Interior and Exterior Decoration of Transition Metal Oxide Through Cu^(0)/Cu^(+) Co-Doping Strategy for High-Performance Supercapacitor

Although CoO is a promising electrode material for supercapacitors due to its high theoretical capacitance,the practical applications still suffering from inferior electrochemical activity owing to its low electrical conductivity,poor structural stability and inefficient nanostructure.Herein,we report a novel Cu0/Cu+co-doped CoO composite with adjustable metallic Cu0 and ion Cu+via a facile strategy.Through interior(Cu+)and exterior(Cu0)decoration of CoO,the electrochemical performance of CoO electrode has been significantly improved due to both the beneficial flower-like nanostructure and the synergetic effect of Cu0/Cu+co-doping,which results in a significantly enhanced specific capacitance(695 F g^(-1) at 1 A g^(-1))and high cyclic stability(93.4%retention over 10,000 cycles)than pristine CoO.Furthermore,this co-doping strategy is also applicable to other transition metal oxide(NiO)with enhanced electrochemical performance.In addition,an asymmetric hybrid supercapacitor was assembled using the Cu0/Cu+co-doped CoO electrode and active carbon,which delivers a remarkable maximal energy density(35 Wh kg^(-1)),exceptional power density(16 kW kg^(-1))and ultralong cycle life(91.5%retention over 10,000 cycles).Theoretical calculations further verify that the co-doping of Cu^(0)/Cu^(+)can tune the electronic structure of CoO and improve the conductivity and electron transport.This study demonstrates a facile and favorable strategy to enhance the electrochemical performance of transition metal oxide electrode materials.

一种估算水平水舌或自由跌水局部冲刷深度的方法

1 引言在水平水舌或自由跌水作用下,局部冲刷是溢洪道、涵洞出口和泄水闸门等水工建筑物设计中极为重要的参数。因冲刷内部水流和冲刷过程之间的关系难以建立,故目前的研究仍基于开发经验和观测的极限冲刷深度经验公式。 Mason和Arumugam(1985)总结考查了近60年间提出的31个冲刷深度公式后发现,冲刷深度完全可仅采用单宽流量q和水头差H计算,而勿需作更为复杂的考虑。他们认为,最能令人满意的公式形式为 h=K((q^xH^y)/d^z) (1)式中h——冲刷深度;d——平均粒径;x、y、z、K——系数。然而,这种形式的公式并未包括时间参数。

Distribution pattern and geochemical analysis of rare earth elements in deep-ocean sediments

The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explored and the resources and geochemical characteristics of REEs in deep-ocean sediments from diff erent oceans were studied.The total REE abundances(ΣREE)in the diff erent oceans ranged as follows:Eastern Pacifi c,56.88–500.02μg/g;Western Pacifi c,290.68–439.94μg/g;Northern Atlantic,55.33–154.90μg/g;Southern Atlantic,40.83–69.30μg/g;and Southwestern Indian Ocean,20.24–64.76μg/g.Their corresponding LREE(La-Eu)/HREE(Gd-Lu)average values were 5.18,5.86,9.01,5.21,and 4.59,which indicated that the light REEs were all evidently enriched.δEu andδCe showed slight Eu-negative anomalies and signifi cant Ce-positive anomalies in all sediments.Although the contents of REEs in the sediments varied among the diff erent oceans,the distribution patterns of REEs were similar,and the correlation coeffi cient was greater than 0.9290.In the Eastern Pacifi c sediments,ΣREE showed a signifi cantly positive correlation with Co,Cu,Zn,Mn,Mo and a weak correlation with Fe.In the Western Pacifi c and Southern Atlantic sediments,ΣREE presented no obvious correlation and a weakly negative correlation with Co,Cu,Zn,Mn,Mo and Fe,respectively.ΣREE in the Southwestern Indian Ocean sediments positively correlated with Cu,Zn,Mn,Mo,Fe,and had a weakly negative correlation with Co.

Research Progress on the Influence of Movement Instruction on Community Life in Patients with Coronary Heart Disease

The incidence of coronary heart disease increases year by year with the material level of our country.It has a harmful effect on the patient’s life health and quality of life.Movement Instruction is an important aspect of the secondary prevention project of cardiac rehabilitation in patients with coronary heart disease.Although it has a history of decades at inland and abroad,the present situation in China is not optimistic.Some studies have shown that the popularization and participation of cardiac rehabilitation is true and lacking.This paper sums up the relevant knowledge of coronary heart disease,coronary heart disease movement instruction and its impact on community life of patients at home and abroad,and reviews the research results of movement instruction on community rehabilitation of coronary heart disease in recent years,which provides a theoretical reference and prospect for the future research of community exercise rehabilitation of coronary heart disease.

Reinstating Traditional Horsemanship of Ethnic Minorities in Southern China by Excavation,Sorting,and Comparative Research

In August 1991,the book Chinese Nation’s Traditional Sports History was published,and it was hailed as the“masterpiece of Chinese folk sports”by academic circles.In this masterpiece,the traditional horsemanship of 23 ethnic minorities and that of 10 southern ethnic minorities represented by the Miao,Yi,Bai,Shui,Hani,Naxi,and other ethnic groups has been included.For the first time,this masterpiece integrates the traditional horsemanship of the ethnic minorities in Southern China in one volume.The disadvantage is that most of the included traditional horsemanship of ethnic minorities only made a brief introduction to the time,place,and form of its development.However,under the global trend of the transition from traditional society to modern society and post-modern society,the traditional horsemanship of ethnic minorities in Southern China is facing an increasingly serious crisis of inheritance and disconnection,resulting in a gradual extinction of related traditional cultural heritage.The characteristics are gradually lost because of it.Therefore,it is essential to return to the historical and cultural field of traditional horsemanship,conduct rescue excavation,sort out the traditional horsemanship of ethnic minorities in Southern China,rescue the records of traditional horsemanship that is disappearing or undergoing drastic changes,as well as carry out comparative studies on this basis.This is not only an important way to inherit the traditional culture of ethnic minorities,but also means to protect the diversity of ethnic cultures and promote the development of exotic villages.

吩嗪类衍生物用于快速充放电和长寿命的水系钾离子全电池负极

有机电极材料因具有结构多样性和可持续性,在水系钾离子电池研究领域展示出广阔的前景,但它们大多数存在导电性差、易溶于电解液的问题,导致电极活性物质利用率低、循环稳定性差.本文通过含氮苯环的共轭延申、引入氰基活性中心,获得了3CN-HATN.与经#吩嗪负极相比,3CN-HATN的最低未占据分子轨道能级更低,更容易被还原,且其能带隙较窄,改善了导电性,其共轭结构可有效抑制循环过程中3CN-HATN的溶解.3CN-HATN负极在80 C(1 C=350 mA g^(-1))下比容量高达233.8 mA h g^(-1),将其与Ni(OH)_(2)正极匹配,构建的水系钾离子全电池具备优异的循环稳定性和快充性能,30 C下循环10,000圈后容量保持率达81.5%.

靶向钝化与界面载流子动力学优化以提高无空穴传输层的窄带隙钙钛矿太阳电池的效率和稳定性

窄带隙锡-铅混合钙钛矿太阳电池(PSCs)的效率有望接近Shockley-Queisser极限,然而,易氧化的亚锡离子Sn^(2+)以及载流子传输层/钙钛矿未优化的界面接触会导致严重的界面电荷复合和器件性能下降,这在很大程度上阻碍了锡-铅混合钙钛矿太阳电池的实际应用,本文通过在钙钛矿中掺入少量有机膦酸咔唑分子,成功地制备了无空穴传输层锡-铅混合钙钛矿太阳电池.相对于Pb^(2+),有机磷酸咔唑分子在晶界处和晶体表面与Sn^(2+)离子有更强的化学配位作用,从而有效抑制Sn^(2+)的氧化,钝化缺陷并抑制非辐射复合。在移除空穴传输层的情况下,此类有机膦酸咔唑分子靶向修饰作用可有效增强内建电场(~100mV),优化透明导电基底与钙钛矿层的能级排列,从而加速光生电荷分离,促进界面空穴抽取和传输.最终,无空穴传输层的锡-铅混合钙钛矿太阳电池获得最高20.21%的光电转换效率,开路电压高达0.87V,同时实现了超过2400小时的长期稳定性。

Grotthuss机制助力微米尺度H_(2)MoO_(3)/PANI用于超快低温质子电池

水系质子电池具有安全、环保、动力学快、成本低等优点,是一种很有前途的电化学储能系统.这些优点的实现依赖于开发合适且易于获取的电极材料.本文研究了微米尺度的H_(2)MoO_(3)/VPANI作为质子电池负极材料的高倍率性能和稳定性.与大多数负极材料的赝电容性质相反,H_(2)MoO_(3)/PANI同时具有的高比容量和高倍率性能是基于扩散控制的电荷存储机制.H_(2)MoO_(3)/PANI电极在1.0 A g^(-1)时具有268.2 mAh g^(-1)的高比容量,在200.0 A g^(-1)的极高电流密度下也仍然具有高达50%的比容量保持率.本文详细分析了H_(2)MoO_(3)/PANI中超快质子传导的Grotthuss机制.基于H_(2)MoO_(3)/PANI构建的质子全电池在800.0 W kg^(-1)下的能量密度高达42.1 Wh kg^(-1).令人印象深刻的是,即使在冷冻电解质中,质子全电池仍然具有快速的质子传输能力,在-20℃保持了约70%的是室温比容量.这些优异的质子存储性能为微米尺度的电极材料在低温质子电池中的实际应用提供了重要见解.

Microwave-assisted pyrolysis of waste plastics for their resource reuse:A technical review

Rapidly increasing plastics have been used and finally become wastes,resulting in increasing pressures to the environment.Microwave-assisted pyrolysis is a promising technology for converting organic wastes as waste plastics into value-added products.At present,many works on microwave-assisted pyrolysis of plastics have been published,but the achievements,challenges,and future directions of microwave-assisted pyrolysis of waste plastics have not been well summarized and discussed.In this work,the principle of microwave-assisted pyrolysis technology is introduced.Then,the progress of its application to recover useful products from plastics is reviewed and discussed in terms of key parameters including microwave power,pyrolysis temperature,reaction time,types of catalyst,microwave absorbents and feedstock mixing ratio.Especially,the yields and properties of the produced oil,gas and char are correlated with the process parameters.Finally,the existing challenges and prospects of disposal/reuse of waste plastics by microwave-assisted pyrolysis technology are discussed.

Perovskite solar cell towards lower toxicity: a theoretical study of physical lead reduction strategy

The huge performance enhancements of the organometal halide perovskite solar cells(OHPSCs) have appealed enormous attention within recent ten years. Although the rapid growth of the device power conversion efficiency(PCE) has attained over 25%, the contamination of health-hazardous components still holds back its sustainable applications. To reduce the lead usage, many groups have tried chemical lead reduction solutions: substituting the lead by other group 14 metal elements to realize the low-lead OHPSCs. Unfortunately, neither the PCE nor the stability, low-lead OHPSCs all lag far behind the state-ofthe-art conventional lead-based OHPSCs. In this work, we present a physical lead reduction(PLR) concept by reducing the perovskite film thickness to restrict the perovskite hazard risk with minor scarification in device performances. Through the simulation of transfer matrix model, we theoretically demonstrated that by introducing the optical space layer, the device PCE could maintain 96% of the original maximum value while attenuating the perovskite film thickness to one-third. This means that the usage of lead can be reduced by $70% with PLR concept, which could have broad appeal as a new lead reduction strategy towards high performance OHPSCs.

An additive dripping technique using diphenyl ether for tuning perovskite crystallization for high-efficiency solar cells

Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells （PvSCs）. Here, we demonstrate that a low temperature additive dripping （AD） treatment step, using diphenyl ether （DPE）, can significantly improve the power conversion efficiency （PCE）, compared to the control device using chlorobenzene （CB）, by 15% up to 16.64%, with a high current density （Jsc） of 22.67 mA/cm^2. We chose DPE for its small and appropriate dipole moment to adjust the solubility of the MAPbI3-xClx precursor during the formation of the intermediate phase and the MAPbI3-xClx phase. The low DPE vapor pressure provides a longer processing window for the removal of residual dimethylformamide （DMF）, during the annealing process, for improved perovskite formation. Imaging and X-ray analysis both reveal that the MAPbI3-xClx film exhibits enlarged grains with increased crystallinity. Together, these improvements result in reduced carrier recombination and hole trap-state density in the MAPbI3-xClx film, while minimizing the hysteresis problem typical of PvSCs. These results show that the AD approach is a promising technique for improving PvSCs.

External-Oxidant-Free Electrochemical Oxidative Trifluoromethylation of Arenes Using CF3SO2Na as the CF3 Source

Summary of main observation and conclusion An efficient and environmentally benign electrochemical oxidative radical C-H trifluoromethylation of arenes by employing Langlois reagent as the CF3 source was developed in this work.Neither transition metal catalysts nor external chemical oxidants were required in this trifluoromethylation process.The reaction could be conducted in gram scale with high reaction efficiency.

Control of vertical phase separation in high performance non-fullerene organic solar cell by introducing oscillating stratification preprocessing

Non-fullerene organic solar cell(NFOSC)has attracted tremendous attention due to their great potential for commercial applications.To improve its power conversion efficiency(PCE),generally,sequential solution deposition(SSD)methods have been employed to construct the graded vertical phase separation(VPS)of the bulk-heterojunction(BHJ)active layer for efficient exciton separation and charge transition.However,a variety of orthogonal solvents used in the SSD may lead to the unpredicted change in the BHJ morphology and introduce additional defects inside the BHJ bulk thus complicate the fabrication process.Here,a simple oscillating stratification preprocessing(OSP)is developed to facilitate the formation of graded VPS among the BHJ layer.As a result,a significant improvement is obtained in PCE from 10.96%to 12.03%,which is the highest value reported among PBDB-T:ITIC based NFOSC.

Tremor and clinical fluctuation are related to sleep disorders in Chinese patients with Parkinson’s disease

Objective:To study the relationship between sleep disturbances and symptoms in patients with Parkinson’s disease(PD).Methods:The Parkinson’s Disease Sleep Scale-Chinese Version(PDSS-CV)was used to evaluate the sleep disturbances of PD patients in a cross sectional study.The Unified Parkinson’s Disease Rating Scale(UPDRS)parts II-IV,and the Hoehn&Yahr(H&Y)stage were used to determine the level of motor function in PD and the severity of PD.The Spearman correlation and a multiple regression analysis were used to identify the relationship between sleep disturbances and symptoms of PD.The quantities derived from the UPDRS and the H&Y stage and disease duration were compared between groups of patients either with or without sleep disturbances identified by the PDSS.This study was conducted from December 2011 to March 2012 at the First Affiliated Hospital of Sun Yat-sen University,in Guangzhou.Results:A total of 136 PD patients were included in this study.The overall total PDSS score in PD patients was 107.58±23.35 points(range:30–146).There were significant differences in the disease duration,the H&Y stage,and the UPDRS section subscores between groups of patients either with or without sleep disturbances(Kruskal-Wallis Test,p<0.05).There were significant negative correlations between PDSS scores and the UPDRS subscores,the H&Y stage and the disease duration(Spearman correlation,p<0.05).The multiple regression analysis indicated that sleep disturbances identified by the PDSS were only associated with daily life activity,tremor intensity and clinical fluctuation(R2=0.22,F(3,132)=12.4,p<0.001).The correlations were also significant when the contribution of the other two factors was excluded using partial correlations.Conclusions:The level of daily life activity and the occurrences of tremor and clinical fluctuation are likely to be important factors that lead to PD patients’sleep disturbances.This study may elucidate an important clue for the relationship between sleep disturbances and PD symptoms.

Facile and Economical Electrochemical Dehalogenative Deuteration of(Hetero)Aryl Halides

Deuterated compounds are valuable in synthetic,pharmaceutical,and analytical chemistry.The deuteration of halides is a widespread method for highly site-selective deuterium installation.However,the facile,efficient,and economical deuterium incorporation remains challenging.In this work,we introduced a practical deuteration of(hetero)aryl halides through an electrochemical reduction method.This transformation proceeded smoothly at room temperature without metal catalysts,external reductants,or toxic or dangerous reagents.Remarkably,low-cost and chemically equivalent D2O was the sole deuterium source in this reaction.Professional electrosynthesis equipment was not essential because we demonstrated common batteries and electrodes were enough for this reaction.

Imbalanced Problem in Initial Coin Offering Fraud Detection

ICOs,the initial coin offerings,are a common way to raise funds for blockchain projects.Fraudulent ICO projects not only cause financial losses to investors but also cause a loss of confidence in the blockchain capital market.Whitepapers are usually the most important information source,so it is feasible to identify fraudulent ICO programs by analyzing whitepapers.However,the fraud samples are difficult to collect,and the classes are imbalanced.In this study,we attempt to solve this problem by extracting linguistic features from the ICO whitepaper and using a variety of cutting-edge machine learning and deep learning algorithms to train the prediction model and attempt to resample,modify the weight and modify the loss function for imbalanced samples.Our optimal method achieves an AUC of 0.94 and an accuracy of 82%,which is better than other traditional standard methods,and the results provide important implications for ICO fraud detection.