微波消解石墨炉原子吸收法测定食用油中铬和镉

本实验专门针对食用油开发出以微波消解-原子吸收石墨炉法准确测定油品中重金属镉、铬的实验方法,研究了油品消解的最佳处理方法及消解条件。通过基体改进剂和灰化温度的改善确定了原子吸收最佳工作条件,方法的相对偏差低于4.04%,仪器检出限为0.01μg/kg,加标回收率在95.0%~102.8%之间。实验结果表明此方法准确、检出限低、灵敏度高、分析结果令人满意。     

60Co-γ射线-离子束复合诱变法选育高产糖化酶菌株的研究

以黑曲霉UV-4为出发菌株,利用60Co-γ射线与离子束进行复合诱变。试验表明:经复合诱变,可以获得高产糖化酶的菌株AnUVγN+7,酶活达到1 100.9U/mL,是原始菌株UV-4(156.1U/mL)的7倍,菌株经过7次传代,结果显示酶活较稳定,以此可选育高产糖化酶菌株。     

Near-Critical Natural Circulation Flows Inside an Experimental Loop: Stability Map and Heat Transfer

The near-critical CO₂-based natural circulation loop (NCL, or thermosyphon) has been proposed in many energy conversion systems, such as the solar heater, waste heat recovery, next-generation nuclear cooling, and so on. There is an increasing need to obtain detailed information about such systems, as it is less verified from a basic system operation viewpoint. This paper presents an experimental investigation of a near-critical CO₂ thermosyphon. The closed thermosyphon is specially designed for high-pressure (in the critical region, from 6.0 MPa to 15.0 MPa), natural circulation flows. The basic transient flow behaviors and parameter behaviors are found to be dependent on initial pressure. The system stability evolution from subcritical oscillating flow to supercritical stable operations is presented. From the experimental data analysis, the stability map for the current supercritical natural circulation loop system is given. It is found that the stability pressure lines will divide the operation into stable, transition, and unstable regions. It is found that the effectiveness of the cooler will greatly affect the system stability, while the heat transfer efficiency is mainly controlled by the heater conditions. Parameter evolutions of the fluid temperature, mass flow rate, and loop pressure are presented in this paper. The heat transfer dependency on operation pressure and evolution mechanisms are also discussed in detail in this paper.     

某含金高硫铜矿石浮选试验研究

采用新药剂对某含金高硫铜矿石进行了系统浮选试验研究.通过对比试验,发现采用传统的捕收剂黄药和黑药选别含金高硫铜矿石,虽然能够有效地回收含金硫化物,但获得的精矿产率高,铜和金的品位低,很难售出.而采用新药剂选别该类型矿石,可以使问题得到有效解决.新药剂对硫化铜矿物具有非常好的选择性,在粗选阶段采用新药剂可以有效回收硫化铜矿物,获得合格的铜精矿;在扫选阶段,采用黄药和黑药可以有效回收黄铁矿和其他硫化矿物,保证铜和金的回收率;扫选中矿单独处理,中矿采用六偏磷酸钠分散剂来消除矿泥对精选作业的影响,精选获得的混合精矿可以直接销售.     

太阳能光伏光热(PV/T)系统在建筑中的应用研究

"碳达峰、碳中和"目标下,可再生能源在建筑中的应用受到越来越多的重视.在诸多可再生能源中,太阳能作为最容易与建筑结合的可再生能源之一,具有清洁、安全、稳定、高效等特点,对其深入开发利用是未来建筑能源结构性改革的需求.本文对国内外太阳能光伏光热系统的技术最新发展现状进行了梳理和总结,研究了太阳能光伏光热(PV/T)系统在建筑中的应用方式,分析了太阳能光伏光热系统的典型案例与发展趋势,为实现产业升级、降低成本、扩大应用提供参考.     

多重PCR-液相芯片技术检测13个品系转基因玉米

为建立多重PCR-液相芯片检测13个品系的转基因玉米的方法,针对BT11,BT176,Mon810,Mon863,T25,GA21,NK603,TC1507,Mon89034,Mir162,Mon88017,MIR604和BVLA430101这13种玉米品系的侧翼序列,设计合成了品系特异性引物/探针。在生物素标记的PCR扩增产物与固定在荧光编码微球上的品系特异探针杂交后,对微球进行流式检测。试验结果显示,13种转基因玉米的引物和探针具有较高的特异性,引物/探针相互之间无交叉扩增和非特异杂交,大部分转基因玉米品系的检测灵敏度达到0.1%水平,符合欧盟和其他国家有关转基因产品标识的要求。本方法的检测效率和准确性均高于传统方法,可作为进出口转基因产品和国内转基因检测的有效方法。     

茂名100kt／a低密度聚乙烯技术特点

介绍了茂名石化乙烯工业从美国匡藤化学公司引进的１００ｋｔ／ａ氏密度聚乙烯装置的工艺流程,技术特点、原料、单体、安全、环保方面的技术情况。     

Intersubband absorption properties of high Al content AlxGa1?xN/GaN multiple quantum wells grown with different interlayers by metal organic chemical vapor deposition

High Al content Al_xGa_1−xN/GaN multiple quantum well (MQW) films with different interlayers were grown by metal organic chemical vapor deposition. These MQWs were designed to achieve intersubband (ISB) absorption in the mid-infrared spectral range. We have considered two growth conditions, with AlGaN interlayer and GaN/AlN superlattice (SL) interlayer, both deposited on GaN-on-sapphire templates. Atomic force microscopy images show a relatively rough surface with atomic-step terraces and surface depression, mainly dominated by dislocations. High-resolution X-ray diffraction and transmission electron microscopy analyses indicate that good crystalline quality of the AlGaN/GaN MQW layer could be achieved when the AlGaN interlayer is inserted. The ISB absorption with a peak at 3.7 μm was demonstrated in MQW films with AlGaN interlayer. However, we have not observed the infrared absorption in MQW films with GaN/AlN SL interlayer. It is believed that the high dislocation density and weaker polarization that resulted from the rough interface are determinant factors of vanished ISB absorption for MQW films with the GaN/AlN SL interlayer.     

独立院校“仪器分析”课程教学组织与设计探讨

仪器分析课是面向化工类相关专业开设的重要专业课程。为提高教学效果,培养学生对综合知识的运用能力,结合课程学时相对较少的实际情况,对教学内容进行了优化处理;对教学中的组织与设计进行了改革和探索,提高了教学水平和质量。     

应用型本科院校仪器分析设计性实验的探索与实践——以食品中亚硝酸盐含量的测定为例

文章分析了"食品中亚硝酸盐含量的测定"的实验过程,阐述了开设仪器分析计性实验对于拓大学生知识面、提高学生的查阅文献和获取信息的能力、加深学生对仪器分析各原理的理解、培养学生分析和解决问题的能力、强化学生的实验技能等各方面的积极意义。