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991.
本文分析了9500B示波器校准仪测量不确定度来源,确定了评定的方法,按JJF 1059.1-2012《测量不确定度的表示与评定》要求,分别对其直流电压、方波电压、时标、上升时间等参数进行了不确定度的分析及评定。 相似文献
992.
X80管线钢因具有高强度、高韧性、抗脆断等性能,已成为现代油气运输中应用最为广泛的钢材之一。X80管线钢在埋地土壤环境中不可避免地受到应力和SRB(Sulfate-reducing bacteria)的共同作用,近年来有关X80管线钢在含SRB的土壤环境中的应力腐蚀开裂已成为一个研究重点。综述了应力腐蚀开裂和SRB腐蚀的影响因素,总结了关于应力和SRB协同作用对X80管线钢腐蚀行为影响的研究现状,分析了现行研究的缺陷和不足,并针对这些问题对今后的研究进行了展望。 相似文献
993.
Molly S. Bazilchuk Takashi Sumigawa Takayuki Kitamura Zhiliang Zhang Helge Kristiansen Jianying He 《Advanced Engineering Materials》2018,20(7)
994.
Engineering High‐Performance MoO2‐Based Nanomaterials with Supercapacity and Superhydrophobicity by Tuning the Raw Materials Source 下载免费PDF全文
Yunqiang Zhang Song Yang Shulan Wang Hua Kun Liu Li Li Shi Xue Dou Xuan Liu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(25)
Herein, a simple self‐assembly method is proposed for the fabrication of MoO2‐based superhydrophobic material with record high contact angles (contact angle up to about 173°) for conductive metal oxides on hard/soft substrates. The spin‐coated surface demonstrates excellent oil–water separation efficiency (>98%) after 50 cycles and robust corrosion resistance after immersion into different pH solutions for 20 d. These water‐resistant coatings retain excellent superhydrophobicity after oil immersion, knife‐scratch, and long‐cycle sandpaper abrasion, which is not observed on most artificial surfaces. Meanwhile, the functionality switching from superhydrophobicity to supercapacity, which have an inverse relationship in aqueous solutions because of poor electrode wettability, is achieved simply by editing the raw materials source. Tuning of the raw materials leads to the same product MoO2/graphitic carbon with different morphologies and functionalities. Different from superhydrophobic MoO2/carbon ball flowers, MoO2 nanotubes with carbon exhibit excellent supercapacity with a large gravimetric capacitance and great cycling stability. 相似文献
995.
The Influence of Carbon Nitride Nanosheets Doping on the Crystalline Formation of MIL‐88B(Fe) and the Photocatalytic Activities 下载免费PDF全文
Zhen‐Dong Lei Yuan‐Cheng Xue Wen‐Qian Chen Lin Li Wen‐Hui Qiu Yong Zhang Liang Tang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(35)
In this research, bulk graphitic carbon nitride (g‐C3N4) is exfoliated and transferred to the carbon nitride nanosheets (CNNSs), which are then coupled with MIL‐88B(Fe) to form the hybrid. From the results of the powder X‐ray diffraction, scanning electronic microscopy and thermogravimetric analysis, it is found that the doping of CNNSs on the surface of MIL‐88(Fe) could maintain the basic structure of MIL‐88B(Fe), and the smaller dimension of CNNSs might influence the crystallization process of metal‐organic frameworks (MOFs) compared to bulk g‐C3N4. Besides, the effects of the CNNSs incorporation on photocatalysis are also investigated. Through the photoluminescence spectra, electrochemical measurements, and photocatalytic experiments, the hybrid containing 6% CNNSs is certified to possess the highest catalytic activity to degrade methylene blue and reduce Cr(VI) under visible light. The improvement of the photocatalytic performance can be attributed to the matched energy level which favors the formation of the heterojunctions. Besides, it promotes the charge migration such that the contact between MOFs and CNNSs is more intimate, which can be inferred from the electronic microscopy images. Finally, a possible photocatalytic mechanism is put forward by the relative calculation and the employment of the scavengers to trap the active species. 相似文献
996.
New Insight into Procedure of Interface Electron Transfer through Cascade System with Enhanced Photocatalytic Activity 下载免费PDF全文
Xingming Ning Wenqi Li Yao Meng Dongdong Qin Jing Chen Xiang Mao Zhonghua Xue Duoliang Shan Samrat Devaramani Xiaoquan Lu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(15)
Recombination of photogenerated electron–hole pairs is extremely limited in the practical application of photocatalysis toward solving the energy crisis and environmental pollution. A rational design of the cascade system (i.e., rGO/Bi2WO6/Au, and ternary composites) with highly efficient charge carrier separation is successfully constructed. As expected, the integrated system (rGO/Bi2WO6/Au) shows enhanced photocatalytic activity compared to bare Bi2WO6 and other binary composites, and it is proved in multiple electron transfer (MET) behavior, namely a cooperative electron transfer (ET) cascade effect. Simultaneously, UV–vis/scanning electrochemical microscopy is used to directly identify MET kinetic information through an in situ probe scanning technique, where the “fast” and “slow” heterogeneous ET rate constants (Keff) of corresponding photocatalysts on the different interfaces are found, which further reveals that the MET behavior is the prime source for enhanced photocatalytic activity. This work not only offers a new insight to study catalytic performance during photocatalysis and electrocatalysis systems, but also opens up a new avenue to design highly efficient catalysts in photocatalytic CO2 conversion to useful chemicals and photovoltaic devices. 相似文献
997.
Monitoring the Dynamic Process of Formation of Plasmonic Molecular Junctions during Single Nanoparticle Collisions 下载免费PDF全文
Jing Guo Jie Pan Shuai Chang Xuewen Wang Na Kong Wenrong Yang Jin He 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(15)
The capability to study the dynamic formation of plasmonic molecular junction is of fundamental importance, and it will provide new insights into molecular electronics/plasmonics, single‐entity electrochemistry, and nanooptoelectronics. Here, a facile method to form plasmonic molecular junctions is reported by utilizing single gold nanoparticle (NP) collision events at a highly curved gold nanoelectrode modified with a self‐assembled monolayer. By using time‐resolved electrochemical current measurement and surface‐enhanced Raman scattering spectroscopy, the current changes and the evolution of interfacial chemical bonding are successfully observed in the newly formed molecular tunnel junctions during and after the gold NP “hit‐n‐stay” and “hit‐n‐run” collision events. The results lead to an in‐depth understanding of the single NP motion and the associated molecular level changes during the formation of the plasmonic molecular junctions in a single NP collision event. This method also provides a new platform to study molecular changes at the single molecule level during electron transport in a dynamic molecular tunnel junction. 相似文献
998.
Ultrathin 2D Zirconium Metal–Organic Framework Nanosheets: Preparation and Application in Photocatalysis 下载免费PDF全文
Ting He Bing Ni Simin Zhang Yue Gong Haiqing Wang Lin Gu Jing Zhuang Wenping Hu Xun Wang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(16)
Synthesizing ultrathin 2D metal–organic framework nanosheets in high yields has received increasing research interest but remains a great challenge. In this work, ultrathin zirconium‐porphyrinic metal–organic framework (MOF) nanosheets with thickness down to ≈1.5 nm are synthesized through a pseudoassembly–disassembly strategy. Owing to the their unique properties originating from their ultrathin thickness and highly exposed active sites, the as‐prepared ultrathin nanosheets exhibit far superior photocatalysis performance compared to the corresponding bulk MOF. This work highlights new opportunities in designing ultrathin MOF nanosheets and paves the way to expand the potential applications of MOFs. 相似文献
999.
Simplified Perovskite Solar Cell with 4.1% Efficiency Employing Inorganic CsPbBr3 as Light Absorber 下载免费PDF全文
Jialong Duan Yuanyuan Zhao Benlin He Qunwei Tang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(20)
Perovskite solar cells with cost‐effectiveness, high power conversion efficiency, and improved stability are promising solutions to the energy crisis and environmental pollution. However, a wide‐bandgap inorganic–semiconductor electron‐transporting layer such as TiO2 can harvest ultraviolet light to photodegrade perovskite halides, and the high cost of a state‐of‐the‐art hole‐transporting layer is an economic burden for commercialization. Here, the building of a simplified cesium lead bromide (CsPbBr3) perovskite solar cell with fluorine‐doped tin oxide (FTO)/CsPbBr3/carbon architecture by a multistep solution‐processed deposition technology is demonstrated, achieving an efficiency as high as 4.1% and improved stability upon interfacial modification by graphene quantum dots and CsPbBrI2 quantum dots. This work provides new opportunities of building next‐generation solar cells with significantly simplified processes and reduced production costs. 相似文献
1000.
Electric Power Generation through the Direct Interaction of Pristine Graphene‐Oxide with Water Molecules 下载免费PDF全文
Tong Xu Xiaoteng Ding Changxiang Shao Long Song Tengyu Lin Xue Gao Jiangli Xue Zhipan Zhang Liangti Qu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(14)
Converting ubiquitous environmental energy into electric power holds tremendous social and financial interests. Traditional energy harvesters and converters are limited by the specific materials and complex configuration of devices. Herein, it is presented that electric power can be directly produced from pristine graphene oxide (GO) without any pretreatment or additives once encountering the water vapor, which will generate an open‐circuit‐voltage of up to 0.4–0.7 V and a short‐circuit‐current‐density of 2–25 µA cm?2 on a single piece of GO film. This phenomenon results from the directional movement of charged hydrogen ions through the GO film. The present work demonstrates and provides an extremely simple method for electric energy generation, which offers more applications of graphene‐based materials in green energy converting field. 相似文献