空冷塔堵塞导致分子筛带水的原因及处理

KDN-6000型空分设备运行中因空冷塔塔板被脏物堵塞,发生分子筛纯化系统带水故障;采取相应的处理措施维持空分设备的运行;按计划停运空分设备后,清洗空冷塔,彻底排除故障。     

分子筛吸附器进水故障及其处理过程

KDONAr-10000／22000／370型空分设备因空冷塔液位计失效而发生分子筛吸附器进水故障。介绍了故障发生的经过和处理过程；最后得出了发现及处理分子筛吸附器进水故障的经验和教训。     

Growth of epitaxial Cu on MgO(001) by magnetron sputter deposition

100-nm-thick Cu layers were grown on MgO(001) substrates by ultra-high vacuum magnetron sputter deposition at substrate temperatures T_s ranging from 40 to 300 °C. X-ray diffraction ω−2θ scans, ω-rocking curves, and pole figures show that layers grown at T_s = 40 and 100 °C are complete single crystals with a cube-on-cube epitaxial relationship with the substrate: (001)_Cu||(001)_MgO with [100]_Cu||[100]_MgO. In contrast, T_s ≥ 200 °C leads to polycrystalline Cu layers with 001, 203, and 1¯75-oriented grains. The transition from a single- to a polycrystalline microstructure with increasing T_s is attributed to temperature-induced mass transport that allows Cu nuclei to sample a larger orientational space and find lower energy (and/or lower lattice mismatch) configurations. The large Cu- to-MgO lattice mismatch of 14% is relieved by 7 × 7 Cu unit cells occupying 6 × 6 MgO cells. In addition, for T_s ≥ 200 °C, the 001-oriented grains relax by tilting by 4° or 15° about 〈110〉 or 〈100〉 axes, respectively, while the 203 and 1¯75-oriented grains exhibit complex epitaxial relationships with the substrate: (203)_Cu||(001)_MgO with [010]_Cu||[110]_MgO and [302¯]_Cu||[11¯0]_MgO; and (1¯75)_Cu||(001)_MgO with [211¯]_Cu||[100]_MgO and [43¯5]_Cu||[010]_MgO. The surface roughness, as determined by X-ray reflectivity, increases with growth temperature. The smoothest layers are grown at 40 °C and exhibit an rms surface and buried interface roughness of 0.7 and 1.4 nm, respectively.     

γ辐射降解法制备小分子水溶性壳聚糖

用γ辐射降解法成功制备了一系列小分子水溶性壳聚糖。研究了不同条件下γ射线对壳聚糖的降解效应以及吸收剂量对产物分子量和水溶性产物得率的影响,分析了不同预处理条件对辐射降解产额(Gd值)的影响,并对壳聚糖辐射降解的机理进行了初步探讨。所得产物用凝胶渗透色谱(Gel permeation chromatography, GPC)、傅立叶变换红外光谱(Fourier transform infrared spectrometer,FT-IR)、紫外-可见光谱(Ultraviolet-Visible spectrophotometry,UV-VIS)等手段进行了表征分析。结果表明,壳聚糖在降解过程中不但分子量显著减少, 而且化学结构发生了明显变化,·OH自由基在壳聚糖辐射降解过程中起着至关重要的作用。     

上海光源同步光监测系统第一面萃取镜设计

本文介绍了上海光源(SSRF)同步光监测系统第一面萃取镜的设计.设计要求从同步光中尽可能不失真地分离出可见光.设计难点在于同步光中的高能X射线会致使萃取器件发热灼损,产生形变,影响可见光成分的波前和幅度.我们通过对同步光的功率谱分析和基于ANSYS程序的受热形变分析,设计出一面带水冷系统的铍镜用以反射可见光和透射X射线,以满足设计要求.     

6500m~3/h空分设备分子筛纯化器电加热器改造

介绍了6 5 0 0m3 /h空分设备分子筛纯化器新配电加热器电加热管烧断的故障现象,分析了故障原因,后通过增加气体挡板解决了问题;并通过改造,既达到了分子筛纯化再生的技术要求,又实现了电加热器的一用一备     

Second-Order Stiffness Matrix and Loading Vector of a Beam-Column with Semirigid Connections on an Elastic Foundation

The second-order stiffness matrix and corresponding loading vector of a prismatic beam–column subjected to a constant axial load and supported on a uniformly distributed elastic foundation (Winkler type) along its span with its ends connected to elastic supports are derived in a classical manner. The stiffness coefficients are expressed in terms of the ballast coefficient of the elastic foundation, applied axial load, support conditions, bending, and shear deformations. These individual parameters may be dropped when the appropriate effect is not considered; therefore, the proposed model captures all the different models of beams and beam–columns including those based on the theories of Bernoulli–Euler, Timoshenko, Rayleigh, and bending and shear.The expressions developed for the load vector are also general for any type or combinations of transverse loads including concentrated and partially nonuniform distributed loads. In addition, the transfer equations necessary to determine the transverse deflections, rotations, shear, and bending moments along the member are also developed and presented.     

An X-ray beam position monitor based on the photoluminescence of helium gas

A new method for white beam position monitoring for both bend magnet and wiggler synchrotron X-ray radiation has been developed. This method utilizes visible light luminescence generated as a result of ionization by the intense X-ray flux. In video beam position monitors (VBPMs), the luminescence of helium gas at atmospheric pressure is observed through a view port using a CCD camera next to the beam line. The beam position, profile, integrated intensity and FWHM are calculated from the distribution of luminescence intensity in each captured image by custom software. Misalignment of upstream apertures changes the image profile making VBPMs helpful for initial alignment of upstream beam line components. VBPMs can thus provide more information about the X-ray beam than most beam position monitors (BPMs). A beam position calibration procedure, employing a tilted plane-parallel glass plate placed in front of the camera lens, has also been developed. The accuracy of the VBPM system was measured during a bench-top experiment to be better than 1 μm. The He-luminescence-based VBPM system has been operative on three CHESS beam lines (F hard-bend and wiggler, A-line wiggler and G-line wiggler) for about a year. The beam positions are converted to analog voltages and used as feedback signals for beam stabilization. In our paper we discuss details of VBPM construction and describe further results of its performance.