论it在英语里的用法

it在英语中的用法较多,且变化不一,导致很多大学生在英语四级考试中失分.     

Whose criterion standard is it anyway?

A criterion-referenced standard is an important element of most successful professional testing programs. A growing body of evidence suggests that judge decisions are influenced by characteristics related to the normative experience of the individual judge (e.g. gender, age, etc.). This investigation used two health-care related boards to explore the effects of judge characteristics on the standards established. Two judge panels (composed of 26 and 30 members respectively) were used in a simplified Objective Standard Setting exercise to define examination cutoff points. Multi-faceted Rasch analyses were employed to detect and explore differences in judgment making. Significant but not necessarily consistent differences were found between panel judges on several examined characteristics. Results suggest that criterion-referenced standards defined by judge panels are inexorably connected to their normative experiences and are therefore wholly sample dependent. While stratification of judge panels is clearly an important element in defining standards, if they are ever to achieve the goals of Glaser (1963) and Majer (1962) including meaningful independence, more must be done to investigate these and other concerns. The case for the predictive validity of criterion-referenced standards has not thusfar been made in any convincing fashion.     

Worldwide Quality - is it Uniformly Controlled?

Abstract

Multiple controls during the manufacture of pharmaceutical products are considered essential for the achievement of consistent high quality in such products. The problem normally associated with manufacturing high quality products are multiplied in the international marketplace. Global scale problems associated with regional jurisdictions and varied control standards will be discussed in detail.     

Nice work if you can get it?

Science, not art reveals the day-to-day graft of science research, the competition for funds, and the poor rewards through the personal diaries of ten scientists, says Nick Russell.     

Chemical genetics: how does it function?

This article highlights recent successes in the field of chemical genetics. It discusses the challenges inherent in this interdisciplinary research field and focuses on the essential role that the biologically aware synthetic chemist can play.     

Is it possible to check microcomponent coatings?

Optical microcomponents are increasingly used in laser optical systems because of their many and novel industrial applications. These components are coated in order to enhance their optical performance, but optical characterizations are very difficult due to the shapes and small size. Thus, to perform this kind of measurement, special devices are needed. It is difficult to check component optical responses after manufacturing. Thus a new method, developed by the French Atomic Energy and Alternative Energies Commission, is proposed to fill this gap.     

Is life what we make of it?

Although astrobiological or SETI detections are possible, actual invasions of sentient extra-terrestrials or plagues of escaped alien microbes are unlikely. Therefore, an anthropological perspective on the question suggests that in the event of a detection, the vast majority of humanity will be dealing not with extra-terrestrial life itself (whether intelligent or not, local or distant), but with human perceptions and representations of that alien life. These will, inevitably, derive from the powerful influences of culture and individual psychology, as well as from science. It may even be argued that in most detection scenarios, the scientific data (and debates about their interpretation) will be nigh-irrelevant to the unfolding of international public reaction. 'Extra-terrestrial life' will, in short, go wild. From this premise, some key questions emerge, including: what can scientists reasonably do to prepare, and what should their responsibilities be, particularly with respect to information dissemination and public discussions about policy? Then, moving beyond the level of immediate practicalities, we might also ask some more anthropological questions: what are the cultural substrates underneath the inquiries of Western science into extra-terrestrial life? In particular, what are the stories we have been told about discovery of rare life, and about contact with other beings, and do these stories really mean what we think they do? Might a closer look at those narratives help us gain perspective on the quest to find extra-terrestrial life, and on our quest to prepare for the consequences of detection?     

Graphene annealing: how clean can it be?

Surface contamination by polymer residues has long been a critical problem in probing graphene's intrinsic properties and in using graphene for unique applications in surface chemistry, biotechnology, and ultrahigh speed electronics. Poly(methyl methacrylate) (PMMA) is a macromolecule commonly used for graphene transfer and device processing, leaving a thin layer of residue to be empirically cleaned by annealing. Here we report on a systematic study of PMMA decomposition on graphene and of its impact on graphene's intrinsic properties using transmission electron microscopy (TEM) in combination with Raman spectroscopy. TEM images revealed that the physisorbed PMMA proceeds in two steps of weight loss in annealing and cannot be removed entirely at a graphene susceptible temperature before breaking. Raman analysis shows a remarkable blue-shift of the 2D mode after annealing, implying an anneal-induced band structure modulation in graphene with defects. Calculations using density functional theory show that local rehybridization of carbons from sp(2) to sp(3) on graphene defects may occur in the random scission of polymer chains and account for the blue-shift of the Raman 2D mode.     

红帽企业虚拟化为Dnshosting.it云服务

<正>全球开源解决方案领导者红帽公司今天宣布,意大利高级Internet解决方案开发商Dnshosting.it将其Cloud Server服务由Vmware迁移到红帽企业虚拟化,以保持其在意大利市场的竞争力和获得基于内核的虚拟机(KVM)虚拟化技术的优势。Dnshosting.it提供域名注册、共享托管、专用服务器和服务。有了红帽企业虚拟化作为基础,该公司现在还可以向其产品添加云服务器和云数据中心服     

红帽企业虚拟化为Dnshosting.it云服务

全球开源解决方案领导者红帽公司今天宣布,意大利高级Internet解决方案开发商Dnshosting.it将其Cloud Server服务由Vmware迁移到红帽企业虚拟化,以保持其在意大利市场的竞争力和获得基于内核的虚拟机(KVM)虚拟化技术的优势。Dnshosting.it提供域名注册、共享托     

Geoengineering: could we or should we make it work?

Schemes to modify large-scale environment systems or control climate have been proposed for over 50 years to (i) increase temperatures in high latitudes, (ii) increase precipitation, (iii) decrease sea ice, (iv) create irrigation opportunities, or (v) offset potential global warming by injecting iron in the oceans or sea-salt aerosol in the marine boundary layer or spreading dust in the stratosphere to reflect away an amount of solar energy equivalent to the amount of heat trapped by increased greenhouse gases from human activities. These and other proposed geoengineering schemes are briefly reviewed. Recent schemes to intentionally modify climate have been proposed as either cheaper methods to counteract inadvertent climatic modifications than conventional mitigation techniques such as carbon taxes or pollutant emissions regulations or as a counter to rising emissions as governments delay policy action. Whereas proponents argue cost-effectiveness or the need to be prepared if mitigation and adaptation policies are not strong enough or enacted quickly enough to avoid the worst widespread impacts, critics point to the uncertainty that (i) any geoengineering scheme would work as planned or (ii) that the many centuries of international political stability and cooperation needed for the continuous maintenance of such schemes to offset century-long inadvertent effects is socially feasible. Moreover, the potential exists for transboundary conflicts should negative climatic events occur during geoengineering activities.     

Local street speed management in Australia--is it "traffic calming"?

A small sample of recent developments in local speed management and safety in Australia is outlined to illustrate conclusions about practice and assessment. This experience seems to support the effectiveness of devices in lowering speeds and reducing accidents, but there is still generally a lack of adequate monitoring and evaluation. Speeds in new residential areas require attention in the planning and design stages; some current fads in neighbourhood planning threaten to perpetuate old traffic problems. The current use of the term traffic calming to mean reduction of car travel demand rather than restraint on driver behaviour and route choice is noted. It is suggested that citywide suppression of traffic goes beyond "traffic calming" as it is commonly understood, into the realm of travel demand management and cultural change.     

Is it feasible to use dyed wool powder as pigment?

In order to make better use of wool powder and explore the feasibility of replacing pigment with dyed wool powder, the dyeing behavior of wool powder was studied firstly. Then, we conducted a series of tests and analyses of the microcosmic structure and properties of powder before and after dyeing. BET test results revealed that the specific surface area of original powder was larger than that of dyed powder. TG and DMA tests indicated that the dyed powder had better thermal stability than the original powder. At last, the dyed wool powder and pigment were mixed and printed on cotton fabric. The dry/wet-rubbing fastness and moisture permeability of cotton fabric printed with dyed powder are better than those of cotton fabric printed with pigment. This indicates that the waste- wool fiber can be processed into applicable printing pigments, which is environmentally friendly and makes full use of natural resources.     

Accident proneness,does it exist? A review and meta-analysis

Accident related health problems have been suggested to cluster within persons. This phenomenon became known as accident proneness and has been a subject of many discussions. This study provides an overview of accident proneness. Therefore, 79 articles with empirical data on accident rates were identified from databases Embase, Medline, and Psychinfo. First, definitions of accidents varied highly, but most studies focused on accidents resulting in injuries requiring medical attention. Second, operationalisations of accident proneness varied highly. Studies categorised individuals into groups with ascending accident rates or made non-accident, accident, and repetitive accident groups. Third, studies examined accidents in specific contexts (traffic, work, and sports) or populations (children, students, and patients). Therefore, we concluded that no overall prevalence rate of accident proneness could be given due to the large variety in operationalisations. However, a meta-analysis of the distribution of accidents in the general population showed that the observed number of individuals with repeated accidents was higher than the number expected by chance. In conclusion, accident proneness exists, but its study is severely hampered by the variation in operationalisations of the concept. In an effort to reach professional consensus on the concept, we end this paper with recommendations for further research.