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991.
Dr. Yinhua Lv Ruihan Yuan Dr. Bing Cai Behzad Bahrami Ashraful Haider Chowdhury Dr. Chi Yang Dr. Yihui Wu Prof. Qiquan Qiao Prof. Shengzhong Liu Prof. Wen-Hua Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):12067-12074
One-dimensional (1D) nanostructured oxides are proposed as excellent electron transport materials (ETMs) for perovskite solar cells (PSCs); however, experimental evidence is lacking. A facile hydrothermal approach was employed to grow highly oriented anatase TiO2 nanopyramid arrays and demonstrate their application in PSCs. The oriented TiO2 nanopyramid arrays afford sufficient contact area for electron extraction and increase light transmission. Moreover, the nanopyramid array/perovskite system exhibits an oriented electric field that can increase charge separation and accelerate charge transport, thereby suppressing charge recombination. The anatase TiO2 nanopyramid array-based PSCs deliver a champion power conversion efficiency of approximately 22.5 %, which is the highest power conversion efficiency reported to date for PSCs consisting of 1D ETMs. This work demonstrates that the rational design of 1D ETMs can achieve PSCs that perform as well as typical mesoscopic and planar PSCs. 相似文献
992.
Jie Liang Qiyuan Chen Xiangbiao Liao Pengcheng Yao Dr. Bin Zhu Guangxin Lv Xinyu Wang Xi Chen Prof. Jia Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(16):6623-6628
Lithium dendrite growth during repeated charge and discharge cycles of lithium-metal anodes often leads to short-circuiting by puncturing the porous separator. Here, a morphological design, the nano-shield, for separators to resist dendrites is presented. Through both mechanical analysis and experiment, it is revealed that the separator protected by the nano-shield can effectively inhibit the penetration of lithium dendrites owing to the reduced stress intensity generated and therefore mitigate the short circuit of Li metal batteries. More than 110 h of lithium plating life is achieved in cell tests, which is among the longest cycle life of lithium metal anode and five times longer than that of blank separators. This new aspect of morphological and mechanical design not only provides an alternative pathway for extending lifetime of lithium metal anodes, but also sheds light on the role of separator engineering for various electrochemical energy storage devices. 相似文献
993.
In this paper, a car-following model considering anticipation-driving behavior is considered to describe the traffic jam. The nature of the model is investigated using linear and nonlinear analysis method. A thermodynamic theory is formulated for describing the phase transitions and critical phenomena, and the time-dependent Ginzburg–Landau equation is derived to describe traffic flow near the critical point. 相似文献
994.
The complete diagonalization (of energy matrix) method (CDM) and the perturbation theory method (PTM) are applied to calculate the spin-Hamiltonian (SH) parameters (electron paramagnetic resonance g factors g //, g ⊥ and zero-field splitting D) of the trigonal Mo 3+ centers in Y 3Al 5O 12 and Lu 3Al 5O 12 crystals. Both methods are based on the cluster approach in which the covalence effect due to the admixture between the d orbitals of central d n ion and p orbitals of ligands is considered. The g factors calculated by both methods are close to each other and agree with the experimental values. However, the calculated zero-field splittings D from PTM for both crystals are about 84% those from CDM. The reasons that the CDM is preferable to the PTM in the calculations of SH parameters are discussed. The angular distortions of Mo 3+ centers in both garnet crystals are predicted. 相似文献
995.
ABSTRACTThe specific activities of 226Ra, 232Th and 40K of 26 samples of granite produced in Xinjiang of China were measured by a high-purity germanium detector, and their radiological hazards of radium equivalent, external hazard index, internal hazard index, absorbed dose rate, annual effective dose rate, gamma index and alpha index were evaluated. The results indicate that the overall average specific activities of 226Ra, 232Th and 40K obtained in the investigated samples are below the world’s average granite values. The average radium equivalent is within the recommended limit of 370?Bq?kg?1. The results obtained further show that the mean values of external hazard index, internal hazard index, absorbed dose rate, annual effective dose rate, gamma index and alpha index are 0.65, 0.77, 111.7?nGy?h?1, 0.55 mSv?y?1, 0.89 and 0.23, respectively. These mean values established that radiological hazards are also found to be below the international recommended values. The results are compared with granite samples from other countries or China-Taiwan province. It can be noticed that the specific activity values of granite samples produced in China are lower or similar to that of other countries or China-Taiwan province, however there are higher specific activity values for 226Ra and 232Th in individual samples, which need to provide proper radiation monitoring before use considering the long term health effect. 相似文献
996.
997.
研究了低(1mg/kg/d)、中(5mg/kg/d)、高(25mg/kg/d)三个剂量组全氟辛酸(Perfluorooctanoic acid,PFOA)致小鼠肝脏脂质过氧化损伤的作用.结果发现,PFOA能抑制小鼠体重的增长,对肝组织造成一定的脂质过氧化损伤.各组小鼠出现不同程度的体重增长缓慢甚至减轻,中、高剂量组出现明显的减轻(P<0.01);低、中、高剂量组肝脏系数,均明显高于对照组(P<0.01);与对照组相比,各剂量组的肝组织中MDA、NO及LDH含量明显增高,SOD、SDH及GSH-Px活性均明显降低(P<0.05). 相似文献
998.
铁皮石斛药用成分研究进展 总被引:2,自引:0,他引:2
在系统的文献调研基础上,结合该实验室先前的科研工作,对兰科石斛属植物铁皮石斛的药用成分和药理活性加以综述.据该文统计,铁皮石斛药用成分的报道主要集中于近20年,主要药用成分有铁皮石斛多糖、生物碱、氨基酸、微量元素.因其具有广泛的药效作用、卓越的经济价值和良好的观赏价值,备受世人关注.该文对其药用成分和药理活性做了详细而全面的总结,为今后铁皮石斛更好的开发利用提供参考. 相似文献
999.
In this paper, we study Toeplitz operators T μ from one Fock space \({F^{p}_{\alpha}}\) to another \({F^{q}_{\alpha}}\) for 1 < p, q < ∞ with positive Borel measures μ as symbols. We characterize the boundedness (and compactness) of \({T_\mu: F^{p}_{\alpha} \to F^{q}_{\alpha}}\) in terms of the averaging function \({\widehat{\mu}_r}\) and the t-Berezin transform \({\widetilde{\mu}_t}\) respectively. Quite differently from the Bergman space case, we show that T μ is bounded (or compact) from \({F^{p}_{\alpha}}\) to \({F^{q}_{\alpha}}\) for some p ≤ q if and only if T μ is bounded (or compact) from \({F^{p}_{\alpha}}\) to \({F^{q}_{\alpha}}\) for all p ≤ q. In order to prove our main results on T μ , we introduce and characterize (vanishing) (p, q)-Fock Carleson measures on C n . 相似文献
1000.
In this paper, a generalized diffusion model driven by the composite-subdiffusive fractional Brownian motion (FBM) is employed. Based on this stochastic process, we derive a fractional Fokker-Planck equation (FFPE) and obtain its solution. It is proved that the Generalized Einstein Relation (GER) and the Metzler and Klafter conjecture on the asymptotic behavior of stretched Gaussian hold the FFPE in a composite-subdiffusive regime. 相似文献