固凝(GT)防水材料在建筑工程中的应用

根据固凝(GT)系列防水材料的技术性能,分析其在寒冷地区屋面工程、厕浴厨房间和地下工程防水设计,以及建(构)筑物的抗冻、抗渗与防护等方面应用时应遵守的技术要点。     

采用听觉外周模型改进电子耳蜗CIS方案

提出了一种改进的CIS电子耳蜗的脉冲刺激方案。利用听觉外周模型产生一种符合听神经发放机制的刺激脉冲序列来刺激电极,代替传统的均匀交替刺激方案,不仅可以通过包络而且可以通过脉冲间隔来传递语音信息,确保了语音的空间编码和时间编码。听觉仿真实验表明,相对于其他两种方案,方案可以有效地传递更多更丰富的语音信息,在汉语声调识别实验中至少提高19.2%识别率,在可懂度的对比实验中具有最高可懂度。     

基于Octave卷积的混合精度神经网络量化方法

浮点数位宽的深度神经网络需要大量的运算资源,这导致大型深度神经网络难以在低算力场景（如边缘计算）上部署。为解决这一问题,提出一种即插即用的神经网络量化方法,以压缩大型神经网络的运算成本,并保持模型性能指标不显著下降。首先,基于Octave卷积将输入特征图的高频和低频成分进行分离;其次,分别对高低频分量应用不同位宽的卷积核进行卷积运算;第三,使用不同位宽的激活函数将高低频卷积结果量化至相应位宽;最后,混合不同精度的特征图来获得该层卷积结果。实验结果证实了所提方法压缩模型的有效性,在CIFAR-10/100数据集上,将模型压缩至1+8位宽时,该方法可保持准确率指标的下降小于3个百分点;在ImageNet数据集上,使用该方法将ResNet50模型压缩至1+4位宽时,其正确率指标仍高于70%。     

Self-orienting wireless multimedia sensor networks for occlusion-free viewpoints

Wireless multimedia sensor networks (WMSN) are formations of a large number of compact form-factor computing devices that can capture multimedia content, such as video and audio, and communicate them over wireless channels. The efficiency of a WMSN heavily depends on the correct orientation (i.e., view) of its individual sensory units in the field. In this paper, we study the problem of self-orientation in WMSN, that is finding the most beneficial orientation for all multimedia sensors to maximize multimedia coverage. We propose a new algorithm to determine a node’s multimedia coverage and find the sensor orientation that minimizes the negative effect of occlusions and overlapping regions in the sensing field. Our approach enables multimedia sensor nodes to compute their directional coverage leading to an efficient and self-configurable sensor orientation calculation. By using simulations, we show that the occlusion-free viewpoint approach increases the multimedia coverage significantly. The self-orientation methodology is designed in the form of a distributed algorithm, making it a suitable candidate for deployment in practical systems.     

微波辐射磷酸催化合成2-羟基-1-萘甲醛

2-羟基-1-萘甲醛简称HNA,其作为一种重要的有机化学合成中间体,在金属络合染料,织物,油墨,橡胶用甲亚胺染料及荧光增白剂等方面有着广泛的应用。其传统合成方法主要有Duff法,Gattermann法和Reimer-Tiemann法等。本文在微波加热条件下,以磷酸代替浓硫酸作催化剂催化2-萘酚与六次甲基四胺反应合成了2-羟基-1-萘甲醛,设计了四因素三水平正交实验方案探讨合成2-羟基-1-萘甲醛的最佳工艺条件,获得最佳反应条件:反应物摩尔比2-萘酚:六次甲基四胺1∶1.3,反应时间5分钟,催化剂磷酸3 mL,微波功率500W,平均产率可以达到76.21%。     

某锡多金属矿石抑硅浮锌试验研究

云南某锡多金属矿矿石中易浮硅质矿物含量高,造成生产上浮选锌的效果很差。为此,对该矿石进行了抑硅浮锌试验研究。试验结果表明,以硫酸铝等作抑制剂、Z-200号作捕收剂,并采用将精选1中矿经扫选后直接排尾的工艺流程,可获得锌精矿锌品位和锌回收率分别为49.51%和85.23%的较好浮锌指标。     

建筑厨、浴、厕房间的固凝(GT)防水设计

在建筑工程设计中,厨房、浴室、厕所的室内防水设计至关重要.固凝(GT)防水材料是一种性能优越、适用范围广的新型高分子防水材料.固凝(GT)防水材料应用于建筑厨、浴、厕等多水房间,能彻底解决渗漏难题.结合固凝(GT)系列材料的特点和适用性,分析了建筑厨、浴、厕房间的固凝(GT)防水设计要点、防水构造做法及施工技术措施.     

An Experimental Study of the Performance Impact of Path-Based DoS Attacks in Wireless Mesh Networks

Wireless mesh networks (WMNs) are considered as cost effective, easily deployable and capable of extending Internet connectivity. However, one of the major challenges in deploying reliable WMNs is preventing their nodes from malicious attacks, which is of particular concern as attacks can severely degrade network performance. When a DoS attack is targeted over an entire communication path, it is called a path-based DoS attack. We study the performance impact of path-based DoS attacks by considering attack intensity, medium errors, physical diversity, collusion and hop count. We setup a wireless mesh testbed and configure a set of experiments to gather realistic measurements, and assess the effects of different factors. We find that medium errors have significant impact on the performance of WMNs when a path-based DoS attack is carried out, and the impact is exacerbated by the MAC layer retransmissions. We show that due to physical diversity, a far attacker can lead to an increased performance degradation than a close-by attacker. Additionally, we demonstrate that the joint impact of two colluding attackers is not as severe as the joint result of individual attacks. We also discuss a strategy to counter path-based DoS attacks which can potentially alleviate the impact of the attack significantly.     

碳酸钙形貌对陶瓷膜过滤性能的影响

陶瓷膜进行超细粉体的固液分离时,粉体性质对膜分离性能影响显著.本文通过控制沉淀反应条件,获得了球形、棒状、方形等不同形貌的碳酸钙超细粉体;采用陶瓷膜过滤碳酸钙悬浮液,得到膜孔径与碳酸钙粉体粒径、形貌的匹配关系,球形粉体的膜渗透通量最高,棒状束粉体居中,方形粉体的膜渗透通量最小;膜孔径越大,粉体形貌对通量的影响越大;粉体粒径与膜孔径比值增大,膜通量增大.