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排序方式: 共有9730条查询结果,搜索用时 15 毫秒
1.
Hu Zhaoyang Suo Xufei Shen Yongxing Jiang Yu-Xi Cheng Jun-Bo 《International Journal of Fracture》2022,235(2):231-242
International Journal of Fracture - Adiabatic shear band (ASB) is one of the most important failure modes under high strain-rate deformation. In this work, we propose a hybrid damage model to... 相似文献
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Jiajia Suo Bowen Yang Edoardo Mosconi Hyeon-Seo Choi YeonJu Kim Shaik M. Zakeeruddin Filippo De Angelis Michael Grätzel Hui-Seon Kim Anders Hagfeldt 《Advanced functional materials》2021,31(34):2102902
Surface passivation treatment is a widely used strategy to resolve trap-mediated nonradiative recombination toward high-efficiency metal-halide perovskite photovoltaics. However, a lack of passivation with mixture treatment has been investigated, as well as an in-depth understanding of its passivation mechanism. Here, a systematic study on a mixed-salt passivation strategy of formamidinium bromide (FABr) coupled with different F-substituted alkyl lengths of ammonium iodide is demonstrated. It is obtained better device performance with decreasing chain length of the F-substituted alkyl ammonium iodide in the presence of FABr. Moreover, they unraveled a synergistic passivation mechanism of the mixed-salt treatment through surface reconstruction engineering, where FABr dominates the reformation of the perovskite surface via reacting with the excess PbI2. Meanwhile, ammonium iodide passivates the perovskite grain boundaries both on the surface and top perovskite bulk through penetration. This synergistic passivation engineer results in a high-quality perovskite surface with fewer defects and suppressed ion migration, leading to a champion efficiency of 23.5% with mixed-salt treatment. In addition, the introduction of the moisture resisted F-substituted groups presents a more hydrophobic perovskite surface, thus enabling the decorated devices with excellent long-term stability under a high humid atmosphere as well as operational conditions. 相似文献
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To efficiently link the continuum mechanics for rocks with the structural statistics of rock masses,a theoretical and methodological system called the statistical mechanics of rock masses(SMRM)was developed in the past three decades.In SMRM,equivalent continuum models of stressestrain relationship,strength and failure probability for jointed rock masses were established,which were based on the geometric probability models characterising the rock mass structure.This follows the statistical physics,the continuum mechanics,the fracture mechanics and the weakest link hypothesis.A general constitutive model and complete stressestrain models under compressive and shear conditions were also developed as the derivatives of the SMRM theory.An SMRM calculation system was then developed to provide fast and precise solutions for parameter estimations of rock masses,such as full-direction rock quality designation(RQD),elastic modulus,Coulomb compressive strength,rock mass quality rating,and Poisson’s ratio and shear strength.The constitutive equations involved in SMRM were integrated into a FLAC3D based numerical module to apply for engineering rock masses.It is also capable of analysing the complete deformation of rock masses and active reinforcement of engineering rock masses.Examples of engineering applications of SMRM were presented,including a rock mass at QBT hydropower station in northwestern China,a dam slope of Zongo II hydropower station in D.R.Congo,an open-pit mine in Dexing,China,an underground powerhouse of Jinping I hydropower station in southwestern China,and a typical circular tunnel in Lanzhou-Chongqing railway,China.These applications verified the reliability of the SMRM and demonstrated its applicability to broad engineering issues associated with jointed rock masses. 相似文献
5.
Xiaohong Hao Hang Suo Hui Peng Peixing Xu Xin Gao Su Du 《International Journal of Hydrogen Energy》2021,46(3):2890-2898
Microalgae is promising to be used as feedstock resources for hydrogen production due to its high oil and grease contents. This promotes the development of extraction technology of microalgae oil. In this study, based on the Rayleigh-Plesset equation, the effects of temperature, pressure, ultrasonic power and frequency on the bubble motion of ethanol ultrasound cavitation are investigated. Subsequently, the effects of different process parameters on the extraction rate are studied using Schizochytrium sp. as raw material by stirring or ultrasonic-assisted extraction. And the composition of algae extraction oil is analyzed. The results show that the amplitude of cavitation bubbles increases with the increase of ultrasonic power and decrease of ultrasonic frequency. The extraction rate of algae oil reaches 93.76 ± 0.48% when the ultrasonic power is 150 W, the reaction time is 30 min, the temperature is 50 °C and the liquid-solid ratio is 10:1. 相似文献
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采用共沉淀法和沉淀浸渍法制备了纳米氧化铈-二氧化硅(CeO2-SiO2)介孔材料吸附剂,主要考察了其对水中铜离子(Cu2+)的吸附行为。通过X射线衍射(XRD)、扫描电镜(SEM)和氮吸附(BET)等手段对合成的介孔材料进行了性能表征,并通过静态吸附实验分析了溶液pH、溶液初始金属离子质量浓度、吸附剂用量、吸附时间等条件对介孔材料吸附Cu2+性能的影响。结果表明:共沉淀法制备的纳米CeO2-SiO2介孔材料对Cu2+的去除效果较沉淀浸渍法要好;当溶液pH=7.0时CeO2-SiO2介孔材料对Cu2+的吸附效果最好,20 min时基本达到吸附平衡;溶液初始Cu2+浓度增大Cu2+去除率降低,Cu2+累计吸附量增大;随着吸附剂用量增加Cu2+去除率增大,当CeO2-SiO2吸附剂用量为0.15 g/L时对Cu2+的去除率趋于稳定;CeO2-SiO2吸附剂对不同金属离子吸附性能由大到小的顺序为Cu2+、Fe2+、Mn2+,该吸附过程均符合准二级动力学模型。 相似文献
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通过优化PCBN复合片合成时组装结构中的盐管厚度及中间垫片材料,分别探究未优化(A)、中间垫片材料优化(B)、盐管厚度优化(C)及中间垫片和盐管厚度二者共同优化(D)4种情况下合成的PCBN聚晶层厚度差、聚晶层同一位置的硬度及其整体耐磨性的影响。结果表明:当盐管厚度由1.0 mm变为1.4 mm、中间垫片材料由石墨变为硬质合金时,4种情况下的PCBN复合片聚晶层同一位置硬度及其整体耐磨性基本不变。在显著性水平为0.05时, B、C、D优化相对A,D优化相对于单一因素的B和C优化,均能改善聚晶层厚度差的均匀性;B、C、D优化相对A,D优化相对于C优化,均能改善聚晶层厚度差的稳定性,但D优化相对于B优化,对聚晶层厚度差的稳定性无改善。 相似文献