中速柴油机机体铸造裂纹的原因分析及防止措施

根据柴油机机体裂纹产生的原因,对机体裂纹缺陷进行分析,找到了机体裂纹产生的主要原因。其主要原因可概括为铸件结构、化学成分、铸件补缩条件及开箱温度等,针对裂纹的主要原因采取相应的措施后,裂纹缺陷得到了根本的控制。     

Nanomaterials for radiotherapeutics-based multimodal synergistic cancer therapy

Over the past decade, numerous studies have attempted to enhance the effectiveness of radiotherapy (external beam radiotherapy and internal radioisotope therapy) for cancer treatment. However, the low radiation absorption coefficient and radiation resistance of tumors remain major critical challenges for radiotherapy in the clinic. With the development of nanomedicine, nanomaterials in combination with radiotherapy offer the possibility to improve the efficiency of radiotherapy in tumors. Nanomaterials act not only as radiosensitizers to enhance radiation energy, but also as nanocarriers to deliver therapeutic units in combating radiation resistance. In this review, we discuss opportunities for a synergistic cancer therapy by combining radiotherapy based on nanomaterials designed for chemotherapy, photodynamic therapy, photothermal therapy, gas therapy, genetic therapy, and immunotherapy. We highlight how nanomaterials can be utilized to amplify antitumor radiation responses and describe cooperative enhancement interactions among these synergistic therapies. Moreover, the potential challenges and future prospects of radio-based nanomedicine to maximize their synergistic efficiency for cancer treatment are identified.

     

Modelling of chromatic contrast for retrieval of wallpaper images

Colour remains one of the key factors in presenting an object and, consequently, has been widely applied in retrieval of images based on their visual contents. However, a colour appearance changes with the change of viewing surroundings, the phenomenon that has not been paid attention yet while performing colour‐based image retrieval. To comprehend this effect, in this article, a chromatic contrast model, CAMcc, is developed for the application of retrieval of colour intensive images, cementing the gap that most of existing colour models lack to fill by taking simultaneous colour contrast into account. Subsequently, the model is applied to the retrieval task on a collection of museum wallpapers of colour‐rich images. In comparison with current popular colour models including CIECAM02, HSI and RGB, with respect to both foreground and background colours, CAMcc appears to outperform the others with retrieved results being closer to query images. In addition, CAMcc focuses more on foreground colours, especially by maintaining the balance between both foreground and background colours, while the rest of existing models take on dominant colours that are perceived the most, usually background tones. Significantly, the contribution of the investigation lies in not only the improvement of the accuracy of colour‐based image retrieval but also the development of colour contrast model that warrants an important place in colour and computer vision theory, leading to deciphering the insight of this age‐old topic of chromatic contrast in colour science. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 361–373, 2015     

黏性土和纤维对风积沙改性土热膨胀特性的影响

风积沙改性土的热膨胀特性对评价风积沙改性土路基温度稳定性至关重要.通过在风积沙中掺入不同质量的水泥、黏性土或聚丙烯纤维制成不同配比的改性土,测试改性土的热膨胀系数,研究外加材料的掺入量对改性土热膨胀特性的影响.试验结果表明:改性土的平均线膨胀系数随着水泥掺入量的增加总体呈增大趋势,随着聚丙烯纤维掺入量的增加而减小,随着黏性土掺入量的增加而增大.聚丙烯纤维的掺入可有效降低改性土的热膨胀系数.研究成果可为进一步优化改性土提供研究方向,为高温差沙漠地区工程建设中风积沙改性土温度裂缝的控制提供试验依据.     

车用塑料的现状及发展趋势

主要介绍了车用塑料的发展情况,并就未来汽车用塑料的发展趋势进行了分析。     

海底电缆交叉鬼波化双检合并技术改进及应用

双检合并技术在海底电缆地震资料处理中被广泛应用,可衰减电缆鬼波的影响。传统方式以水、陆检记录的波场记录相同为假设,电缆鬼波压制效果差,合并效果并不理想。在分析交叉鬼波化双检合并技术基本原理的基础上,综合利用水检资料与陆检鬼波褶积的结果和陆检资料与水检鬼波褶积的结果求取刻度算子,同时在地震资料处理中利用陆检资料标定水检资料,从而优化了交叉鬼波化双检合并技术。实际资料处理结果表明,改进后的技术可有效衰减电缆鬼波,分离出上行波场,大幅度拓宽地震资料频带,提高地震资料分辨率,从而提供更丰富的构造细节信息。     

Broad-Spectral-Range Sustainability and Controllable Excitation of Hyperbolic Phonon Polaritons in α-MoO3

Hyperbolic phonon polaritons (HPhPs) in orthorhombic-phase molybdenum trioxide (α-MoO₃) show in-plane hyperbolicity, great wavelength compression, and ultralong lifetime, therefore holding great potential in nanophotonic applications. However, its polaritonic response in the far-infrared (FIR) range remains unexplored due to challenges in experimental characterization. Here, monochromated electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) is used to probe HPhPs in α-MoO₃ in both mid-infrared (MIR) and FIR frequencies and correlate their behaviors with microstructures and orientations. It is found that low structural symmetry leads to various phonon modes and multiple Reststrahlen bands (RBs) over a broad spectral range (over 70 meV) and in different directions (55–63 meV and 119–125 meV along the b-axis, 68–106 meV along the c-axis, and 101–121 meV along the a-axis). These HPhPs can be selectively excited by controlling the direction of swift electrons. These findings provide new opportunities in nanophotonic and optoelectronic applications, such as directed light propagation, hyperlenses, and heat transfer.     

稀土石膏常压酸化法制备硫酸钙晶须的研究

以含稀土的石膏为原料运用常压酸化法合成硫酸钙晶须,探讨了不同工艺条件对生成的硫酸钙晶须形貌的影响,同时还考察了晶型助长剂的种类和晶型助长剂的含量对硫酸钙晶须生长的影响,利用SEM和XRD分别对硫酸钙晶须的表面形貌、物相特征做了表征分析。实验得到制备硫酸钙晶须的最佳的反应条件：稀土石膏质量浓度为0.22 g/mL、反应时间为25 min、盐酸浓度为2.8 mol/L、反应温度为70 ℃、陈化时间为4 h,在此条件下合成的硫酸钙晶须平均长度为61 μm,平均长径比为30.5;通过对比实验选出了CuCl₂作为促进硫酸钙晶须生长的助长剂,在添加5%（质量分数）的CuCl₂的情况下可使硫酸钙晶须长径比从30.5增至41,长度从61 μm增至81 μm。     

HP295中间裂纹产生机理分析及控制措施

通过对HP295封头冲压开裂件缺陷光电镜分析,查找到缺陷产生部位及其导致原因。对多组铸坯低倍样检查,发现中间裂纹是缺陷根源。此后,根据现场生产情况,分析钢中磷、硫含量、钢水过热度、铸机设备精度、拉速和二次冷却强度等因素对铸坯中间裂纹的影响。通过降低磷、硫,控制过热度,调整设备精度,降低拉速以及优化二次冷却等措施,HP295铸坯中间裂纹得到有效控制,用户加工开裂现象完全杜绝。