Metal Hydride Based Materials for Advanced Lithium Storage Applications

The state of the art, commercial used graphite anode materials are far from meeting the increasing demand for high-energy density devices. It is necessary to develop anode materials with high energy density, low-cost and superior safety. Generally, compared with classical intercalation anodes, conversion type anodes display higher theoretical capacity have been paid widely attention. Some of the emerging metal hydrides demonstrate high specific capacity, small polarization and suitable working potential. This thesis focusing on two metal hydrides both with relatively high specific capacity, sodium alanate (NaAlH4) and mageneisum hydride (MgH2) as anodes materials in LIBs. In order to enhance the electronic conductivity of the material and relieve the volume variation, four methods of carbon doping, nano crystallization, surface modification and process modification were used to raise the lithium storage performance of metal hydride-based anode materials (NaAlH4 and MgH2). By way of self-assembly, gas-solid reaction and other synthesis methods, the multi nanostructure of metal hydride-based anode materials (NaAlH4 and MgH2) were designed, and a variety of composite materials of metal hydride and graphene with different structures were successfully prepared. Through a facile solvent evaporation induced deposition method, NaAlH4 nanoparticles with an average size of ~ 12 nm encapsulated in graphene nanosheets has been developed. The SAH@G-50 electrode exhibits an discharge capacity about 1995 mAh g-1 at 100 mAh g−1 at first cycle, with a coulombic efficiency (CE) of 85.7%. The specific discharge capacity slowly decayed and then was stabilized at ~698 mAh g-1 after 200 cycles. It has been founded in this thesis, graphene could act as an effective platform to tailor the metal-hydrogen bonds of NaAlH4 through their favorable molecular interaction. Theoretical and experimental results confirm that graphene is capable of weakening the Al-H bonds of NaAlH4, thus facilitating the breaking and recombination of Al-H bonds towards advanced lithium storage performance. In addition, The synergistic effects of the favorable molecular interaction between graphene and NaAlH4, and the noticeable decrease in particle size significantly boost the lithium storage performances of NaAlH4

« Hors de la ferme ! » (tiaochu nongmen)

Depuis la fin des années 1950, la mise en place du système d’enregistrement des ménages (hukou) a fait de la conversion du hukou rural en hukou urbain une des principales voies d’ascension sociale en Chine rurale. Partant d’une approche biographique, cet article tente de saisir, parallèlement aux évolutions historiques entre 1950 et 2012, les hauts et les bas de diverses formes de conversion du hukou et d’ascension sociale. Il s’efforce également de rendre compte de la manière dont ces possibilités fluctuantes ont été perçues, interprétées, mises en œuvre et actualisées par les habitants d’un village de Chine centrale, ainsi que leurs conséquences en termes de répartition genrée des ressources éducatives entre les enfants au sein d’un ménage. En cela, il participe aux débats en cours portant sur la relation entre allocation des ressources du ménage, inégalité des genres et mobilité sociale dans la Chine rurale. En examinant les dynamiques de ces trajectoires de mobilité sociale, cet article prête une attention toute particulière à l’éducation et aux transformations de sa fonction d’ascenseur social, et affirme qu’il existe un lien involontaire entre la réussite universitaire, les améliorations de l’égalité des sexes en matière d’éducation en Chine rurale et la mobilité sociale. Ce lien est néanmoins faible, du fait de la logique développementaliste qui le sous-tend

« Hors de la ferme ! » (tiaochu nongmen)

Depuis la fin des années 1950, la mise en place du système d’enregistrement des ménages (hukou) a fait de la conversion du hukou rural en hukou urbain une des principales voies d’ascension sociale en Chine rurale. Partant d’une approche biographique, cet article tente de saisir, parallèlement aux évolutions historiques entre 1950 et 2012, les hauts et les bas de diverses formes de conversion du hukou et d’ascension sociale. Il s’efforce également de rendre compte de la manière dont ces possibilités fluctuantes ont été perçues, interprétées, mises en œuvre et actualisées par les habitants d’un village de Chine centrale, ainsi que leurs conséquences en termes de répartition genrée des ressources éducatives entre les enfants au sein d’un ménage. En cela, il participe aux débats en cours portant sur la relation entre allocation des ressources du ménage, inégalité des genres et mobilité sociale dans la Chine rurale. En examinant les dynamiques de ces trajectoires de mobilité sociale, cet article prête une attention toute particulière à l’éducation et aux transformations de sa fonction d’ascenseur social, et affirme qu’il existe un lien involontaire entre la réussite universitaire, les améliorations de l’égalité des sexes en matière d’éducation en Chine rurale et la mobilité sociale. Ce lien est néanmoins faible, du fait de la logique développementaliste qui le sous-tend

“Jumping Out of the Agricultural Gate” (tiaochu nongmen)

Since the late 1950s, the implementation of the household registration (hukou) system has made converting rural hukou to urban status a central aspect of upward social mobility in rural China. Through a biographical approach, this article attempts to capture, in relation to historical periods between 1950 and 2012, the ups and downs of various forms of hukou conversion and social mobility channels, how these fluctuating routes have been perceived, interpreted, pursued, and actualised by the rural people in a central Chinese village, and their consequences in terms of gendered household educational resources distribution among children. By doing this, it addresses ongoing debates about the relationship between allocation of household resources, gender inequality, and social mobility in rural China. While examining the dynamics of these avenues to social mobility, this paper pays particular attention to education and its changing function as an important social mobility channel, and argues that there is an unintended link between higher educational attainment, improvements in gender equality in education in rural China, and social mobility. This link is nevertheless weak due to its logic of developmentalism

The crosstalk of intratumor bacteria and the tumor

The in-depth studies reveal the interaction between the host and commensal microbiomes. Symbiotic bacteria influence in tumor initiation, progression, and response to treatment. Recently, intratumor bacteria have been a burgeoning research field. The tumor microenvironment is under vascular hyperplasia, aerobic glycolysis, hypoxia, and immunosuppression. It might be attractive for bacterial growth and proliferation. As a component of the tumor microenvironment, intratumor bacteria influence tumor growth and metastasis, as well as the efficacy of anti-tumor therapies. Therefore, understanding the intricate interplay of intratumoral bacteria and the host might contribute to better approaches to treat tumors. In this review, we summarize current evidence about roles of intratumor bacteria in tumor initiation and anti-tumor therapy, and what is remained to be solved in this field

Measuring the Instability of China’s Financial System: Indices Construction and an Early Warning System

In this paper, employing several econometric techniques, we construct a financial stress index (CNFSI) and a financial conditions index (CNFCI) to measure the instability of China’s financial system. The indices are based on the monthly data collected from China’s inter-bank markets, stock markets, foreign exchange markets and debt markets. Using two indices, we identify the episodes of systemic financial stress, and then evaluate the indices. The empirical results suggest that the CNFSI performs better than the CNFCI. Furthermore, we propose four leading indicators for monitoring China’s financial instability, and provide a primary early warning system for China’s macroprudential regulations