Carbon–Oxygen‐Bridged Ladder‐Type Building Blocks for Highly Efficient Nonfullerene Acceptors

Recently, acceptor–donor–acceptor (A–D–A) small molecules have emerged as promising nonfullerene acceptors (NFAs) for organic solar cells and have attracted great attention. The carbon‐bridged (C‐bridged) ladder‐type D unit plays a crucial role in developing high‐performance A–D–A NFAs. However, the medium electron‐donating capability of C‐bridged units is unfavorable for making NFAs with strong light‐harvesting capability. In this regard, carbon–oxygen‐bridged (CO‐bridged) ladder‐type units present advantages in developing strong light‐absorbing NFAs. Here, recent progress in the newly emerging CO‐bridged NFAs is highlighted. The synthetic methods for the polycyclic CO‐bridged building blocks are introduced. The photovoltaic performance for CO‐bridged NFAs is summarized and discussed. Perspectives on developing high‐performance CO‐bridged‐NFA‐based solar cells are made.     

制备条件对纳米TiO2-石棉尾矿酸浸渣复合材料光催化性能的影响

为了提高纳米TiO2的稳定性,以TiCl4为前驱体,采用水解沉淀法在石棉尾矿酸浸渣表面负载纳米TiO2,制备纳米TiO2-石棉尾矿酸浸渣复合材料,并以罗丹明B为模拟降解物,研究水与酸浸渣质量比、反应液pH、反应时间等因素对复合材料光催化性能的影响,采用X射线衍射仪和扫描电子显微镜对复合材料进行表征。结果表明:在水与石棉尾矿酸浸渣的质量比为30∶1,pH为6,反应时间为1.5 h的优化条件下制备的复合材料,经800℃煅烧2 h后对罗丹明B的降解率为90.5%;复合材料呈现疏松多孔的松散形态,复合材料中纳米TiO2的平均晶粒度为20.9 nm。     

A CFD model of autothermal reforming

A numerical model based on computational fluid dynamics (CFD) was developed and validated to simulate the performance of a catalytic monolith reformer for the production of hydrogen that could be used in fuel cell systems. The whole reactor was modeled as porous media for the process of autothermal reforming with n-hexadecane feed. CFD results provided an adequate match to experimental data from literature with respect to temperature and the mole fractions of H₂, CO₂ and CO products. The percentage difference between each experimental measurement of the mole fraction of hydrogen and the corresponding CFD prediction was less than 16.8%. It was found that the thermal conductivity of the solid catalyst substrate affected the temperature profile in the reactor, but its effect on product hydrogen concentration was negligible. The calculated reforming efficiency based on hydrogen decreased by 11.8% as power input was increased from 1.7 to 8.4 kW.     

TNFSF15 Inhibits Blood Retinal Barrier Breakdown Induced by Diabetes

Tumor necrosis factor superfamily 15 (TNFSF15) is an endogenous neovascularization inhibitor and an important negative regulator of vascular homeostasis. This study aimed to explore the potential role of TNFSF15 in diabetic retinopathy. Vitreous TNFSF15 and VEGF levels in proliferative diabetic retinopathy (PDR) patients were detected by ELISA. Retinal expression of TNFSF15 and the content of tight junction proteins (TJPs) in rats were detected by immunohistochemistry and Western blot, respectively. The blood retinal barrier (BRB) permeability was evaluated using Evans Blue (EB) dye. The TNFSF15/VEGF ratio was decreased in the vitreous fluid of patients with PDR relative to the controls, even though the expression levels of TNFSF15 were higher. TNFSF15 was dramatically decreased one month later after diabetes induction (p < 0.001), and then increased three months later and thereafter. TNFSF15 treatment significantly protected the BRB in the diabetic animals. Diabetes decreased TJPs levels in the retina, and these changes were inhibited by TNFSF15 treatment. Moreover, TNFSF15 decreased activation of VEGF both in mRNA and protein levels caused by diabetes. These results indicate that TNFSF15 is an important inhibitor in the progression of DR and suggest that the regulation of TNFSF15 shows promise for the development of diabetic retinopathy treatment strategies.     

提高Φ2700×3600型湿式球磨机传动齿轮的使用寿命

对Φ2700×3600型湿式球磨机在实际使用中传动齿轮损坏的主要形式和原因分别作了介绍和分析，并提出了提高其使用寿命应采取的具体措施。     

我国煤制天然气发展的探讨

分析了煤制天然气相关产业政策情况、国内天然气市场状况和甲烷化技术。煤制天然气项目具有能量效率高、单位热值耗水量低和CO2排放量低等特点,是煤制能源产品最有效的利用方式之一。立足于国内能源结构,统筹考虑水资源及生态环境承载力,以城市燃气为目标市场,在某些富煤地区适度发展煤制天然气,可以缓解国内天然气供求矛盾,并且通过合理优化项目建设方案,还可作为城市燃气的重要调峰手段。     

High Quality and Yield in Potassium Titanate Whiskers Synthesized by Calcination from Hydrous Titania

Hydrous titanium dioxide (TiO₂· n H₂O) was used to prepare K₂Ti₂O₅ single crystals, K₂Ti₄O₉ whiskers and K₂Ti₆O₁₃ whiskers at 820°, 940°, and 1110°C, respectively, by calcination. At T < 820°C, dehydration of hydrous titania, decomposition of potassium carbonate, and reaction between titanate and potassium oxide occurred simultaneously, ending with a crystallization reaction of K₂Ti₂O₅ single crystals at 820°C. Subsequently, K₂Ti₂O₅ single crystals convert into K₂Ti₄O₉ whiskers at 940°C, and K₂Ti₄O₉ whiskers further convert into K₂Ti₆O₁₃ whiskers at 1110°C. The reaction temperatures for the generations of these types of potassium titanates were all 10°–40°C lower than the corresponding temperatures when anatase was used as the reactant. The whiskers synthesized in the present study exhibited uniform size, good morphology, and a high yield.     

浅谈挤压铸造中的工艺参数

详细阐述了挤压铸造过程中工艺参数的特点以及它们对铸件品质的影响,对实际生产有一定的指导作用。     

紫铜与低碳钢厚板搅拌摩擦焊工艺分析

用搅拌摩擦焊方法成功焊接了 10 mm 厚的紫铜与低碳钢板,得到了内部无缺陷、外观成形良好的接头.紫铜位于搅拌摩擦焊返回边时,能使焊缝形成良好接头.反之,位于前进边时则有沟槽和未焊合等缺陷.右旋螺纹搅拌针会使焊缝材料向上作螺旋形运动,接头有明显的轴肩影响区,缺陷容易在焊缝底部出现.左旋螺纹搅拌针使搅拌针周围的塑化金属向下迁移,在焊缝下部形成明显的呈"洋葱环"形焊核区,缺陷容易在焊缝上部出现.搅拌针偏移量对焊缝形貌有较大影响.接头抗拉强度达 233 MPa,为铜母材强度的 95%,断裂位置在铜侧热影响区.焊核区抗拉强度达 296 MPa,远超过紫铜母材的强度.

Abstract：

The joining of dissimilar metals, T2 copper and Q235 mild steel plates with 10 mm thickness, is carried out in friction stir welding. Excellent welds can be gained when copper is fixed at the retreating side, but defects can be produced in welds when copper is fixed at the advancing side. The pin shapes influence the flow of the plasticized metal in the weld, which results in the variety of the morphology of the weld. If the screw thread on the pin is clockwise, the metal around the pin will move upwards to the root of the pin, which causes that the shoulder affected zone is clear and the weld defects would form at the lower part of the weld section. If the screw thread on the pin is counter-clockwise, the metal around the pin will move downwards, which drives the metal around the pin tip to move around and upwards. The onion ring pattern, which appears like lamellar structure, is observed in the stir zone. The shoulder-affected zone is not clear; the weld defects will form at the upper part of the weld section. Various pin offsets will affect the flow of weld metal. If an optimization of the process parameters is performed, defeet-free joints can be formed. The tensile test results show that the maximum joint tensile strength can reach 233 MPa, which is 95% of the parent materials of copper, and the fracture happens in the HAZ of copper. The maximum tensile strength of the nugget zone can reach 296 MPa, which is very considerably larger than that of the parent materials of copper.