The Russian Connection

Well, it seems that our good friends in Russia have gotten the new year off to a great start, great that is if you are a cyber criminal. The exploits of the now nearly world-famous hacker ‘Maxus’ are spreading quickly in the popular media. According to press reports (largely formed from the information Maxus has doled out to the reporters), Maxus penetrated the customer database of an online retailer of CDs and claims he made off with perhaps as many as 300 000 individual credit card accounts. This incident should serve as a sobering wake-up call to all the eager executives who have been early adopters of E-commerce. Although it is too early to know the full extent of confirmed losses, there has been some preliminary confirmation by a number of online and print media journalists of the validity of several of the accounts that were compromised. This leads me to believe Maxus is probably telling the truth about the extent of the ‘achievement’, but I will reserve judgement as to whether he’s only 18 years old and is in fact, even a ‘he’ at all.     

高速系统的信号质量管理

受到平板印刷技术进步的推动，IC转换速度继续保持不断提升的势头。与此同时，时钟速度的逐步加快则使得时序余量大大减少。     

Technology trends of high‐pressure mercury short‐arc lamps for projection systems

Abstract— We will discuss the advantages and limitations of ac and dc lamp technology for microdisplay‐based projection systems. The performance of the lamp in terms of brilliance and thermal robustness together with the potential lamp lifetime for ac and dc lamps will be discussed. ac and dc lamp designs will be evaluated to judge their potential for future improvements in terms of usable projector lumens.     

Controlled-release behavior of diphenhydramine hydrochloride loaded neutral microgranules and coated using ethylcellulose water dispersion

The development of a loading method of a water-soluble drug using aqueous binding solution to produce microgranules that were then coated with an aqueous ethylcellulose dispersion to sustain drug release is described. The results, in terms of drug used, showed that besides the fluidized bed parameters, the amount of drug dissolved in the binder solution plays an important role in obtaining a satisfying result during the spraying process. Thus, it seems necessary to determine the critical concentration above which the material started to adhere to the interior of the fluidization column, and the possibility of drug layering onto carrier material is aggravated. ANOVA of the time parameter for release of 63.2% of total drug (td) value showed significant influence of ethylcellulose (Aquacoat ECD-30) and dibutyl sebacate concentration on diphenhydramine hydrochloride (DPH) release. The dissolution rate decreased with an increase in polymer concentration. The diffusional exponent n of the Peppas equation indicated that the DPH release kinetic was non-Fickian but approached Fickian diffusion, particularly at higher coating levels.     

高性能低功率有源混频器为3.3～3.8GHz WiMAX应用转换频率

LT5560是一种双平衡有源混频器，它采用高频双极型工艺制造，实现了较宽的带宽和非常低的功耗。其信号端口几乎可在从DC直到4GHz的频率上工作，这为上变频和下变频转换应用提供了方便。在恰当匹配的情况下，能以低成本、低直流功耗和高性能将频率转换为3．3GHz～3．8GHz的WiMAX工作频率或对3．3GHz～3．8GHz范围的频率进行转换。大多数无源混频器都有几个dB的转换损耗，并需要高LO驱动电平。而这种新型有源混频器却能提供转换增益，而且LO信号功率仅为-2dBm。     

Intercalation and Superconductivity in Molecular Crystals

Intercalating polyatomic molecules into a superconductor can noticeably affect the properties of the compound. We propose a mechanism leading to a large increase in T _c for such systems. The enhancement of T _c is related to the additional pairing interaction arising from the interaction of electrons with the vibrational manifold of the molecules. One immediate prediction of the model is the possibility to observe a site-selective isotope effect. The proposed mechanism explains the recent observation of high-T _c superconductivity in hole-doped intercalated fullerides. The value of T _c for the C ₆₀ 2 CHBr₃ compound is calculated withouth any adjustable parameter. The theory also suggests that intercalating CHI₃ would further increase the critical temperature to T _c 140 K.     

Introduction to the principles of ultramicroheptodes in ring-disk interactions

The use of ring-disk ultramicroelectrodes as tips as a means of extending the methodology of the scanning electrochemical microscope is described. Electrodes consisting of one centered disk with six interconnected disks surrounding it served as the ring-disk electrodes. Basic experiments illustrate the behavior in the feedback mode and the generation collection mode. The dependence on the electrodes' size, both potentials, the tip-sample distance, and the local properties of the underying sample were studied. When approaching an electrode to the surface of a sample, steady-state collection efficiencies between zero and unity were elegantly altered by adjusting the distance between tip and sample. The shielding factor could be varied between 0.25 and 0.82 the same way. Concerning feedback methods, the results presented illustrate the new principle of applying a precisely located external stimulus as a separate electrochemical means of analyzing the sample's response. Obviously, this technique can be extended to irreversible redox mediators, which are not treated here explicitly, but give this concept even greater flexibility. The interpretation of such data can be deduced directly from this contribution.