浅论基于局域网的计算机机房管理维护

随着计算机技术的不断迅猛发展,现在的计算机机房面对大量的计算机设备,传统的管理维护方法已不能胜任,必须充分利用局域网的特性,大量采用新技术,新手段,新软件的辅助,批量的管理维护,提高效率,让计算机设备更好地为人们服务。本文就通过笔者的一些经验来讲述了对于局域网的计算机机房管理维护的一些基本方法。     

中学计算机多媒体技术应用

在新课改的推动下,初中课堂教学改革掀起来热潮,计算机多媒体技术的应用是其中一大亮点。但长期以来,由于很多教师对计算机多媒体技术的初中课堂教学中的作用认识不足,导致应用中出现了一些问题。文章基于初中课堂教学中计算机多媒体技术应用现状的分析基础上来审视计算机多媒体技术的作用,并提出应用策略。     

Correlations between visible light scattering and CO2 laser damage to reflective and antireflective coatings

In this work, 10.6-microm pulsed laser damage studies were performed on reflective and antireflective coatings on Si, Ge, and ZnSe substrates. Single-pulse damage threshold determinations were conducted at two different laser spot sizes. A high-resolution TV system was used to perform visible light scattering studies, the results of which correlated with laser damage at 10.6 microm. Single-pulse damage determinations along with visible light scattering and multipulse damage determinations indicate that coating performance can be improved substantially by reducing the density of scattering centers present on the coatings.     

锻造质量对冷挤压模具寿命的影响

通过改变锻造方法，观察金相组织及模具现场试用，探讨锻造质量对高速钢及基体钢模具寿命的影响，结果表明：控制碳化物不均匀性在三级以内及合理的纤维流线分布，可显著提高引进冷挤压设备上的模具寿命。     

多系列铸铁光电发射光谱标准样品的研制

采用中频炉熔炼，用自行设计的多孔隔离式金属型和独特的补缩和浇注系统及临界激冷工艺进行浇铸，成功地研制出了带有高低标的铸铁系列多元素光电光谱分析标样。对标样的白口化程度、均匀性、呈线性分布及分析精度等进行了检测并得出可行性结论。     

不同增塑体系对丁腈橡胶老化前后及胶管扣压过程性能的影响

本文主要研究了不同增塑体系对丁腈橡胶老化前后物理机械性能的影响,以热油老化后的丁腈橡胶的应力-应变曲线作为材料参数,考察不同增塑体系对丁腈胶管扣压过程中性能变化的影响;硫化特性实验结果表明:使用DOP或DOA作为增塑剂时,硫化胶转矩差值较大,使用液体丁腈或聚硫橡胶作为增塑剂时,转矩差值相对较低,其中使用聚硫橡胶作为增塑剂时,焦烧时间较短;物理机械性能实验结果表明:使用液体丁腈或聚硫橡胶作为增塑剂时,丁腈橡胶硫化胶耐热空气老化性能保持率相对较高,耐热油老化后质量体积变化率相对较低;仿真计算结果表明:使用DOP或DOA作为增塑剂时,静刚度、应变能密度及节点处Mises应力较大,使用液体丁腈或聚硫橡胶作为增塑剂时,静刚度、应变能密度及节点处Mises应力相对较小。     

稀土元素对钯室温电学性能的影响

研究了稀浓度(0.6at％以下)稀土元素(La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Er、Yb)对钯的室温电学性能的影响。所有稀土元素均提高钯的电阻率(p)、降低电阻温度系数(α),实验结果与理论分析证明(p·α)_((?)d-RE)d=(p·α)_(Pd)。Gd以前的稀土元素降低钯的对铜热电势(ε),其余重稀土元素增大钯的对铜热电势。按0.1at％RE归一化处理的实验数据表明,轻稀土元素对钯电阻率的影响稍大于重稀土,但Ce、Eu、Yb呈反常影响,化合价和尺寸因素是影响电学性能的主要因素。     

Optimization of post-classification processing of high-resolution satellite image: A case study

The application of remote sensing monitoring techniques plays a crucial role in evaluating and governing the vast amount of ecological construction projects in China. However, extracting information of ecological engineering target through high-resolution satellite image is arduous due to the unique topography and complicated spatial pattern on the Loess Plateau of China. As a result, enhancing classification accuracy is a huge challenge to high-resolution image processing techniques. Image processing techniques have a definitive effect on image properties and the selection of different parameters may change the final classification accuracy during post-classification processing. The common method of eliminating noise and smoothing image is majority filtering. However, the filter function may modify the original classified image and the final accuracy. The aim of this study is to develop an efficient and accurate post-processing technique for acquiring information of soil and water conservation engineering, on the Loess Plateau of China, using SPOT image with 2.5 m resolution. We argue that it is vital to optimize satellite image filtering parameters for special areas and purposes, which focus on monitoring ecological construction projects. We want to know how image filtering influences final classified results and which filtering kernel is optimum. The study design used a series of window sizes to filter the original classified image, and then assess the accuracy of each output map and image quality. We measured the relationship between filtering window size and classification accuracy, and optimized the post-processing techniques of SPOT5 satellite images. We conclude that (1) smoothing with the majority filter is sensitive to the information accuracy of soil and water conservation engineering, and (2) for SPOT5 2.5 m image, the 5×5 pixel majority filter is most suitable kernel for extracting information of ecological construction sites in the Loess Plateau of China.     

企业文化需要追求个性创新发展

企业文化理论从20世纪80年代提出以来,经过20多年的实践,如今发展快、口号多、落地难,有的演变为企业文化的“作秀”。要提升企业核心竞争力,必须在塑造优秀企业文化中,追求企业个性,避免雷同,求得创新发展。     

Functionalized metal–organic frameworks with strong acidity and hydrophobicity as an efficient catalyst for the production of 5-hydroxymethylfurfural

In the dehydration of fructose to 5-hydroxymethyl furfural(HMF), in situ produced water weakens the acid strength of the catalyst and causes the rehydration of HMF, causing unsatisfactory catalytic activity and selectivity. In this work, a class of benzenesulfonic acid-grafted metal–organic frameworks with strong acidity and hydrophobicity is obtained by the direct sulfonation method using 4-chlorobenzenesulfonic acid as sulfonating agent. The resultant MOFs have a specific surface area of greater than 250 m~2·g~(-1), acid density above 1.0 mmol·g~(-1), and water contact angle up to 129°. The hydrophobic MOF-Ph SO_3 H exhibits both higher catalytic activity and selectivity than MOF-SO_3 H in the HMF synthesis due to its better hydrophobicity and olephilicity. Moreover, the catalyst has a high recycled stability. At last, fructose is completely converted, and 98.0% yield of HMF is obtained under 120 °C in a DMSO solvent system. The successful preparation of the hydrophobic acidic MOF provides a novel hydrophobic catalyst for the synthesis of HMF.