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921.
Zhe Hu Qiannan Liu Weihong Lai Qinfen Gu Lin Li Mingzhe Chen Wanlin Wang Shu‐Lei Chou Yong Liu Shi‐Xue Dou 《Liver Transplantation》2020,10(19)
Copper is used as current collector in rechargeable ion batteries due to its outstanding electronic conductivity and low cost. The intrinsic inactivity of copper, however, makes it a poor candidate for an electrode material without further structural modification. To fully utilize its high electronic conductivity, herein, the incorporation of heterogeneous phosphorus combined with building a unique 3D hollow structure is proposed. The as‐prepared copper phosphide hollow nanocubes deliver a stable capacity of 325 mAh·g?1 at 50 mA·g?1 and fast charging and discharging via pseudocapacitance behavior. The outstanding electrochemical performance is attributed to the synergetic effects of high electronic conductivity of copper and the high sodium storage capability of phosphorus. In addition, this facile synthesis method is also easily scaled up for practical applications. Thus, copper phosphide is a promising anode material for sodium ion batteries. 相似文献
922.
Qingbing Xia Yaru Liang Zeheng Lin Shiwen Wang Weihong Lai Ding Yuan Yuhai Dou Qinfen Gu Jia‐Zhao Wang Hua Kun Liu Shi Xue Dou Shaoming Fang Shu‐Lei Chou 《Liver Transplantation》2020,10(36)
Sodium‐ion batteries have attracted ever‐increasing attention in view of the natural abundance of sodium resources. Sluggish sodiation kinetics, nevertheless, remain a tough challenge, in terms of achieving high rate capability and high energy density. Herein, a sheet‐in‐sphere nanoconfiguration of 2D titania–carbon superlattices vertically aligned inside of mesoporous TiO2@C hollow nanospheres is constructed. In such a design, the ultrathin 2D superlattices consist of ordered alternating monolayers of titania and carbon, enabling interpenetrating pathways for rapid transport of electrons and Na+ ions as well as a 2D heterointerface for Na+ storage. Kinetics analysis discloses that the combination of 2D heterointerface and mesoporosity results an intercalation pseudocapacitive charge storage mechanism, which triggers ultrafast sodiation kinetics. In situ transmission electron microscope imaging and in situ synchrotron X‐ray diffraction techniques elucidate that the sheet‐in‐sphere architecture can maintain robust mechanical and crystallographic structural stability, resulting an extraordinary high rate capability, remarkable stable cycling with a low capacity fading ratio of 0.04% per cycle over 500 cycles at 0.2 C, and exceptionally long‐term cyclability up to 20 000 cycles at 50 C. This study offers a method for the realization of a high power density and long‐term cyclability battery by designing of a hierarchical nanoarchitecture. 相似文献
923.
Huan Li Yitong Zhou Ming Zhao Bo Jin Zi Wen Haiming Xie Shixue Dou Qing Jiang 《Liver Transplantation》2020,10(3)
The development of lithium–sulfur batteries is limited by the poor conductivity of sulfur cathodes and soluble long‐chain lithium polysulfides (LPSs), which cause the low utilization of sulfur and the aversive shuttle effect, and further, give rise to self‐discharge, rapid reversible capacity fading, and low Coulombic efficiency. In this work, a novel configuration is built for high‐performance lithium–organosulfur batteries, in which the organosulfur hybrid material and lithium metal are used as the cathode and the anode, respectively, and are separated by a functional separator decorated with nitrogen and sulfur co‐doped reduced graphite oxide. The organosulfur in the cathode prevents the shuttle effect by inhibiting the formation of long‐chain LPSs. In addition, the functional separator effectively adsorbs LPSs escaping from the cathode by electrostatic interactions and further restrains the shuttle effect. These effects are confirmed by density‐functional theory calculations. As a result, this novel configuration provides a high initial discharge capacity of 1364 mAh g?1 at 0.2 C and a high discharge capacity of 750 mAh g?1 at 1 C after 700 cycles with a very low capacity decay rate of 0.037% per cycle. 相似文献
924.
925.
Qian Xie Juan Wu Ying Tang Yafang Dou Sijie Hao Feijia Xu Xiaoyuan Feng Zonghui Liang 《PloS one》2013,8(11)
Background
This study was performed to assess whether iterative reconstruction can reduce radiation dose while maintaining acceptable image quality, and to investigate whether perfusion parameters vary from conventional filtered back projection (FBP) at the low-tube-voltage (80-kVp) during whole-pancreas perfusion examination using a 256-slice CT.Methods
76 patients with known or suspected pancreatic mass underwent whole-pancreas perfusion by a 256-slice CT. High- and low-tube-voltage CT images were acquired. 120-kVp image data (protocol A) and 80-kVp image data (protocol B) were reconstructed with conventional FBP, and 80-kVp image data were reconstructed with iDose4 (protocol C) iterative reconstruction. The image noise; contrast-to-noise ratio (CNR) relative to muscle for the pancreas, liver, and aorta; and radiation dose of each protocol were assessed quantitatively. Overall image quality was assessed qualitatively. Among 76 patients, 23 were eventually proven to have a normal pancreas. Perfusion parameters of normal pancreas in each protocol including blood volume, blood flow, and permeability-surface area product were measured.Results
In the quantitative study, protocol C reduced image noise by 36.8% compared to protocol B (P<0.001). Protocol C yielded significantly higher CNR relative to muscle for the aorta, pancreas and liver compared to protocol B (P<0.001), and offered no significant difference compared to protocol A. In the qualitative study, protocols C and A gained similar scores and protocol B gained the lowest score for overall image quality (P<0.001). Mean effective doses were 23.37 mSv for protocol A and 10.81 mSv for protocols B and C. There were no significant differences in the normal pancreas perfusion values among three different protocols.Conclusion
Low-tube-voltage and iDose4 iterative reconstruction can dramatically decrease the radiation dose with acceptable image quality during whole-pancreas CT perfusion and have no significant impact on the perfusion parameters of normal pancreas compared to the conventional FBP reconstruction using a 256-slice CT scanner. 相似文献926.
Robert A. Morris Lei Dou James Hanken Maureen Kelly David B. Lowery Bertram Lud?scher James A. Macklin Paul J. Morris 《PloS one》2013,8(11)
Electronic annotation of scientific data is very similar to annotation of documents. Both types of annotation amplify the original object, add related knowledge to it, and dispute or support assertions in it. In each case, annotation is a framework for discourse about the original object, and, in each case, an annotation needs to clearly identify its scope and its own terminology. However, electronic annotation of data differs from annotation of documents: the content of the annotations, including expectations and supporting evidence, is more often shared among members of networks. Any consequent actions taken by the holders of the annotated data could be shared as well. But even those current annotation systems that admit data as their subject often make it difficult or impossible to annotate at fine-enough granularity to use the results in this way for data quality control. We address these kinds of issues by offering simple extensions to an existing annotation ontology and describe how the results support an interest-based distribution of annotations. We are using the result to design and deploy a platform that supports annotation services overlaid on networks of distributed data, with particular application to data quality control. Our initial instance supports a set of natural science collection metadata services. An important application is the support for data quality control and provision of missing data. A previous proof of concept demonstrated such use based on data annotations modeled with XML-Schema. 相似文献
927.
928.
Liang Jin Guiqi Zhang Xiaojuan Wang Cunyan Dou Mu Chen Shuangshuang Lin Yuanyuan Li 《Symbiosis (Philadelphia, Pa.)》2011,55(1):29-38
In order to investigate the function of arbuscular mycorrhizae in Tibetan Plateau Alpine meadow ecosystems, experiments were
carried out to evaluate the influence of arbuscular mycorrhizal (AM) fungi on inter-specific competition between the poisonous
plant, Ligularia virgaurea, and the grazing grass, Elymus nutans, at different relative densities. Our results showed that the biomass of L. virgaurea significantly declined in AM treatments while the biomass of E. nutans increased in our inter-specific competition system. Relative yields and root/shoot ratios of these two species indicated
that AM fungi had a significant influence on the growth of L. virgaurea and E. nutans. This implies that arbuscular mycorrhiza do not benefit both plant species equally but rather contribute to the growth of
E. nutans more than L. virgaurea. We thus provide evidence that AM fungi could regulate plant interactions and influence the plant community structure in the
Tibetan Plateau Alpine meadow ecosystem. 相似文献
929.
930.
为阐明氨基脱氧分支酸合成酶(ADC合成酶)在Corynebacterium glutamicum SYPS-062体内积累L-丝氨酸过程中的作用,通过交叉PCR以及同源重组的方法敲除叶酸途径关键酶ADC合成酶的编码基因pabAB,构建了叶酸缺陷型菌株Corynebacterium glutamicum SYPS-062△pabAB,同时构建pabAB基因增强表达重组菌C.glutamicum SYPS-062(pJC Ⅰ-pabAB).分别考察了ADC合成酶对菌株生长的影响、对L-丝氨酸降解途径关键酶丝氨酸羟甲基转移酶(SHMT)的影响以及其对L-丝氨酸积累的影响.结果表明,与出发菌株相比,增强表达基因pabAB重组菌的ADC合成酶的酶活力提高了33%.SHMT酶的酶活力提高了30%,其最大比生长速率(μm)提高了48%,单位细胞产酸率(Yp/x)降低了36.2%;而敲除基因pabAB重组菌的ADC合成酶的酶活力降低了61%.SHMT酶的酶活力降低了20%,最大比生长速率降低了32%,单位细胞产酸率提高了12%. 相似文献