2-(苯甲基)-7-氯茚并[1,2-e][1,3,4]噁二嗪-2,4a(3H,5H)-二羧酸4a甲酯的合成

以5-氯-1-茚酮为起始原料,经羰基化、不对称氧化、腙化和缩合反应合成了高效杀虫剂茚虫威的关键中间体2-(苯甲基)-7-氯茚并[1,2-e][1,3,4]噁二嗪-2,4a(3H,5H)-二羧酸4a甲酯。以5-氯-1-茚酮计,产品总收率达61.1%,产品结构经核磁共振分析验证。探讨了原料配比、溶剂的选择、氧化剂等因素对反应收率的影响。     

巨型水轮发电机组高可靠性电源冗余控制技术应用与研究

针对某巨型水电站巨型水轮发电机组电气盘柜DC 24V电源冗余控制系统,通过对不同种类DC 24V电源冗余控制方式及电气元件性能的分析,研究一种适用于巨型水电机组电气盘柜各类工况、电气元件表现良好、稳定、可靠且利于维护的DC 24V电源冗余供电控制系统,并将研究成果应用于现场设备.     

网络控制机器人无线通信系统的设计

文章给出了网络控制机器人系统的一种无线通信设计方案,首先规划了完整的硬件架构和电路图,然后完成了详细的软件设计,包括协议算法、帧格式以及具体的程序流程图,最后对系统的性能进行了分析和测试。     

称重法和24h膳食回顾法用于评估住院病人一日膳食的比较

目的：评价我院日常开展的24h膳食回顾在评估住院病人膳食摄入状况的准确性。方法：选取我院40名普通饭住院病人,分别用称重法、24h膳食回顾法对其进行一日膳食调查。将24h膳食回顾法获得的食物消费量和营养素摄入量,与称重法获得的相应数据进行比较,计算两者差值占称重法数据的比例,以此判断24h膳食回顾法数据的准确性。结果：...     

多羟基甾醇的合成研究——胆甾-3,7,24-三醇的合成

以去氧胆酸为起始原料,与甲醇反应得到去氧胆酸甲酯,然后在超声波环境下用硼氢化钠-聚乙二醇400-四氢呋喃体系还原得到胆甾-3,7,24-三醇.     

无定形态H3PW12O40/TiO2光催化剂降解有机染料

以钛酸丁酯和磷钨酸为主要原料,采用溶胶-凝胶法制备H₃PW₁₂O₄₀/TiO₂光催化剂,采用红外光谱、X射线衍射、热重分析和比表面分析对光催化剂进行表征。结果表明,H₃PW₁₂O₄₀/TiO₂光催化剂为无定形态,比表面积202 m²·g^-1,杂多阴离子保持了Keggin骨架结构。在TiO₂中掺杂H₃PW₁₂O₄₀,使催化剂的光响应范围扩展到可见光区,从而提高光催化活性。光催化剂对甲基橙、酸性红、罗丹明B和亚甲基蓝均有较好的光催化降解活性,催化剂易于分离,重复使用稳定性较好。对甲基橙降解的适宜条件为：1.7×10-5 mol·L^-1甲基橙溶液50 mL,H₃PW₁₂O₄₀/TiO2光催化剂用量0.03 g,500 W碘钨灯照射60 min,此条件下,甲基橙脱色率可达到96%。     

基于nRF24L01的小车自动识别红绿灯的设计

为了防止汽车闯红灯,初步设计了一个智能小车自动识别十字路口红绿灯的系统.以STC89C52最小操作系统为控制核心、采用nRF24L01无线通讯等智能模块,实现车自动识别十字路口红绿灯功能.小车通过nRF24L01无线通讯识别直行方向是红灯还是绿灯,绿灯则通行、红灯则等待.主要给出了设计方案、无线通信模块的原理和2.4G...     

SAC0307-xNi/Ni焊点的IMC及镍镀层的消耗

利用扫描电镜(SEM)对焊点SAC0307/Ni(Sn-O.3Ag-0.7Cu/Ni)和SAC0307-0.05Ni/Nj(Sn-O.3Ag-0.7Cu-0.05 Ni/Ni)经过180℃老化后的界面金属问化合物(IMC)的微观结构及镍镀层的消耗进行了研究.结果表明,回流焊后,SAC0307/Ni和SAC0307-O.05Ni/Ni焊点的IMC层均为(Cu_(1-x)Ni_x)_6Sn_5,且随着老化时间的延长,IMC层的厚度均逐渐增加,化合物类型没有变化,但IMC的化学组成有所改变.SAC0307-0.05Ni/Ni焊点中IMC层形貌为蠕虫状,厚度比不加镍时有所降低.回流焊后两种钎料焊盘的镍层消耗几乎相同,但老化384h后SAC0307/Ni的焊盘镍层的剩余厚度明显比SAC0307-0.05Ni/Ni的小.因此,钎料中添加适量的镍可以有效地降低焊盘镍层在时效过程中的消耗速率,即显著提高镍焊盘的抗老化能力.

Abstract：

The micrestmcture of interfacial IMC and the consumption of Ni layer for SAC0307/Ni ( Sn-0.3Ag-0.7Cu/Ni ) soldered joint and SAOY307-0.05Ni/Ni (Sn-O. 3Ag-0.7Cu-0.05Ni/Ni) soldered joint after aging at 180℃ were studied by scanning electron microscope( SEM ). The results indicated that the IMC layer of SAC0307/Ni and SAC0307-0.05Ni/Ni are both (Cu_(1-x),Ni_x)_6Sn_5 after reflow soldering. With the increasing of aging time, the thickness of IMC layer increases gradually, the type of IMC is not changed, but the chemical composition changes. The morphology of IMC is stormshaped and the thickness of IMC is much thinner when SAC0307 solder added 0. 05 % Ni is used. The consumption of Ni layer is nearly the same using both solders "after the first time reflow soldering, but the residual thickness of the Ni layer in SACO307/Ni solder is thinner than that in SAC0307-0.05Ni/Ni after aging for 384 h. So solders with a little Ni element can decrease the consumption rate of Ni layer effectively during aging, that is, the aging-resistant abihty of Ni pad is improved obviously.     

Radiosynthesis and biodistribution of [^18F]-tetracosactide using a semi-automated [^18F]SFB production module

In order to prepare a specific melanocortin type 2 receptor (MC2R) ligand, b1-24-corticotrophin was pre-pared in one-step reaction with [18F] SFB and b-1-24-corticotrophin pharmaceutical solution (1 mg/mL, pH=6.5). [18F]SFB was prepared in a semi-automated module in two steps with an overall radiochemical yield of 47% to EOB (not-decay corrected) in 90 min. The 18F-labeled intermediates and 18F-labeled peptide was checked by RTLC and HPLC. The results show that the radiochemical purity is >95% and the yield to EOB (not-decay corrected) is 29% for final 18F-labeled peptide at optimized conditions. Preliminary in vivo studies in normal mice were performed to deter-mine biodistribution of the 18F-labeled peptide for 150 min. The results show that the major tracer uptake is consistent with the natural distribution of MC2R receptors in mammals. Testes/blood and testes/muscle ratios for 18F-labeled peptide at 150 min were 184 and 1.56, respectively, and adipocyte/blood and adipocyte/muscle ratios at 120 min were 221 and 142, respectively. The data support the specific receptor binding of the radiolabeled peptide as reported for MC2R receptor accumulation in adipocytes and testes and demonstrates the retention of biological activity of the pep-tide. This tracer can be used in detection of MC2R distribution in malignancies and sex organ diseases.     

U-10wt%Mo合金与LT24Al的反应层性质研究

对U-10wt%Mo合金和LT24Al合金的反应层性质做了较详细的研究.将U-Mo/Al扩散偶试样在不同条件下进行热压处理,用光学显微镜(OM)和扫描电子显微镜(SEM)分析反应层的厚度,用能谱仪(EDS)分析各元素在反应区内的分布情况,用X射线衍射仪(XRD)测定了反应层的相组成.分析结果表明:U-Mo合金与Al的扩散方式是反应扩散,方向主要为Al原子通过空位扩散向U-Mo合金中迁移;反应层生长动力学表明反应为扩散所控制;U-Mo/Al的单相反应层主要由(U, Mo)Al3组成;两相或多相反应层主要由(U, Mo)Al3和(U, Mo)Al4组成,此外还含有Al20Mo2U;Al中的杂质Si容易在反应层中富集,这种趋势说明Si对改善U-Mo合金和Al的相容性起积极作用.