Comparison Study on Anode Materials of Lithium-Ion Battery Applied in Tibet

Lithium-ion battery is facing the capacity fade in cold area. It reports in this paper to improve the temperature-tolerance using the novel materials in the battery design. Mesophase carbon microspheres (MG11) composed of 2H + 3R graphite phase with more uniform size were used as anode material and a new binder (WRA268) was used. The tests results show that at 0°C, MG11 using conventional binder (styrene butadiene rubber, SBR) attains 66% of reversible capacity retention rate, and synthetic graphite (FSN-1) using WRA268 as binder attains 76.9% of reversible capacity retention rate, but it attains 34% for the FSN-1 using SBR as the binder. These results show that MG11-WRA268 is promising materials using for battery in cold areas such as Tibet.

Disinfection byproducts in drinking water and regulatory compliance： A critical review

Disinfection by-products （DBPs） are regulated in drinking water in a number of countries. This critical review focuses on the issues associated with DBP regulatory compliance, including methods for DBP analysis, occurrence levels, the regulation comparison among various countries, DBP compliance strategies, and emerging DBPs. The regulation comparison between China and the United States （US） indicated that the DBP regulations in China are more stringent based on the number of regulated compounds and maximum levels. The comparison assessment using the Information Collection Rule （ICR） database indicated that the compliance rate of 500 large US water plants under the China regulations is much lower than that under the US regulations （e.g. 62.2% versus 89.6% for total trihalomethanes）. Precursor removal and alternative disinfectants are common practices for DBP regulatory compliance. DBP removal after formation, including air stripping for trihalomethane removal and biodegradation for haloacetic acid removal, have gained more acceptance in DBP control. Formation of emerging DBPs, including iodinated DBPs and nitrogenous DBPs, is one of unintended consequences of precursor removal and alternative disinfection. At much lower levels than carbonaceous DBPs, however, emerging DBPs have posed higher health risks.

Preparation of nitrogen doped clews-like carbon materials and their application as the electrode in supercapacitor

In this work, nitrogen doped clews-like carbon materials were successfully fabricated through hydrothermal polymerization method, followed by post treatment that integrated the carbonization,activation and post-nitrogen doping into one process. This preparation method can form particular hierarchical porous structure without using any sacrificial templates. The experimental results show that the nitrogen doped clews-like hierarchical porous carbon materials possess a relatively high specific surface area of 815 m^2/g with the nitrogen content of 10.58 at%. The electrochemical properties show that the resulting sample delivers 258 F/g at a 0.5 A/g and excellent capacity retention of 79% at 20 A/g. After conducting 10,000 charge-discharge cycles at 10 A/g, the capacitance retention of 98.3% is achieved.These intriguing results demonstrate that the obtained nitrogen doped clews-like carbon materials will be promising electrode materials for supercapacitor and other energy storage devices.

Machine learning in polymer informatics

Polymers have been widely used in energy storage,construction,medicine,aerospace,and so on.However,the complexity of chemical composition and morphology of polymers has brought challenges to their development.Thanks to the integration of machine leaming algorithms and large data resources,the data-driven methods have opened up a new road for the development of poly-mer science and engineering.The emerging polymer informatics attempts to accelerate the performance prediction and process optimization of new poly-mers by using machine learning models based on reliable data.With the grad-ual supplement of currently available databases,the emergence of new databases and the continuous improvement of machine learning algorithms,the research paradigm of polymer informatics will be more efficient and widely used.Based on these points,this paper reviews the development trends of machine learning assisted polymer informatics and provides a simple introduc-tion for researchers in materials,artificial intelligence,and other fields.

骶骨肿瘤切除术中运用动脉气囊阻塞技术减少出血的临床研究

背景：动脉气囊阻塞技术已在骶骨肿瘤手术中被用来减少术中的大出血。本回顾性临床研究的目的是确定骶骨肿瘤手术动脉气囊阻塞技术在减少术中及术后出血的有效性及分析其并发症。方法：回顾研究1997至2009年接受手术治疗的215例骶骨肿瘤患者，95例患者在接受骶骨肿瘤切除术时未采用动脉气囊阻塞技术，而另外120例患者在术中使用了该技术。患者性别、年龄、可能影响出血的因素以及总的出血量（包括术中及术后）等信息均来自病案记录，对两组数据进行比较研究。结果：患者性别、年龄、肿瘤恶性分级、肿瘤血供、肿瘤部位、肿瘤复发率或术前放疗比例、手术入路以及切除方式，两组间无显著性差别。接受动脉气囊阻塞组患者平均肿瘤体积更大，骶骨重建率更大，平均手术时间更长，然而该组病例平均总出血量（2963ml）及平均术中出血量（2236ml）均比未接受动脉气囊阻塞组患者低（分别为4337ml和3935m1）（p〈0．001）。与动脉气囊阻塞相关的并发症包括3例股动脉栓塞和5例穿刺部位血肿。结论：动脉气囊阻塞技术可减少需广泛切除手术的骶骨肿瘤患者总出血量及术中出血量。动脉气囊阻塞相关的并发症发生率较低。

Degradation mechanism analysis of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) single crystal cathode materials through machine learning

LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)has become one of the most popular cathode materials for current lithium-ion batteries due to its high-energy density and cost performance.However,the rapid capacity fading of NCM severely hinders its development and applications.Here,the single crystal NCM523 materials under different degradation states are characterized using scanning transmission electron microscopy(STEM).Then we developed a neural network model with a two-sequential attention block to recognize the crystal structure and locate defects in STEM images.The number of point defects in NCM523 is observed to experience a trend of increasing first and then decreasing in the degradation process.The space between the transition metal columns shrinks obviously,inducing dramatic capacity decay.This analysis sheds light on the defect evolution and chemical transformation correlated with layered material degradation.It also provides interesting hints for researchers to regenerate the electrochemical capacity and design better battery materials with longer life.