SYNTHESES OF AZETIDINES VIA PHOTOCYCLOADDITION OF C=C TO C=N DOUBLE BONDS

ＳＹＮＴＨＥＳＥＳＯＦＡＺＥＴＩＤＩＮＥＳＶＩＡＰＨＯＴＯＣＹＣＬＯＡＤＤＩＴＩＯＮＯＦＣ＝ＣＴＯＣ＝ＮＤＯＵＢＬＥＢＯＮＤＳ￥ＳＹＮＴＨＥＳＥＳＯＦＡＺＥＴＩＤＩＮＥＳＶＩＡＰＨＯＴＯＣＹＣＬＯＡＤＤＩＴＩＯＮＯＦＣ＝ＣＴＯＣ＝ＮＤＯＵＢＬＥＢＯＮ...     

CALIXE［4］ARENE AS A TEMPLATE FOR CONTROLLING REGIOCHEMISTRY OF PHOTODIMERIZATION OF 9－SUBSTITUTED AN

ＣＡＬＩＸＥ［４］ＡＲＥＮＥＡＳＡＴＥＭＰＬＡＴＥＦＯＲＣＯＮＴＲＯＬＬＩＮＧＲＥＧＩＯＣＨＥＭＩＳＴＲＹＯＦＰＨＯＴＯＤＩＭＥＲＩＺＡＴＩＯＮＯＦ９－ＳＵＢＳＴＩＴＵＴＥＤＡＮＴＨＲＡＣＥＮＥＬＩＹＩ；ＴＯＮＧＺＨＥＮ－ＨＥ（ＣＨＥＮ－ＨＯＴＵＮＧ...     

THEORETICAL STUDIES ON REACTION SELECTIVITY IMPROVEMENT FOR REDUCTION OF NITROBENZENE IN A PACKED－BED ELECTRODE REACTOR UNDER PERIODIC－CURRENT CONTROL

ＴＨＥＯＲＥＴＩＣＡＬＳＴＵＤＩＥＳＯＮＲＥＡＣＴＩＯＮＳＥＬＥＣＴＩＶＩＴＹＩＭＰＲＯＶＥＭＥＮＴＦＯＲＲＥＤＵＣＴＩＯＮＯＦＮＩＴＲＯＢＥＮＺＥＮＥＩＮＡＰＡＣＫＥＤ－ＢＥＤＥＬＥＣＴＲＯＤＥＲＥＡＣＴＯＲＵＮＤＥＲＰＥＲＩＯＤＩＣ－ＣＵＲＲＥＮ...     

STUDY ON MECHANISM OF SUPERSENSITIZATION OF SOME ALLOPOLAR TRINUCLEAR CYANINE DYES

ＳＴＵＤＹＯＮＭＥＣＨＡＮＩＳＭＯＦＳＵＰＥＲＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＳＯＭＥＡＬＬＯＰＯＬＡＲＴＲＩＮＵＣＬＥＡＲＣＹＡＮＩＮＥＤＹＥＳＺＨＡＮＧＪＩＮ－ＬＯＮＧ；ＣＨＥＮＬＩＡＮ－ＳＨＥＮ；ＺＨＵＺＨＥＮＧ－ＨＵＡ（ＲｅｓｅａｒｃｈＩｎｓｔ...     

CHEMICAL SENSITIZATION OF TABULAR－GRAIN EMUL－SIONS IN THE PRESENCE OF SENSITIZING DYE

ＣＨＥＭＩＣＡＬＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＴＡＢＵＬＡＲ－ＧＲＡＩＮＥＭＵＬ－ＳＩＯＮＳＩＮＴＨＥＰＲＥＳＥＮＣＥＯＦＳＥＮＳＩＴＩＺＩＮＧＤＹＥ￥ＣＨＥＭＩＣＡＬＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＴＡＢＵＬＡＲ－ＧＲＡＩＮＥＭＵＬ－ＳＩＯＮＳＩＮＴ...     

Y－TYPE ZEOLITES AS MICRO－REACTORS FOR PHOTOCHEMICAL PREPARATION OF LARGE－RING COMPOUNDS

Ｙ－ＴＹＰＥＺＥＯＬＩＴＥＳＡＳＭＩＣＲＯ－ＲＥＡＣＴＯＲＳＦＯＲＰＨＯＴＯＣＨＥＭＩＣＡＬＰＲＥＰＡＲＡＴＩＯＮＯＦＬＡＲＧＥ－ＲＩＮＧＣＯＭＰＯＵＮＤＳ￥ＴＯＮＧＺｈｅｎｈｅ；（ＴＵＮＧＣｈｅｎｈｏ）；ＷＵＬｉｚｈｕ（ＩｎｓｔｉｔｕｔｅｏｆＰｈｏ...     

EXPERIMENTAL INVESTIGATION OF KINETIC AND TRANSPORT PARAMETERS IN A WALL－COOLED FIXED－BED REACTOR

ＥＸＰＥＲＩＭＥＮＴＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＫＩＮＥＴＩＣＡＮＤＴＲＡＮＳＰＯＲＴＰＡＲＡＭＥＴＥＲＳＩＮＡＷＡＬＬ－ＣＯＯＬＥＤＦＩＸＥＤ－ＢＥＤＲＥＡＣＴＯＲＺｈｅｎ－ＭｉｎＣＨＥＮＧａｎｄＷｅｉ－ＫａｎｇＹＵＡＮ（ＵＮＩＬＡＢＲｅｓｅ...     

A KINETIC MODEL FOR HYDRODESULFURIZATION OF PETROLEUM FRACTIONS

ＡＫＩＮＥＴＩＣＭＯＤＥＬＦＯＲＨＹＤＲＯＤＥＳＵＬＦＵＲＩＺＡＴＩＯＮＯＦＰＥＴＲＯＬＥＵＭＦＲＡＣＴＩＯＮＳＬＵＯＸｉｏｎｇｌｉｎ；ＬＩＲｕｉｌｉ（ＵｎｉｖｅｒｓｉｔｙｏｆＰｅｔｒｏｌｅｕｍ，Ｄｏｎｇｙｉｎｇ，Ｓｈａｎｄｏｎｇ２５７０６２，Ｃｈｉ...     

永芳高级系列产品为联合国第四次世界妇女大会唯一指定专用护肤品

永芳高级系列产品为联合国第四次世界妇女大会唯一指定专用护肤品ＹＯＮＧＦＯＮＧＳＵＰＥＲＨＩＧＨ－ＱＵＡＬＩＴＹＰＲＯＤＵＣＴＳＳＥＲＩＥＳＩＳＴＨＥＳＯＬＥＳＫＩＮＣＡＲＥＣＯＳＭＥＴＩＣＳＳＰＥＣＩＡＬＬＹＤＥＳＩＧＮＡＴＥＤＢＹＴＨＥＦＯＵＲＴＨ...     

改性泥炭腐植酸净化剂对锌,镍,镉等重金属离子吸附效果的研究

改性泥炭腐植酸净化剂对锌、镍、镉等重金属离子吸附效果的研究周群ＡＢＳＯＲＰＴＩＯＮＥＦＦＥＣＴＯＦＭＯＤＩＦＩＥＤＰＥＡＴＨＵＭＩＣＡＣＩＤＰＵＲＩＴＹＩＮＧＡＧＥＮＴＯＮＺＮ￣２＋、Ｎｉ￣２＋、Ｃｄ￣２＋ＡＮＤＯＴＨＥＲＨＥＡＲＹＭＥＴＡＬＩＯＮＳ...     

沉淀法制备羟基磷灰石反应条件控制研究

为了方便快速地获得高纯度羟基磷灰石,本研究以（NH4）2HPO4和Ca（NO3）.24H2O为原料,利用沉淀法制备纳米级羟基磷灰石粉末。对温度、pH值、分散剂添加比例、钙磷比、烧结温度等反应控制条件进行了研究,对钙磷比及烧结温度做了详细的讨论。结果表明：此法可以得到分散性、均匀性好,纯度高、颗粒小、晶形完整的纳米级羟基磷灰石。     

用于低损耗特种玻璃熔炼的高纯致密锆英石的研制

以纯度大于99.9%(质量分数)的高纯ZrO₂和SiO₂为原料,少量TiO₂为添加剂,采用高温固相法合成高纯锆英石(ZrSiO₄)粉料。研究温度和反应时间对高纯锆英石合成效率的影响,发现粒度小于50 μm的原料粉末经1 500 ℃反应48 h后,ZrSiO₄相的含量可以达到95.77%(质量分数)。将合成的高纯锆英石粉料球磨并冷等静压成型后,在1 550 ℃高温烧结成高纯致密锆英石砖。高纯致密锆英石中杂质Fe的含量仅为29 μg/g,Cu的含量小于1 μg/g,是普通商用致密锆英石的1/10;对磷酸盐玻璃静态光吸收损耗的影响仅为普通致密锆英石材料的1/3。将这种高纯致密锆英石材料用于激光玻璃窑炉,有助于降低玻璃对1 053 nm激光的损耗,提升激光玻璃的激光性能。     

Synthesis of high-purity high-entropy metal diboride powders by boro/carbothermal reduction

Synthesis of high-purity high-entropy metal diboride powders is critical to implementing their extensive applications. However, the related studies are rarely reported. Herein we first theoretically studied the synthesis possibility of high-purity high-entropy diboride powders, namely (Hf_0.25Ta_0.25Nb_0.25Ti_0.25)B₂ (HTNTB), via boro/carbothermal reduction by analyzing the thermodynamics of the possible chemical reactions and then successfully synthesized the high-purity and superfine HTNTB powders via boro/carbothermal reduction for the first time. The as-prepared powders exhibited low-oxygen impurity content of 0.49 wt% and small average particle size of 260 nm. Meanwhile, they possessed good single-crystal hexagonal structure of metal diborides and high-compositional uniformity from nanoscale to microscale. This work will open up a new research field on the synthesis of high-purity high-entropy metal diboride powders.     

Fabrication of high-purity HfSi2 powder via molten salt-assisted magnesium thermal reduction

In this work, high-purity HfSi₂ powders were successfully fabricated via a molten salt-assisted magnesium thermal reduction method using HfO₂ and Si as raw materials. The effects of reaction temperature and time on the formation of HfSi₂ were systemically investigated. The morphological and phase composition of as-prepared HfSi₂ powders were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and nitrogen/oxygen determinator. The results indicated that as-obtained HfSi₂ powders possess the orthorhombic structure with approximately 6.4 μm in size and the oxygen content as low as 0.20%. This work can provide a novel route to fabricate the high-purity transition metal silicides powders.     

水热沉淀法制备TiO2纳米粉体影响因素的研究

以硫酸钛水溶液为前驱物 ,尿素为沉淀剂 ,采用水热沉淀法制备了TiO2 纳米粉体 ,利用正交实验方法 ,XRD、TEM等分析测试手段 ,研究了前驱物浓度、尿素浓度、保温温度及保温时间对粉体粒径的影响。实验结果表明 :所制得的粉体为锐钛矿型TiO2 ,颗粒分散良好 ,平均粒径为十几纳米     

Synthesis and Sintering of Large Batches of Barium Zirconate Nanopowders

The acrylamide gelification process is a fast, inexpensive, reproducible, and easily scaled up chemical method for obtaining nanopowders of BaZrO₃ that can be used for sintering crucibles and many electronic applications. This method enables the production of 100 g of high-purity powders in one run, using simple laboratory equipment and low-cost raw materials. The gelification process, synthesis temperature, and gas conditions required for obtaining high-quality powders were the subjects of the present study. Fine powders were sintered to full density at 1450°C, making the fabrication of BaZrO₃ crucibles possible for many laboratories.     

纳米SnO2粉体及其掺杂体系液相化学法的研究进展

概述了近年来SnO2粉体及SnO2掺杂体系粉体的液相制备的研究近况。利用化学液相法能够制备出晶体结构完整、粒径分布范围窄、团聚少、粉体分散性能良好的纳米SnO2粉体以及SnO2掺杂体系粉体。     

Comparison of Ba(OH)2, BaO, and Ba as Starting Materials for the Synthesis of Barium Titanate by the Alkoxide Method

A discussion of the relative merits and problems of using Ba(OH)₂, BaO, and Ba as starting materials for the synthesis of barium titanate by the alkoxide method is presented. The Ba(OH)₂ process is promising because it does not involve the synthesis of barium alkoxide, whereas the BaO (93% pure) process suffers from complex chemical reactions; the impurities in BaO cause unknown effects on the composition and properties of the final ceramic. Use of high-purity Ba metal (99.99%) for the synthesis of barium alkoxide is more desirable since it results in high-purity, ultrafine barium titanate powders.     

流化床化学气相沉积法制备近化学计量比的TiN粉体

传统气-固反应工艺制备TiN粉体存在难以逾越的内扩散控制过程，导致制备高纯、正化学计量比的TiN粉体至今存在巨大困难。提出了流态化化学气相沉积工艺(FBCVD)制备高质量TiN粉体，即基于TiCl₄-N₂-H₂体系，在往复运动的TiN种子粉体上沉积新生高质量TiN粉体的新方法。实验发现，当TiN种子粉体粒径大于52.95 μm时，即使在1000℃沉积2 h也不会失流，同时在TiN种子粉体上获得了亚微米级的结节状新生TiN颗粒。通过氧氮分析仪和XRD分析发现，新方法显著提升了粉体的氮含量，获得了近化学计量比的TiN_0.96，且氧含量下降了约40%。此外，流化床中气相沉积TiN的生长模式为岛状生长模式，为工业中制备高质量TiN粉体提供了一种新的方法。     

Frictional assessment of magnesium stearate and palmitate lubricant powders

A method has been developed for the frictional assessment of powder lubricants using a shear-box tester similar to that employed by Jenike. One commercial magnesium stearate, three high-purity magnesium stearates and three high-purity magnesium palmitates were assessed using this method. Powders with a well-ordered crystal structure and particle shape have a lower initial maximum coefficient of friction μ_a. The difference between μ_a and μ_b, the equilibrium dynamic friction coefficient, gives an indication of lubricant film-forming propensity. The basic friction equation is obeyed by the powders for most of the load range studied but deviates slightly approaching zero normal load.