非共沸混合工质有机朗肯循环系统变工况特性研究

鉴于分布式能源系统中燃气轮机负荷波动较大,而目前对有机朗肯循环（Organic Rankine Cycle,ORC）研究更注重相同吸热量及其热力性能随初始参数变化的对比,很少考虑燃气轮机负荷降低时导致烟气温度和质量流量均下降对系统性能的影响。通过HYSYS平台构建特性模型,以换热器内窄点温差为约束条件,研究变工况特性ORC工质优选方案。在燃气电厂变负荷工况下,寻求对应系统最大净输出功的最佳运行参数,从热耗率、质量流量和AP值等特性比较,采用不同组分工质的循环性能,经对比发现R152a系统净输出功、热耗率、质量流量在所选工况区间内相比混合工质具有明显优势,而冷凝器AP值及系统热回收率却相反。研究结果为ORC系统二元非共沸混合工质优选提供参考。     

食品用洗涤剂中甲基异噻唑啉酮类防腐剂检测的必要性

甲基异噻唑啉酮类防腐剂是一类具有高效、广谱的杀菌和抑菌性能的防腐剂,广泛应用于各类防腐领域,但该类防腐剂能否用于食品相关产品还有待研究。文章主要介绍了甲基氯异噻唑啉酮与甲基异噻唑啉酮的混合物和甲基异噻唑啉酮两类防腐剂,以及近年各国对化妆品中甲基异噻唑啉酮类防腐剂的限量要求。从调查数据看,市场上大多食品用洗涤剂都含有甲基异噻唑啉酮类防腐剂,有的含量甚至超过化妆品安全技术规范中最大允许浓度,对人体健康可能会产生较大威胁。因此,有必要对食品用洗涤剂中甲基异噻唑啉酮类防腐剂进行检测,并建议在食品用洗涤剂国家标准中列入对甲基异噻唑啉酮类防腐剂的限量。     

烧结混合料水含量自动控制系统开发与应用

烧结过程中混合料水含量对烧结矿的产量和质量有至关重要的影响。传统的烧结混合料加水量控制是以目标水含量与混合料原始水含量的偏差作为前馈量调整加水量,该方式只是对加水量进行简单控制,不能根据实时的混合料水含量偏差和料种变化情况对加水量进行精准控制。为此,开发了烧结混合料水含量自动控制系统,采用前馈和后馈相结合以及红外水分仪和微波水分仪联合后馈控制的调整方式,应用原燃料数据动态追踪技术,通过混合料加水过程的自动控制,将混合料水含量波动范围控制在目标水含量的±0.15%以内,实现了烧结混合料加水量的精准控制,提高了烧结矿的质量和产量,经济效益和社会效益显著。     

Biosorption behaviors of Cu, Zn, Cd and mixture by waste activated sludge

Biosorption of heavy metal ions, such as Cu²⁺, Cd²⁺ and Zn²⁺, was carried out using waste activated sludge from municipal sewage treatment plant as adsorption material, and the effects of parameters, such as pH value, temperature, reaction time and sorption duration, were studied in detail. The results indicate that the removal rates of Cu²⁺, Zn²⁺ and Cd²⁺ with low concentration are 96.47%, 80% and 90%, respectively, adsorbed by waste activated sludge. Little effect of dosage of activated sludge on the adsorption of Cu²⁺ and more effects on the adsorption of Zn²⁺ and Cd²⁺ are observed. Little effect of temperature is observed, while pH value and adsorption time exert important influence on the sorption process. The adsorption behaviors of heavy metal ions all have parabolic relationships with pH value. The optimum pH value is between 6 and 10, and the optimum adsorption time is 1 h. In single heavy metal ion system, the sorption processes of Cu²⁺, Zn²⁺ and Cd²⁺ are in accordance with Freundlich model, which indicates that it is suitable for the treatment of these three heavy metal ions using intermittent operation. In addition, the sorption capacity of the sludge for Cu²⁺ is preferential to the other two ions.     

磁性纤维随机混合媒质等效电磁参数的计算

为计及强散射偶极子间的相互作用,引入参量εh和μh,利用广义多重散射理论及MATLAB计算机软件对在2 GHz～18 GHz频率下的体积占空比为8%的铁纤维随机混合媒质等效磁导率的实验值进行曲线的拟合,导出了耦合系数εh和μh,并在此基础上,对体积占空比分别为30%和20%的铁纤维随机混合媒质等效磁导率进行了计算,计算结果与实验吻合良好.     

灰铁铸件牌号要求与熔炼配料选择

由于铸件壁厚对其性能有明显影响，牌号要求相同、壁厚不同的灰铁铸件必须采用不同的成分和配料。介绍不同灰铁铸件牌号标准的对照，并用生产实例说明如何根据图纸牌号要求、铸件结构和使用性能要求选择化学成分控制标准和熔炼配料。     

正负离子表面活性剂相互作用的理论和实验研究

Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantumchemical method. Interaction energies are -0.2378kJ·mol~(-1),-3.3394kJ·mol~(-1) and 0.1204kJ·mol~(-1) for the molec-ular pairs with fluocarbon and hydrocarbon chain: C_4H_(10)/C_5H_(12), C_4F_(10)/C_5H_(12), and C_4F_(10)/C_5F_(12), respectively.When hydrophilic group with cationic and anionicions is introduced, interaction energies are -287.40kJ·mol~(-1),-311.18kJ·mol~(-1) and -345.83kJ·mol~(-1). The results show that there is strong static interaction between cationicand anionic surfactants. It has been predicted that mixed monolayer may be formed and surface activity is en-hanced favorably, especially for mixtures of cationic and anionic surfactants with fluocarbon and hydrocarbonchains. The anionic surfactants, sodium octadecylbenzenesulfonate perfluopolyetherbenzenesulonate(ANF-Ⅰ)wassynthesized, mixture effects of ANF-Ⅰ with sodium octadecylbenzenesulfonate or dodecyldimethyl benzylammonium     

尾煤泥水煤浆高效制浆工艺在临涣选煤厂的应用

分析了临涣选煤厂浮选尾煤的性质及成浆性。为了把高粘性尾煤泥滤饼制备成水煤浆，研制了循环剪切桶和剪切泵。实践证明，浮选尾煤泥可以制备出浓度高、稳定时间长和流变性好的水煤浆。研制的制浆设备结构紧凑、电耗低、效率高。笔者介绍了该设备的结构、工作原理以及制浆生产线。     

基于新型混合模型的欠定盲分离方法

针对欠定盲分离问题,提出了一种新的源恢复方法. 在时频域局部区域采用复高斯分布对源信号进行建模,将语音信号的稀疏性和局部平稳性结合在一起,提出了一种新的混合模型来描述观测信号在局部区域的概率分布.通过该模型,将每个时频点的源信号状态的判断问题转换成模型的参数估计和后验概率的计算问题,最后通过子混合矩阵的逆恢复出源信号. 实验结果表明,该方法具有很快的收敛速度,并且比已有方法具有更好的分离性能.     

28%乙.嗪可湿性粉剂防除大豆田杂草

乙。嗪可湿性粉剂虽一次性大豆田除草剂。试验结果表明，亩用有效剂量６０克，除草效果达９０％以上，对大豆安全，扩大了杀草谱，可防除整个大豆生长期杂草。