环境中氚和碳-14

本文介绍了加拿大恰克河实验室有关氚和碳－14在环境中行为和评价的研究。     

Intercomparison of scanning probe microscopes

Comparison measurements on reference standards are reported in which 13 partners with different instruments took part. A set of prototype standards which had been produced and calibrated within a European project were used for the measurements. Here, results of measurements on a 240 nm step height standard and a two-dimensional lateral standard with a nominal pitch of 1 μm are reported.     

Indicators for inspection and maintenance planning of concrete structures

Based on an idea introduced by Benjamin and Cornell (1970. Probability, statistics and decision for civil engineers. New York: McGaw Hill) and previous works by the authors it is demonstrated how condition indicators may be formulated for the general purpose of quality control and for assessment and inspection planning in particular. The formulation facilitates quality control based on sampling of indirect information about the condition of the considered components. This allows for a Bayesian formulation of the indicators whereby the experience and expertise of the inspection personnel may be fully utilized and consistently updated as frequentistic information is collected. The approach is illustrated on an example considering a concrete structure subject to corrosion. It is shown how half-cell potential measurements may be utilized to update the probability of excessive repair after 50 years. Furthermore in the same example it is shown how the concept of condition indicators might be applied to develop a cost optimal maintenance strategy composed of preventive and corrective repair measures.     

The effect of aluminium coating on elemental standards in X-ray microanalysis

The standardisation of frozen hydrated bulk biological specimens using gelatin standards is described. The relationship between corrected elemental X-ray counts and ionic concentration was found to be linear, and minimum detectable limits for each element are stated. Variations in uncorrected standard curves were found to be due to changes in aluminium coating thickness. There was an inverse relationship between coating thickness and elemental X-ray counts. The factors causing this are discussed. To avoid errors arising from inconsistent aluminium thickness, experimental material should only be compared with standards of similar aluminium net counts. This can be achieved most easily by mounting and analysing specimen and standard together.     

熔窑玻璃液流数值模拟的新发展

熔窑玻璃液流数值模拟的新发展赵国昌（清华大学核能技术设计研究院，１０００８４）ＮｅｗＤｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅＮｕｍｅｒｉｃａｌＳｉｍｕｌａｔｉｏｎｆｏｒＦｌｏｗａｎｄＨｅａｔＴｒａｎｓｆｅｒｏｆＧｌａｓｓＭｅｌｔｉｎＴａｎｋＦｕｒｎａｃｅ￥Ｚ...     

材料研究中系列试样的单标样法 X 射线定量分析

本文提出了用一个标样进行系列试样 X 射线定量相分析的方法.它克服了一般 X 射线定量方法需要混合研磨和手续烦复的缺点以及无标样 X 射线定量方法存在病态方程不易解决的问题.该方法对常规 X 射线定量分析具有普遍的实用性.     

秦山核电厂气载放射性释放的环境影响

本文评价了秦山核电厂气载放射性流出物对环境的影响。应用现场及风洞大气扩释实验结果和厂址周围的人口与食谱调查资料,估算了秦山核电厂在正常运行和事故条件下释放的气载放射性流出物对公众产生的个人有效剂量当量和集体有效剂量当量。计算结果表明,正常运行时厂址边界(0.5km)处的最大个人有效剂量当量为2.7×10~(-2)mSv/a,该剂量的大部分来自~(137)Cs 的食入(主要由地表湿沉积引起);80km 范围内的集体有效剂量当量为1.1人·Sv/a,归一化集体有效剂量当量为3.7人·Sv/GW(e)·a。文中还给出了事故情况下剂量估算结果。     

Handwriting versus wordprocessed print: an investigation into teachers' grading of English Language and Literature essay work at 16 +

Abstract Selections of English Language and Literature CSE (now GCSE) course work essays are graded by a total of 411 teachers in two forms: handwritten and wordprocessed. Mistakes in the original handwritten versions are not edited out. It is found that the wordprocessed English Language essays are, on average, marked up a grade. However, it is found that relatively high quality English Literature work is not affected. Results suggest:
— that the less directly pupil work is specifically related to an external referent (such as a work of literature), the more likely it is that computer-assisted methods of presentation will significantly enhance its apparent quality relative to handwritten work.
— that relatively lower quality work will tend to be enhanced more than relatively higher quality work.
The implications of the results for examination boards are also considered.     

Quantitative description of the microstructure–porosity of sialons and iron silicide inclusions

Sialon ceramics are a modern type of engineering ceramics with excellent mechanical, thermal and corrosion resistant properties. This paper describes the structure characterisation of porous sialon ceramics. It is possible to significantly improve the strength and crack resistance of sialon ceramics as a result of a reduction of the volume fraction of porosity.     

Novel Fiberoptic Sensing Array an Fundamental Experiments

A suitable fiberoptic sensing array embedded in the smart structure to monitor quasi-distrbuted froces on the structrue in presented in this paper.Artificial neural networks are used in processing of fiberoptic sensing array signals.Fundamental experiments have been done and the results are also given.