Efficient Synthesis and Plant-Growth Regulating Activities of 1-Aryloxyacetyl-4-(2-benzofuroyl)- semicarbazides

Under grinding and solvent-free conditions via a one-pot procedure, the reaction of 2-benzofuroyl chloride with ammonium thiocyanate and aryloxyacetetic acid hydrazide afforded 1-aryloxyacetyl-4-(2-benzofuroyl)-thiosemicarbazide. Not isolating, the resulting thiosemicarbazides were further ground with HIO₄·H₂O to give a series of new 1-aryloxyacetyl-4-(2-benzofuroyl)-semicarbazides in high yields. Structures of compounds are confirmed by elemental analyses and IR and ¹H NMR spectra.     

A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method

<正>Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.     

光学元件双转子抛光技术中类高斯型去除函数建模与逼近

在Preston假设基础上,研究并推导了光学元件抛光过程中"花瓣"型截面磨头在双转子运动形式下的去除函数.提出了"花瓣"型截面磨头的离散点弧长表达方法,并讨论了该方法的适用范围;基于离散点弧长法,推导了"花瓣"型截面磨头在双转子运动形式下的去除函数表达式;根据可调步长式曲线逼近原理研究了类高斯型目标去除函数的逼近算法;并得到了类余弦型去除函数的双转子抛光模参量.从而证明了双转子抛光技术可以得到类高斯型去除函数.     

Development of candidate reference materials for the measurement of lead in bone

The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of 2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis.

Controlling subsurface damage in neodymium-doped phosphate glass

We investigate the removal mechanism of neodymium-doped phosphate glass dominated in loose abrasive grinding and bound abrasive grinding. Moreover, we investigate the surface roughness and subsurface damage change with optical fabrication parameters, such as different spindle speed, load and abrasive size under different grinding processes in details. For a range of experimental conditions, we find that fracture is the principal removal mechanism for loose abrasive grinding, while plastic scratching is the dominating mechanism for bound abrasive grinding. The load has more influence on subsurface damage for bound abrasive grinding than for loose abrasive grinding. However, the spindle speed has different effect on subsurface damage produced with loose abrasive grinding and bound abrasive grinding. Moderate spindle speed and low load is preferred to produce smaller subsurface damage for loose abrasive grinding. Moreover, higher spindle speed and lower load are preferred to plastic scratching for bound abrasive grinding. Bound abrasive grinding produces 4 times lower surface roughness and 3 times lower subsurface damage than loose abrasive grinding.     

研磨破乳的规律及其机理

报道了研磨破乳的实验规律，讨论了研磨破乳的基本步骤：（１）过滤过程中乳状液内相液滴在研磨剂表面铺展成膜并进一步聚结──过滤破乳；（２）研磨剂的相互碰撞使乳状液的分散液滴受到摩擦力和剪切力，导致液滴聚结──研磨破乳。     

高分子吸附剂GDX 101用于高效液相色谱固定相的性能研究

GDX 101是苯乙烯和二乙烯基苯的共聚物,具有强吸附性能,耐腐蚀,且无流失现象,已被广泛用作气相色谱固定相。     

An efficient, catalyst- and solvent-free, four-component, and one-pot synthesis of polyhydroquinolines on grinding

An efficient synthesis of polyhydroquinolines is achieved via a four-component reaction of aldehydes, dimedone, active methylene compounds, and ammonium acetate in one-pot under solvent-free conditions at room temperature on grinding. The present method does not involve any hazardous organic solvent or catalyst. The key advantages are the short reaction time, high yields, simple workup, and purification of products by non-chromatographic methods, i.e., by simple recrystallization from ethanol.     

An efficient solvent-free synthesis of NH-pyrazoles from β-dimethylaminovinylketones and hydrazine on grinding

A series of NH-pyrazoles was efficiently synthesized from the reaction of β-dimethylaminovinylketones ([R¹C(O)C(R²)CHN(Me₂)], where R¹ = Me, Ph, 3-MeO-Ph, 4-Me-Ph, 4-MeO-Ph, 4-F-Ph, 4-Cl-Ph, 4-Br-Ph, 4-O₂N-Ph, fur-2-yl, thien-2-yl; R² = H, 2-MeO-Ph; R¹, R² = -(CH₂)₃C(O)-) and hydrazine sulfate in solid state on grinding in the presence of p-toluenesulfonic acid (PTSA). Most of the reactions proceeded smoothly at room temperature under solvent-free conditions. In comparison with the classical reaction conditions, which employ molecular solvent (ethanol), this new synthetic method has the advantages of shorter times, higher yields, mild reaction conditions as well as being environmentally friendly.     

HDP-HSMM的磨削声发射砂轮钝化状态识别*

在高精度金属材料磨削加工中,刀具即砂轮的状态对加工效率和加工质量具有重要的影响。钝化程度较高的砂轮不适于加工精密工件,需提前预警并修整更换砂轮。该文提出一种通过磨削声发射信号来检测砂轮钝化状态的方法。首先,对于采集到的信号进行小波软阈值降噪。然后,将其分割成多个有重叠的帧,并提取每帧信号的8个特征组成声发射数据集。最后,通过分层Dirichlet过程-隐半马尔可夫模型来建立声发射数据集和不同的砂轮钝化状态之间的非线性关系,旨在识别砂轮钝化状态。结果表明,上述检测方法能有效识别砂轮的不同钝化状态并能对整个加工过程中的砂轮钝化程度进行自动划分,其在测试数据集上的准确率达到93.7%,可以为实际工业应用提供理论指导。