Interaction of Metamitron and Fenhexamid with Ca2+-Montmorillonite Clay Surfaces: A Density Functional Theory Molecular Dynamics Study

Metamitron (Meta), an herbicide, and fenhexamid (Fen), a fungicide, are authorized by the European Union to be used in agriculture. This article reports theoretical calculations about Meta and Fen in interaction with a clay surface: a Ca-montmorillonite (Mont). Conformational searches have been performed thanks to Car–Parrinello molecular dynamics simulations from which geometries have been extracted. Interaction and adsorption energies have been calculated for isomers of Meta or Fen in interaction with Mont to understand the relative stability of various kinds of complexation. Substantial adsorption energies are comparable for Meta and Fen: around −40 kcal/mol. For Fen-Mont, the CO monodentate family is surprisingly the lowest in energy. Moreover, the 10 lowest-energy isomers involve complexation on Fen carbonyl oxygens. The Meta-Mont lowest-energy family, N-N, does not involve π delocalization breaking within Meta. At the same time, the stronger the interaction energy is, the larger the structural modifications within Mont are, particularly concerning the interacting cation distance to the surface. The non-negligible charge transfer and the magnitude of the adsorption energy speak in favor of the chemisorption of the pesticide on the surface. © 2019 Wiley Periodicals, Inc.     

Magnetic solid-phase extraction of organophosphorus pesticides from apple juice and environmental water samples using magnetic graphene oxide coated with poly(2-aminoterephthalic acid-co-aniline) nanocomposite as a sorbent

An effective magnetic solid-phase extraction method was proposed using magnetic graphene oxide coated with poly(2-aminoterephthalic acid-co-aniline) as a sorbent for preconcentration and extraction of organophosphorus pesticides from environmental water and apple juice samples, and determined using the gas chromatography-mass spectrometry analysis. To approve the successful synthesis of the magnetic nanocomposite, the prepared sorbent was characterized by field emission scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer, and Fourier transforms infrared techniques. The main parameters affecting the extraction efficiency were considered and studied to afford an optimized procedure. Systematic method validation verified its suitable recoveries (89.4–107.3%), and precision (relative standard deviations < 6.8%). The method showed a wide linear dynamic range (0.04–700 ng/mL) with low limits of detection (0.01–0.06 ng/mL) and quantification (0.04–0.21 ng/mL). This method presented good potential and great sensitivity for the pesticides determination.     

以创新能力培养为导向的分析化学课程教学改革*——以应用化学专业为例

面向国家亟需创新型人才这一新形势,分析化学课程围绕高素质、创新人才的培养,针对教学过程中存在的问题,重点在教学内容、教学方法、教学手段、综合考评等方面进行了改革创新。主要措施包括构建新的教学内容体系,探究多手段立体化教学,期中考试引入“一页纸”开卷考试并将“课题成绩”引入课程考核体系,将“知识传授、价值引领和能力培养”有机融合,实现立德树人的根本任务,取得了良好效果。     

Genomic Intelligence as Über Bio-Cybersecurity: The Gödel Sentence in Immuno-Cognitive Systems

This paper gives formal foundations and evidence from gene science in the post Barbara McClintock era that the Gödel Sentence, far from being an esoteric construction in mathematical logic, is ubiquitous in genomic intelligence that evolved with multi-cellular life. Conditions uniquely found in the Adaptive Immune System (AIS) and Mirror Neuron System (MNS), termed the genomic immuno-cognitive system, coincide with three building blocks in computation theory of Gödel, Turing and Post (G-T-P). (i) Biotic elements have unique digital identifiers with gene codes executing 3D self-assembly for morphology and regulation of the organism using the recursive operation of Self-Ref (Self-Reference) with the other being a self-referential projection of self. (ii) A parallel offline simulation meta/mirror environment in 1–1 relation to online machine executions of self-codes gives G-T-P Self-Rep (Self-Representation). (iii) This permits a digital biotic entity to self-report that it is under attack by a biotic malware or non-self antigen in the format of the Gödel sentence, resulting in the “smarts” for contextual novelty production. The proposed unitary G-T-P recursive machinery in AIS and in MNS for social cognition yields a new explanation that the Interferon Gamma factor, known for friend-foe identification in AIS, is also integral to social behaviors. New G-T-P bio-informatics of AIS and novel anti-body production is given with interesting testable implications for COVID-19 pathology.     

基于物理化学MOOC的混合式教学实践

Based on the massive open online course (MOOC) of physical chemistry from Chinese university MOOCs platform, the authors introduce some initiatives and experiences in the MOOC course construction and the application for undergraduate teaching in Dalian University of Technology. The blended teaching and learning mode made up of "online" and "offline" was put into practice in other universities, and a new "1 + M + N" mode to provincial cross-school sharing has been demonstrated. It was shown that only the enhancement of MOOC teaching be highly valued throughout whole course of teaching, the students' quality and ability could be better cultivated followed by improving teaching quality.     

论如何通过设计性实验提升学生的综合创新能力——以分光光度法同时测定维生素C和维生素E为例

Simultaneous determination of vitamin C and vitamin E by spectrophotometry is a typical experiment of simultaneous determination of multiple components. However, the current experimental method has a large relative error (13.7%) in the determination of vitamin C. In this paper, according to the molecular structural characteristics of vitamin C and vitamin E, we studied the factors affecting the measurement accuracy of vitamin C and improve the experimental method by optimization pf design, and the error is reduced to 1.98%. Results proved that the improved method achieved higher accuracy, better reproducibility, more reliable results and better teaching responses. Through this designed experiment, the students are guided from many aspects such as aiming at practical problems and using theoretical knowledge to optimize the experimental scheme, therefore their comprehensive innovation abilities are improved.     

Monitoring pesticide residues in dates marketed in Al‐Qassim,Saudi Arabia using a QuEChERS methodology and liquid chromatography–tandem mass spectrometry

A sensitive, simple and rapid QuEChERS extraction method and liquid chromatography equipped with triple quadrupole mass spectrometry (LC‐MS/MS) were used to determine 42 pesticides in dates. Acidified acetonitrile and citrate buffer salts were used to extract re‐hydrated samples. Acceptable validation performances were achieved, i.e. recovery range of 70−120% and RSD values ≤20% for 42 analytes at three different concentrations:100, 50 and 10 μg/kg. This method was used to analyse 200 date fruit samples (var. Sukkari) collected from different large markets in the Al‐Qassim region in Saudi Arabia. Pesticide residues were detected in 36 (18%) of the date fruits samples, and 15 samples (7.5%) exceeded the maximum residue levels. The ruggedness test results showed that this method is robust and suitable for the determination of pesticide residues in dates. Additionally, the results showed that the monitored dates did not have a health impact on consumers in Saudi Arabia during the study period.     

Liquid Chromatography-Tandem Mass Spectrometry for the Simultaneous Analysis of 353 Pesticides in the Edible Insect Tenebrio molitor Larvae (Mealworms)

Tenebrio molitor larvae (mealworm) is an edible insect and is considered a future food. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a novel method for simultaneous analysis of 353 target analytes was developed and validated. Various sample preparation steps including “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) extraction conditions, number of acetonitrile-hexane partitions, and dispersive-solid phase extraction (dSPE) sorbents were compared, and the optimal conditions were determined. In the established method, 5 g of homogenized mealworms was extracted with acetonitrile and treated with QuEChERS EN 15662 salts. The crude extract was subjected to three rounds of acetonitrile-hexane partitioning, and the acetonitrile layer was cleaned with C18 dSPE. The final solution was matrix-matched and injected into LC-MS/MS (2 μL). For target analytes, the limits of quantitation (LOQs) were ≤10 μg/kg, and the correlation coefficient (r²) of calibration was >0.990. In recovery tests, more than 90% of the pesticides showed an excellent recovery range (70–120%) with relative standard deviation (RSD) ≤20%. For more than 94% of pesticides, a negligible matrix effect (within ±20%) was observed. The analytical method was successfully applied and used for the detection of three urea pesticides in 4 of 11 mealworm samples.     

河北省高耗能行业创新绩效评价研究

创新绩效评价是对创新投入产出过程和结果的监督和管理,通过创新绩效评价,发现创新中存在的问题和改进的方向,使后续的创新工程更能满足社会经济需要.运用突变级数法,从投入产出的角度对河北省高耗能行业创新绩效进行了研究.结果表明,除黑色金属冶炼和压延加工业属于高投入高产出、创新绩效一般外,其他高耗能行业创新绩效低.最后针对此种情况,提出了提升高耗能行业创新绩效的对策建议.     

基于鹰鸽量子博弈理论评价科研院所的科技自主创新能力(英文)

科研院所的科技自主创新能力是推动国家科技进步和经济发展,应对国际经济危机的主要动力,创建科学、完善的科技创新能力评价方法有助于提升科研院所科技创新能力,并为国家制定科技创新决策提供参考依据。本文基于鹰鸽量子博弈理论,提出了一种评价科研院所自主创新能力的方法。介绍了量子博弈论的各基本要素在科技自主创新体系中所对应的物理内涵,根据鹰鸽量子博弈理论建立了科技自主创新能力评价模型,分析了纠缠度与收益矩阵之间的关系,确立了依靠各参与者在鹰鸽量子博弈中的纠缠度来表征科技自主创新能力的方法。给出了科研院所科技自主创新能力的量子博弈论解释,构建了科技自主创新能力评价指标体系,并确定了评价的合成计算方法,即量子纠缠度的计算方法。最后,以中科院部分研究所为实例进行了科技自主创新能力的评价,并利用主成份分析法和中物院的简单统计方法对得到的数据进行了对比分析,结果证明了提出的方法合理且有可操作性。