心池微澜

涟漪：轻易地得到了点什么，就一个劲地扩大欲望，哪能不很快走向消亡。

Preparation and electrochemical performance of hollow-spherical polypyrrole/V_2O_5 composite

In order to improve the lower practical capacity and bad cyclability of crystalline V2O5（c-V2O5）,the vanadium oxide（V2O5） and polypyrrole（PPy） hybrid with hollow-spherical（HS） structure was studied.HS nanocomposite comprised of conductive polypyrrole and vanadium pentoxide（PPy/V2O5） was synthesized by polymerization of pyrrole monomer（Py） in the hollow-microspherical V2O5 host.This novel hybrid was characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM） and tested as the cathode material for lithium-ion batteries（LIB） by galvanostatic cell cycling and electrochemical impedance spectroscopy（EIS）.The hollow-spherical polypyrrole/vanadium oxide（HS-PPy/V2O5） composites,in which PPy molecules are intercalated between the layers of V2O5,exhibit slight reduced capacity and substantially improve cyclability and electrochemical activity compared with the pure HS-V2O5.

桑榆唱晚归倦舟

'买条黄牛学种田,结间茅屋傍林泉。因思老去无多日,且向山中过几年。'学古人,桑榆唱晚,寄情山水田园。光阴不再矫健,退休,让灵魂停泊,倦舟靠岸。回到那条轮回的小巷,于生命的节点,抛弃烦忧,爽快拐弯;于老巷的拐角处,找到一处安放灵魂的老宅,敲开锈迹铜环,迈进寂静门槛,慢慢翻找散落的从前,让一汪于闹市里逐渐干枯的心池渐渐盈满欢快的清泉。

Movements of the Western Pacific Warm Pool Centroid and Their Relationship to Sea Surface Temperature Changes in Nino Regions

By using monthly historical sea surface temperature (SST) data for the yearsfrom 1950 to 2000, the Western Pacific Warm Pool (WPWP) climatology and anomalies are studied inthis paper. The analysis of WPWP centroid (WPWPC) movement anomalies and the Nino-3 region SSTanomalies(SSTA) seems to reveal a close, linear relation between the zonal WPWPC and Nino-3 regionSSTA, which suggests that a 9° anomaly of the zonal displacement from the climatological positionof the WPWPC corresponds to about a 1℃ anomaly in the Nino-3 region area-mean SST. This studyconnects the WPWPC zonal displacement with the Nino-3 SSTA, and it may be helpful in betterunderstanding the fact that the WPWP eastward extension is conducive to the Nino-3 region SSTincrease during an El Nino-Southern Oscillation (ENSO) event.

A Preliminary Study on the Relation Between the Thermal and Geometric Surface Centroids of the Western Pacific Warm Pool

Numerous published results have showr the importance of the Wcstern Pacific Warm Pool （WPWP）surface centroid movement in ENSO-（EI Nino/Southcrn Oscillation）rclated studies .Howcver,some rccent research conclusions make it necessary to clarify the differenccs of the currently exicing two types of WPWP surface centroid：the geometric centroid and the thermal （heat）centrold.This study analyzes the physical backgrounds of the two typcs of centroid and points out their differenccs.which suggest that different types of ccntroid may scrve different study purposes.This study also shows that the ‘geometric center’of WPWP.actually a close approximation to the mass ccntroid,is more related to the Nino-3 region sca surfacc temperaturc（SST）ancmaly and can also be regarded as an important indicator of ENSO events.

风筝又飞扬

我从一沓厚厚的书本与试卷中抬起头,觉得好累。父母和老师的关心让我感觉身上的背囊,沉沉的,喘不过气来。不知从何时起,我的世界像快进的无声电影,分不清哪里是起点,哪里又是终点。我害怕浪费时光,可是这匆匆行走的日子却是灰色的。早起的时候,我莫名烦躁,归家的夜晚我又黯然神伤。突然,一声清脆的鸟叫声传来,在我的心池荡起了一圈圈涟漪。我来到阳台上。

Enhanced electrochemical performance in lithium ion batteries of a hollow spherical lithium-rich cathode material synthesized by a molten salt method

A high voltage layered Li1.2Ni0.16Co0.08Mn0.56O2 cathode material with a hollow spherical structure has been synthesized by molten-salt method in a NaCI flux. Characterization by X-ray diffraction and scanning electron microscopy confirmed its structure and proved that the as-prepared powder is constituted of small, homogenously sized hollow spheres （1-1.5 μm）. The material exhibited enhanced rate capability and high first cycle efficiency due to the good dispersion of secondary particles. Galvanostatic cycling at different temperatures （20, 40, and 60 ℃） and a current rate of 2 C （500 mA.g-1） showed no significant capacity fade.

Composite of sulfur impregnated in porous hollow carbon spheres as the cathode of Li-S batteries with high performance

Carbon-sulfur composites as the cathode of rechargeable Li-S batteries have shown outstanding electrochemical performance for high power devices. Here, we report the promising electrochemical charge-discharge properties of a carbon-sulfur composite, in which sulfur is impregnated in porous hollow carbon spheres （PHCSs） via a melt-diffusion method. Instrumental analysis shows that the PHCSs, which were prepared by a facile template strategy, are characterized by high specific surface area （1520 m2.g 1）, large pore volume （2.61 cm^3·g^-1）, broad pore size distribution from micropores to mesopores, and high electronic conductivity （2.22 S·cm-1）. The carbon-sulfur composite with a sulfur content of 50.2 wt.% displays an initial discharge capacity of 1450 mA.h·g^-1 （which is 86.6% of the theoretical specific capacity） and a reversible discharge capacity of 1357 mA.h·g^-1 after 50 cycles at 0.05 C charge-discharge rate. At a higher rate of 0.5 C, the capacity stabilized at around 800 mA-h·g^-1 after 30 cycles. The results illustrate that the porous carbon-sulfur composites with hierarchically porous structure have potential application as the cathode of Li-S batteries because of their effective improvement of the electronic conductivity, the repression of the volume expansion, and the reduction of the shuttling loss.

Rational synthesis of SnS_2@C hollow microspheres with superior stability for lithium-ion batteries

Tin-based nanomaterials have been extensively explored as high-capacity anode materials for lithium ion batteries（LIBs）. However,the large volume changes upon repeated cycling always cause the pulverization of the electrode materials. Herein,we report the fabrication of uniform SnS_2@C hollow microspheres from hydrothermally prepared SnO_2@C hollow microspheres by a solid-state sulfurization process. The as-prepared hollow SnS_2@C microspheres with unique carbon shell,as electrodes in LIBs,exhibit high reversible capacity of 814 mA h g^（-1） at a current density of 100 mA g^（-1）,good cycling performance（783 mA h g^（-1） for 200 cycles maintained with an average degradation rate of 0.02% per cycle） and remarkable rate capability（reversible capabilities of 433 mA h g^（-1）at 2C）. The hollow space could serve as extra space for volume expansion during the charge-discharge cycling,while the carbon shell can ensure the structural integrity of the microspheres. The preeminent electrochemical performances of the SnS_2@C electrodes demonstrate their promising application as anode materials in the next-generation LIBs.

Optimization and temperature effects on sandwich betavoltaic microbattery

The design scheme of a sandwich-structure betavoltaic microbattery based on silicon using63Ni is presented in this paper.This structure differs from a monolayer energy conversion unit.The optimization of various physical parameters and the effects of temperature on the microbattery were studied through MCNP.For the proposed optimization design,P-type silicon was used as the substrate for the betavoltaic microbattery.Based on the proposed theory,a sandwich microbattery with a shallow junction was fabricated.The temperature dependence of the device was also measured.The open-circuit voltaic(Voc)temperature dependence of the optimized sandwich betavoltaic microbattery was linear.However,the Voc of the betavoltaic microbattery with a high-resistance substrate exponentially decreased over the range of room temperature in the experiment and simulation.In addition,the sandwich betavoltaic microbattery offered higher power than the monolayer betavoltaic one.The results of this paper provide a significant technical reference for optimizing the design and studying temperature effects on betavoltaics of the same type.

SnO_2 hollow spheres:Polymer bead-templated hydrothermal synthesis and their electrochemical properties for lithium storage

SnO2 hollow spheres have been synthesized via a facile hydrothermal method using sulfonated polystyrene beads as a template followed by a calcination process in air.X-ray diffraction,scanning electron microscopy,and transmission electron microscopy show that the as-obtained SnO2 hollow spheres have a wall thickness of about 50 nm,and consist of nanosized SnO2 particles with a mean diameter of about 15 nm.Electrochemical measurements indicate that the SnO2 hollow spheres exhibit improved electrochemical performance in terms of specific capacity and rate capability in comparison with commercial SnO2 when used as anode materials for lithium-ion batteries.The enhanced performance may be attributed to the spherical and hollow structure,as well as the building blocks of SnO2 nanoparticles.