Research on the performances of VPEG macromonomer grafted different functional groups to prepare polycarboxylate superplasticizers

The advent of novel polyether macromonomer has garnered significant attention within the industrial domain. In this study, a range of polycarboxylate superplasticizers (PCEs) was produced via free radical polymerization, employing a new polyether monomer, 4-hydroxybutyl vinyl polyethylene glycol ether (VPEG). This monomer served as the predominant component and was grafted with various functional monomers on its main chain. The molecular configuration of the resultant PCEs was discerned through Fourier infrared spectroscopy and gel permeation chromatography, while the surface tension underwent assessment via a surface tension meter. Both the initial and subsequent fluidity of cement paste and mortar were leveraged to ascertain the dispersion and retention efficacy of the synthetic PCEs. The ramifications of diverse functional group grafts of the new polyether monomer on the cement hydration procedure and strength attributes were elucidated via setting time, hydration heat assays of cement paste, SEM analysis, and compressive strength evaluations of mortar. Observations reveal that the carboxylic acid group significantly reduces surface tension, whereas the sulfonic acid group's effect remains minimal. The incorporation of both the amide and sulfonic acid groups marginally impacts the preliminary dispersion efficacy of PCEs but notably affects dispersion retention. Furthermore, these functional groups facilitate cement hydration, expedite the primary setting time of the cement paste, and bolster the initial compressive strength of the mortar. Specifically, the grafted of sodium methacrylsulfonate (SMAS) yields the most noticeable results. Finally, the working mechanism of PCEs with varying molecular structures has been explained in light both theoretical and experimental results. This research offers valuable insights for subsequent investigations into the fabrication of polycarboxylate superplasticizers using the VPEG macromonomer.     

Opal photonic crystal double-network hydrogel for visual detection through structural color and fluorescent responsiveness

Photonic crystal hydrogels are widely used in the field of visual detection, based on the response of the structural color to external stimulus, such as pH, temperature, near-infrared light, and so on. Here, we develop an opal photonic crystal hydrogel by combining polystyrene (PS) photonic crystals with a fluorescent double-network hydrogel and focus on both its visual detection function and mechanical property. The opal hydrogel is composed of nanocomposite hydrogel as the first network and ionic crosslinked hydrogel as the second network. The introduction of PS photonic crystals and terbium ions endows the opal hydrogel distinctive structural colors and fluorescence, respectively. Because of volume changes, the structural color of the opal hydrogel selectively responses to metal ions and organic solvents. Attributing to the ion exchange interaction, the opal hydrogel exhibits fluorescent responses to various metal ions. Combining the responsiveness of structural color and fluorescence, a visual dual-detection mode is set up, with better detection sensitivity and selectivity. Moreover, the characteristics of nanocomposite and double-network crosslinking ensure the opal hydrogel enough mechanical properties to undergo cycle visual detection. Consequently, the fabricated opal hydrogel is promising for use in visual detection to multiple substances in single- or dual-detection mode.     

白骛鸭常压杀菌保鲜技术的研究

为获得软包装白鹜鸭在常压杀菌工艺下的最佳品质,采用微波脱水与预杀菌处理技术并结合使用乳酸链球菌素(Msin),对产品品质及保鲜防腐的应用效果进行了研究.结果表明,在微波脱水6.5 min后,加入净鸭质量0.02%的乳酸链球菌素和0.08%的柠檬酸,真空包装后采用常压杀菌,使白鸭产品的保鲜防腐效果达到预期目的,且产品的品质、口感和风味均达到最佳.     

BIM技术助力企业快速提升项目总控能力

上海现代工程咨询有限公司自2009年在世博会德国馆与奥地利馆设计中成功应用BIM技术后, 公司以此为契机, 开始大力推广BIM理念与技术在实际工程中的应用, 目前公司已将BIM技术应用在设计、项目管理咨询、施工等方面, 并取得了一定成绩。BIM在建筑全生命周期中的应用, 正在不断帮助公司深化“全过程服务、设计施工一体化”的业务定位。     

基于小冲杆试验技术评估充氢锆合金材料的拉伸性能

锆合金由于具有良好的机械性能、耐腐蚀性能等而被用作反应堆内燃料元件的包壳材料。然而,Zr-4已不能满足核电技术在更高燃耗条件下的使用要求,因此,通过调控合金成分开发新型锆合金具有重要意义。本研究对Zr-4以及其他两种新型锆合金材料在室温、315℃条件下进行常规拉伸试验,结合计算结果分析了成分差异造成的沉淀相改变,提出了析出强化机制对于锆合金性能提升的重要意义。首次利用小冲杆试验对锆合金原样的力学性能进行测试,该工作确定了常规拉伸试验与小冲杆试验结果之间的经验公式中与锆合金材料本身相关的系数数值,验证了小冲杆试验用于锆合金拉伸性能评估的可行性。利用气相渗氢法在400℃对Zr-4以及其他两种新型锆合金进行充氢处理,并利用小冲杆试验对锆合金充氢试样的力学性能进行测试。结果显示,充氢锆合金在载荷-位移曲线的塑性失稳阶段出现“平台区”特殊现象。本论文对该现象进行探究,用金相分析表征了氢化物的形貌特征并对其含量进行了定量估算,推测氢化物与基体断裂韧性上的差异、氢化物相特殊的长链构型以及强取向性与这一现象有着重要关联。     

Traffic Signal Timing via Deep Reinforcement Learning

In this paper, we propose a set of algorithms to design signal timing plans via deep reinforcement learning. The core idea of this approach is to set up a deep neural network (DNN) to learn the Q-function of reinforcement learning from the sampled traffic state/control inputs and the corresponding traffic system performance output. Based on the obtained DNN, we can find the appropriate signal timing policies by implicitly modeling the control actions and the change of system states. We explain the possible benefits and implementation tricks of this new approach. The relationships between this new approach and some existing approaches are also carefully discussed.      

基于轻量化BIM技术的施工技术交底研究

在施工阶段,基于BIM技术的施工技术交底成为项目的重要管理手段,受BIM软硬件配置和人员操作水平等条件限制,交底过程中易出现模型传导失败、交底偏差和信息传递交互慢等问题。本文介绍了十三种基于轻量化BIM技术的施工技术交底方法,从信息完整性、数据轻量化、软件功能性、操作复杂性和实施经济性多个维度对BIM技术辅助技术交底优化程度进行评价和优劣势对比,为交底过程提供方法选择,保证交底人和接底人在低端设备的轻量化浏览,有效提高项目相关方交底和沟通的效率。     

面向国产神威众核架构的区域气候模式CWRF性能优化技术

区域气候模式CWRF(Climate-Weather Research and Forecasting model)是国家气候中心区域气候预测系统的重要组成部分,也是系统最耗时的程序.高性能计算是提高CWRF数值预报计算性能的关键技术,开展CWRF模式在国产神威众核架构上的移植和优化,提高模式的模拟效率,对模式的扩展、...     

A Hybrid Learning Method for the Data-Driven Design of Linguistic Dynamic Systems

In lots of data based prediction or modeling applications, uncertainties and/or noises in the observed data cannot be avoided. In such cases, it is more preferable and reasonable to provide linguistic (fuzzy) predicted results described by fuzzy memberships or fuzzy sets instead of the crisp estimates depicted by numbers. Linguistic dynamic system (LDS) provides a powerful tool for yielding linguistic (fuzzy) results. However, it is still difficult to construct LDS models from observed data. To solve this issue, this paper first presents a simplified LDS whose inputoutput mapping can be determined by closed-form formulas. Then, a hybrid learning method is proposed to construct the data-driven LDS model. The proposed hybrid learning method firstly generates fuzzy rules by the subtractive clustering method, then carries out further optimization of centers of the consequent triangular fuzzy sets in the fuzzy rules, and finally adopts multiobjective optimization algorithm to determine the left and right end-points of the consequent triangular fuzzy sets. The proposed approach is successfully applied to three real-world prediction applications which are: prediction of energy consumption of a building, forecasting of the traffic flow, and prediction of the wind speed. Simulation results show that the uncertainties in the data can be effectively captured by the linguistic (fuzzy) estimates. It can also be extended to some other prediction or modeling problems, in which observed data have high levels of uncertainties.      

水下无线光通信链路构成与性能优化进展

水下无线光通信(UWOC)可为水下平台提供高速灵活的通信选择。本文介绍了UWOC的基本链路构成,并指出UWOC系统的优化方案。吸收、散射和湍流都会影响UWOC的性能,深入研究信道特性可以指导发射器、接收器和相关信号处理技术的设计。UWOC性能还能够通过复用技术、单光子探测技术和对准系统等进行优化。功能全面的测试平台可以为UWOC系统提供必要的测试环境,为海试与工业化应用奠定基础。本文期望能为UWOC相关研究者带来帮助。