珠状交联烯丙基葡聚糖凝胶的合成

通过改变分散剂的种类和用量，引发剂的用量及聚合反应时间等实验条件，在能获得轴向流型的聚合反应釜中，烯丙基葡聚糖与Ｎ，Ｎ‘－亚甲基双丙烯酰胺可以悬浮聚合，形成分布较窄的珠状亲水层析凝胶。     

The effects of oxygenation aeration treatment on dissipation behaviors of tricaine mesylate in carp (Cyprinus carpio) muscle and water

Tricaine mesylate (MS-222) is one of the most used anesthetics in fish. It can be absorbed by the human body via food consumption, with related detriments to human health. In this study, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was developed for the determination of MS-222 in carp muscle and water samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). For cleanup procedure, multiplug filtration cleanup (m-PFC) method with n-Hexane delipidation was adopted. The extraction solvent, cleanup methods and sorbents were optimized. All method validation parameters were in the acceptable range. The dissipation behavior study was followed by the method development. Firstly, the anesthesia dose and time were optimized in application study. Secondly, carps were revived for different period of time with (experimental group) and without (control group) the oxygenation aeration treatment to compare the dissipation rate of MS-222. After being anesthetized for 6 h at 50 mg/L and 12 h of elimination, the concentrations of MS-222 in crap muscle and water of experimental group was lower than those of control group. After 36 h of elimination under oxygenation aeration, over 90% of MS-222 was dissipated in carp muscle. The results showed that the half-life of MS-222 in carp muscle was 6.2 h. The findings suggested that the commonly-used oxygenation aeration treatment in aquaculture production had potential effects in accelerating the dissipation of MS-222 in carp and water. In this study, three days of withdrawal period was recommended in carps after MS-222 administration under oxygenation aeration.     

Heterogeneous Gold‐Catalyzed Selective Reductive Transformation of Quinolines with Formic Acid

Single phase rutile titania supported gold nanoparticles (Au/TiO₂‐R) are found to be efficient and versatile catalysts for chemo‐ and regioselective transfer hydrogenation of quinoline derivatives to 1,2,3,4‐tetrahydroquinolines (THQs) using formic acid (FA) as a safe and convenient hydrogen source under mild conditions. The activity and chemoselectivity of the Au/TiO₂‐R catalyst towards THQs is excellent, with a substrate to catalyst ratio (S/C) of 1000 being feasible. Furthermore, a straightforward and selective route to N‐formyltetrahydroquinolines (FTHQ) directly from quinoline compounds and FA by one‐pot, gold‐catalyzed reductive N‐formylation protocol is also established.

     

1-氨基-2-(N,N-二甲氨基)-4-羟基-蒽醌的合成新方法

以分散红60和DMF为原料,在碳酸钾作用下反应制备得到1-氨基-2-(N,N-二甲氨基)-4-羟基-蒽醌,产品收率92.8%。     

激光熔覆制备原位自生增强颗粒复合涂层

采用高能束横流HL-5000型CO2激光器在铸钢表面熔覆了含有碳氮化钛增强粒子的铁基熔覆层。利用X射线衍射(XRD)和能谱EDAX对熔覆层进行了分析, 并采用光学显微硬度计对熔覆层的硬度进行了测试。利用金相显微镜(OM)和扫描电镜(SEM)对激光熔覆层的微观组织进行了研究。结果表明: Ti(C0.3N0.7)可以通过原位反应合成, 新的颗粒状强化相Ti(C0.3N0.7)的形貌特征多呈不规则形状, 弥散分布在熔覆层基体中。熔覆层与母材形成良好的冶金结合, 熔覆层内为方向性强的胞状树枝晶, 晶粒细小。熔覆层的显微硬度HV0.3达到730～850。     

Co_3O_4/mpg-C_3N_4催化剂的制备及其可见光催化性能研究

采用浸渍法制备了载钴介孔石墨相氮化碳(Co3O4/mpg-C3N4)催化剂,并对其进行X射线衍射(XRD),红外光谱(FT-IR),N2吸附脱附,紫外漫反射光谱(UV-vis DRS)和光生电流的表征。结果显示,Co3O4的引入提高了mpg-C3N4的光吸收性能,利于其表面光生电子和空穴的分离。将制得的Co3O4/mpg-C3N4用于可见光催化降解水中的亚甲基蓝(MB),其催化效率远高于mpg-C3N4,且最佳的钴负载量为3%。     

Mn18Cr18N护环钢静态再结晶组织及模型

在Gleeble-1500D热模拟机上,采用双道次热压缩试验研究Mn18Cr18N护环钢高温变形后不同停留时间内的静态软化行为,分析热变形温度、应变速率、变形程度以及初始奥氏体晶粒对静态再结晶行为的影响.通过应力补偿法计算静态再结晶软化率,并结合金相组织作了修正.建立其静态再结晶动力学模型,获得静态再结晶激活能249.3 k J/mol.研究表明:Mn18Cr18N钢静态再结晶软化曲线呈"S"形,符合Avrami方程.静态再结晶体积分数随着停留时间延长而增加,热变形温度越高,静态再结晶分数越大,而在较低温度和较小变形程度时,孕育时间较长,主要发生静态回复,将静态再结晶动力学模型的预测结果与实测值进行比较,二者吻合较好,为护环钢后续热镦粗工艺模拟提供更为详尽的模型.     

Gold‐Catalyzed Redox Synthesis of Imidazo[1,2‐a]pyridines using Pyridine N‐Oxide and Alkynes

A mild, catalytic, atom economical synthesis of imidazo[1,2‐a]pyridines has been developed: catalytic dichloro(2‐pyridinecarboxylato)gold [PicAuCl₂] in the presence of an acid produces a range of imidazo[1,2‐a]pyridines in good yields starting from alkynes and 2‐aminopyridine N‐oxides. This strategy is mild and foreseen to be of particular use for the installation of stereogenic centers adjacent to the imidazo[1,2‐a]pyridine ring without loss of enantiomeric excess.

     

NMR Studies of the Dynamic Motion of Encapsulated Ions and Clusters in Fullerene Cages: A Wheel Within a Wheel

Nuclear magnetic resonance (NMR) has provided an important approach to investigate the structure and dynamics of encapsulated metal ions and clusters in endohedral metallofullerenes (EMFs). In this paper, we review NMR studies of the environment and dynamics of dimetallic, trimetallic nitride, metal carbide and metal cyanide clusters encapsulated in EMFs. The NMR chemical shielding parameter is a sensitive probe for monitoring the carbon cage (¹³C) and encapsulated clusters (¹³C, ¹⁴N, ¹³⁹La, ⁴⁵Sc, and ⁸⁹Y). Future NMR EMF studies could be very fruitful and help elucidate coupled motion between the carbon cage and encapsulated cluster or other “wheel within a wheel” motional processes.