REGIOSELECTIVE OXIDATION OF KETONE BY AN OXIDATIVE REAGENT SYSTEM KH/O_2/18-CROWN-6/THF:APPLICATION TO SYNTHESIS OF VARIOUS LACTONES

the regioselectivity in the oxidation of different types of ketone compounds 1--6 with an oxidative reagent system,KH/O_2/18- Crown-6/THF is described.From these oxidative products,the various lactones have been prepared.

Thermodynamic theory of flotation for a complex multiphase solid -liquid system and high-entropy flotation

The flotation of complex solid–liquid multiphase systems involve interactions among multiple components,the core problem facing flotation theory.Meanwhile,the combined use of multicomponent flotation reagents to improve mineral flotation has become an important issue in studies on the efficient use of refractory mineral resources.However,studying the flotation of complex solid–liquid systems is extremely difficult,and no systematic theory has been developed to date.In addition,the physical mechanism associated with combining reagents to improve the flotation effect has not been unified,which limits the development of flotation theory and the progress of flotation technology.In this study,we applied theoretical thermodynamics to a solid–liquid flotation system and used changes in the entropy and Gibbs free energy of the reagents adsorbed on the mineral surface to establish thermodynamic equilibrium equations that de-scribe interactions among various material components while also introducing adsorption equilibrium constants for the flotation reagents adsorbed on the mineral surface.The homogenization effect on the mineral surface in pulp solution was determined using the chemical potentials of the material components of the various mineral surfaces required to maintain balance.The flotation effect can be improved through synergy among multicomponent flotation reagents;its physical essence is the thermodynamic law that as the number of compon-ents of flotation reagents on the mineral surface increases,the surface adsorption entropy change increases,and the Gibbs free energy change of adsorption decreases.According to the results obtained using flotation thermodynamics theory,we established high-entropy flotation theory and a technical method in which increasing the types of flotation reagents adsorbed on the mineral surface,increasing the adsorption entropy change of the flotation reagents,decreasing the Gibbs free energy change,and improving the adsorption efficiency and stability of the flotation reagents improves refractory mineral flotation.

Studies on sulfinatodehalogenationⅩⅫ.A new sulfinatodehalogenation reagent system:NaHSO3/K3[Fe(CN)6]

Sodium dithionite-initiated addition of R_FI(1)[R_F.=1a,Cl(CF_2)_4;1b,Cl(CF_2)_6;1c, Cl(CF_2)_6;1d,n-C_6F_(13);1e,n-C_8F_(17)]to the properly protected glucose derivatives 2,9,12 and 15 gave polyfluoroalkylated glucose derivatives 7,11,14 and 17 respectively in good yields after reduction and deprotection.These compounds are strongly surface active.

Oxidation of Partially Hydrolyzed Polyacrylamide from Polymer Flooding Processes Using Fenton Reagents

The degradation of partially hydrolyzed polyacrylamide(HPAM) found in alkaline/surfactant/polymer flooding sewage was investigated using Fenton-type reagents. Different Fenton reagent treatments for HPAM degradation were compared. The effects of pH, hydrogen peroxide(H_(2)O_(2)), ferrous ion(Fe^(2+)), and tartaric ion(C_(4)H_(4)O_(6)^(2-)) concentrations were studied. The degradation reaction occurred within a wide range of pH(3–9). The HPAM degradation performance of photo-Fenton processes using solar light and UV were compared with that of the Fenton process. The degradation rate was found to be strongly dependent on the H_(2)O_(2)/Fe^(2+)/C_(4)H_(4)O_(6)^(2-)molar ratio. The HPAM degradation efficiency was 90%, and the chemical oxygen demand removal efficiency was 85%. HPAM could be degraded into a compound with a lower molecular weight, but it was difficult to achieve complete mineralization to CO_(2). The presence of intermediate products hindered further oxidation in the Fenton process.

硫化铅锌矿浮选分离研究进展

铅锌分离目前仍是选矿领域的一大难题,介绍了闪锌矿和方铅矿的晶体结构与可浮性,指出了优先浮选、混合浮选、等可浮浮选和异步浮选等传统工艺以及电化学浮选、分支浮选、载体浮选和高浓度浮选等新工艺的特点和适用对象;综述了硫化铅矿捕收剂、硫化锌矿捕收剂、硫化铅锌矿调整剂的研究现状;分析指出了浮选分离工艺的发展方向为高浓度浮选工艺、低碱工艺和无氰工艺等绿色工艺,优化药剂制度和研发环保高效新药剂是未来硫化铅锌矿选矿药剂研究的重要方向。

医学实验室试剂管理系统的构建与实践

为实现医学实验试剂管理的信息化、网络化建设,以提升医学实验室管理质量和能力,设计了一套医学实验室试剂管理系统。该系统集成了基础设置、试剂入库、试剂出库、库存管理模块,通过钉钉平台及氚云开发工具实现低成本、定制化的管理功能定制。该系统的构建遵循CNAS按照国际标准ISO15189:2022对医学实验室质量和能力认可的要求,实现了自助扫码出库、过期与低库存预警、多仓库管理和多项目独立管理等功能,兼具开发周期短、管理高效、便于维护等特点。实践表明,该系统可以满足医学实验室教学、科研工作中试剂管理的需求以及精准实验室标准化的管理要求,并在医学实验室试剂管理中起到了良好示范作用,为实验室其他应用场景提供有益借鉴。

Sensitivity of Commercial Enzyme Inhibition Colorimetric Pesticide Residue Rapid Test Kit to a Variety of Pesticides

[Objectives]To fully understand the quality of commercial enzyme inhibition-colorimetric pesticide residue rapid detection kits,so that they can play a greater role in the detection and supervision of agricultural products.[Methods]The sensitivity of 28 kinds of pesticides was determined by using the commercially available enzyme inhibition colorimetric rapid detection kit with Hendu brand.[Results]There was a significant difference in the sensitivity of the kit to each pesticide,and the kit was more sensitive to dichlorvos among the 28 pesticides tested.The sensitivity to methyl isosalifos,dimethoate,isocarbophos,fenthion and phorate was poor,and the sensitivity to quinalphos was different between 3.0 and 2.5 mL.[Conclusions]The large difference of the sensitivity of the enzyme inhibition-colorimetric rapid detection kit for pesticide residues to different kits is a reason for the false positive and false negative test results of the kit,which needs to be considered by relevant personnel.

基于唯一识别码的医用体外诊断试剂管理信息系统的设计与实现

医院医用体外诊断试剂的管理常常面临缺乏统一的物资编码、使用量难以管理、成本收益难以计算等问题。为了实现精细化的管理、可追溯性和成本效益的核算,需要借助信息化工具。本研究介绍了一种院内使用的基于唯一识别码的医用体外诊断试剂管理信息系统。该系统为每种试剂分配唯一的识别码,并将其纳入数据库进行管理。所有的订货、验收、分发和使用都是通过唯一识别码来进行的,并且将各个检验项目与试剂的使用量相结合,用于成本收益的核算。这个系统提高了试剂供应链的管理效率和试剂使用的精细化管理水平。

实验室化学试剂管理研究进展

目前国内大部分化学试剂使用实验室对化学试剂的管理属于粗放型管理方式,存在较大试剂使用浪费和管理安全隐患。对当前国内外化学试剂的管理研究进展进行综述,指出目前我国化学试剂主要采用的实验室专人管理、软件系统管理、物理分割试剂柜管理模式存在的不足,并对未来化学试剂管理研究一定是人工智能和物联网的结合应用进行了展望,以期为我国监管部门和化学试剂使用者提供参考。

选煤厂浮选系统优化改进研究

通过对泰山隆安煤矿选煤厂浮选系统现状及存在问题进行分析,并结合现场实际情况提出了具有较强操作性的浮选系统优化改进方案,并进行工程应用。该方案现场应用后,不仅提升了浮选系统效率、提高了产品品质、降低了药剂消耗量,而且取得较好的经济效益,预计年可直接增加经济效益约1186.8万元。

基于浏览器与服务器架构的体外诊断试剂管理系统构建

目的:构建体外诊断(IVD)试剂管理系统,实现对IVD试剂的有效管理和监控。方法:基于浏览器与服务器(B/S)架构,采用前后端分离开发模式构建IVD试剂管理系统,系统前端采用Vue框架和Element-Plus组件库完成界面设计和展示,后端采用SpringBoot框架进行开发,前后端之间的数据传输使用网络请求库(Axios)通过JavaScript对象简谱(JSON)格式进行传递,实现数据的异步交互。对比系统应用前后医院IVD试剂的管理与监控效果。结果:IVD试剂管理系统实现了IVD试剂的权限管理、系统管理、入库管理、出库管理和库存管理等功能。IVD试剂管理系统应用后,通过系统的试剂定时任务预警,医院试剂过期量比应用前减少近60%;库存盘点所需时间由应用前的每次约5h减少至应用后的3h,试剂查找时间由应用前平均15min缩短至应用后的7min,试剂查找效率提升了50%。结论:IVD试剂管理系统能够实现IVD试剂信息共享和交流,提高协作效率,减少信息传递中的误差和延迟,提升医院IVD试剂管理效率。

中枢神经系统感染病原体宏基因组测序试剂性能评估关注点

从性能评估的角度,简述中枢神经系统感染病原体宏基因组测序试剂检测的病原体范围、企业参考品的设置、反应体系的研究以及分析性能评估等研究内容的关注点,包括研究方法以及质量控制要求等。该研究意在提高产品研发效率,推动行业发展。

Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning

The use of Fenton＇s reagent （Fe^2＋/H2O2） and Fenton-like reagents containing transition metals of Cu（Ⅱ）, Zn（Ⅱ）, Co（Ⅱ）, and Mn（Ⅱ） for an alum sludge conditioning to improve its dewaterability was investigated. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton＇s reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time （CST） reduction efficiency of 47% can be achieved under test conditions of Fe^2＋/H2O2 = 20/125 mg/g DS （dry solid） and pH 6.0. The observation of floc-like particles after Fenton＇s reagent conditioning of alum sludge suggested that the mechanism of Fenton＇s reagent conditioning was different from that of polymer conditioning. In spite of the lower efficiency in the CST reduction of Fenton＇s reagent in alum sludge conditioning compared to that of polymer conditioning, Fenton＇s reagent offers a more environmentally safe option. Tiffs study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.

Mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes from stone coal

The mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes were researched by comparing the blank extraction with the extraction with calcium fluoride as aid-leaching reagent. The leaching experiments were carried out under the conditions of 95 ~C, 6 h, 1.5 ml.g-1, 15 vol % H2SO4, and 5 % calcium fluoride （mass ratio of CaF2 to stone coal）. The concentrations of hydrogen ion were adjusted from initial 1.82 and 4.79 mol.L-1 to the pH of 1.80 4- 0.05 by 200 g.L-1 lime milk, respectively. The solvent extraction experiments were carded out under the organic phase using 15 vol% D2EHPA, 5 vol% TBP, and 80 vol% sulfonated kerosene and O/A phase ratio of 1/4. The leaching rate of vanadium and six-stage countercurrent solvent extraction rate of vanadium can be remarkably improved from 66.71 to 92.97 % and 81.15 to 98.81%, respectively, when calcium fluoride was added as aid-leaching reagent. In the leaching process, fluorine can enhance the breakage of the structure of vanadium-bearing minerals. Meanwhile, fluoride ion can combine with iron ion to generate acid-insoluble iron fluoride hydrate （Fe2Fs.7H20） and consume all ferric ions and a portion of ferrous ions. In adjusting pH value process, the massive impurities are decreased to form KA1SO4 and FeA1Fs. In solvent extraction process, fluorine can prevent the formation of ferric hydroxide colloids and eliminate the formed unstable ferric hydroxide colloids and the silicon-containing colloids to promote the sufficient contact between the aqueous phase and the organic phase and the sufficient reaction.

试剂用量预测与智慧管理平台

通过试剂用量的预测,能够有效地管理实验室试剂,对于一定周期内的试剂预存储量的掌控具有重要意义。为解决检验试剂用量难以精准掌握的问题,文章提出了一种基于深度学习的神经网络模型,并在真实数据集上进行了验证性实验,将其成功整合到试剂管理系统中。利用这一系统,实验室管理者可以及时获取试剂的使用情况,准确预测试剂需求量,从而及时储备检验试剂,提高检验效率的同时减少试剂的超期和浪费情况。

Reagent types and action mechanisms in ilmenite flotation:A review

Ilmenite is an essential mineral for the extraction of titanium.Conventional physical separation methods have difficulty recovering fine ilmenite,and dressing plants have begun applying flotation to recover ilmenite.The interaction of reagent groups with Ti and Fe sites on the ilmenite surface dramatically influences the ilmenite flotation.However,the investigation on Fe sites has received more attention because the activity of Ti is lower than that of Fe.For the activators on ilmenite flotation,most are metal ions but typically lead ions.The metal ions of activators promote ilmenite flotation by increasing the active sites on the ilmenite surface.Combined reagents have a better selective separation of ilmenite than single reagents due to their synergistic effect.Combining the lead ion(Pb^(2+))and the benzyl hydroxamic acid(BHA)into a Pb-BHA complex has a marked effect on ilmenite flotation,which puts forward a new idea of developing combined reagents for ilmenite flotation.This review considers reagent types and action mechanisms in ilmenite flotation.On the basis of the analysis of previous research,a brief future outlook of reagent types and action mechanisms in ilmenite flotation is also proposed in this study.

Novel Synthetic Method for the Vilsmeier-Haack Reagent and Green Routes to Acid Chlorides, Alkyl Formates, and Alkyl Chlorides

An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.

Optimization of efficient stable reagent of alkaline thiourea solution for gold leaching

Na2SiO3 and Na2SeO3 were chosen as stable reagents of alkaline thiourea solution substituting Na2SO3, according to the structure-property relationship between the stability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of the stable reagents on stability of alkaline thiourea was investigated. The results show that contrary to Na2SeO3, Na2SO3 and Na2SiO3 affect the stability of alkaline thiourea solution remarkably. The stable effect of Na2SiO3 on alkaline thiourea is obviously better than that of Na2SO3. The stable reagents Na2SO3 and Na2SiO3 decrease the decomposition rate of alkaline thiourea solution greatly, and the decomposition rate of alkaline thiourea reduces from （72.5%） to （33.8%） with addition of (0.3 mol·L-1) Na2SiO3. Dissolution currents of gold in the alkaline thiourea solution containing Na2SO3 and Na2SiO3 are （2.0） (mA·cm-2) and （3.5） (mA·cm-2) at the potential of 0.42 V, respectively, and Na2SO3 is consumed excessively due to the oxidation reaction of Na2SO3 occurring in the studied potential range. Na2SiO3 is an efficient stable reagent of alkaline thiourea solution, and gold dissolution is accelerated much more obviously by Na2SiO3 than by Na2SO3.

Studies on New Additions to 5-Methoxy-2 (5H)-Furanone: 1, 4-Addition of Grignard Reagents, and 1,3-Dipolar Cycloaddition of Silyl Nitronates

1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.