数字新年简单任务

马上就要过年了，也许大家还在琢磨着新年怎么过吧，没关系，我们已经开始为你打算了。来，一个数字化的新年吧。我们不要繁琐，不要复杂，只要简单！[编者按]     

印度水电方面的技术成就

大型水电工程需要大量的开挖隧洞，作者是负责印度国家水电公司（NHPC）所属的Tessta Ⅱ级水电工程的总工程师，现对印度在水电开发中的最新隧洞开挖工程做了一个展望。     

乱花渐欲迷人眼手机摄像头组件

手机摄像头作为手机的新功能之一．经过几年的发展．已经成为手机的标准配置。同时．也出现了许多以前只在数码相机上才被应用的名词．下面我们就来给大家简单解释一下。[编者按]     

绝世好计砍掉乱收费的毒瘤

相信现在的手机用户，多多少少都在使用SP（移动增值服务提供商）提供的服务，不过大家可能很少知道SP的收费流程，甚至有很多朋友在莫名其妙中就被一些违规SP的乱收费给砸中了，每个月不但要交上一笔莫名其妙的包月费，而且还经常被垃圾短信骚扰。我们现在就来教给大家如何查询自己订阅的短信服务及其提供商的各种信息，以及如何取消这些收费。[编者按]     

The Old-Age Healthy Dependency Ratio in Europe

The aim of this study is to answer the question of whether improvements in the health of the elderly in European countries could compensate for population ageing on the supply side of the labour market. We propose a state-of-health-specific (additive) decomposition of the old-age dependency ratio into an old-age healthy dependency ratio and an old-age unhealthy dependency ratio in order to participate in a discussion of the significance of changes in population health to compensate for the ageing of the labour force. Applying the proposed indicators to the Eurostat's population projection for the years 2010-2050, and assuming there will be equal improvements in life expectancy and healthy life expectancy at birth, we discuss various scenarios concerning future of the European labour force. While improvements in population health are anticipated during the years 2010-2050, the growth in the number of elderly people in Europe may be expected to lead to a rise in both healthy and unhealthy dependency ratios. The healthy dependency ratio is, however, projected to make up the greater part of the old-age dependency ratio. In the European countries in 2006, the value of the old-age dependency ratio was 25. But in the year 2050, with a positive migration balance over the years 2010-2050, there would be 18 elderly people in poor health plus 34 in good health per 100 people in the current working age range of 15-64. In the scenarios developed in this study, we demonstrate that improvements in health and progress in preventing disability will not, by themselves, compensate for the ageing of the workforce. However, coupled with a positive migration balance, at the level and with the age structure assumed in the Eurostat's population projections, these developments could ease the effect of population ageing on the supply side of the European labour market.     

Quartz crystal resonator g sensitivity measurement methods and recent results

A technique for accurate measurements of quartz crystal resonator vibration sensitivity is described. The technique utilizes a crystal oscillator circuit in which a prescribed length of coaxial cable is used to connect the resonator to the oscillator sustaining stage. A method is provided for determination and removal of measurement errors normally introduced as a result of cable vibration. In addition to oscillator-type measurements, it is also possible to perform similar vibration sensitivity measurements using a synthesized signal generator with the resonator installed in a passive phase bridge. Test results are reported for 40 and 50 MHz, fifth overtone AT-cut, and third overtone SC-cut crystals. Acceleration sensitivity (gamma vector) values for the SC-cut resonators were typically four times smaller (5x10(-10) per g) than for the AT-cut units. However, smaller unit-to-unit gamma vector magnitude variation was exhibited by the AT-cut resonators. Oscillator sustaining stage vibration sensitivity was characterized by an equivalent open-loop phase modulation of 10(-6) rad/g.     

Low-noise microwave signal generation using bulk- and surface-acoustic-wave resonators

An overview is provided of some of the more important resonator utilization and associated circuit-design considerations involved in the generation of low-noise microwave signals. Signal spectral relationships in acoustic resonator-controlled oscillators are considered. Possible methods for providing additional signal short-term stability improvements are discussed.     

Cooled, ultrahigh Q, sapphire dielectric resonators for low-noise, microwave signal generation

Ultra-high Q, X-band resonators, used in a frequency discriminator for stabilization of a low-noise signal generator, can provide a means of obtaining significant reduction in phase noise levels. Resonator unloaded Qs on the order of 500 K can be obtained in sapphire dielectric resonator (DR) operating on a low-order (i.e. TE(01)) mode at 77 K and employing high-temperature superconducting (HTS) films installed in the DR enclosure covers. Rigorous analysis for the determination of resonator frequency, modes, and unloaded Q have been carried out using mode matching techniques. Trade-off studies have been performed to select resonator dimensions for the optimum mode yielding highest unloaded Q and widest spurious mode separation. Field distributions within the resonator have been computed to enable practical excitation of the required mode. The results of both analysis and prototype device evaluation experiments are compared for resonators fabricated using enclosures consisting of conventional, metal sidewalls and covers employing HTS films as a function of cover conductivity.