12.00R24混合型花纹全钢载重子午线轮胎的设计

介绍12．00R24混合型花纹全钢载重子午线轮胎的设计。结构设计：外直径1223mm,断面宽310mm,行驶面宽度236mm,行驶面弧度高8mm,胎圈着合直径612．5mm,胎圈着合宽度230mm,断面水平轴位置（H1／H2）1．059,花纹深度22mm,花纹周节数52,花纹饱和度65．1％,采用混合型花纹设计。施工设计：胎体采用3＋9＋15×0．22＋0．15HT钢丝帘线,1^#和2^#带束层采用1×0．365＋6×0．35HT钢丝帘线,30带束层采用3×4×0．22HE钢丝帘线,0°带束层采用2层3×7×0．20HE钢丝帘线;采用两鼓一次法成型机成型,蒸锅式定型硫化机硫化。成品性能试验结果表明,成品轮胎充气外缘尺寸、强度性能和耐久性能符合相应设计和国家标准要求。     

纳米TiO2光催化剂在污水处理中的应用

纳米二氧化钛作为一种重要的光催化材料,由于具有化学性质稳定、便宜、无毒并具有较高活性等优点而得到了广泛的研究与应用。论文在综合分析相关文献的基础上,概述了二氧化钛光催化剂在污水处理中的应用,介绍了纳米二氧化钛在光催化处理污水方面的成果和研究进展,探讨了纳米二氧化钛工业应用的研究方向。     

失效阴离子交换树脂复苏工艺

分析了阴离子交换树脂使用过程中失效(即钠含量升高)的主要原因,并根据实际情况,对失效阴离子交换树脂进行了复苏试验。结果表明:用分析纯氢氧化钠还原的阴离子交换树脂重新使用后,阴床出水钠含量高;用质量分数为10%的盐酸浸泡后再用碱还原的阴离子交换树脂重新使用后,阴床出水钠含量正常。     

Fast-swelling porous starch-g-poly(acrylic acid) superabsorbents

The fast-swelling porous starch-g-poly(acrylic acid) (St-g-PAA) superabsorbents were prepared simply by free-radical graft polymerization between acrylic acid and potato starch in the aqueous phase by using Triton X-100 as the pore-forming agent. The porous superabsorbents were characterized by FTIR and scanning electron microscopy. The effects of weight ratio of acrylic acid to starch and the Triton X-100 content on water absorbency were investigated. In addition, the effects of Triton X-100 on swelling rate, water absorbency in 0.9 % NaCl and in the artificial urine solution, and reswelling ability were studied in detail. The superabsorbent prepared with an acrylic acid/starch ratio of 6:1 and a Triton X-100 content of 0.4 % has a water absorbency of 683 g g^?1 in distilled water and 72.8 g g^?1 in 0.9 % NaCl. The content of Triton X-100 has great influence on the water absorbency and the swelling rate. The porous sample prepared with 0.4 % Triton X-100 only needs about 5 min to reach 80 % of its equilibrium water absorbency which is obviously shorter in comparison with the nonporous sample (about 90 min). The porous samples also show nice urine absorbency and excellent reswelling ability. We believe the reported method may find some applications in preparing novel porous hydrogels.     

PVC防水卷材挤出过程中真空孔“冒料”原因及解决措施

从配方、工艺和设备等三个方面对PVC防水卷材生产过程中出现挤出机真空孔“冒料”现象的原因进行了分析,并给出了相应的解决措施;指出该现象的本质是PVC物料塑化不良,其原因是配方、工艺、设备三方面共同造成的,应将三者视作一个整体加以分析并寻找对策。     

A DCT/DST-based error propagation-free data hiding algorithm for HEVC intra-coded frames

Currently, two error propagation-free discrete cosine transform (DCT)-based data hiding algorithms, one by Ma et al. and the other by Lin et al., were presented for H.264/AVC intra-coded frames. However, the state-of-the-art video codec, high efficiency video coding (HEVC), adopts both integer DCT and discrete sine transform (DST) such that the previous DCT-based algorithms cannot fully utilize available capacity for data hiding in HEVC. This paper presents the first DCT/DST-based data hiding algorithm for HEVC intra-coded frames where the block DCT and DST coefficient characteristics are investigated to locate the transformed coefficients that can be perturbed without propagating errors to neighboring blocks. Experimental results confirm the merits of the proposed algorithm in providing the intra-frame error propagation-free advantage, the quality improvement for marked images, the compression power inherited from HEVC, and the superiority of embedding capacity for low bitrate coding when compared with the previous two algorithms for H.264/AVC.     

基于BP神经网络的海洋平台振动载荷识别

利用ANSYS软件建立了W12-1海洋平台的有限元模型，通过在模型识别点上施加激励得到的响应方法获得了BP神经网络的训练数据。建立了关于W12-1海洋平台的BP神经网络模型，并对其振动载荷进行了识别。识别结果表明，在对海洋平台这样的大型复杂结构进行载荷识别时，神经网络方法相对于传统载荷识别方法具有更高的识别精度。     

Computer-aided prediction of structure and hydrogen storage properties of tetrakis(4-aminophenyl)silsesquioxane based covalent-organic frameworks

With the aid of computer simulation, we have designed four covalent-organic frameworks based on tetrakis(4-aminophenyl)silsesquioxane (taps-COFs) and their hydrogen storage properties were predicted with grand canonical Monte Carlo (GCMC) simulation. The structural parameters and physical properties were investigated after the geometrical optimization. The accessible surface for H₂ molecule (5564.68–6754.78 m²/g) were estimated using the numerical Monte Carlo integration and the pore volume (4.06–10.74 cm³/g) was evaluated by the amounts of the containable nonadsorbing helium molecules at low pressures and room temperature. GCMC simulation reveals that at 77 K, tapsCOF1 has the highest gravimetric H₂ adsorption capacity of 51.43 wt% and tapsCOF3 possesses the highest volumetric H₂ adsorption capacity of 58.51 g/L. Excitedly, at room temperature of 298 K, the gravimetric hydrogen adsorption capacities of tapsCOF1 (8.58 wt%) and tapsCOF2 (8.20 wt%) have exceeded the target (5.5 wt%) of onboard hydrogen storage system for 2025 set by the U.S Department of Energy.     

Numerical investigation of combustion characteristics for hydrogen mixed fuel in a can-type model of the gas turbine combustor

Numerical simulations are performed to analyze the combustion characteristics of propane fuel mixed with different amounts of hydrogen in a can-type combustor. The volume fraction of the hydrogen fuel varies from 0% to 100% in the fuel mixture. The results indicate that the hydrogen enrichment of the fuel significantly affects the flow structure, mixture fraction, and combustion characteristics. An increase in the volume fraction of hydrogen significantly affects the mean mixture fraction distribution, promotes combustion, and increases the flame temperature and the width of the flammable range within the combustor. Therefore, the degree of temperature uniformity at the outlet of the combustor increases with hydrogen enrichment, corresponding to an increase of 49.64% in the uniformity factor. The hydrogen enriched fuel can also reduce the emissions of CO and CO₂, owing to the reduced amount of carbonaceous fuel.     

酯交换法合成邻苯二甲酸二环己酯的研究

邻苯二甲酸二环已酯（DCHP）是一种特殊增塑剂,它具有防潮性,大量的研究证明,它的毒性很低,目前。国内生产能力比较低,绝大多数依靠进口,工业上主要通过酯化法进行生产。文章以邻苯二甲酸二甲酯和环己醇作原料,用甲醇钠作为催化剂,通过酯交换的方法在没有溶剂的条件下催化合成邻苯二甲酸二环己酯。从催化剂、催化剂的用量、温度、反应时间、反应物料比等方面进行了研究。