高分辨电感耦合等离子体磁质谱法测定含铜不锈钢中痕量磷

作者通过试验,用电感耦合等离子体磁质谱(HR-ICP-MS)测定含铜不锈钢中磷含量时,采用高分辨率模式,选择分辨率为4000,在此条件下磷峰可与干扰双原子分子或离子的峰分开。又通过以含铁基的磷标准溶液优化了气体流量和离子透镜的参数,使磷的信号值提高至3×105cps。而加入45Sc作为内标元素又可显著提高测定的稳定性。分别用不锈钢样品和纯铁粉作基体,加入标准溶液制作标准曲线。结果表明:两种方法的线性均较好,分别测得实际样品的结果及其相对标准偏差也基本一致。但两种方法的检出限(3s)不同,前者为1.0μg·g^-1,后者为0.18μg·g^-1。所提出方法的样品处理过程如下:称取样品0.10g置于消解罐中,加入盐酸溶液2mL及硝酸溶液1mL,待剧烈反应缓解时,将消解罐加盖并置于微波消解仪中,于100℃消解10min,升温至200℃继续消解20min。冷却后将溶液转移至100 mL石英容量瓶中,加入0.2mg·L^-1钪内标溶液1mL,加水至刻度,摇匀。此溶液在仪器工作条件下进行HR-ICP-MS测定。对含磷51μg·g^-1的含铜不锈钢,按本方法测定所得结果的相对标准偏差(n=10)小于4%。应用本方法分析了7种标准物质或已知样品(包括低合金钢、含铜不锈钢、高温合金),并同时用ICP-AES进行校对分析。结果表明,本方法与ICP-AES的测定结果基本一致。但本方法的结果与标准物质的认定值更接近,而且对低含量磷(9μg·g^-1)也可很好测定。     

BiPO4/石墨烯光电极的制备及其光电催化性能（英文）

光电催化(PEC)氧化法是一种使用半导体电极材料在光和电的共同作用下处理水中有机污染的有效方法.在PEC工艺中,施加偏压不仅可以利用电催化对有机污染物进行降解,而且在偏压作用下,光生电子-空穴对能够得到有效的分离和传输,从而大大提高了机物污染物的去除速率.尽管PEC技术已经取得了许多重要的突破,但是能量转换效率仍然无法满足实际应用.因此,开发具有优异性能,良好稳定性和低成本的光电极材料是一项具有挑战性的研究工作.本文采用两步电沉积法制备了BiPO4纳米棒/还原氧化石墨烯/FTO复合光电极(BiPO4/r GO/FTO).电镜结果表明,电沉积制得的纳米棒状磷酸铋均匀负载在石墨烯纳米片层表面.采用甲基橙为模型体系,考察了复合光电极的光电催化活性.BiPO4/r GO/FTO复合电极的光电催化降解速率是BiPO4/FTO光电极的2.8倍,显示出优良的光电催化活性.实验进一步研究了工作电压和BiPO4沉积时间对甲基橙光电降解性能的影响.最佳的BiPO4沉积时间为45 min,最佳工作电压为1.2 V.捕获实验和ESR实验表明羟基自由基(·OH)和超氧化物自由基(·O2-)是该电极的主要活性物种.BiPO4/r GO/FTO复合电极经过四次循环实验后其降解甲基橙效率保持不变,显示出高稳定性,采用光电流,交流阻抗及其荧光测试对其光催化机理进行推测.结果表明该复合光电极具有高PEC活性的主要原因是:石墨烯的引入加快了BiPO4的电子空穴的分离,拓宽了石墨烯的可见光吸收范围;同时,石墨烯诱导产生的BiPO4混合相也进一步促进了光生电子空穴的分离,提高了光电降解活性.     

Integrating photocatalytic reduction of CO_2 with selective oxidation of tetrahydroisoquinoline over InP–In_2O_3 Z-scheme p-n junction

The development of a facile strategy to construct stable hierarchal porous heterogeneous photocatalysts remains a great challenge for efficient CO_2 reduction. Additionally, hole-trapping sacrificial agents(e.g., triethanolamine, triethylamine, and methanol) are mostly necessary, which produce useless chemicals, and thus cause costs/environmental concerns. Therefore,utilizing oxidation ability of holes to develop an alternative photooxidation reaction to produce value-added chemicals, especially coupled with CO_2 photoreduction, is highly desirable. Here, an in situ partial phosphating method of In_2O_3 is reported for synthesizing In P–In_2O_3 p-n junction. A highly selective photooxidation of tetrahydroisoquinoline(THIQ) into value-added dihydroisoquinoline(DHIQ) is to replace the hole driven oxidation of typical sacrificial agents. Meanwhile, the photoelectrons of In P–In_2O_3 p-n junction can induce the efficient photoreduction of CO_2 to CO with high selectivity and stability. The evolution rates of DHIQ and CO are 2 and 3.8 times higher than those of the corresponding In_2O_3 n-type precursor, respectively. In situ irradiated X-ray photoelectron spectroscopy and electron spin resonance are utilized to confirm that the direct Z-scheme mechanism of In P–In_2O_3 p-n junction accelerate the efficient separation of photocarriers.     

Regulating silver nanowire size enables efficient photoelectric conversion

The increasing demand for the state-of-the-art transparent conductive electrodes has received great interest in synthesizing silver nanowires(AgNWs) with a uniform diameter that exhibit excellent conductance, transparency, flexibility and mechanical ductility. Herein, we report the controllable synthesis of ultrathin AgNWs with high aspect ratio via a polyol-assisted process.The diameter of AgNWs can be continuously modulated from 20 to 80 nm by simply adjusting the aging time. The selfassembled films fabricated by using AgNWs with a diameter of 20 nm as building blocks enable an excellent performance and show a sheet resistance of ～30 Ω/sq and an optical transmittance of 94%. In addition, such nanowire-based conductive films can keep the excellent flexibility and resistance after bending 10,000 cycles. Similarly, the intelligent dimming films prepared by this AgNW films also have excellent flexibility and stability.     

直接二氟甲硫基化与一氟甲硫基化反应研究进展

含有二氟甲硫基基团(SCF2H)与含有一氟甲硫基基团(SCFH2)的有机化合物具有独特的物理和化学性质,在医药及农药等领域具有潜在的应用价值.这两类化合物的传统制备方法是巯基底物的二氟甲基化与一氟甲基化,但含巯基底物本身种类有限,极大地限制了该类化合物的应用与开发,因此开发新的直接二氟/一氟甲硫基化方法和开拓新型直接二氟/一氟甲硫基化试剂具有重要的意义.综述了直接二氟甲硫基化反应和一氟甲硫基化反应的最新研究进展,并对反应的相关机理进行了论述.     

Photo-induced Charge Separation of p-Tricyanovinyl-N,N-Dialkylanilines

In this paper,p-tricyanovinyl-N,N-dialkylanilines were synthesized as model compounds and through their spectroscopic behavior,the photo-induced electron transfer,charge separation were discussed and the aggregation in DMSO-H_2O system was investigated.     

新型烷氧基嘧啶拼接3-吡咯螺环氧化吲哚类化合物的合成及其抗肿瘤活性

以取代烷氧基嘧啶3-烯键氧化吲哚衍生物为原料,与肌氨酸及多聚甲醛在甲苯中回流经1,3-偶极子3+2环加成反应,合成了8个新型烷氧基嘧啶拼接3-吡咯螺环氧化吲哚类化合物(3a~3h),产率67%~82%,d/r值6/1~20/1,其结构经~1H NMR,~(13)C NMR和HR-MS(ESI-TOF)表征。采用MTT法研究了3a~3h对人肺癌细胞(A549)、人前列腺癌细胞(PC-3)和人白血病细胞(K562)的体外抗肿瘤活性。结果表明:3d和3g对人白血病细胞K562具有明显的活性,IC50分别为24.1 mol·L~(-1)和32.4μmol·L~(-1),接近阳性对照药顺铂。     

In-tip nanoreactors for cancer cells proteome profiling

Mass spectrometry (MS)-based proteome profiling is essential for molecular diagnostics in modern biomedical study. To date, sample preparation including protein extraction and proteolysis is still very challenging and lack of efficiency. Recently tips-based sample preparation protocols exhibit strong potentials to achieve the goal of “a proteome in an hour”. However, in-tip proteolysis is still rarely reported and far from ideal for dealing with complex bio-samples. In this work, nanoreactors encapsulated micropipette tips were demonstrated as high performance devices for fast (∼minutes) and multiplexing proteolysis to assist the profiling of cancer cells proteome. Nanoporous silica materials with controlled pore size and surface chemistry were prepared as nanoreactors and encapsulated in micropipette tips for efficient in situ proteolysis. The as-constructed device showed desirable sensitivity (LOD of 0.204 ± 0.008 ng/μL and LOQ of 0.937 ± 0.055 ng/μL), selectivity, stability (two months under −20 °C), reusability (at least 10 times), and little memory effect in MS based bottom-up proteomic analysis. It was used for comprehensive protein mapping from cancer cell lines. The number of identified proteins was increased by 18%, 22%, 52%, and 52% dealing with HepG2, F56, MCF7, and HCCLM3 cancer cells, compared to traditional in-solution proteolysis based bottom-up proteomic strategy. With the enhanced performance, our work built a novel, efficient and miniaturized platform for facile proteomic sample preparation, which is promising for advanced biomarkers discovery in biomedical study.     

Recent Progress of Synthesis and Application in Au@MOFs Hybrid Materials

The combination of gold nanoparticles and metal–organic frameworks is one of the new directions of current research. It has applications in many aspects, especially as a catalyst for a variety of reactions. Therefore, this paper describes recent progress of synthesis and application in Au@MOFs hybrid materials.     

Effective transformation of cellulose to 5-hydroxymethylfurfural catalyzed by fluorine anion-containing ionic liquid modified biochar sulfonic acids in water

This article first discloses that the fluorine anion-containing ionic liquids-functionalized biochar sulfonic acids (BCSA-IL-F_1–3s), which were simply synthesized by an ionic exchange of 1-trimethoxysilylpropyl-3-methylimidazolium chloride (IL-Cl) grafted on the BCSA with CF₃SO₃H (HF₁), HBF₄ (HF₂), HPF₆ (HF₃), respectively, can efficiently catalyze cellulose hydrolysis into reducing sugars (RSs) and 5-hydroxymethyl furfural (HMF) in water under microwave irradiation. This process provides a very high catalysis efficiency (turnover numbers, 4.03–4.89) at mild temperature (80 °C) for 3 h, but also possesses an excellent repeatability. More outstandingly, they can achieve much higher HMF yields (12.70–27.94%) compared to the IL-Cl-functionalized BCSA catalyst (HMF yields are lower than 0.1%) under the same reaction conditions. This is likely because the introduction of IL-F_1–3s groups can significantly improve the accessibility, acidity and thermal stability of BCSA’s SO₃H sites, as supported by evidence from a solid ³¹P NMR spectrum and thermogravimetric analysis. It is proposed that the good selectivity for HMF perhaps originates from a co-catalysis action of the IL-F_1–3s and SO₃H groups on BCSA-IL-F_1–3s in the further conversion of RSs to HMF.