One‐Step Synthesis of Superbright Water‐Soluble Silicon Nanoparticles with Photoluminescence Quantum Yield Exceeding 80%

Fluorescent silicon nanoparticles (SiNPs) have shown potential applications in bioimaging/biolabelling, sensing, and nanomedicine/cancer therapy due to their superior properties such as excellent photostability, low cytotoxicity, and versatile surface modification capability. Here, a simple, high‐yield, and one‐pot method is developed to prepare superbright, water‐soluble, and amine‐functionalized SiNPs with photoluminescence quantum yield (PLQY) comparable to fluorescent II–VI semiconductor quantum dots (QDs) but with much lower cytotoxicity. By introducing a commercially available amine‐containing silane molecule, N‐[3‐(trimethoxysilyl)propyl]ethylenediamine (DAMO), water‐soluble SiNPs are prepared with PLQY of 82.4% via a microwave‐assisted method. To the best of our knowledge, this is the highest PLQY value ever reported for water‐soluble fluorescent SiNPs. The silicon element in our SiNPs is mainly four‐valent silicon and thus these SiNPs may also be termed as oxidized silicon nanospheres or silica nanodots. We have also demonstrated the importance of the silane structure (e.g., a suitable amine content) on the photoluminescence property of the prepared SiNPs. As revealed by the time‐resolved photoluminescence technique, the highest PLQY value of DAMO SiNPs is correlated with their monoexponential decay with a relatively long fluorescence lifetime. In addition, the potential use of these SiNPs has also been demonstrated for fluorescent patterning/printing and ion sensing (including Cu²⁺ and Hg²⁺).     

A canonical structure for constrained optimal control problems

We consider a general class of optimal control problems with regional pole and controller structure constraints. Our goal is to show that for a fairly general class of regional pole and controller structure constraints, such constrained optimal control problems can be transformed to a new one with a canonical structure. A three-step transformation procedure is used to achieve our goal, which essentially amounts to repeated augmentations of plant dynamics and repeated reductions of the controller. The transformed problem is one of the standard optimal static output feedback with a decentralized and repeated structure.     

智能数字式绝缘电阻测量仪的研制

针对目前高压绝缘电阻测量普遍存在的抗干扰性较差、输出不够精确稳定等问题,设计了一种智能化高压绝缘电阻测量仪.该仪器能在高压输出档位控制和自动调节,微电流放大和量程自动切换.人机接口和红外线收发等部分都采用了单片机控制,以保证每个部分都具有一致的稳定性和高精度;并且在高、低压端分别采用独立的A/D转换和单片机控制电路,彼此之间采用红外线收发器共享数据,做到了电气上的完全隔离,大大提高了整个系统的抗干扰性.     

浅析绝缘子钢化玻璃件的内应力和寿命周期

绝缘子玻璃件经高温特殊热处理,获得均匀分布的钢化内应力,显著地提高了它的热稳定性和机械强度。由于这种钢化内应力是一种永久应力,随着产品运行时间的延伸,它不会产生内应力衰减现象。因此,悬式钢化玻璃绝缘子(简称玻璃绝缘子)具有寿命周期长和不易老化的特性。     

绿色上网及相关技术发展趋势

利用互联网内容管理技术,有效防范互联网上不良信息对青少年的危害,保护青少年的健康上网是当今社会义不容辞的责任.本文从互联网不良信息日益泛滥的严峻形势出发,指出了网络色情的危害性和绿色上网的必要性,介绍了国内外绿色上网相关管理、业务和产品现状,提出了绿色上网产品实现的参考模型,并分析了数据获取、内容识别以及内容过滤3类绿色上网相关技术现状、研究重点及其发展趋势.     

基于CPLD的多路全并行连续数据采集技术研究

本文介绍了一种多路全并行连续数据采集技术,该技术利用复杂可编程逻辑阵列在时序设计中的灵活性实现多路同步采样数据在单采样周期内的分时存储,并采用硬双缓冲技术实现连续交替存储。使高速数据采集和数据传输同时进行。与通常的分立式设计比较而言,该设计减少了实现的复杂程度并具有更好的稳定性。     

甲壳素负载金属离子催化氧化处理造纸废水的研究

以甲壳素负载金属离子(Pd2 )利用空气中的氧气催化氧化处理造纸废水,得到了负载金属离子的甲壳素对造纸废水进行催化氧化处理的较佳工艺条件.废水的pH为6.0～9.0,空气流量5.0L/min,Pd-甲壳素与废水质量比1.2×10-3,反应时间4.0 h,处理效率在82%左右.     

316L不锈钢凝汽管在运河水质循环水中的应用

简述了运河徐州段的水质状况和316L不锈钢凝汽器管的物化性能,给出了一种以PBTCA、POCA、PESA、PAPEMP和T-225为主要成分的复合阻垢剂,用极限碳酸盐硬度法和动态模拟法试验,结果表明:在按补水计投药质量浓度为10 mg/L时系统可在k=3.5±0.5的浓缩倍数下安全运行;运河水对碳钢、HSn70-1B铜合金及316L不锈钢均具有较强的腐蚀作用,阻垢剂的加入将加剧金属的腐蚀;在系统中投加一定浓度的BTA-TTA-有机胺混合物可保证316L不锈钢的腐蚀率＜0.003 mm/a.     

高浓度制药发酵废水处理工程技术

制药发酵废水具有有机物浓度高、成分复杂等特点.采用PW膜法处理高浓度制药发酵废水,解决了污染问题.经过多年的运行表明,其处理效果好、运行性能稳定、操作和维护管理方便且运行费用低廉,具有较高的推广价值.