双光束流动注射光度法测定生活用水中氯离子

将流动注射分析技术应用到双光束分光光度法中，对其理论和实验技术进行了研究，采用自行组装的流动注射系统进行了生活用水中氯离子的测定，获得满意结果。     

The enormity of the zinc deficiency problem and available solutions; an overview

The societal cost of micronutrient deficiency (MND) or the “hidden hunger” is in millions of dollars/year, reducing the GDP of some countries by as much as 11%. Zn is an important micronutrient for both plants and animals. An estimated 17% of the world population, or around 1.1 billion people, are at the risk of zinc (Zn) deficiency. The deficiency has been related to adverse pregnancy outcomes, stunted growth, premature deaths, immune system dysfunctions, neuro-behavioral disorders, and recently with the failure to recover from COVID-19. These health risks associated with Zn deficiency have compelled FAO and WHO to recommend Zn fortification of diet. Correcting Zn deficiency is a challenge due to several reasons. Close to half of the agricultural soils are Zn deficient, and chemical Zn fertilizers are costly and ineffective. Developing Zn-rich crops through plant breeding and genetic engineering is challenging. Zn-dense diet is costly and cannot be implemented in the low-income region most affected by Zn deficiency. Lack of consensus among regulatory bodies on defining and diagnosing Zn deficiency in plants and Humans. Awareness and other sociocultural issues. Among the most important available solutions are zinc biofortification of the cereal crops, use of zinc biofertilizers, development of Zn-efficient crops with reduced phytate content. The use of Zn supplements, dietary modification, and diversification, especially with fish, are proposed as the most accessible and affordable solutions. Awareness programs in areas suffering the most from Zn deficiency are required. Despite the suggestions from FAO and WHO, global efforts to combat Zn deficiency matching those for combating diseases like HIV are not in place. Coordinated efforts of the international community, especially policy-makers, agricultural scientists, dieticians, physicians, and others, are required to address the issue of hidden hunger.     

Ultrasound‐assisted dispersive liquid–liquid microextraction coupled with capillary gas chromatography for simultaneous analysis of nine pyrethroids in domestic wastewaters

A simple and rapid ultrasound‐assisted dispersive liquid–liquid microextraction method coupled with GC‐flame ionization detection was developed for simultaneous determination of nine pyrethroids in domestic wastewater samples. An ultrasound‐assisted process was applied to accelerate the formation of the fine cloudy solution using small volume of disperser solvent, which markedly increased the extraction efficiency and reduced the equilibrium time. Various parameters affecting the extraction efficiency were investigated, including the type and volume of extraction solvent and disperser solvent, extraction and ultrasonic time. Good linearity was obtained for all analytes in the range of 0.8–100 μg/L with the correlation coefficient (r²)≥0.998. The recoveries at three spiking levels ranged from 75.3 to 101.2% with the RSD less than 8.7% (n=5). Under the optimum condition, the enrichment factors for the nine pyrethroids ranged from 728‐ to 1725‐fold. This method offered a good alternative for routine analysis due to its simplicity and reliability.     

Derived Equivalence Classification of Nonstandard Selfinjective Algebras of Domestic Type

We give a complete derived equivalence classification of all nonstandard representation-infinite domestic selfinjective algebras over an algebraically closed field. As a consequence, a complete stable equivalence classification of these algebras is obtained.     

带冷凝热回收的家用空调器的研究

随着生活水平的提高,家用空调器的使用逐年增加.空调器在夏季向室内供冷的同时,不仅给室外环境造成了热污染,而且还造成了能源的浪费.因此,很多学者都提出了空调冷凝热回收理论并进行了实验研究.文中分析了在家用空调器回收冷凝热的可行性及研究现状;介绍了家用空调器采用的冷凝热回收系统的形式及其分类;提出了一种带冷凝热回收装置的多...     

自然冷源在家用冰箱系统应用及性能分析

空气自然冷源已逐渐用于制冷系统中,引入自然冷源能提高冷凝器出口过冷度,或将自然冷源冷却载冷剂经节流直接引入蒸发器,可有效提高系统COP;基于国内冬春季温度≤5℃的自然冷源分布状况,设计了一种引入自然冷源用于家用冰箱的新型制冷系统,并建立热力学计算模型,分析了不同自然冷源工况时冷凝器过冷度在0、5、10、15℃下的系统COP、压缩机指示功率、系统耗电量及冷凝器热负荷,经计算,冬春季时与传统家用冰箱制冷系统相比,系统COP提高了12%,日均系统耗电量节约0.48kWh。     

Microalgae and bioremediation of domestic wastewater

Domestic wastewaters are produced in huge volumes and abundant with carbon, nitrogen and phosphorous, which are a promising source of nutrients for production of microalgae. Microalgae-based bioremediation of domestic wastewater offers various advantages over traditional treatment approaches because the process consumes CO₂, completely removes nitrogen and phosphorous for production of green biomass and oxygen. Moreover, the abundance of biochemical compositions (e.g., lipids, proteins, carbohydrates, bioactive compounds) of microalgae biomass is superior to terrestrial plant biomass in refining to multi-products having variety of commercial values. In this review, the most dominant microalgae used for simultaneous removal of pollutants and production of biomass and metabolites from domestic wastewater are presented. Biorefinery of microalgae biomass produced from domestic wastewater for production of multiple products is also explored. Finally, challenges and perspectives of successful microalgae-based bioremediation of domestic wastewater toward the biorefinery are briefly discussed.     

污泥吸附剂的制备及其光谱性能研究

以城市和石化污水厂生化活性污泥及剩余污泥为原料,采用热解法制备烟气脱硫吸附剂,并与商品活性炭对比进行了孔结构、扫描电镜、X射线衍射、热分析及元素分析性质表征,利用傅里叶红外光谱法研究污泥吸附剂在SO₂-O₂-N₂及SO₂-O₂-H₂O_(g)-N₂体系的吸附机理。结果表明城市污水厂剩余污泥制备的吸附剂脱硫性能较好,其次为石化活性污泥,生化活性污泥吸附剂脱硫性能较差,剩余污泥制备的吸附剂脱硫率略低于商品活性炭。SO₂-O₂-N₂体系吸附机理主要为物理吸附,SO₂-O₂-H₂O_(g)-N₂体系SO₂发生了催化氧化,以化学吸附为主。吸附过程中起吸附作用的主要是微孔结构。     

Chemometric procedure for the study of fractionated wastewater ingredients using RP-HPLC/diode array spectrophotometer

A fast screening method of domestic wastewater is reported based on fractionation with RP-HPLC and diode array absorption detection implemented by chemometric treatment of the spectra using cluster analysis, deconvolution, simulation, and multiple regression statistical techniques. The proposed method is limited to constituents that absorb in the UV-Vis region which include most of the toxic organic pollutants.