Tamarindus indica mucilage and its acrylamide-grafted copolymer as flocculants for removal of dyes

The application of Tamarindus indica seed mucilage (Tam), a food grade polysaccharide, and its acrylamide grafted copolymer as flocculants was assessed for the first time for removal of various types of dyes from model textile wastewater containing azo, basic, and reactive dyes. Acrylamide grafted T. indica mucilage (Tam-g-PAM) was obtained by ceric ion initiated polymerization technique. A series of contact time experiments were conducted to assess the system variables such as concentrations of mucilage and dyes and pH. These flocculants reduce the dye concentration by flocculation and settling. The grafted copolymer, Tam-g-PAM showed better results for dye removal. The optimal flocculant concentration, which was required to effect flocculation, was independent of dye concentration within the range examined. Both the flocculants performed better for removal of azo dyes than for reactive and basic dyes.     

The American (USA) perspective six years after implementation of CLIA'88 (Federal) regulations

 On September 1, 1992 all testing sites in the United States were required to comply with the Clinical Laboratory Improvement Amendments of 1988 (CLIA'88). These regulations, based on both total quality management (TQM) and continuous quality improvement (CQI) principles, reshaped the environment for more than 90% of laboratories. CLIA'88 represented a revolutionary change by imposing universal, uniform regulations based on test complexity for all sites examining materials derived from the human body for the purpose of providing information for the diagnosis, prevention, or treatment of disease. CLIA'88 specifies minimum requirements for personnel, quality control, and proficiency testing (PT). In addition, laboratories are required to follow manufacturers' directions and comply with other specified good laboratory practices. PT is mandated for most of the frequently run analyses and quality assurance requirements integrate the principles of CQI as well as TQM into the regulatory process. Biannual inspection is integral to CLIA'88, however, laboratories can choose other federally approved ("deemed") professional organizations, such as the Commission on Office Laboratory Accreditation, the College of American Pathologists, or the Joint Commission on Accreditation of Healthcare Organization, having standards that meet or exceed those of CLIA'88. CLIA'88 has still not been finalized. This article discusses the impact and changes since CLIA's implementation in 1992. Received: 5 October 1998 · Accepted: 20 October 1998     

近5年化学奥林匹克(初赛)试题的分析及建议

从化学核心素养出发，分析近5年化学奥林匹克（初赛）试题考查的学生知识水平、能力水平、素养水平，并针对培养中学生核心素养的教学实践提出建议。     

生物检材中乌头类生物碱的检验

 用薄层 (TLC)、高效液相 光电二极管阵列检测器 (HPLC/DAD)、动物实验等方法对生物检材中乌头生物碱进行检验 ,并对这些方法进行比较。结果发现 ,TLC法为此类药物检验筛选的首选方法 ,最小检出量为 0 3μg。在进行HPLC检测时 ,以乌头生物碱的特征紫外吸收光谱和动物实验结果为重要的定性手段 ,其特征吸收波长为 (2 2 8± 2 )nm和 (2 75± 2 )nm。乌头生物碱在 2mg/L～ 5 0mg/L时其峰面积与质量浓度有很好的线性 ,相关系数为 0 9996。经实际案件证明 ,方法准确、灵敏 ,可用于生物检材中乌头类生物碱的检验。     

Design of experimental routes and data processing for the determination of the depth-distribution of energy in real solids

No adequate thermodynamic definition of non-equilibrated solids is available at present. In this paper a method is suggested for the energetic characterization of solids by estimation of the distribution of the differential molar internal energies — as they appear during the breakdown of sample e.g. by chemical reaction, i.e. the ‘depth distribution of differential energies’ (DDE) of samples. Thermodynamic considerations are presented for approximating this quantity — and experimental possibilities proposed to attain the needed input information by thermoanalytical methods. Application of the suggested procedure is supposed to contribute to the better understanding of structure — energy — reactivity relations in real solids.     

农残水平测试中数据多态性分析及指定值估计研究

对全国农残水平测试中毒死蜱、氯氰菊酯数据进行统计分析,在数据统计分布特征研究基础上,使用内核密度估计进行数据多态性分析,使用bootstrap模拟取样法对数据样本值重复取样,以获得稳健的水平测试样品待测物含量代表值估计、标准误差及置信区间描述,证明以bootstrap模拟取样法获取的均值与标准偏差作为有限单次样本代表值是合理、有效的,解决了四分位稳健统计方法对非正态多态分布代表值估计不稳定问题及取样理论中取样样本数限制的瓶颈,为能力验证计划指定值的获取提供了一种新方法。     

Modeling research in low-medium temperature geothermal field, Tianjin

The geothermal reservoir in Tianjin can be divided into two parts: the upper one is theporous medium reservoir in the Tertiary system; the lower one includes the basement reservoir inLower Paleozoic and Middle-Upper Proterozoic. Hot springs are exposed in the northern mountainand confined geothermal water is imbedded in the southern plain. The geothermal reservoir is in-cised by several fractures. In recent years, TDS of the geothermal water have gone up along withthe production rate increasing, along the eastern fracture zone (Cangdong Fracture and West Bai-tangkou Fracture). This means that the northern fracture system is the main seepage channel ofthe deep circulation geothermal water, and the reservoir has good connection in a certain area anddefinite direction. The isotopic research about hydrogen and carbon chronology indicates that themain recharge period of geothermal water is the Holocene Epoch, the pluvial and chilly period of20 kaBP. The karst conduits in weathered carbonate rocks of the Proterozoic and Lower Paleozoicand the northeast regional fracture system are the main feeding channels of Tianjin geothermalwater. Since the Holocene epoch, the geothermal water stayed at a sealed warm period. Thetracer test in WR45 doublet system shows that the tracer test is a very effective measure forunderstanding the reservoir's transport nature and predicting the cooling time and transportvelocity during the reinjection. 3-D numerical simulation shows that if the reinjection well keeps asuitable distance from the production well, reinjection will be a highly effective measure to extractmore thermal energy from the rock matrix. The cooling of the production well will not be a problem.     

茉莉醛相转移催化合成法的改良

茉莉醛又称2-戊基肉桂醛,具有优雅的茉莉花香,是一种深受调香师喜爱的合成香料。目前已广泛应用于各种日用化学品中。     

Characterisation of inhibitors of acetylcholinesterase by an automated amperometric flow-injection system

Acetylcholinesterase was immobilised on magnetic particles and integrated in a flow-injection system via a magnetic reactor. Enzyme activity was determined amperometrically using acetylthiocholine chloride as enzyme substrate. This system was applied to enzyme inhibition tests. Inhibition constants and lower detection limits were determined for carbofuran, paraoxon, malaoxon and paraoxon-methyl. The resulting data were compared to those obtained with a photometric test, i.e. the determination of thiocholine via its reaction with the Ellman's reagent 5,5'-dithio-bis-2-nitrobenzoic acid using the same flow system. As they correlated well to those reported for the native enzyme the flow-injection analysis device can be applied to automated determination and characterisation of enzyme inhibitors.     

“线上线下-虚实结合”在有机化学实验教学中的应用探索——以正溴丁烷的制备实验为例

In response to the impact of the Covid-19 epidemic on organic chemistry laboratory teaching, this article analyzes and discusses the current limitation of traditional organic chemistry laboratory teaching. Taking the "preparation of n-bromobutane" as an example, a new "online-offline and virtual-actual combination" teaching mode with the combination of "Tencent Meeting, MLabs, laboratory and WeChat group" is introduced. The practice of the new mode of teaching includes the following steps: pre-class online guiding by teacher, student preview and practice based on the virtual simulation platform, students and teacher discussion and operation in laboratory, and post-classcomprehensive assessment and Q&A", and good teaching effects have been received. It is significant in cultivating and improving the independent innovation and practical ability, and provides reference for the organic chemistry laboratory teaching reform and also lays a foundation for the construction of "outstanding course" of organic chemistry.