导电涂料的研制

为了获得性能优良的导电涂料 ,采用对比试验和正交试验的方法对导电涂料进行了研究 ,分别对导电涂料的电阻、硬度、耐冲击强度、柔韧性等性能进行了测试 ,经过试验 ,确定了无机导电涂料的最佳配方为 :石墨 10 0g ,铅酸钡 10g ,三氧化二锑 5g ,二氧化钛 35g ,碳化硅 10g ,硅酸盐溶胶 170g。以此配方研制出了一种成本较低、生产工艺简单、具有良好的导电、导热性能的无机导电涂料。     

求解声波动方程的隐格式有限体积法

为研究声传播问题,提出一种声波动方程的隐格式有限体积法,该方法将格点型有限体积法与Newmark格式相结合.模拟平面波的传播过程,对比分析隐格式有限体积法和文献中显格式有限体积法的精度、稳定性及计算消耗等方面的性能.数值结果表明:当λ/Δx≥10时,两种算法均能得到满足精度要求的解;采用无条件稳定的隐格式算法,当满足ω0Δt≤0.3时,预测声压的相对峰值误差1%;当采用相同时间、空间步长时,隐格式算法精度高于显格式算法;隐格式算法对吸收边界的处理精度高于显格式算法,但对全反射边界的处理精度低于显格式算法;两种算法内存消耗比较接近,显格式算法的CPU耗时较少.     

高速公路建设和运营期水污染控制技术研究

在国内外类似工程水污染控制技术研究和工程经验的基础上,研究并总结出一种简便易行、经济实用、具有推广应用价值的公路工程水污染控制技术手段。本文总结的高速公路水污染控制措施体系主要包括施工期废水处理技术、公路路面径流处理技术、敏感路段应急事故防范及应急体系研究、服务区污水处理技术等,该研究成果对新建高速公路的水污染控制具有指导意义。     

Aerodynamic performance analysis of trains on slope topography under crosswinds

This work used the computational fluid dynamics method combined with full-scale train tests to analyze the train aerodynamic performance on special slope topography. Results show that with the increment in the slope gradient, the aerodynamic forces and moment increase sharply. Compared with the flat ground condition, the lateral force, lift force, and overturning moment of the train on the first line increase by 153.2%, 53.4% and 124.7%, respectively, under the slope gradient of 20°. However, with the increment of the windward side's depth, the windbreak effect is improved obviously. When the depth is equal to 10 m, compared with the 0 m, the lateral force, lift force and overturning moment of the train on the first line decrease by 70.9%, 77.0% and 70.6%,respectively. Through analyzing the influence of slope parameters on the aerodynamic performance of the train, the relationships among them are established. All these will provide a basic reference for enhancing train aerodynamic performances under different slope conditions and achieve reasonable train speeds for the operation safety in different wind environments.     

层间接触状态和横向力大小对车辙贡献率的影响

车辙贡献率是反映沥青路面各结构层车辙病害程度的一个主要参数,可用于指导沥青路面的设计和施工.利用三维有限元计算软件建立三维有限元模型用于理论分析,将有限元计算结果与理论解进行对比,验证了该三维有限元模型的可靠性.采用实测的轮胎接地压力,考虑不同层间接触状态和横向力大小,结合有限元计算的数据,分析了沥青路面结构层的车辙贡献率.结果表明:在层间完全连续状态下,横向力大小的选取不能简单地选取最大垂直轮胎接地压力的一定比例,而是要根据所研究的具体情况具体分析.在对沥青路面车辙贡献率的研究中,可以忽略层间接触状态,即假定层间完全连续.     

中国信息服务业空间集聚研究

通过产业集聚的EG指数对中国各省份信息服务业的空间集聚程度进行研究,得出集聚程度比较显著.在此基础上,找到这一服务业的两个相关指标,利用产业集中度CRn判断出信息服务业主要集中于北京、广东等六个地区,然后对两指标数据进行无量纲化处理,加权求和得到新的综合指标,最后对这一新指标进行了系统聚类分析,得知这一产业主要集中在北京和广东两个地区.     

氧化鸡肉脂肪制备肉味香精前体物质的研究

研究以鸡肉脂肪为主要原料制备肉味香精的前体物质,通过单因素和正交试验确定氧化反应的最佳反应条件.结果表明氧化鸡肉脂肪的最佳条件是:氧化温度为120℃,氧化时间为3h,VE的添加量为1.0%,不添加水和NaCl.在最优条件下进行氧化试验,得到产物的酸值和过氧化值分别为1.472 mg/g和193.51 mmol/kg,感官评价值为4.905,具有典型特征的鸡肉香气.     

Degradability and biocompatibility of bioglass/poly(amino acid) composites with different surface bioactivity as bone repair materials

Bioglass (BG) possesses excellent bioactivity and has been widely used in the manufacture of biomaterials. In this study, a composite with different surface bioactivity was fabricated via in situ melting polymerization by incorporating BG and poly(amino acid) (PAA) at a suitable ratio. The structure of the composite was characterized by Fourier transform infrared spectroscopy and XRD. The compressive strength of the BG/PAA composites was 139 MPa (BG:PAA = 30:70). The BG/PAA composites were degradable, and higher BG in composite showed higher weight loss after 4 weeks of incubation in simulated body fluid. In addition, the BG/PAA composite maintained adequate residual compressive strength during the degradation period. The SEM results showed the differences in surface bioactivities of the composites directly, and 30BG/PAA composite showed thicker apatite layer and higher Ca/p than 15BG/PAA. in vitro MG-63 cell culture experiments showed that the composite was noncytotoxic and thus allows cells to adhere, proliferate, and differentiate. This indicates that the composite has good biocompatibility. The implantations in the bone defects of rabbits for 4 and 12 weeks were studied. The composites had good biocompatibility and were capable of guiding new bone formation without causing any inflammation. The composite may be successfully used in the development of bone implants.     

纳米金刚石的应用

纳米金刚石不仅具有金刚石所固有优异特性，而且还具有纳米材料所拥有的奇异性能。正是这些综合技术特性，使得它在传统的和新的技术领域中得到应用，并初见成效，本文从超精抛光、润滑、复合镀、磁性录音系统和医疗等方面的应用做了扼要的叙述，指出，纳米金刚石颗粒具有球形和准球形的特点，使得摩擦表面形成滚珠轴承效应，而表现出良好的润滑性，从而避免于摩现象的发生，而对一些主要因接触疲劳或高温磨损而失效的工件，纳米金刚石金属的复合涂层，则具有明显的优越性。