Synthesis of CuS@CoS2 Double‐Shelled Nanoboxes with Enhanced Sodium Storage Properties

Metal sulfides have received considerable attention for efficient sodium storage owing to their high capacity and decent redox reversibility. However, the poor rate capability and fast capacity decay greatly hinder their practical application in sodium‐ion batteries. Herein, an elegant multi‐step templating strategy has been developed to rationally synthesize hierarchical double‐shelled nanoboxes with the CoS₂ nanosheet‐constructed outer shell supported on the CuS inner shell. Their structure and composition enable these hierarchical CuS@CoS₂ nanoboxes to show boosted electrochemical properties with high capacity, outstanding rate capability, and long cycle life.     

Porphyrin Nanocage‐Embedded Single‐Molecular Nanoparticles for Cancer Nanotheranostics

Single molecular nanoparticles (SMNPs) integrating imaging and therapeutic capabilities exhibit unparalleled advantages in cancer theranostics, ranging from excellent biocompatibility, high stability, prolonged blood lifetime to abundant tumor accumulation. Herein, we synthesize a sophisticated porphyrin nanocage that is further functionalized with twelve polyethylene glycol arms to prepare SMNPs ( porSMNPs ). The porphyrin nanocage embedded in porSMNPs can be utilized as a theranostic platform. PET imaging allows dynamic observation of the bio‐distribution of porSMNPs , confirming their excellent circulation time and preferential accumulation at the tumor site, which is attributed to the enhanced permeability and retention effect. Moreover, the cage structure significantly promotes the photosensitizing effect of porSMNs by inhibiting the π–π stacking interactions of the photosensitizers, ablating of the tumors without relapse by taking advantage of photodynamic therapy.     

Microwave assisted hydrothermal synthesis of tin niobates nanosheets with high cycle stability as lithium-ion battery anodes

SnNb₂O₆ and Sn₂Nb₂O₇ nanosheets were synthetized via microwave assisted hydrothermal method, and innovatively employed as anode materials for lithium-ion battery. Compared with Sn₂Nb₂O₇ and the previously reported pure Sn-based anode materials, the SnNb₂O₆ electrode exhibited outstanding cycling performance.     

全自动QuEChERS样品制备系统结合高效液相色谱-串联质谱法检测植物源性食品中34种农药残留

建立了全自动QuEChERS样品制备系统结合高效液相色谱-串联质谱（HPLC-MS/MS）同时检测植物源性食品中34种农药残留的分析方法。方法利用全自动QuEChERS样品制备系统涡旋振动和离心功能，将手动QuEChERS方法中样品提取和分散固相萃取相结合；优化了操作参数及前处理步骤，在多反应监测（MRM）模式下检测，基质匹配外标法定量。从方法学验证角度对全自动QuEChERS法与手动QuEChERS法进行了比较。结果表明：该方法中大多数农药在一定范围内呈现良好的线性关系，相关系数（R²）均大于0.99，检出限为0.76~3.60 μg/kg，定量限为2.28~10.80 μg/kg，加标回收率为53.0%~125.2%，相对标准偏差（RSD）<15.9%（n=5）。该方法与手动QuEChERS法的方法验证比对结果显示差异不明显，用于植物源性食品中多农药残留检测可有效降低劳动强度和出错概率。     

Electrocatalytic reduction of nitrite on the surface of a glassy carbon electrode modified by palladium(II)-substituted Dawson type heptadecatungstodiphosphate

A palladium(II)-substituted Dawson type heptadecatungstodiphosphate, K₈[P₂W₁₇O₆₁Pd(H₂O)](abbreviated as P₂W₁₇Pd in the following), was used to construct a new kind of chemically modified electrode (CME) by electrodeposition on the surface of a glassy carbon electrode for the first time. This modified electrode was characterized by Fourier transform infrared reflection absorption spectroscopy (FTIRRAS), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). FTIRRAS and XPS suggested that the adsorbed species on the electrode surface has the same Dawson type structure as the heteropolyanion in buffer solution. A couple of waves was observed on the P₂W₁₇Pd CME, which was ascribed to the redox process of the palladium center in the heteropolytungstate. After continuous potential scanning for 30 min in a pH 4.0 buffer, 94% of the original coverage remains for the CME. The P₂W₁₇Pd CME had high electrocatalytic activity for nitrite reduction and exhibited good reproducibility and stability. The catalytic peak current was found to be linear with the nitrite concentration in the range of 1 ∼ 50 mmol/L, with a correlation coefficient of 0.994. The effect of solution pH on the catalytic activity of the CME for nitrite reduction was also investigated. Received: 20 May 1998 / Revised: 7 September 1998 / Accepted: 15 September 1998     

Thermodynamic Modeling of Actinide Complexation with Acetate and Lactate at High Ionic Strength

The stability constants of NpO ₂ ⁺ , UO ₂ ²⁺ Am³⁺, and Th⁴⁺ with acetate and lactate anions has been measured in 0.3–5.0m NaCl media at 25°C by the solvent extraction technique. For the 1:1 complexation, the values of the stability constants increased in the order: NpO ₂ ⁺ < Am³⁺ < ₂ ²⁺ < Th⁴⁺, in accordance with the actinide charge density and reflecting the strongly ionic bonding of the complexes. The Pitzer ionic interaction parameters were calculated and used to estimate the thermodynamic stability constants at I = 0. Because our data were collected mainly in the high ionic strength region values of ⁽¹⁾ were estimated from values reported in the literature. For all stability constants the Pitzer model gives an excellent representation of the data using three interaction parameters ⁽⁰⁾, ⁽¹⁾, and COn leave from Institute of     

Metal Ion Complexation of Bilirubin Monolayer

Recently.biomimeticstrategieshavefocusedontheapplicationofbioinorganicnanocompositesandshapedhybridmaterialswithmicroscaleorganization'.Becauseoftheimportanceofbilepigmentsinphysiologicalsystemsuchascalciumbilirubinates,themaincomponentofblack-pigmentgallstones,anabnormalproductofbiomineralizationinmammalbodiesandcopperbilirubinate,afree-radicalscavengerinbileandprotectingphospholipidsfromperoxidation',agreatdealofattentionhasalreadybeengiventothestudyofbilirubin(BR)andotherbilepigments'.Excel…     

3-取代酚酮5位偶联产物的溴氧化成环反应

报道了采用溴氧化3-异丙烯基(艹卓)酚酮和3-肉桂酰基(艹卓)酚酮合成杂环并(艹卓)酮化合物的新方法。3-异丙烯基(艹卓)酚酮5位偶联产物1a～1f和3-肉桂酰基(艹卓)酚酮5位偶联产物3a～3d分别在吡啶介质中与过量溴作用生成5-取代苯偶氮基-7-溴-3-甲基-8-氢环庚并呋喃-8-酮2a～2f和6-取代苯偶氮基-2-苯基-8-溴-4,9-二氢环庚并吡喃-4,9-二酮4a～4d。     

从诺贝尔化学奖看20世纪的化学发展

本文通过对oble析统计,来揭示20世纪化学发展的水准和脉络,着重阐述了20世纪化学的发展特征和趋势。     

空气中电晕放电高能电子密度沿反应器分布的光谱研究(英)

利用目前在等离子体特性诊断方面较为先进实用的发射光谱法,在常温常压下测量了正脉冲电晕放电空气中的Ｎ２（Ｃ３ Πｕ →Ｂ３ Πｇ） 发射光谱相对强度沿线－ 筒式反应器的径向分布,由此得到了正脉冲电晕放电等离子体中高能电子（ ≥１１ ．０３ｅＶ） 的电子密度沿线－ 筒式反应器的径向分布．随径向距离增大高能电子密度呈非线性递减,对于不同放电电压这种递减规律相同．