Towards traceable particle number concentration standard: Single charged aerosol reference (SCAR)

A concept of realizing a standard for aerosol particle number concentration was tested, based on generating singly charged aerosol particles in the size range from 10 up to 500 nm. To this end, a device named single-charged aerosol reference (SCAR) was designed, built, and tested. The device is based on electrical charging of nanoparticles and subsequent growth of the particles. With an accurate measurement of volume flow and electrical current from the singly charged particles, the number concentration can be accurately, and in the end, traceably determined. Laboratory tests have shown that the device can be used to generate a narrow (GSD<1.3) particle size distribution of singly charged particles. The device can be used for traceable calibration of instruments measuring the number concentration of the particles.     

粘接型氯丁橡胶胶液色泽的改进

研究了终止剂、抗氧剂的种类及用量对粘接型氯丁橡胶甲苯溶液色泽以及生胶贮存稳定性的影响。结果表明:当采用盐酸羟胺做终止剂,2.6-二叔丁基对甲基苯酚做抗氧剂,所得氯丁橡胶具有良好的贮存稳定性,其甲苯溶液色泽较浅。     

A review and assessment of numerical shade sorting methods

The properties of current shade sorting geometries are evaluated on a mathematically generated, spherical population of normally distributed data points. The results compare well with those obtained from preuiously cited populations of textile production goods. Thefixed-grid geometries (cubic, rhombic dodecahedra1 and truncated octahedral) are not as efficient in terms of the numbers and uniformity of shade sorting groups as the grid-free spherical clusters employed by Clemson Color Clustering (CCC).     

Effective carbon number molecular weight carbon number Pressure Temperature

A method based on the effective carbon number (ECN) has been developed for the prediction of the vapor pressures of carboxylic acids over a range of temperatures. Good representation of the vapor pressures is obtained in the range 1 kPa to HOkPa with an overall average absolute deviation of 2.26%for 31 carboxylic acids which included saturated as well as unsaturated acids. The method requires a knowledge only of the normal boiling point or the boiling point at 1.3 kPa (lOmmHg) of the substance     

单身礼

情人节是情侣们大秀恩爱甜蜜的节日,而11月11日则是专属于单身人士的节日. 在这个日子里,为自己选-枚精美别致的单身戒,自己宠爱自己;或者宅在家里玩＂单身贵族棋＂和＂桌面保龄球＂,一个人,其实也可以很快乐. 如果想结束单身的话,带着＂Momiji娃娃＂去参加单身派对吧,或者赶紧把＂月小老＂请回家.幸福,就在下一站.     

单身礼

情人节是情侣们大秀恩爱甜蜜的节日,而11月11日则是专属于单身人士的节日. 在这个日子里,为自己选-枚精美别致的单身戒,自己宠爱自己;或者宅在家里玩"单身贵族棋"和"桌面保龄球",一个人,其实也可以很快乐. 如果想结束单身的话,带着"Momiji娃娃"去参加单身派对吧,或者赶紧把"月小老"请回家.幸福,就在下一站.     

CR-244氯丁橡胶及甲苯胶液色泽的改善

笔者从聚合配方和终止剂体系两个方面入手，介绍了改善CR-244氯丁橡胶及甲苯胶液色泽并能保证其抗老化性能的方法。     

Regression analysis to determine the optimum colour tolerance level for instrumental shade sorting

An investigation of the correlation between visual colour assessment and instrumental colour acceptance determination using regression analysis has been carried out. Three colour-difference equations, CIELAB, CMC(2:1) and CIE94(2:1:1), were studied in order to determine which is the best for generating a uniform colour space/microspace for allocating the colour population in shade sorting. Determination of optimum colour tolerance for further shade sorting was also undertaken. Some 1320 pairs of dyed samples distributing around 20 shade standards were measured instrumentally and also evaluated visually by a panel of 32 observers. Percentage rejection was plotted against colour difference and different mathematical regression relationships were then imposed. As a result, both CMC and CIE94 showed better correlation between the two colour assessment methods than the CIELAB colour-difference equation. Consequently, optimum colour tolerance limits were determined for subsequent development of shade sorting, with the findings being equally applicable to colour acceptance (shade passing).     

The Porto Torres biodepyritization pilot plant: Light and shade of one year operation

The nominal 50 kg h⁻¹ dry coal biodepyritization pilot plant was built at Porto Torres (Sassari, Italy) in the area of EniChem S.p.A. Chemical Works, with financial support of the Commission of European Communities and with the participation of the DMT of Essen (Germany), the Mining and Mineral Processing Department of the University of Cagliari (Italy), the Technical University of Delft (The Netherlands) and the Warren Spring Laboratory of Stevenage (UK). The plant went on stream in early September 1992. Test runs were carried in the range 6.5–41.5% solids concentration. For every solids concentration the steady state was attained in about 10 d. For all the test runs the assays showed that more than 90% pyrite removal is achieved in the first five bioreactors; for a pulp flow rate of 6.94 × 10⁻² dm³ s⁻¹, (250 l h⁻¹) and useful bioreactor volume of 7.5 m³, this corresponds to a residence time of 540 345 s, i.e., 6.254 d, and to a pyritic iron biosolubilization rate of 36 mg dm⁻³ h⁻¹. The pyrite biosolubilization rate constant is 1.53 × 10⁻² h⁻¹. The power input per bioreactor operating on a 40% solids pulp is 4 kW with cos Φ = 0.76. Hence, the power required for processing 100 kg h⁻¹ coal at 40% solids in the bioreactor section is 4 × 5 = 20 kW h, i.e. 200 kW h per tonne dry coal.     

两类距离图的分式色数和点色数

分式色数和点色数是图的两个重要参数。本文在文献 [1]的基础上给出了两类距离图G(Z ,Dm ,k,k + 1)与G(Z ,Dm ,k ,k + 1,k + 2 )的分式色数和点色数。     

Crystallization of lead zirconate titanate without passing through pyrochlore by new solution process

We report a novel low-temperature crystallization path for perovskite lead zirconate titanate (PZT) from solution. The modification of a PZT solution by monoethanolamine (MEA) resulted in a change in the crystallization behavior. MEA was strongly coordinated to the metal ions, resulting in destroy of multinuclear metal organic complexes. This led to a remarkably increased pyrolysis temperature, and Pb²⁺ was reduced into Pb⁰ because of a reducing environment at 200–300 °C. Nanoscopic separations of Pb⁰ was later transformed into uniformly distributed α-PbO nanocrystals and clusters in the amorphous Zr/Ti–O matrix, and finally the sample crystallized into perovskite at 400–500 °C. On the other hand, pyrochlore phase was observed in the conventional crystallization process. The avoidance of pyrochlore formation is the key for the low-temperature crystallization of perovskite. X-ray absorption fine structure (XAFS) analysis was performed to reveal the structures in solutions and amorphous phases.     

单身普洱房

到成都,不能不去的是少城,她代表了成都的市井文化,也见证了一个城市的变迁。少城因巷子而闻名,有大家熟悉的宽窄巷子,也少不了美丽的小通巷。     

单组分环氧粘合剂

<正> 环氧粘合剂在国内50年代开始研制,迄今已有不少品种牌号。这些产品均是包含环氧树脂基体(包括增塑剂及填料等)和固化剂的双组分环氧粘合剂,又称二液型环氧粘合剂。使用时须临时进行称量、搅拌混和,而且胶的适用时间极短。另外,使用时需要现配,这样给施工带来麻烦,剩余的胶也不能再用,从而造成浪费。单组分环氧粘合剂采用独特的固化剂及催化剂,调配均匀,一组分包装,故又称一液型环氧粘合剂。它具有很长的贮存期(即适用期),可达半年以上不变质,因此使用方便,大大改进了双组分环氧粘合剂的缺点,达到提高劳动生产率和节省粘合剂的目的。单组分环氧粘合剂所采用的固化剂,在常温和加     

Single nanotube Raman spectroscopy

A review is presented on the observation of the resonant Raman spectra from one isolated single wall carbon nanotube, focusing on the important structural information that is provided by single nanotube spectroscopy including the (n, m) determination of the individual tubes. The special sensitivity of the radial breathing mode to the (n, m) determination is emphasized, and the corroboration of this (n, m) assignment by diameter- and chirality-dependent phenomena in other Raman modes, such as the G-band, D-band, and G'-band features is also discussed. The significance of single nanotube spectroscopy for future nanotube research in general is briefly reviewed.     

灯箱布用涤纶工业丝纺丝工艺研究

利用正交试验和单因子试验,对影响灯箱布用涤纶工业丝的断裂强度和干热收缩率指标的工艺因素进行了研究。优化了灯箱布用工业丝的纺丝工艺,物理指标满足灯箱布使用要求。