Static and Dynamic Mechanical Analyses for the Vacuum Vessel of EAST Superconducting Tokamak Device

EAST （experimental advanced superconducting tokamak） is an advanced steadystate plasma physics experimental device, which is being constructed as the Chinese National Nuclear Fusion Research Project. During the plasma operation the vacuum vessel as one of the key component will withstand the electromagnetic force due to the plasma disruption, the Halo current and the toroidal field coil quench, the pressure of boride water and the thermal load due to 250℃ baking by pressurized nitrogen gas. In this paper a report of the static and dynamic mechanical analyses of the vacuum vessel is made. Firstly the applied loads on the vacuum vessel were given and the static stress distribution under the gravitational loads, the pressure loads, the electromagnetic loads and thermal loads were investigated. Then a series of primary dynamic, buckling and fatigue life analyses were performed to predict the structure＇s dynamic behavior. A seismic analysis was also conducted.

Design,preparation,application of advanced array structured materials and their action mechanism analyses for high performance lithium-sulfur batteries

Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.

Mechanism Analyses for Elucidating the Role of LOXL2 Silencing in Hepatocellular Carcinoma

The paper aimed to study the effect of lysyl oxidase-like 2 （LOXL2） on hepatocellular carcinoma （HCC） and explore the biological mechanisms of tumorigenicity and progression in HCC. The authors used four HCC cell lines to identify LOXL2. A lentiviral vector containing LOXL2-siRNA was constructed to silence the LOXL2 gene in SMMC-7721 cell line, and mRNA of the target gene was detected by real-time polymerase chain reaction （RT-PCR）. The effect of LOXL2 silencing on the growth of SMMC-7721 cells was explored with flow cytometry profiling and BrdU labeling. Downstream genes of LOXL2 were selected by microarray and verified by Western Blotting. In the results, LOXL2 expression was significantly up-regulated in four types of HCC cell lines, therefore, SMMC-7721 cell line was selected for further exploration. When SMMC-7721 cell line was infected with LOXL2-siRNA, the expression of LOXL2 mRNA decreased. The silencing of LOXL2 resulted in the cell cycle arrest at the G 1-phase, the increased apoptosis and the decreased growth of SMMC-7721 cells on the indicated days by BrdU. Moreover, the MDM2, BIRC3, CDC42, FOS and TGFBR2 genes were selected and verified to be the downstream genes of LOXL2. In conclusion, LOXL2 contributes to the genesis and progression of HCC cells and works by regulating downstream genes of LOXL2 in certain pathways. Therefore, LOXL2 may play an important role in the progression and prognosis of HCC.

A DUCTILE FRACTURE CRITERION BASED ON THREEDIMENSIONAL VOID MODEL

A fracture criterion derived from a microscopic point of view is proposed and has proved to be effective in the analysis of uniaxial tension. On the one hand, a method of predicting a ductile fracture is proposed using a three-dimensional void model and the assumption of velocity discontinuity. The relationship between the void volume fraction and the critical strain to fracture, calculated with the help of the new model, shows the same tendency as that obtained from the modified Thomason model. On the other hand, the mechanical and metallographic analyses of the uniaxial tension experiment are performed using four kinds of carbon steel. The relationship between the void volume fraction and the critical strain to fracture, calculated from the new model, agrees better with the result obtained from the experiment, rather than that calculated by the modified Thomason model, which confirms the validity of the ductile fracture criterion based on the three-dimensional void model.

The Earliest Onset Areas and Mechanism of the Tropical Asian Summer Monsoon

The multi-yearly averaged pentad meteorological fields at 850 hPa of theNCEP/NCAR reanalysis dada and the TBB fields of the Japan Meteorological Agency during 1980-1994 areanalyzed. It is found that if the pentad is taken as the time unit of the monsoon onset, then thetropical Asian summer monsoon (TASM) onsets earliest, simultaneously and abruptly over the wholearea in the Bay of Bengal (BOB), the Indo-China Peninsula (ICP), and the South China Sea (SCS), eastof 90°E, in the 27th to 28th pentads of a year (Pentads 3 to 4 in May), while it onsets later inthe India Peninsula (IP) and the Arabian Sea (AS), west of 90°E. The TASM bursts first at the southend of the IP in the 30th to 31st pentads near 10°N, and advances gradually northward to the wholearea, by the end of June. Analysis of the possible mechanism depicts that the rapid changes of thesurface sensible heat flux, air temperature, and pressure in spring and early summer in the middleto high latitudes of the East Asian continent between 100°E and 120°E are crucially responsiblefor the earliest onset of the TASM in the BOB to the SCS areas. It is their rapid changes thatinduce a continental depression to form and break through the high system of pressure originallylocated in the above continental areas. The low depression in turn introduces the southwesterly tocome into the BOB to the SCS areas, east of 90° E, and thus makes the SCS summer monsoon (SCSSM)burst out earliest in Asia. In the IP to the AS areas, west of 90° E, the surface sensible heatflux almost does not experience obvious change during April and May, which makes the tropical Indiansummer monsoon (TISM) onset later than the SCSSM by about a month. Therefore, it is concluded thatthe meridian of 90° E is the demarcation line between the South Asian summer monsoon (SASM, i.e.,the TISM) and the East Asian summer monsoon (EASM, including the SCSSM). Besides, the temporalrelations between the TASM onset and the seasonal variation of the South Asian high (SAH) arediscussed, too, and it is found that there are good relations between the monsoon onset time and theSAH center positions. When the SAH center advances to north of 20°N, the SCSSM onsets, and tonorth of 25° N, the TISM onsets at its south end. Comparison between the onset time such determinedand that with other methodologies shows fair consistency in the SCS area and some differences inthe IP area.