏体长大方式的TEM研究

利用ＴＥＭ考察了钢中贝氏体铁素体／奥氏体相界面台阶结构及奥氏体精细结构。用ＴＥＭ温台发现在贝氏体增厚过程中新形成的贝氏体中存在奥氏体预存孪晶；在贝氏体铁素体／奥氏体相界面存在台阶结构，但台阶阶面可对应于母相奥氏体中孪晶面或层错面，表明台阶的阶面为共格的滑移界面。因而贝氏体铁素体／奥氏体相界面可通过界面台阶沿面缺陷进行保守滑移，贝氏体长大具有滑移切变特征。根据实验结果提出了贝氏体二次层错切变模型及组     

A scalable, self-analyzing digital locking system for use on quantum optics experiments

Digital control of optics experiments has many advantages over analog control systems, specifically in terms of the scalability, cost, flexibility, and the integration of system information into one location. We present a digital control system, freely available for download online, specifically designed for quantum optics experiments that allows for automatic and sequential re-locking of optical components. We show how the inbuilt locking analysis tools, including a white-noise network analyzer, can be used to help optimize individual locks, and verify the long term stability of the digital system. Finally, we present an example of the benefits of digital locking for quantum optics by applying the code to a specific experiment used to characterize optical Schr?dinger cat states.     

脱离菜鸟（上）——数码相机新手成长指南

入门级消费类数码相机已卖到了几百元的“白菜价”,入门级数码单反相机的价格也日渐走低,拥有数码相机的人越来越多。但面对机身上众多的功能按键、菜单中五花八门的设置功能和枯燥干巴的说明手册,你是不是会觉得“一阵眩晕”？你是不是总是将相机设置在“AUTO”（自动）模式下拍摄一些平淡无奇的照片,然后在家里对着电脑屏幕郁闷不已呢？其实要拍出一张令亲友满意、自己得意的照片并不难,目前的数码相机虽然不能“自觉主动”地拍出一张伟大的作品,但你只要进行一两步简单的设置就能获得意想不到的效果。     

你知道电脑中的灰尘危害有多大吗？

"Windows 7是Vista的加强版"等类似评论层出不穷,Vista或许是件失败的产品,连微软也想通过Windows 7来终结这一痛苦的经历.在PDC大会上,微软Windows产品部经理GabrieI Aul简单解释了,Windows7是有资格"上位"的,是可以超越Vista的,以下就是Windows 7的特性.     

Effect of molecular anisotropy on backscattered ultraviolet radiance

The effect of molecular anisotropy on backscattered UV (BUV) radiances is computed by accounting for it in both Rayleigh optical thickness and the scattering-phase matrix. If the effect of molecular anisotropy is included only in the optical thickness and not in the phase matrix, then for high sun (θ(0) ～ 0°), the nadir radiance (I(0)) leaving the top of the atmosphere is approximately 1.8% higher than the radiance (I(op)) computed with the effect included in the phase matrix. For very low sun (θ(0) > 80°), I(0) is approximately 2.3% lower than I(op). For off-nadir radiances the relative increase (decrease) depends on both the local zenith angle as well as the azimuth angle. Also, an increase in the surface reflectivity decreases the effect of molecular anisotropy on the upwelling radiances. Exclusion of the anisotropy factor in the Rayleigh-phase matrix has very little effect (<1%) on ozone retrieval from the BUV-type instruments. This is because of the ratio technique used in the retrieval algorithm, which practically cancels out the anisotropy effect.