M2M大型装备远程监控

M2M产生于20世纪90年代中后期,以监控设备和资产为目标而产生.随着社会的不断发展和技术的不断进步,M2M不再是简单的数据在机器间的传输,更重要的是,它是机器与机器间智能化、交互式的通信.利用M2M网络实现大型装备的远程实时监控.对于企业和国家都越发重要.     

一种大管径煤气管道带压堵漏的应用

文章介绍了针对DN2200煤气总管泄漏,一种新型大管径煤气管道带压堵漏的性能和工作原理.     

浅议原平市糯玉米的发展

糯玉米营养价值高,经济效益好,原平市发展糯玉米产业前景广阔.通过加强政策引导,统一规划布局,完善产销体系,采用先进的栽培技术发展无公害、绿色的糯玉米,提高糯玉米及系列产品的精加工,根据市场需求,生产出能满足各种消费层次的系列产品,实现优质糯玉米产品的多层次增值,以生产促基地建设,推进农业产业化的发展.     

Assignment of the μ4-O5 atom in catalytic center for water oxidation in photosystem II

The detailed structure of catalytic center of water oxidation, Mn4Ca-cluster, in photosystem ⅡI (PSII) has been reported recently. However, due to the radiation damage induced by X-ray and the complexity of the Mn4Ca-cluster, the assignment of the μ4-O5 atom coordinated by three Mn and one Ca2+ ions is still lack of essential evidences. In this article, we synthesized one Mn complex containing two μ4-O atoms. It is found that the lengths of all μ4-O-Mn bonds in this Mn complex are in the range of 1.89-2.10 , which are significantly shorter than 2.40-2.61 distance of μ4-O5-Mn bonds in Mn4Ca-cluster observed in the crystal structure of PSII. In addition, DFT calculations have been carried out on the Mn4Ca-cluster. It is found that the O atom of μ4-O or μ4-OH always trends to deviate from the center position of four metal ions, resulting in unequal bond lengths of four μ4-4-M (M=Mn or Ca), which is obviously different with larger and nearly equal distances between μ4-O and four metal ions observed in the crystal structure. Based on these results, we suggest that the μ4-atom in Mn4Ca-cluster of PSII is unlikely to be a μ4-O, μ4-OH or μ4-OH2 , and its assignment is still an open question.     

Effect of KNbO3 content on the crystal structure and electrical properties of (1 − x)PbZr0.54Ti0.46O3-xKNbO3 piezoelectric ceramics

(1 ? x)PbZr_0.54Ti_0.46O₃-xKNbO₃ (0 ≤ x ≤ 25mol%) (abbreviated as PZT-xKN) piezoelectric ceramics were successfully fabricated by a traditional sintering technique at 1225°C for 30 min. The influence of KNbO₃ content on the crystal structure and electrical properties of the PZT-xKN piezoelectric ceramics was studied. Samples with 0 ≤ x ≤ 0.20 show a pure perovskite structure, indicating that all KNbO₃ diffused into the crystal lattice of PZT to form a single solid solution in this compositional range. A second Pb₃Nb₄O₁₃ phase is observed in the PZT-0.25KN sample, showing that the maximum solid solubility of KNbO₃ in PZT matrix ceramic is less than 25mol%. Compared with pure PZT piezoelectric ceramics, samples containing KNbO₃ have smaller crystal grains. PZT-0.15KN exhibits excellent piezoelectric properties with d ₃₃ = 209 pC/N.     

利用哈代-温伯格不平衡系数检验配对病例对照数据的关联性(英文)

针对配对的病例对照数据,利用偏离哈代-温伯格平衡的信息构造了用于估计基因模型的检验,称为配对的哈代-温伯格不平衡检验(mHWD).基于mHWD估计基因模型并应用相应的配对趋势检验进行关联性分析,称为基于模型选择的趋势检验(GMS).GMS是从数据驱动的角度提出的一种稳健有效的检验,模拟结果显示GMS在现有的关联性检验方法中具有最大的稳健有效性.对类肉样瘤病研究数据的分析进一步表明了基于模型选择的趋势检验的良好性质.     

中国“红歌会”的当代教育价值实现

几年来,"中国红歌会"通过深入挖掘红色资源的精神内涵,不断提升作品的艺术表现力和感染力,在潜移默化中传播先进文化,在交流互动中弘扬红色精神,产生了巨大的社会效应。唱红歌是个好形式,"中国红歌会"已然成为革命传统教育的好办法,主流文化传承的好媒介,红色精神培养的好平台,对青少年的思想政治工作有着极好的启示作用。     

单-6-叠氮-β-环糊精与苯乙炔的点击化反应

利用CuI/NBS这种新型催化体系来促进单-6-叠氮-β-环糊精与苯乙炔之间的偶联反应,通过这个多组分反应可以高效地以炔和叠氮为原料一锅法制备5-碘代-1,4-取代-1,2,3-三氮唑类化合物.     

铁路营业线施工安全惯性问题及对策

铁路营业线施工的特点是时间紧、涉及部门多、对运输生产干扰大。文章通过对施工前预备工作超量、损坏运营设备、营业线附近作业侵限、作业方式不当,造成红光带、封锁施工不能按计划完成、应急预案研究不细等惯性问题进行分析,找出了产生这些问题的原因,提出了针对性的对策。