Solid-phase microextraction of triazine herbicides via cellulose paper coated with a metal-organic framework of type MIL-101(Cr), and their quantitation by HPLC-MS

Microchimica Acta - A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable...     

Direct coupling of haloquinolines and sulfonyl chlorides leading to sulfonylated quinolines in water

A simple and efficient method has been developed for construction of sulfonylated quinolines via coupling of haloquinolines and sulfonyl chlorides in water. The present methodology provides an attractive approach to various sulfonylated quinolines in moderate to good yields with favorable functional group tolerance, which has the advantages of operation simplicity, readily available starting materials, excellent regioselectivity, scale-up synthesis, and organic solvent-free conditions.     

Synthesis, spectroscopic characterization, axial base coordination equilibrium and photolytic kinetics studies of a new coenzyme B12 analogue-3'-deoxy-2',3'-anhydrothymidylcobalamin

A new coenzyme B12 (AdoCbl) analogue, 3'-deoxy-2',3'-didehydrothymidylcobalamin (2',3'-anThyCbl) was prepared by the reaction of 5'-iodo-3'-deoxy-2',3'-dihydrothmidine with reduced B12a, and characterized by UV-Vis, CD, ESI-MS and NMR spectroscopies. Its axial base (dbzm) coordination equilibria with pH's and temperatures were investigated and showed similar features to those of coenzyme B12. Photolytic dynamics studies under homolytic and heterolytic conditions demonstrated that the Co-C bond of the analogue is slightly more photolabile relative to coenzyme B12.     

Combinatorial Hopf Algebras and Towers of Algebras—Dimension, Quantization and Functorality

Bergeron and Li have introduced a set of axioms which guarantee that the Grothendieck groups of a tower of algebras $\bigoplus_{n\ge0}A_n$ can be a pair of graded dual Hopf algebras. Hivert and Nzeutchap, and independently Lam and Shimozono constructed dual graded graphs from primitive elements in Hopf algebras. In this paper we apply the composition of these constructions to towers of algebras. We show that if a tower $\bigoplus_{n\ge0}A_n$ gives rise to a pair of graded dual Hopf algebras, then $\dim(A_n)=r^nn!$ where $r = \dim(A_1)$ . In the case of r?=?1 we give a conjectural classification. We then investigate a quantum version of the main theorem. We conclude with some open problems and a categorification of these constructions.     

5.1-ps passively mode-locked Nd:Gd0.42Y0.58VO4 laser with a LT-GaAs absorber

We propose a diode end-pumped passively mode-locked Nd: Gd0.42 Y0.58 VO4 (Nd: GdYVO4) laser at 1064nm using a GaAs absorber grown at low temperature as the output coupler.Stable continuous-wave (CW) mode locking with a 5.1-ps pulse duration at a repetition rate of 113MHz is obtained.The maximum average output power is 2.29W at the incident pump power of 12W with the slope efficiency of about 24.8%.     

Pinning lag synchronization of complex dynamical networks with known state time-delay and unknown channel time-delay

In this paper, a linear and adaptive feedback pinning strategy is used to study the lag synchronization of complex dynamical networks with known state time-delay and unknown channel time-delay. Firstly, based on the Lyapunov stability theory, a novel Lyapunov functional, which involves the estimated error \(\hat{e}_{i}(t)\) rather than the general synchronization error \(e_{i}(t)\), is constructed. Secondly, in view of the unknown information of the channel time-delay, two available pinning controllers are designed such that the considered networks achieve lag synchronization. Furthermore, by a proper adaptation mechanism, we estimate the unknown channel time-delay successfully under the case that the initial value of the estimated channel time-delay is larger than true channel time-delay, i.e., \(\hat{\tau }(0)>\tau \) and the another case \(\hat{\tau }(0)<\tau \). Finally, the effectiveness and correctness of the lag synchronization criteria are verified through two simulation experiments.     

Qualitative-quantitative analysis of multi-mycotoxin in milk using the high-performance liquid chromatography-tandem mass spectrometry coupled with the quick,easy, cheap,effective, rugged and safe method

High-performance liquid chromatography-tandem mass spectrometry coupled with the quick, easy, cheap, effective, rugged and safe method was established for the qualitative and quantitative detections of 20 mycotoxins in milk. The linear range of this method was 0.01–10 μg/L and the correlation coefficients were all greater than or equal to 0.9933. At three levels of addition, the spiked recoveries ranged from 80.00 to 112.50%, relative standard deviations were 2.67–14.97%, limits of quantitation were 0.02–4.00 μg/kg, and limits of detection were 0.007–1.300 μg/kg. This developed procedure for the identification and quantitation of mycotoxins provided prospective support for quality regulation.     

Detection of multiple endocrine-disrupting chemicals in milk: Improved and safe high performance liquid chromatography tandem mass spectrometry method

Herein, an improved method for detecting the endocrine-disrupting chemicals in milk is presented, which is based on high performance liquid chromatography tandem mass spectrometry, coupled with a quick, effective, and safe method. The linearity of the proposed method was in the range of 0.05–100 μg/L, and all correlation coefficients were ≥0.9973. At three concentration levels, the spiked recoveries ranged from 77.7 to 107.5%, relative standard deviations ranged from 0.2 to 14.6%, limits of quantitation ranged from 0.1 to 40 μg/kg, limits of detection ranged from 0.03 to 13.3 μg/kg. The proposed method for the identification and quantitation of 26 endocrine disruptors present in milk is not only easy, fast, and cost-efficient but also provides a reference for the detection of various endocrine disruptors in milk and other dairy products.     

C5烃中双环戊二烯过氧化物的分光光度测定

本报道了Ｃ５烃中双环戊二烯过氧化物（ＰＤＣＰＤ）快速准确的分析方法。在ＨＯＣ２Ｈ４ＯＣＨ３－Ｈ２Ｏ介质中，ＰＤＣＰＤ与ＫＩ反应生成Ｉ３＾－而Ｉ３＾－与ＰＤＣＰＤ的量成正比，在λｍａｘ＝３５２ｎｍ处可进行ＰＤＣＰＤ的光度测定，测定下限为３．２×１０＾－５ｍｏｌ／Ｌ，ＳＤ＝０．３４，ＲＳＤ＝１．４０％。     

辅酶B12模型化合物的研究 α.RCo(salen) L(R=n-C3H7,i-C4H9;L=H2O,py,γ-pic)的电化学性质

用循环伏安法研究了辅酶Ｂ１２模型化合物ＲＣｏ（ｓａｌｅｎ）Ｌ（Ｒ＝ｎ－Ｃ３Ｈ７，ｉ－Ｃ４Ｈ９；Ｌ＝Ｈ２Ｏ，ｐｙ，γ－ｐｉｃ）的电化学行为，讨论了轴向碱基Ｌ对氧化还原电位的影响，结果表明：随着碱基Ｌ给电子能力的谱强，其氧化还原电位均发生负移。