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991.
针对公司调度自动化机房网络配线无图纸管理和标签标识不规范的情况,自主研发了一套机房网络配线管理软件。首先,分析了配线可视化管理软件应对网络配线绘图和标签信息自动生成的功能需求,并运用MVC模式理论进行软件架构设计;其次,重点阐述了基于QT图形库的关键功能实现,包括核心图元类的构建、元件库组件可配置生成、图形序列化反序列操作、拓扑查找、设备图元属性管理及标签信息自动生成功能等;最后,通过举例说明该软件在实际机房管理中的使用方法和应用成效。应用结果表明,通过绘制整个机房的网络连接图并录入相关设备属性信息,有助于提高机房网络故障的诊断效率和降低机房系统的运维风险。 相似文献
992.
Wang J Chen Y Lin M Fan G Zhao W Wu Y Yan C Wang J 《Journal of separation science》2007,30(3):381-390
A pressurized CEC (pCEC) method with postcolumn detection cell had been developed for quantifying the lignans from Fructus schisandrae extracts. The effects of different experimental conditions, such as the ACN content of the mobile phase, the concentration and pH of the buffer, the applied voltage, and the supplementary pressure were studied. Five lignans (schisandrin, gomisin A, schisantherin C, deoxyschizandrin, schisandrin B) were baseline separated using a mobile phase of ACN-phosphate buffer (pH 5.4; 5 mM) (40:60 v/v) under -4 kV applied voltage. The method showed the satisfactory retention time and peak area repeatability. The calibration curves were linear in the range 50.0-1000.0 microg/mL for schisandrin, 20.0-500.0 microg/mL for gomisin A, 10.0-200.0 microg/mL for schisantherin C, 20.0-500.0 microg/mL for deoxyschizandrin, and 20.0-500.0 microg/mL for schisandrin B. The correlation coefficients were between 0.9978 and 0.9989. With this pCEC system, fingerprints of F. schisandrae were preliminarily established to distinguish two members S. chinensis (Turcz.) Baill. and S. sphenanthera Rehd. Et Wils. of F. schisandrae by characteristic peaks, and evaluate the quality of various sources of raw materials by determining the contents of the five lignans. 相似文献
993.
[structure: see text]. The first asymmetric synthesis of the (S)-1,1-dioxido-isothiazolidin-3-one ((S)-IZD) pTyr mimetic, which has been incorporated into the recently reported potent protein tyrosine phosphatase 1B (PTP1B) inhibitors, is presented herein. The key reaction is the reduction of the (R)-oxido-isothiazolidin-3-one heterocycle with excellent regiochemical and stereochemical control (>98% ee; 82% yield). 相似文献
994.
Two new ruthenium(II) polypyridyl complexes
(1) (dtmi = 3-(pyrazin-2-yl)-as-triazino[5,6-f]-5-methoxylisatin) and
(2) (dtni = 3-(pyrazin-2-yl)-as-triazino[5,6-f]-5-nitroisatin) have been synthesized and characterized by elemental analysis,
FAB-MS, ES-MS and 1H-n.m.r. The DNA-binding patterns of complexes were investigated by spectroscopic titration, viscosity measurements and thermal
denaturation. The results indicate that the complexes (1) and (2) interact with calf thymus DNA (CT-DNA) by intercalative mode. Due to the withdrawing electronic substitutent in the intercalative
ligand, ptni, the DNA-binding affinity of the complexes (2) is larger than that complex (1) does. 相似文献
995.
Hu ML Jiang M Wang P Mei SR Lin YF Hu XZ Shi Y Lu B Dai K 《Analytical and bioanalytical chemistry》2007,387(3):1007-1016
Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using tebuconazole (TBZ) as a template.
Frontal chromatography and selectivity experiments were used to determine the binding capabilities and binding specificities
of different MIPs. The polymer that had the highest binding selectivity and capability was used as the solid-phase extraction
(SPE) sorbent for the direct extraction of TBZ from different biological and environmental samples (cabbage, pannage, shrimp,
orange juice and tap water). The extraction protocol was optimized and the optimum conditions were: conditioning with 5 mL
methanol:acetic acid (9:1), 5 mL methanol and 5 mL water respectively, loading with 5 mL aqueous samples, washing with 1.2 mL
acetonitrile (ACN):phosphate buffer (5:5, pH3), and eluting with 3 mL methanol. The MIPs were able to selectively recognize,
effectively trap and preconcentrate TBZ over a concentration range of 0.5–15 μmol/L. The intraday and interday RSDs were less
than 9.7% and 8.6%, respectively. The limit of quantification was 0.1 μmol/L. Under optimum conditions, the MISPE recoveries
of spiked cabbage, pannage, shrimp, orange juice and tap water were 62.3%, 75.8%, 71.6%, 89% and 93.9%, respectively. MISPE
gave better HPLC separation efficiencies and higher recoveries than C18 SPE and strong cation exchange (SCX) SPE.
Figure HPLC analysis of spiked pannage after MISPE (A) and after C18 SPE (B). HQ (1), E3 (2), p-NP (3), FTF (4), TBZ (5), PNZ (6),
HXZ (7)
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
996.
ZnO nanocrystals, nanorods, and tablets were prepared at 110, 140, and 180 degrees C in a water-ethanol system. Nanorods (~2 x 40 nm) arranged in serpentine morphologies formed by the oriented coalescence of anhedral ZnO nanocrystals (~3.5 nm diameter), while tabular ZnO grew by [1210] textural attachment of the nanorods. The development of these crystal habits is believed to proceed via a dissolution and growth mechanism mediated by a transient amorphous phase. Materials synthesized at intermediate temperatures (125 and 160 degrees C) possessed microstructures containing mixed crystal forms in the expected orientation relationship. Photoluminescent spectra of the nanocrystals and nanorods showed blue shifts of 0.16 and 0.13 eV with respect to the bulk ZnO band gap (3.26 eV) due to quantum confinement, with the narrow emission peaks typical of particles possessing uniform size and shape. The larger tablets displayed a less energetic emission (3.10 eV) ascribed to exciton-exciton collisions. 相似文献
997.
Xiang‐Shan Wang Mei‐Mei Zhang Zhao‐Sen Zeng Da‐Qing Shi Shu‐Jiang Tu Xian‐Yong Wei Zhi‐Min Zong 《Journal of heterocyclic chemistry》2007,44(2):441-447
A clean and simple synthesis procedure for benzo[f]quinolin‐3‐carbonyl urea and thiourea derivatives was developed based on the reaction between N‐arylidenenaphthalen‐2‐amine and barbituric acid or thiobarbituric acid in aqueous media catalyzed by triethylbenzylammonium chloride (TEBAC). It was interesting that the structures of products in solvent of DMSO‐d6 solution were different from those of the crystal states, which keep the enol form. The products were characterized by 1H NMR, and 13C NMR, and the crystal state was confirmed by X‐ray diffraction study of 3e . In addition, water was chosen as green solvent. 相似文献
998.
Effect of sulfonic acid containing mesogens on liquid-crystalline behavior of polysiloxane-based polymers 总被引:1,自引:0,他引:1
Zhang BY Meng FB Li QY Tian M 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):6385-6390
A series of liquid-crystalline polysiloxanes synthesized by cholest-5-en-3-ol (3beta)-10-undecenoate and 4'-octanoyloxy-biphenyl-4-yl 4-allyloxy-3-sulfo-benzoate were prepared in a one-step reaction with sulfonic acid group contents ranging between 0 and 2.73 wt %. All the polymers displayed smectic mesophases with a large temperature range for the mesophases. With an increase of sulfonic acid containing mesogens in the polymers, the temperature of the glass transition did not change greatly, while the temperature of the clear point decreased. The hydrogen-bonding mesogen aggregates in the domains disturb the liquid-crystalline molecular mobility and orientation, leading to a decrease in temperature from the mesophase to the isotropic transition. Unlike the polymers containing lower sulfonic acid mesogens, some polymers showed a dendritic texture of the SmB* phase, indicating that the sulfonic mesogens enhanced the rigid moieties of the supermolecular structure of the liquid-crystalline phases. All the polymers displayed sharp and strong peaks at low angles around 2theta approximately 2.6 degrees and broad peaks at wide angles around 2theta approximately 17 degrees in X-ray measurements. The intensity of the strong peak at low angles in the X-ray profiles decreased with an increase of sulfonic acid mesogens in the polymer systems. 相似文献
999.
PERTURBATION TO THE SYMMETRIES AND ADIABATIC INVARIANTS OF HOLONOMIC VARIABLE MASS SYSTEMS 总被引:1,自引:0,他引:1 下载免费PDF全文
The perturbation problem of symmetries for the holonomic variable mass systems under small excitation is discussed. The concept of high-order adiabatic invariant is presented, and the form of adiabatic invariants and the conditions for their existence are given. Then the corresponding inverse problem is studied. Finally an example is presented to illustrate these results. 相似文献
1000.
EFFECTS OF NONHOLONOMIC CONSTRAINT ON LIE SYMMETRIES AND CONSERVED QUANTITIES OF LAGRANGIAN SYSTEMS 总被引:1,自引:0,他引:1 下载免费PDF全文
After a Lagrangian system is constrained by nonholonomic constraints, the determining equations, the structure equation and the form of conserved quantities corresponding to the Lie symmetries will change. Some symmetries vanish and under certain conditions some Lie symmetries still remain. 相似文献