新型磁性纳米级油酸改性铁氧磁流体磁性粒子的制备及表征

用油酸钠作为表面活性剂,采用化学共沉淀法制备纳米级油酸改性铁氧体磁性粒子,从温度T、碱的过量比y、表面活性剂的用量比n、反应时间t4个方面进行研究。确定高纯度、小粒径、强磁性、均匀分散的Fe3O4磁性粒子的合理工艺条件:t=180 min,T=80℃,y=0.25,n=0.6。红外光谱测试,证明产品为表面活性剂油酸包裹的纳米级磁性粒子,粒径<10 nm,XRD分析证实了产品为铁氧体磁性粒子,古埃磁天平对产品进行了性能测试。     

FCIM:一种新的闭模式挖掘算法

闭模式挖掘在关联规则挖掘算法中获得了较广的应用,提出一种新的挖掘频繁闭项目集的算法,该算法可以充分利用挖掘过程中已获取的信息,直接使用FP-Tree产生闭项目集,实验结果表明该算法是有效的。     

Microwave-Assisted Azidation Reaction for Rapid Synthesis of Poly(3,3ʹ-Bisazidomethyl Oxetane)

We successfully designed and developed a new strategy for synthesizing an energetic material, poly(3,3?-bisazidomethyl oxetane) (PBAMO), by microwave assistance, which dramatically shortened the reaction time and improved the safety of the synthetic process.     

The role of Chinese universities in enterprise–university research collaboration

In this paper the role of Chinese universities in enterprise–university research collaboration is investigated. This study focuses on a special aspect of the collaboration—co-authored articles. The two cases are analyzed: (1) research collaboration between Baosteel Group Corporation and Chinese universities; (2) research collaboration between China Petroleum & Chemical Corporation and Chinese universities. The co-authorship data over the period 1998–2007 were searched from CNKI database, the largest Chinese publication and citation database. The main findings are as follows: the number of articles co-authored by enterprise and university scientists has been increasing rapidly; the share of co-authored articles has been growing; the authors from universities are more possible to be the first authors; as a whole, enterprise–university co-authored articles tend to receive more citations and get downloaded more frequently; a mathematical orientation emerges in the enterprise–university articles. To reveal and describe such a trend the methods of keywords analysis and co-occurrence analysis are applied. The Chinese government’s policy instruments and substantial supports for pushing and improving enterprise–university research collaboration are introduced and analyzed.     

Spiralling elliptic vortex solitons in nonlocal nonlinear media

We have introduced a class of spiralling elliptic vortex (SEV) solitons in nonlocal nonlinear media. The SEV soliton has more complicated structures both in its amplitude and in its phase compared with conventional vortex solitons. Different from the circularly symmetric amplitude profile of vortex solitons, the SEV solitons exhibit the elliptic optical spots. Furthermore, the SEV solitons have the special modulated helical phase structures, which make the SEV solitons rotate. For different topological charges, all the SEV solitons own the same critical power, critical cross-term phase coefficient and the critical angular velocity for fixed semiaxis of the elliptic spots. The stability of the SEV solitons is confirmed by the direct numerical simulations with random noises.     

11βHSD1抑制剂1-(4-三氟甲氧基苯甲酰基)-4-(4-甲氧基苯甲酰基)哌啶的合成研究

以4-甲氧羰基哌啶盐酸盐(1)和对三氟甲氧基苯甲酰氯(2)为起始原料,在三乙胺的作用下以92.7%的收率制得1-(4-三氟甲基苯甲酰基)-4-甲氧羰基哌啶(3);化合物(3)在羰基二咪唑与N,O-二甲基羟胺盐酸盐(4)作用下,以89.9%的收率制得1-(4-三氟甲氧基苯甲酰基)-4-(N-甲基-N-甲氧基羰基)哌啶(5);化合物(5)和4-甲氧基苯基溴化镁(6)偶联,以60.1%的收率制得化合物1-(4-三氟甲氧基苯甲酰基)-4-(4-甲氧基苯甲酰基)哌啶(7)。三步反应总收率50.0%。     

Structure and photocatalytic property of a new Cu(II) based framework with jsm topology

A new coordination polymer [Cu(mip)(bpy)_0.5]_n (1) was obtained through reaction of 5-methylisophthalic acid (H₂mip) and 4,4′-bipyridine (bpy) with copper nitrate under hydrothermal condition. X-ray single crystal diffraction analysis reveals that complex 1 exhibits a 3D network with jsm topology. Photocatalytic activity of the complex has also been characterized. Notably, complex 1 represents the rare example of visible-light-driven photocatalyst based on coordination polymer and shows good degradation ability over methylene blue (MB).     

Synthesis and characterization of iron(II) and iron(III) complexes with a tridentate O,N,O′-ligand

The coordination chemistry of the ligand precursor 1-benzoyl-4,5-dihydro-3,5-bis(trifluoromethyl)-1H-pyrazol-5-ol (1a) to iron(II) acetate was studied. In dependence of the added co-ligand different complex geometries were observed. In case of 4-dimethylaminopyridine (DMAP) as co-ligand an octahedral iron(II) complex was found with an O,N,O′-coordination of the tridentate ligand (1a-2H), in which the ligand is planar, the oxygen donors are trans to each other, and the nitrogen donor is in a cis position. The other coordination sites on the iron center are occupied by DMAP ligands. In contrast to that, with triphenylphosphane as the co-ligand an oxidation process took place, which revealed an octahedral iron(III) complex with a comparable geometry for the tridentate ligand (O,N,O′-coordination, 1a-2H) demonstrating the usefulness of 1a-2H to stabilize different oxidation states. The additional coordination sites are occupied by one triphenylphosphane oxide and ethoxide ligands. Interestingly, the ethoxide ligands act as bridging ligands to form a bimetallic complex.     

Re-determination of the crystal structure of Ca2Y8Si6O26 and study on the luminescent properties of Ca2Y8Si6O26:Tb3+

The crystal structure of silicate oxyapatite Ca₂Y₈Si₆O₂₆ was indexed as hexagonal, space group P6₃/m, α=0.93515 nm, c=0.67872 nm, α=β=90°, γ=120°, V=0.5138692 nm³. Three strong peaks located at 32.079°, 32.595°, and 50.104° with d=2.7903, 2.74649, 1.8194 was in accordance with (211), (112), and (213) planes. The optimum concentration of Tb³⁺ in Ca₂Y₈Si₆O₂₆ to yield highest photoluminescence intensity was 10 mol.% of Y³⁺. The corresponding excitation spectrum consisted of an intense broad band from 220 to 260 nm. The photoluminescence measurements showed that the green emission originated from ⁵D₄?⁷F₅ was predominant in the measured range with strong doublet lines at 543 and 549 nm.     

企业计算机资源优化系统

为优化企业内部的计算机资源,研究开发了计算机资源优化分析系统.通过数据收集、采样、建模等方法,对企业内部的计算机各项性能数据进行测量和分析.系统采用了Structs和Hibernate相结合的框架,使用POI技术将分析结果以图表形式呈现给用户,采用Ajax技术实现了Web页面的动态刷新功能.运行结果表明,该系统可为企业正确决策提供有力支撑,采用的MVC设计模式能提高系统的可重用性和可扩展性.