Synergistic flame retardant effects of activated carbon and molybdenum oxide in poly(vinyl chloride)

The synergistic effects of activated carbon (AC) and molybdenum oxide (MoO₃) in improving the flame retardancy of poly(vinyl chloride) (PVC) were investigated. The effects of AC, MoO₃ and their mixture with a mass ratio of 1:1 on the flame retardancy and smoke suppression properties of PVC were studied using the limiting oxygen index and cone calorimeter tests. It was found that the flame retardancy of the relatively cheaper AC was slightly weaker than that of MoO₃. In addition, the incorporation of AC and MoO₃ greatly reduced the total heat release and improved smoke suppressant property of PVC composites. When the total content of AC and MoO₃ was 10 phr, PVC/AC/MoO₃ had the lowest peak heat release rate and peak smoke production rate values of 173.80 kW m^?2 and 0.1472 m² s^?1, which represented reductions of 47.3 and 59.9%, respectively, compared with those of PVC. Furthermore, thermogravimetric analysis and gel content tests were used to analyze the flame retardant mechanism of AC and MoO₃, with results showing that AC could promote early crosslinking in PVC. Char residue left after heating at 500 °C was analyzed using scanning electron microscopy and Raman spectroscopy, and the results showed that MoO₃ produced the most compact char, with the smallest and most organized carbonaceous microstructures. © 2017 Society of Chemical Industry     

智能变电站预制舱底座夹层走线结构设计分析

为了保证预制舱走线整齐美观,以及设备运行安全稳定,就需要对舱内电光缆走线进行一定的合理规划.针对预制舱底座夹层的走线形式进行了初步研究,提出了通过在底座夹层开设电/光缆进线口,用于走舱外到舱内设备的线缆;在底座夹层设置动力电缆走线槽,用于走强电电缆;在底座夹层设置绑线网或槽盒,用于走弱电电缆.由此可实现强弱电分离和电光缆分离,进一步保证舱内走线的整齐美观和设备运行的安全稳定.     

Mimic Drug Dosage Modulation for Neuroplasticity Based on Charge-Trap Layered Electronics

The human brain is often likened to an incredibly complex and intricate computer, rather than electrical devices, consisting of billions of neuronal cells connected by synapses. Different brain circuits are responsible for coordinating and performing specific functions. The reward pathway of the synaptic plasticity in the brain is strongly related to the features of both drug addiction and relief. In the current study, a synaptic device based on layered hafnium disulfide (HfS₂) is developed for the first time, to emulate the behavioral mechanisms of drug dosage modulation for neuroplasticity. A strong gate-dependent persistent photocurrent is observed, arising from the modulation of substrate-trapping events. By controlling the polarity of gate voltage, the basic functions of biological synapses are realized under a range of light spiking conditions. Furthermore, under the control of detrapping/trapping events at the HfS₂/SiO₂ interface, positive/negative correlations of the A_n/A₁ index, which significantly reflected the weight change of synaptic plasticity, are realized under the same stimulation conditions for the emulation of the drug-related addition/relief behaviors in the brain. The findings provide a new advance for mimicking human brain plasticity.     

Defect Engineering in Ambipolar Layered Materials for Mode-Regulable Nociceptor

Defect engineering represents a significant approach for atomically thick 2D semiconductor material development to explore the unique material properties and functions. Doping-induced conversion of conductive polarity is particularly beneficial for optimizing the integration of layered electronics. Here, controllable doping behavior in palladium diselenide (PdSe₂) transistor is demonstrated by manipulating its adatom-vacancy groups. The underlying mechanisms, which originate from reversible adsorption/desorption of oxygen clusters near selenide vacancy defects, are investigated systematically via their dynamic charge transfer characteristics and scanning tunneling microscope analysis. The modulated doping effect allows the PdSe₂ transistor to emulate the essential characteristics of photo nociceptor on a device level, including firing signal threshold and sensitization. Interestingly, electrostatic gating, acting as a neuromodulator, can regulate the adaptive modes in nociceptor to improve its adaptability and perceptibility to handle different danger levels. An integrated artificial nociceptor array is also designed to execute unique image processing functions, which suggests a new perspective for extension of the promise of defect engineered 2D electronics in simplified sensory systems toward use in advanced humanoid robots and artificial visual sensors.     

黎里古镇传统营建生态之历史经验

中国古代在营建活动中积累了大量朴素的生态学思想和历史经验,它浸透在中国人生活的方方面面。本文以江苏黎里古镇为例,从古镇的选址规划、建筑布局、建筑营建等层面,对其聚落建筑在特定时期、特定气候条件下建立起来的生态适应性设计经验进行探讨,总结该地区传统聚落在布局与营建活动中的生态历史经验。     

三元混合气体燃料爆炸特性实验研究

利用定容燃烧弹爆炸实验平台结合高速纹影摄像技术,系统研究了组分浓度和当量比对氢气/二甲醚/甲烷三元混合气体燃料爆炸特性的影响。结果表明：平均火焰传播速度S_a随氢气浓度X_{{\mathrm{H}}_{\mathrm{2}}}的增加单调递增,随二甲醚浓度X_DME和甲烷浓度X_{\mathrm{C}{\mathrm{H}}_{\mathrm{4}}}的增加单调递减。压力峰值p_max与X_{{\mathrm{H}}_{\mathrm{2}}}的关系受到当量比φ的强烈影响,当φ=0.8、1.0和1.2时,p_max随X_{{\mathrm{H}}_{\mathrm{2}}}先缓慢线性增加然后快速增加;而当φ=0.6、1.4和1.6时,p_max始终线性增加;同时,p_max随X_{\mathrm{C}{\mathrm{H}}_{\mathrm{4}}}线性递减,而随X_DME的变化可分为两个时期。X_{{\mathrm{H}}_{\mathrm{2}}}与最大压力上升速率(dp/dt)_max呈正相关关系,X_{\mathrm{C}{\mathrm{H}}_{\mathrm{4}}}与之呈负相关关系,而X_DME对(dp/dt)_max的影响不大。燃烧时间t_c与X_{{\mathrm{H}}_{\mathrm{2}}}和X_{\mathrm{C}{\mathrm{H}}_{\mathrm{4}}}存在线性关系;而X_DME对t_c的影响较为复杂,与φ有关。     

浅谈无机化学元素部分教学中"思政元素"的初探

无机化学课程是化学、化工、材料、生科等理工科专业的一门必修基础课.本课程知识体系完善,蕴含着丰富的"思政元素".本文将从科学家精神、中国传统文化、学科前沿研究、绿色化学思想、生活热点话题等方面浅谈无机化学元素部分教学中"思政元素"的挖掘和融合,寓价值观引导于知识传授之中,为无机化学中思政教学研究提供参考.     

中间包水模型数据的流出百分比分析方法

针对已有停留时间分布曲线或F曲线分析方法在归一化过程中,将单流中间包流出百分比或多流中间包中各流流出百分比之和限定为100%,将示踪剂流出总量信息掩盖,导致结果不精确的问题,本工作提出了流出百分比的分析方法,通过计算可以将物理实验结果转化为各流实时的流出百分比曲线。以流出百分比曲线为基础,计算得到时间加权平均方差和剩余示踪剂百分比,并以此对单流、四流中间包水模型实验结果进行分析。结果表明,采用流出百分比方法能对实验结果进行校对,进一步验证实验的可重复性。同时可对比双挡墙和U型挡墙控制装置设置下,四流中间包监测时间终点流出百分比差异及两倍理论停留时间时刻的死区比例大小。并可直观对比多流中间包不同挡墙下各流的一致性,及在单流堵塞后示踪剂在其他各流的分配及一致性。     

微型反应堆卸料装置设计及可靠性分析

微型反应堆（简称“微堆”）低浓化及退役都包含乏燃料卸出的操作,而保证乏燃料安全卸出的关键设备之一就是卸料装置。现有的卸料装置在操作过程中会破坏微堆堆筒体密封性,并且无法恢复,但微堆低浓化后还需利用原有堆筒体进行装料运行,所以本文在此需求的基础上设计了一套新型的卸料装置,可在不分离筒节、不破坏筒体完整性及密封性的前提下完成卸料操作。新设计的卸料装置包含卸料操作工具和辅助机械装置两部分。卸料操作工具通过小盖开口即可实现燃料组件的抓取,实施吊装。卸出的微堆乏燃料具有很高的放射性,卸料操作工具配合辅助机械装置,可实现远距离起升平移的操作,这种设计便于屏蔽,同时可有效降低工作人员所受辐射剂量。对该卸料装置进行计算和可靠性分析,结果表明其强度远大于实际使用载荷,安全可靠,能较好地满足微堆使用需求。新型微堆卸料装置具有经济性好、易制备、易操作的特点,下一步将在国内外微堆低浓化卸料或退役中推广应用。     

感潮河段交汇区水流特性数值模拟 --以宁波三江口为例

河流交汇为城市的发展提供了便利,对区域防洪、航运及河道演变影响重大。针对感潮河段交汇区域特有的非恒定往复流条件,以宁波三江口为例,运用Delft-3D建立二维水动力数学模型。基于实测水文和地形资料,引入四种评估参数对模型进行了率定与验证。重点分析了洪、枯两季涨、落急时刻,交汇区流速分布及水面形态等水流特性。结果表明:涨潮时,交汇区流场可类比分叉水流;落潮时,则为交汇水流;交汇区顶点及左支入汇侧下游存在两个低流速区,并可形成分离区;汇流区流速整体呈落潮大于涨潮的趋势,洪、枯季间最大流速相近。此外,涨、落急时刻典型特征断面水面呈单一横比降,且落急时刻比降明显大于涨急时刻;落急时,交汇口水面呈混合层附近高,两侧低的"马鞍形"分布。