Dearomatization of Indole Derivatives via Palladium‐Catalyzed C?H Bond Functionalization of Pyrroles: Convenient Construction of Spiroindolenines

An intramolecular palladium(II)‐catalyzed dearomative arylation reaction of indoles via C H bond functionalization was developed, providing access to structurally novel spiroindolenines with moderate to good yields. A one‐pot process for the synthesis of spiroindoline derivatives was also realized.

     

Copper(I) Bromide‐Dimethyl Sulfide‐Catalyzed Direct Sulfanylation of 4‐Hydroxycoumarins and 4‐Hydroxyquinolinones with Arylsulfonylhydrazides and Selective Fluorescence Switch‐ On Sensing of Cadmium(II) Ion in Water

An efficient protocol for the direct sulfanylation of various 4‐hydroxycoumarins and 4‐hydroxyquinolinones in good yield with arylsulfonylhydrazides as sulfanylating agents was developed via copper(I) bromide⋅dimethyl sulfide‐catalyzed S–O, S–N bond cleavage and C–S cross‐coupling reactions. A highly selective fluorescence turning‐on sensing of cadmium(II) ions in water using the synthesized 3‐sulfanyl‐4‐hydroxycoumarin derivative was also investigated.

     

Efficient Catalyst for Both Suzuki and Heck Cross‐Coupling Reactions: Synthesis and Catalytic Behaviour of Geometry‐ Constrained Iminopyridylpalladium Chlorides

A series of geometry‐constrained iminopyridyl‐palladium chlorides were synthesized and characterized. These phosphine‐free palladium complexes were explored for their catalytic activities in both Suzuki and Heck cross‐coupling reactions, achieving turnover numbers as high as 10⁶ towards various aryl bromides, even those containing various functionalities. In addition, the influence of substituents with steric and electronic factors was reflected by the differences observed in their activities.

     

Kinetics and effect of surfactant and cosurfactant on miniemulsion polymerization of acrylate monomers

The effects of the type and amount of the surfactant and cosurfactant on the miniemulsion polymerization of acrylate monomers were studied, and the comparison of the kinetics between miniemulsion polymerization and conventional emulsion polymerization was discussed in the presence of reactive surfactant allyloxy nonylphenol propyl polyoxyethylene (10), ether sulfate (DNS-86), and reactive cosurfactant stearyl methacrylate (SMA). The results showed that the obtained polyacrylate miniemulsion had a high monomer conversion rate and a low coagulum fraction, which were affected little by the surfactant and cosurfactant type. When the surfactant and cosurfactant amounts were all 2 wt%, the contact angle of the prepared polyacrylate miniemulsion with DNS-86/SMA and the water absorption fraction of the latex film were 39° and 8.3 wt%, respectively. FTIR results confirmed that DNS-86 and SMA took part in the polymerization of acrylate monomers. In the miniemulsion polymerization of acrylate monomers with DNS-86/SMA, monomer droplet nucleation was the main nucleation style.     

中国服装企业库存问题的分析与探讨

从库存的概念及成因入手,分析了我国各类服装企业库存现状及产生原因,并提出解决我国服装企业库存问题的方法及建议.有效的库存能确保物畅其流,提高周转率,提高经济效益.     

基于欠驱动原理的5指残疾人假手设计

采用欠驱动自适应原理设计了与成年人手大小相仿的5指残疾人假手,所设计的假手结构简单,质量轻,适应性强。假手主控制器采用TMS320F2810来实现对传感器信号的采集,步进电机的控制。并利用所设计假手进行了多种抓握实验,表明该假手可对多种形状物体进行抓、握、捏等多种操作。     

基于功能元的网络化工装信息管理平台研究

针对当前专业工艺员只熟悉自己所设计的工装,容易出现工装管理和设计"各自为政"的混乱局面,为了降低工装准备时问,缩短产品制造周期,提出建立基于功能元的网络化工装信息管理平台,实现工装信息的共享.介绍了工装功能元和功能元库的概念模型设计、工装信息管理平台体系结构设计及系统实现中的相关关键技术.     

基于CPSO滚动优化的堆芯功率自适应预测控制

针对核反应堆变功率过程中系统的非线性和反应性增量约束问题,本文将具备模型参数自适应辨识能力的改进型广义预测控制器(JGPC)应用于堆芯功率控制,该控制器通过预测模型参数和递推关系计算未来时刻的预测输出值,同时采用经正弦混沌策略和非线性惯性权重改进的混沌粒子群算法(CPSO)进行滚动优化,在优化过程中通过设定优化边界和混沌策略来处理反应性约束;以堆芯功率的受控自回归积分滑动平均模型(CARIMA)作为预测模型,并采用遗忘因子递推最小二乘法(FFRLS)自适应辨识模型参数,以克服堆芯功率模型非线性。基于MATLAB平台对本文控制器进行仿真验证,结果表明,该控制器在满足约束条件的情况下,能使堆芯功率快速、稳定地跟随设定值,且具备一定的抗干扰能力。     

国内在役核电厂首例电气贯穿件更换改造

核电厂电气贯穿件作为安全壳上的关键设备,承担着核岛内外各种电力和信号传输以及保证安全壳压力边界完整性的重要功能。通过秦山核电厂一期工程30万千瓦机组第18次大修期间国产在役DDG-1型电气贯穿件更换改造项目的实施,分析了秦山核电厂一期工程在役电气贯穿件设备现状和改造的必要性;针对在役核电厂更换改造工期短和贯穿件密封性能验证难等问题,通过优化检验工序、制作专用检漏工装的方法,缩短了贯穿件改造的工期并验证了贯穿件密封性能。     

基于时间序列神经网络的蒸汽发生器传热管泄漏程度诊断研究

针对蒸汽发生器U形传热管泄漏,本文提出了一种基于时间序列神经网络对蒸汽发生器传热管泄漏程度进行诊断研究的方法。首先,对核电厂蒸汽发生器U型传热管泄漏进行机理分析,构建其数学模型,提取其泄漏的直接特征参数,再依据Fisher得分法,提取其间接特征参数;其次,通过滑动时间窗口法从预处理后的时间序列数据中生成数据样本,作为时间序列神经网络的输入,并以蒸汽发生器U形传热管泄漏程度信息为标注,基于反向传播(BP)算法对五层神经网络系统进行训练,得到蒸汽发生器U形传热管泄漏的时间序列神经网络模型;最后,模拟核电厂运行过程蒸汽发生器U形传热管泄漏时的时间序列测试数据。仿真结果表明,时间序列神经网络对演变事件的处理具有较好的有效性和较高的泛化能力,对故障程度的诊断研究具有参考价值。