二茂铁甲叉基酮的固相合成

无溶剂条件下,分别采用研磨及微波辐射方法使二茂铁甲醛与含活性亚甲基的化合物缩合得到二茂铁甲叉基酮。产物结构经^3H NMR、IR及元素分析进行了表征。     

研磨影响粘土结构的红外光谱研究

将高岭石和蒙石两种粘土矿物分别用干法和湿法连续研磨,通过不同研磨时间的各粉城叶变换红外光谱（ＦＴ－ＩＲ）的实测和比较,发现干法研１２ｈ高岭石和蒙脱古老珠结构均开发改变,经４２ｈ高岭石的层状结构完全破坏,而经２４ｈ蒙脱石的层状结构即被破坏,但在湿法条件下研磨５４ｈ,它们的结构均无明显变化。由此可见,湿法研磨比干法好,文中还初步探讨了研磨影响粘土结构的原因。     

Aqueous-mediated green synthesis of 3-carboxyxoumarins using grinding technique

A simple, efficient and green procedure for the synthesis of 3-carboxycoumarins has been developed which involves the grinding of 2-hydroxybenzaldehydes with Meldrum's acid (2,2-dimethyl-1,3-dioxan-4,6-dione) in aqueous moist conditions at room temperature. The protocol is much more efficient as the reactions are carried out at room temperature and yields are also quite high. All the compounds were characterized by their IR, ¹H NMR and mass spectral data and compared with authentic samples.     

关于澳洲GoLden Grove金精矿磨样方法的研究

金精矿样品的粒度,直接影响金精矿中金含量测定的精密度和稳定性,本文通过对Golden Grove金精矿采用不同的磨样工具和磨样时间,得到不同粒度的样品,对不同样品进行了金含量的测定,并对测定结果的精密度进行了分析。其中磨样方式：滚筒磨样机、磨样时间为5h、磨样粒度为0.040mm(360目)95%以上的B样品,测定精密度最好。C样品测定精密度相对较差,反映出振动粉碎机磨样均匀度相对较差。     

Evaluation of sample preparation (grinding and sieving) of bivalves, coffee and cowpea beans for multi-element analysis

Elemental analyses of food samples require several pre-treatment steps that constitute a great potential source of errors. In this study, the influence of cryogenic, ball and knife mill devices and also sieving using different sizes of sieve (100, 300 and 500 μm) was evaluated for samples of bivalves, coffee and cowpea beans. A two-factor ANOVA was performed in each sample to test for differences between macro, micro and trace element concentrations determined by ICP OES. Results showed that the efficiency of the particle size reduction and sample homogeneity depends on the milling device and the nature of samples. Food samples may present segregation after comminution, and sieving might become a necessary step. Nevertheless, the sieve aperture has to be chosen cautiously, once it might influence the final element concentration. Overall, the expected results by employing cryogenic grinding, such as rapid sample homogenization and small particle size generated were also observed for ball mill. Contamination can be a critical issue for some elements and need to be evaluated individually.     

Effect of sample pre-treatment on the determination of steroid esters in hair of bovine calves

The effect of three sample pre-treatment steps, washing, cutting and grinding on the determination of steroid esters in hair is studied. The study is performed by using hair samples obtained after pour-on application of steroid esters to bovine calves. After sample pre-treatment the hair is treated with a mild reducing agent [tris(2-carboxyethyl)phosphine hydrochloride] to extract the steroid esters. After a solid-phase extraction clean-up step the extracts are analysed by using liquid chromatography combined with triple–quadrupole mass spectrometric detection. For the washing step the use of non-organic washing solvents like (warm) water and a solution of 0.1% sodium dodecyl phosphate and organic solutions containing different percentages of methanol are tested. By using the non-organic solvents and the organic solvents with a percentage of methanol <20% the recovery results are as good as the results obtained without washing the hair. Cutting the hair samples increases the analyte recoveries of incurred steroid esters by 20% compared to the non-cut hair. The analyte recoveries of cut hair samples are about 60–80% that of ground hair samples. The obtained surface expansion of hair samples by grinding proves to be necessary in order to achieve the highest possible analyte yields. Finally the use of pressurised liquid extraction (PLE) for the extraction of steroid esters from plain (no washing, cutting or grinding) hair is investigated. The first results show lower (up to 40%) extraction recoveries in comparison with the classical solvent extraction procedures. If the limit of detection requirement is met, PLE may be an alternative for extracting large numbers of hair samples due to the short sample treatment procedure involved.     

Using acoustic emission signals for monitoring of production processes

The systems for in-process quality assurance offer the possibility of estimating the workpiece quality during machining. Especially for finishing processes like grinding or turning of hardened steels, it is important to control the process continuously in order to avoid rejects and refinishing. This paper describes the use of on-line monitoring systems with process-integrated measurement of acoustic emission to evaluate hard turning and grinding processes. The correlation between acoustic emission signals and subsurface integrity is determined to analyse the progression of the processes and the workpiece quality.     

大负载超声振动磨削系统的设计

设计了一种大负载超声振动磨削系统,超声系统由换能器、圆柱圆锥形变幅杆和轮辐式砂轮组成。首先将轮辐式砂轮等效成轮毂为圆柱杆、辐板与轮缘为中厚板的复合模型,利用各接触面边界连续的条件推导系统的频率方程,完成了超声磨削系统的设计,制作了实验装置并分析验证了其声学振动特性。实验结果表明:利用轮辐式砂轮复合模型求解系统频率方程,在解决大负载超声振动磨削系统设计难题上的有效性。该超声系统结构简单,声学振动特性稳定,可输出均匀的位移振幅,有望在大负载的超声磨削领域获得应用。     

Dry grinding effect on pyrophyllite–quartz natural mixture and its influence on the structural alternation of pyrophyllite

Infrared spectroscopy (IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray analysis (EDS) were used to investigate the evolution of mechanical destruction of the pyrophyllite structure and final ground products upon grinding with a laboratory planetary ball mill. The raw ore used in this present work was mainly composed of pyrophyllite and quartz. This pyrophyllite was more resistant toward mechanical destruction, and the crystalline order of pyrophyllite was not completely destroyed until grinding for 240 min with a 20:1 of weight ratio of the balls to powder. The existing crystalline phase in the final ground product was found to be quartz, which served as the associated phase in the original pyrophyllite mineral. The rate of destruction of pyrophyllite structure depended on the types of chemical bonds. Additionally, increasing the intensity of grinding resulted in acceleration of the mechanically induced amorphization of the pyrophyllite structure, whereas the associated quartz grains contributed to the deceleration of the amorphization of pyrophyllite.     

An Efficient and Simple Reaction: Solvent-Free Preparation of Rosolic Acid Under Microwave Irradiation

1 Introduction Rosolic acid, also called as resinous acid, is a trihydroxyphenyl methane dye mainly used as an oxidation resistant indicator in acid-base titration with sharp color change depending on the pH, from 5.0（yellow） to 6.8（pink）. It is also used as an initial reactant in the syntheses of 4,4＇,4＂-tris（acyloxy）trityl chloride and its bromide for protection of primary hydroxyl groups, and a monomer in polyreaction to prepare color polymer fiber as pH probe.