A ratiometric fluorescent sensor for zinc(II) with high selectivity

Spectroscopic studies revealed that the compound [N,N′-di(quinoline-2-methylene) -1,2-phenylenediimine] (1) exhibited a rather high selectivity toward Zn²⁺ over other metal ions, even Cd²⁺. In acetonitrile, the red shift of fluorescent emission from 396 nm to 426 nm upon zinc binding is due to the formation of a 1:1 metal/ligand complex.     

尿素设备的腐蚀与维护

论述氨汽提尿素装置主要设备的腐蚀问题，分析腐蚀的原因及预防措施。     

Characterization of the adipose tissue atrophy induced by peroxisome proliferators in mice

In the present study, we characterized the effects of peroxisome proliferators (PP) on adipose tissue in mice. Treatment with potent PP, such as perfluorooctanoic acid (PFOA), 2-methyl-2-(p(1,2,3,4-tetrahydroxy-naphthyl)-phenoxy)propionic acid, (4-chloro-6-(2,3-xylidino)2-pyrimidinylthio) acetic acid, and di(2-ethylhexyl)phthalate, caused dramatic decreases in adipose tissue weight, whereas the moderately potent PP, acetylsalicylic acid, had a relatively weak effect. This decrease in weight reflects a loss of fat from adipocytes rather than a loss of cells, as demonstrated by constant DNA content. The dose-dependency and time-course experiments indicate that peroxisome proliferation occurs simultaneously with or prior to adipose tissue atrophy. Thus, hepatic peroxisome proliferation might result in the increased mobilization of lipids and lipid utilization in liver. The enhanced adipose tissue hormonesensitive lipase (HSL) activity and down-regulated lipoprotein lipase (LPL) activity observed upon PP treatment might, at least in part, explain the loss of fat via increase FA release from adipocytes and/or decreased FA uptake from the circulation, respectively. In addition, the possible involvement of the increased tumor necrosis factor α expression found upon PFOA treatment in reducing the insulin sensitivity of adipose tissue and thereby altering LPL and HSL activities is discussed.     

防止过拟合的属性约简

近年来,机器学习的过拟合问题备受关注,尤其在属性约简中。为解决这一难题,提出一种融合集成策略和去除操作的算法。首先将训练模型数据平分为◢M份;然后将其中M◣-1份采用集成策略进行潜在约简计算;最后将剩余的一份进行提前测试,一旦发生过拟合则将刚加入的属性从潜在约简集中去除。利用提前测试潜在属性约简的方法来防止过拟合现象的发生,几组UCI数据的实验结果说明了新算法的有效性,同时为丰富和发展属性约简提供了一种新的方向。     

高热稳定性和可逆交联性质的含新型偶氮发色团电光聚合物的研究

制备了两种新型的分别含有以三苯胺为电子给体的偶氮类发色团作为特征活性官能团和3-呋喃甲酸及受保护的马来酰亚胺的可交联型聚合物体系．通过研究表明利用该制备方法，发色团在聚合物中的含量得到了极大的提高，分别达到32．1％（NLO1_P1）和44．4％（NLO1_P2）．该聚合物体系以“DielsAlder”[4＋2]环加成反应作为其交联特征，具有高温非交联、低温交联的特点，其过程与以往的热交联型聚合物相反，可解决传统电光交联聚合物中存在的热交联对极化效率影响的问题并用热失重分析法（TGA）和差示扫描量热法（DSC）分析了这一过程．此外DA交联型聚合物，不需要引入额外的助交联剂，克服了传统热交联聚合物分离难的问题，最大程度的保证了材料的纯度．     

药物中间体3,5-二甲氧基-邻苯二甲酸酐的合成及表征

以3,5-二甲氧基苯甲酸甲酯为原料经过羟烷基化反应、酯交换反应、水解反应、脱羧反应、氧化反应、脱水反应来合成3,5-二甲氧基-邻苯二甲酸酐这一中间体,每步反应的收率均在90%以上。通过差热分析、红外、质谱、核磁等分析手段对合成的化合物的结构表征,结果表明,所合成的化合物的结构、性能指标与目标要求一致。     

Volume phase transition of polyelectrolyte gels in dimethyl sulfoxide/ tetrahydrofuran mixtures

Copolymer gels were prepared from 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS), N,N-dimethylacrylamide (DMAA, comonomer) and N,N′-methylenebis(acrylamide) (BIS). The mole fraction of AMPS were 0.2674 and 0.4318, respectively, with the same BIS mole fraction of 0.013. These gels with counterions H⁺, Na⁺, and K⁺ were swollen at 25°C in mixtures of dimethyl sulfoxide (DMSO) and tetrahydrofuran (THF). A volume phase transition was observed at the THF volume fraction of about 0.58, indicating that the volume phase transition in a polyelectrolyte gel occurs when the medium polarity decreases sufficiently for ion-pair formation. On changing the counterion, the fraction of DMSO in the solvent mixture which is required to initiate swelling decreases in the order Na⁺, H⁺, and K⁺, the same as for counterion condensation in identical gels.     

Consolidation of Nano-Sized TiN Powders by Spark Plasma Sintering

Nano-sized TiN powders with an average particle size of 19 nm were synthesized via a new method, reduction–nitridation reaction in liquid ammonia. A consolidation procedure using spark plasma sintering (SPS) was used, and a dense TiN ceramic (>98% of theoretical) with mean grain size of 100–150 nm was obtained at 1380°C. The influence of sintering temperature on grain growth and microstructural evolution was also discussed.     

GOR-C降烯烃催化剂的工业应用

大庆炼化公司林源生产指挥部催化裂化装置原料油为典型石蜡基原油的常压渣油，生产的催化汽油中的烯烃含量较高，为此试用长岭炼化公司催化剂厂生产的降烯烃催化剂GOR-C。结果表明，降烯烃效果明显，产品分布无明显变化，能满足现有生产要求，经济效益显著。     

低萃取及B级聚酯绝缘膜研究 Ⅰ．国内研制动态

介绍了开发低萃取及B级聚酯(PET)薄膜的意义和要求,回顾了国内研制的情况,同时对其发展进行了讨论。