Hole Transport Materials Based on 6,12‐Dihydroindeno[1,2‐b]fluorine with Different Periphery Groups: A New Strategy for Dopant‐Free Perovskite Solar Cells

Although several hole‐transporting materials (HTMs) have been designed to obtain perovskite solar cells (PSCs) devices with high performance, the dopant‐free HTMs for efficient and stable PSCs remain rare. Herein, a rigid planar 6,12‐dihydroindeno[1,2‐b]fluorine (IDF) core with different numbers of bulky periphery groups to construct dopant‐free HTMs of IDF‐SFXPh, IDF‐DiDPA, and IDF‐TeDPA is modified. Thanks to the contributions of the planar IDF core and the twisted SFX periphery groups, the dopant‐free IDF‐SFXPh‐based PSCs device achieves a device performance of 17.6%, comparable to the doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD)‐based device (17.6%), with much enhanced device stability under glovebox and ambient conditions.     

Cold Modelling of Slag Splashing in LD Furnace by Oxygen Lance with Twisted Nozzle Tip

The effects of a conventional lance tip with 4 normal nozzles and a lance tip with 4 twisted nozzles on slag splashing were investigated. A cold model for LD converters, Jiuquan Iron & Steel Co., was established and the amount of slag splashed onto the model walls was measured in the cold modelling experiments. The results from the experiments show that at low top gas flow rate the amount of slag splashing for the tip with twisted nozzles is less than that for the conventional tip, whereas at high top gas flow rate the amount of slag splashing for the nozzle twisted lance is greater than that for the conventional lance. For the nozzle twisted lance tip, slag splashing rates increase with increase in slag amount, lance height and top gas flow rate and the maximum amount of slag splashing for the tip with twisted nozzles can be obtained under the process parameters of 47.6 Nm³/h gas flow rate, 12% slag amount and 247 mm lance height. More slag droplets can be directed onto the cone with a nozzle twisted lance tip than with a normal lance tip at high top gas flow rate.     

冷轧扭钢筋混凝土连续梁、板塑性调幅设计

冷轧扭钢筋以强度高、粘结强度好、延性可靠等优点广泛用于楼盖体系中。为了节省钢材用量,通常采用塑性设计。热轧钢筋的调幅值及相应的内力系数已有文献给出,但是冷轧扭钢筋却缺少这方面数据。给出的当调幅值为１５％时的冷轧扭钢筋混凝土连续梁、板的内力系数,为工程设计提供了可靠而实用的数据。     

复合换热管过冷沸腾换热实验与关联式评价

以去离子水为实验介质,在单面受热流密度条件下,开展了聚变装置偏滤器的过冷流动沸腾强化换热特性实验研究,将内肋强化换热技术与内插扭带结构相结合,利用两者的协同强化传热效应,设计出一种复合换热管。实验参数为：质量流速,992～4 960 kg/(m2·s);压力,04～2 MPa;入口过冷度,8701～11921 ℃;热流密度,1～163 MW/m2。对4种强化换热管（光管、内插扭带管、内螺纹肋管和复合换热管）的管内过冷流动沸腾换热特性和综合性能评价指标（PEC）进行了对比实验。结果表明：与其他3种管道相比,复合换热管的对流换热系数和PEC最高,传热特性最好。研究了复合换热管的扭带扰动比、螺距、压力和质量流速对管内两相流动对流换热系数的影响规律,发现对流换热系数与螺距、质量流速呈正比,与扭带扰动比、压力呈反比。最后对比了4个现有的过冷流动沸腾换热经验公式,并在无量纲模型基础上,增加了扰动比和螺径比（t/Dh）进行修正,利用非线性拟合方法提出了适合复合换热管过冷流动沸腾的努塞尔数新公式。     

垂直排列一扭曲向列液晶显示的阈值特性

从液晶体系的总自由能出发,通过欧拉-拉格朗日方程组的推导,得到了手性向列相液晶从垂直排列状态转变成平面扭曲排列时的Freedericksz转变阈值电压公式Vth=π×     

弱捻度粗纺纱的纺制

介绍了通过加装一套实用的环锭细纱机主轴牙来纺制弱捻度粗纱的工艺计算方法,并通过实例介绍了工艺参数的选择及其取得的效果,结果表明：此方法可用于生产弱捻粗纺毛纱。     

不同宽度扭带传热与阻力特性试验研究

本文对管内扭带旋流装置在不同扭带宽度下的传热与阻力进行了试验研究，并得到了传热与阻力拟合式。     

透平弯扭导叶在部分负荷下气动性能的研究

应用数值计算的方法，研究透平导叶弯扭联合方案在部分负荷下，叶栅内的流动性能。计算方法基于时均N—S方程，湍流模型为Baldwin—Lomax模型。结果包括总压损失系数、出口气流角等参数在流场中的分布。结果表明，弯扭导叶在部分负荷工况下运行时，流动性能稳定，同样能改善整个流场结构。     

一种新型传热管自动清洗用强化斜齿扭带研究

光滑扭带具有自动清洗传热设备水垢的功能，但是在管内低流速下由于自转力矩太小而不能应用。为此研制一种能够显著增大自转力矩的强化型斜齿扭带。试验结果表明：在管内流速相同情况下，强化型斜齿扭带与结构参数相同的光滑扭带相比：自转力矩增大277％，传热系数提高22％，流体阻力保持在工程许可的范围内。因此，这种强化型斜齿扭带可以在低流速的列管式传热设备中广泛应用。     

盐矿电厂真空冷凝器的纽带自动清洗技术研究

本文简要介绍了污垢对电厂冷凝器真空度和出力的严重影响，叙述了自转塑料纽带的污垢自动清洗原理，模拟试验证明自转纽带的清洗除垢能力强，足以满足传热设备的清洗防垢要求。以电厂汽轮机的凝汽器污垢清洗为例，定量分析了不同厚度污垢对传热系数的影响幅度，举例计算采用自转塑料纽带清洗技术可以创造的高效益。