城市天际轮廓线的保护与设计——以重庆主城区天际轮廓线为例

城市天际轮廓线是城市生活事实的物质反映,不同的城市拥有不同的天际轮廓线,它反映了城市的独特性格。在城市建设中,我们应该考虑到城市自身的历史发展脉络和城市所在的地理环境,在城市规划的控制中强调对历史上形成的天际轮廓线进行有效的保护,对城市中建筑和环境的改变要采取谨慎的态度。本文探讨了城市天际轮廓线保护的重要性和城市天际轮廓线保护面临的主要问题,并以重庆为例谈了城市天际轮廓线的设计。     

施工作业面管理浅析

介绍了建设工程施工作业面管理的重要性，从现场管理、进度管理、安全管理等方面进行了论述，指出搞好施工作业面管理，是整个施工项目管理的重要环节。     

Pharmacokinetic investigation on a novel antitumour platinum compound in rabbit plasma by inductively coupled plasma mass spectrometry after intravenous administration

The purpose of this study was to investigate a novel platinum anticancer compound named as SM54111 [cis-3, 5-diisopropylsalylic cyclohexanodiaminoplatinum (II)], which is under development as a new drug candidate, on its pharmacokinetics in plasma after intravenous administration to rabbits at concentration of 2.5, 5.0, and 9.0 mg/kg. The concentration of SM54111 in plasma expressed as Pt was determined utilizing ICP-MS method, and the method was thoroughly validated. The data were analyzed with 3P97 pharmacokinetic software to find the parameters. The results showed that the linear range lay at the 1 approximately 1000 ng/mL level, and the LOD and LOQ were 0.4 ng/mL and 1 ng/mL, respectively. It proved that this new drug candidate underwent disposition in rabbit plasma by a two-compartment open model at the three doses above, and the main pharmacokinetic parameters were obtained as the initial concentrations of three doses (C(0)) were 8.68 +/- 0.80, 20.04 +/- 1.92, and 28.88 +/- 2.32 mg/L, respectively; the areas under concentration-time profile from time 0 to 72 h (AUC(0 approximately t)) were 90.0 +/- 13.0, 251.3 +/- 45.3, and 396.9 +/- 61.1 mg*h/L, respectively; the terminal elimination half-life times (t(1/2beta)) 29.1 +/- 4.8, 35.2 +/- 7.5, and 29.4 +/- 2.8 h, respectively; and the total clearances (CL(tot)) were 0.026 +/- 0.004, 0.019 +/- 0.002, and 0.022 +/- 0.004 L/h, respectively. First order rate pharmacokinetics were observed for SM54111 with the doses used, and it showed a long retention and slow elimination in vivo, There showed no prolongation of the t(1/2beta) with larger dose, and the CLs of the three doses were proximate. It is reasonable to surmise that SM54111 follows first order rate pharmacokinetics, and no saturation was detected at concentrations from 2.5 to 9.0 mg/kg. This result suggested that SM54111 experienced an amiable procedure in vivo and was worthy of the further development.     

Tribological properties of Fe3Al material under water environment

The tribological properties of Fe₃Al material under water environment sliding against Si₃N₄ ceramic ball were studied using an Optimol SRV oscillating friction and wear tester in a ball-on-disc contact configuration. Effects of load and sliding speed on tribological properties of the Fe₃Al material were investigated. The worn surfaces of the Fe₃Al material were analyzed by a scanning electron microscopy (SEM) and an X-ray photoelectron spectroscopy (XPS). Wear rate of the Fe₃Al material was in the orders of 10⁻⁴ mm³ m⁻¹ and increased with increasing load and increasing sliding speed. Friction coefficient of the material was in the range of 0.37–0.6, and decreased slightly with increasing load, but increased at first and then did not vary with increasing sliding speed. The wear mechanism of the material was transformed from microploughing to delaminating with increasing load and sliding speed.     

Effect of Host Plant Xylem Fluid on Growth,Aggregation, and Attachment of <Emphasis Type="BoldItalic">Xylella fastidiosa</Emphasis>

In the Temecula Valley of California the proximity of citrus groves to vineyards influences the incidence and severity of Pierce’s disease (PD) in grapes, a disease caused by the gram-negative bacterium, Xylella fastidiosa. Although the glassy-winged sharpshooter (GWSS), the major insect vector of the bacterium, feeds on and moves back and forth between citrus groves and vineyards, there are no visible symptoms of disease caused by X. fastidiosa in citrus. Previous evidences suggested that while grapevines are susceptible to the PD strain of X. fastidiosa, citrus trees are resistant or tolerant but could be a reservoir to harbor the pathogen for the GWSS acquisition. We investigated the mechanisms of host plant resistance/susceptibility by examining the in vitro effect of xylem fluid from grapefruit, orange, lemon, and grape on the growth, aggregation, and attachment of a X. fastidiosa strain isolated from grape. Our results revealed that xylem fluid from grapefruit, orange, and lemon trees caused the bacterial cells to form aggregations of large whitish clumps, whereas the xylem fluid from grape vines created a visible thick biofilm. The densities of X. fastidiosa cells in grapefruit xylem fluid treatment were significantly higher at 6, 8, and 9 d postinoculation compared with those in grape xylem fluid treatment. The cell densities of X. fastidiosa cultures in orange or lemon xylem fluid were generally lower than those in grape xylem fluid treatment, whereas citrus xylem fluid significantly inhibited X. fastidiosa biofilm formation compared to grape xylem fluid.     

酸白土催化体系开环八甲基环四硅氧烷的研究及机理探讨

Cationic ring opening polymerization of octamethylcyclotetrasiloxane （Da） initiated by acid treated bentonite was investigated. The experimental conditions were chosen on the basis of preliminary experiments.Higher temperature was found beneficial for the reaction process while stirring intensity beyond a certain level showed no obvious effect on the reaction rate. Polymers were characterized by Fourier transform infrared, proton nuclear magnetic resonance （IH-NMR） and gel perneation chromotography. The width of molecular mass distribution was found ranging between 1.2 and 1.4, which is extraordinarlly narrow compared with that of cationic polymerizations reported elsewhere （〉 1.9）. The results were believed due to the absence of free proton and counter ion which simplifies the polymerization process and the huge steric hindrance provided by bentonite particles which keeps the propagation of polysiloxane onto the surface of bentonite particles in a much more regular way. A feasible mechanism is proposed and seems to be supported well by experiments. Additionally, from the results of α, ω-dihydrogen terminated polysiloxanes prepared, the possibility of applying this potential environmentally friendly heterogeneous catalyst in industrial polymerization of cyclosiloxanes is anticipated.     

德国萨其宾公司考察记实

介绍了作者赴欧洲考察萨其宾公司的概况、该公司的生产工艺及重要操作程序;介绍了萨其宾公司的主要产品牌号及性能;着重叙述了萨其宾公司三废治理及所取得的环境效益,发表了四个方面的观后感。     

离子束刻蚀正交位相型Ronchi光栅研究

本文报道了采用紫外光刻和离子束刻蚀方法制作正交位相互Ｒｏｎｃｈｉ的工艺技术,并讨伐春衍射效率,给出公式及实验结果。     

Templated spherical coassembly strategy to fabricate MoS2/C hollow spheres with physical/chemical polysulfides trapping for lithium-sulfur batteries

Rational design of advanced polar hosts with high sulfur loading,facilitated ionic/electronic transport and effectively suppressed shuttling effect has great po...     

砂型铸造D型石墨铸铁的研究

研究了冷却速度和含钛量对砂型铸件金相组织的影响,通过控制含钛量和壁厚获得了Ｄ型石墨铸铁