Comprehensive Evaluation of Nutrients Based on Matter-Element Model in the Northeastern Sichuan Basin——A Case of Pingchang County in Sichuan Province

选择川东北平昌县农业土壤有机质、全氮、全磷、全钾、速效钾、有效氮、速效磷、有效铜、有效锌、有效铁、有效锰、有效硼和有效钼共13个指标,土壤养分含量统计显示:平昌县土壤养分指标中全钾、速效钾、有效铁和有效锰平均含量高于全省平均值,其余9项指标均低于全省平均水平。与第二次土壤普查农耕地普查资料相比,平昌县农业土壤有效铜、锌、铁、锰含量有上升趋势,全磷和全钾含量呈下降趋势。运用物元模型对土壤养分进行综合评价,结果表明:研究区没有Ⅰ级养分土壤,其中Ⅱ级养分土壤占6.12%,Ⅲ级养分土壤占8.16%,Ⅳ级养分土壤占78.57%,Ⅴ级养分土壤占7.14%。处于养分贫乏(Ⅳ级)和极贫乏(Ⅴ级)的土壤共占85.71%,总体看来,平昌县土壤养分状况较差

Electrochemical Synthesis of Porous Polyaniline Electrodes Using HKUST-1 as a Template and their Electrochemical Supercapacitor Property

以涂敷在碳布基体上的金属有机骨架多孔材料HKUST-1为硬模板，使用单极脉冲法沉积聚苯胺制备了具有电活性的多孔复合电极Micro-PANI/CC，同时以空白碳布(Carbon Cloth，CC)为基体制备了聚苯胺电极PANI/CC，并研究、比较了它们的电化学电容器性能. 使用XRD、SEM分析了所得电极的结构，结果显示电极Micro-PANI/CC表面具有大量的纳米孔状结构. 在0.5 mol·L-1硫酸为电解液的体系中测试了循环伏安、恒电流充放电、阻抗以及稳定性等特性，在扫速为2 mV·s-1 时，电极Micro-PANI/CC和PANI/CC的比电容分别为895.6 F·g-1和547.6 F·g-1，在其它测试条件相同的情况下，前者的比电容保持在后者的1.64倍以上，且具有更好的倍率特性、更低的电阻和较好的稳定性等特点，说明这种以HKUST-1为模板形成的多孔聚苯胺更适于超级电容器电极材料.Excellent electrode plays vital important role in the performance of supercapacitors. Polyaniline (PANI) with good conductivity is often used to prepare electrode. However, its available surface is limited and results in a poor supercapacitance in many cases. It is desirable to fabricate an electrode containing electroactive PANI with high surface area deriving from its porous structure. Here, the metal-organic framework (MOF) material with high surface area was selected as a hard template for synthesizing porous PANI. Microporous PANI composite electrodes (Micro-PANI/CC) were fabricated by depositing aniline on to carbon cloth (CC) pre-coated with MOF material of HKUST-1 using a unipolar pulse electro-polymerization method. At the same time, the PANI electrodes (PANI/CC) were also synthesized on blank carbon cloth for further comparatively studying their supercapacitor performances. Their microstructure and morphology were characterized by using XRD and SEM. Results indicate that the micro-PANI/CC electrode was composed of aggregated nanosized PANI spheres with pore structure. The cyclic voltammetry, constant current charge and discharge, impedance and stability tests were performed to evaluate the supercapacitor properties in 0.5 mol·L-1 sulfuric acid electrolyte. Specific capacitances of micro-PANI/CC and PANI/CC electrodes were 895.6 F·g-1 and 547.6 F·g-1  at scan rate of 2 mV·s-1 , respectively. At the same given conditions, the specific capacitance of micro-PANI/CC electrode was always 1.64 times higher than that of PANI/CC electrode. Meanwhile, the micro-PANI/CC electrode exhibited better rate capability, lower resistance and better stability of charge and discharge than PANI/CC. all the results imply that the microporous PANI templated from HKUST-1 could be a good candidate for the electrode of supercapacitors.国家自然科学基金项目（No. 21476156）山西省自然科学基金项目（No. 2014011012-05）资助作者联系地址：太原理工大学化学工程系，山西 太原 030024Author's Address: Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China通讯作者E-mail：[email protected]

Synthesis of PANI/NiHCF Nanocomposite Particles and EQCM Measurement of Ion Exchange Properties in Solutions Containing Cd2+

本文采用循环伏安一步共聚法在碳纳米管(CNTs)修饰的铂基底上制备了聚苯胺/铁氰化镍(PANI/NiHCF)纳米复合颗粒. 通过电化学石英晶体微天平(EQCM)技术检测了复合颗粒制备过程的质量改变量，并用扫描电镜(SEM)、透射电镜(TEM)和傅立叶变换红外光谱(FTIR)分析了复合颗粒的微观形貌和组成. 结合循环伏安法和EDS能谱考察了该复合电极对Cd2+离子的交换性能. 结果表明，三维多孔的CNTs不仅可促进复合颗粒的沉积，而且其独特的网络结构和表面特性对形成PANI/NiHCF复合颗粒的立方体构型起至关重要的作用. 该复合电极在0.1 mol·L-1 Cd(NO3)2溶液中显示了良好的电活性，对Cd2+离子有可逆的离子交换性能，通过电控离子交换法可实现废水中Cd2+离子的高效分离.The PANI/NiHCF nanocomposite particles were synthesized on the CNTs-modified Pt substrate by one-step co-polymerization using cyclic voltammetry. Electrochemical quartz crystal microbalance (EQCM) technique was adopted to investigate the polymerization process of the nanocomposite particles and the mechanism of ion exchange in aqueous solution containing Cd2+． The morphology and structure of the as-prepared composite particles were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). Combined with cyclic voltammetry (CV) and energy dispersive spectroscopy (EDS), the electrochemical behavior and the mechanism of ion exchange were also investigated in electrolytes of Cd2+. Experimental results indicated that the cubic nanocomposite particles of PANI/NiHCF were formed and distributed uniformly on the CNTs substrate. The particles exhibited good electroactivity and reversible electrochemical behavior in aqueous solution containing Cd2+, and the Cd2+ ions could be separated from aqueous solutions by ESIX processes.国家自然科学基金(No. 20676089)，山西省自然科学基金(No. 2012011020-5, No. 2012011006-1)及山西省国际科技合作计划项目(No. 2011081028)资助作者联系地址：太原理工大学，化学化工学院化学工程系，山西 太原 030024Author's Address: Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China通讯作者E-mail：[email protected]

Electrochemically Switched Ion Exchange Properties of PANI-SnP Composite Films in Wastewater Containing Ni2+ and Cd2+

采用滴涂法在铂基底制备了电活性聚苯胺-磷酸锡(PANI-SnP)复合膜电极，考察了该电极在Ni2+、Cd2+溶液的电控离子交换性能. 用傅立叶变换红外光谱和扫描电镜分析观察复合膜的组成及表面形貌；在0.1 mol·L-1 Ni(NO3)2、Cd(NO3)2溶液，通过循环伏安法比较了PANI膜、SnP膜及PANI-SnP复合膜电极的电化学性能，并结合电化学石英晶体微天平技术重点考察了PANI-SnP复合膜的离子交换机制；同时，通过循环伏安法调控复合膜电极的氧化还原电位，结合X射线能谱和X射线光电子能谱分别测定了其氧化和还原状态的元素组成. 结果表明，PANI-SnP复合膜电极在Ni2+、Cd2+溶液均有良好的氧化还原电活性和可逆离子交换性能，其Cd2+离子选择性优于Ni2+离子，通过电控离子交换可使Cd2+离子从镍镉废水高效分离.Electroactive PANI-SnP composite films were prepared by drop-coating method on Pt electrodes and investigated as electrochemically switched ion exchange (ESIX) materials for the separation of Cd2+ from aqueous solutions. The composition and morphology of the composite film were characterized by Fourier transform infrared spectrometer (FTIR) and scanning electron microscope (SEM). In solutions containing 0.1 mol·L-1 Ni(NO3)2 and Cd(NO3)2, cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM) were used to investigate the electrochemical behavior and ion-exchange mechanism of PANI-SnP composite film. The elementary composition of PANI-SnP composite films in both oxidation and reduction states were also characterized by energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Experimental results show that the PANI-SnP composite films have reversible electrochemical behavior in aqueous solutions containing Cd2+ and Ni2+, respectively. The PANI-SnP composite film electrodes displayed a high selectivity toward Cd2+ in Cd2+/Ni2+ binary mixtures and the Cd2+ ions could be separated effectively from aqueous solutions by ESIX processes.国家自然科学基金(No. 20676089)，山西省自然科学基金(No. 2012011020-5, No. 2012011006-1)，山西省国际科技合作计划项目(No. 2011081028)资助作者联系地址：太原理工大学化学化工学院化学工程系，山西 太原 030024Author's Address: Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China通讯作者E-mail：[email protected]

Electrochemically Switched Separation of Yttrium Ion Using Electroactive Nickel Hexacyanoferrate Thin Films in Rare Earth Metal Solution

通过电沉积方法分别在镀铂石英晶片和铂基底上制备了电活性铁氰化镍膜，并考察了膜电极在含钇离子溶液中的电控离子交换性能. 在0.1 mol·L-1的硝酸钇溶液中，使用循环伏安法及石英晶体微天平技术测试考察了铁氰化镍膜对钇离子的置入释放性能及对应的质量变化，同时比较了铁氰化镍膜电极在Y(NO3)3和Sr(NO3)2溶液中的电化学性能. 在0.1 mol·L-1 [Y(NO3)3 + Sr(NO3)2]混合溶液中，通过循环伏安法分析了薄膜对Y3+/Sr2+离子的选择性. 用扫描电子显微镜观察了铁氰化镍膜的表面形貌，并通过X射线光电子能谱仪测定了膜在氧化和还原状态下的元素组成. 结果表明，铁氰化镍膜在含Y3+溶液中具有良好的离子交换行为，其中氧化过程薄膜质量减少，对应着钇离子的释放；还原过程薄膜质量增加，对应钇离子的置入；在0.0 V或0.9 V调控膜电极的氧化还原状态实现对钇离子的有效分离.Electroactive nickel hexacyanoferrate (NiHCF) thin films were synthesized by cathodic deposition and investigated as electrochemically switched ion exchange (ESIX) materials for the separation of Y3+ from aqueous solutions. In 0.1 mol·L-1 Y(NO3)3 solution, cyclic voltammetry (CV) combined with electrochemical quartz crystal microbalance (EQCM) technique was used to investigate the electroactivity, reversibility of the film electrodes and the mechanism of ion exchange. The electrochemical behavior of NiHCF film electrodes was also compared with that in Sr(NO3)2 solutions. The ion selectivity of the film was investigated in 0.1 mol·L-1 solutions containing [Y(NO3)3 + Sr(NO3)2]. The elementary composition of NiHCF films in reduced and oxidized forms were also characterized by X-ray photoelectron spectroscopy (XPS). Experimental results show that the electroactive NiHCF films have reversible electrochemical behavior in aqueous solutions containing Y3+ and Sr2+, respectively. The NiHCF film electrodes displayed a high Y3+ selectivity in Y3+/Sr2+ binary mixtures and the Y3+ ions could be separated effectively from aqueous solutions by ESIX processes.国家自然科学基金项目(No. 21276173)、山西省自然科学基金项目(No. 2012011020-5，No. 2012011006-1)及山西省国际科技合作计划项目(No. 2011081028)资助作者联系地址：太原理工大学化学化工学院，山西 太原 030024Author's Address: Department of Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China通讯作者E-mail：[email protected]

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies