共查询到20条相似文献，搜索用时 171 毫秒
1.
方芳 《铜陵职业技术学院学报》2014,(3):64-66
通过对比分析水泥窑脱硝技术并结合我国具体国情,探讨出适合我国的水泥窑脱硝技术—SNCR技支。阐述了SNCR技术的原理、特点、工艺、减排效益;并通过SNCR在水泥窑烟气脱硝中的实际应用情况、监测数据、减排效益等,为我国水泥行业氮氧化物减排治理工作提供参考。 相似文献
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为了克服传统深度学习在排水管道缺陷检测方面识别正确率较低的缺点,在Faster R-CNN算法基础上,利用聚类分析方法改进候选区域设置,提出一种优化的排水管道缺陷检测模型,并采用VGG、AlexNet、GoogleNet、ResNet代替Faster R-CNN网络中的特征提取层进行模拟计算。计算结果表明,K-means方法的最优类别数为5,虽然ResNet网络训练时间成倍增加,但其识别正确率达到0.89,比VGG网络提高了0.14。优化后的Faster R-CNN网络有效提高了排水管道缺陷检测的识别正确率。 相似文献
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文章主要介绍了广东罗定电厂SNCR+SCR脱硝技术的基本原理,工程简介,同时对运行中存在的氮氧化物浓度偏高、反应器入口烟温偏高、喷枪堵塞、尿素站稀释水泵切换时打不起压等问题进行分析并采取措施予以解决。 相似文献
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遗传算法本身固有的并行处理性和开放性,使得它在优化识别方面的效率非常之高,而且受到越来越广泛的研究,然而,遗传算法自身也有一些缺点．遗传算法在寻优过程中易出现“早熟”,设计变量增多时效率较低以及结构分析时间长．论文分析了遗传算法的常见缺陷,并通过采用小生境技术、基于多父体变量级别的杂交以及小生境技术的改进策略,遗传算法的优化性能（优化效率和质量）得到了大大的提高。 相似文献
5.
在高一化学教材第二章第二节钠的化合物中,关于Na2O_2与 CO_2的反应。教师通常采用的实验是:用棉花包住少量的 Na2O_2,然后放入装满 CO_2气体的集气瓶中。我认为,此实验有如下缺陷:反应瞬间完成,具有一定的危险性;不能很好地观察到白色产物 Na_2CO_3;不能形象地说明反应有氧气生成。为了克服以上缺陷,特设计 Na_2O_2与 CO_2反应的实验装置如下图所示: 相似文献
6.
陶海军张贝贝 《南通职业大学学报》2022,(1):88-92
为更好地脱除废气中的氮氧化物,从氨在活性焦表面的吸附量,以及活性焦脱硫再生后的脱硝性能等方面,探究活性焦脱硝机理。通过活性焦吸附氨、新鲜活性焦脱硝及脱硫再生后的活性焦脱硝实验,计算氨溢出浓度、氨消耗量及脱硝效率,分析活性焦脱硝性能。结果表明:新鲜活性焦吸附氨的能力较弱,但吸附态的氨能与一氧化氮全部发生选择性催化还原反应(SCR反应);活性焦表面的含氮基团数量和吸附氨的能力决定其脱硝性能;脱硫再生后的活性焦能够增加其表面氨的吸附能力,活性焦的脱硝性能也因此得到显著提升。 相似文献
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郭晓丽 《江西电力职业技术学院学报》2018,(5)
零部件作为制造行业的基础,其质量高低直接影响到该行业未来的发展,加强对零部件表面缺陷或尺寸等质量的检测显得尤为重要。随着零部件趋向精细化发展,传统的质量检测技术已经不能满足零部件检测的需要,以机器视觉技术为代表的新型零部件质量检测技术得到了广泛应用,具有非接触、精度高和反应快等优点。零部件的质量检测是零部件加工后的重要环节,而传统检测方法对螺栓和气门关键部分的质量检测精度和效率较低。根据螺栓和气门的检测特点设计基于机器视觉的检测方案。 相似文献
8.
分别对已有文献提出的两种没有双线性对的无证书签名方案进行分析,发现王方案虽然算法简单.效率高,签名长度短,但安全性低;陈方案安全性虽高,但计算量大,效率较低,签名长度长,在要求带宽较低的无线网络环境中不实用.为克服两种方案的缺点,提出一种新的没有双线性对的无证书签名方案,新方案算法简单,效率高,签名长度较短,在离散对数... 相似文献
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针对当前云计算模式下显卡虚拟化的效率问题,提出一种基于KVM虚拟化的显卡直传技术方案。在KVM的基础上进行了二次开发和优化,提高了虚拟机显卡的数据传输速率。实验结果表明,显卡直传技术优化后的技术方案可以将显卡虚拟化的性能提高到原来的2倍,使用户体验达到本地化效果。 相似文献
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基于离散对数问题和单向函数的安全性,提出了一个新的安全的代理签名方案。方案引入授权文书和时间证书等概念,克服了代理人滥用权力的缺陷,使代理人只能在特定时间内进行次数一定的代理签名;新设计的算法,有效分离了实际签名权和代理签名权,克服了签名验证者不易理解所收到的签名究竟是某人自己的真实签名还是受人之托的代理签名的缺陷;最后对方案的安全性和算法效率进行了分析。结论表明,新方案是一个安全可行的代理签名方案,具有较好的理论价值和应用价值。 相似文献
11.
Experiment and mechanism investigation on advanced reburning for NOx reduction： influence of CO and temperature 总被引：4，自引：0，他引：4
Wang ZH Zhou JH Zhang YW Lu ZM Fan JR Cen KF 《Journal of Zhejiang University. Science. B》2005,6(3):187-194
Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were investigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the needed flue gas. Four kinds of pulverized coal were fed as reburning fuel at constant rate of 1g/min. The coal reburning process parameters including 15%～25% reburn heat input, temperature range from 1100 ℃ to 1400 ℃ and also the carbon in fly ash, coal fineness, reburn zone stoichiometric ratio, etc. were investigated. On the condition of 25% reburn heat input, maximum of 47% NO reduction with Yanzhou coal was obtained by pure coal reburning. Optimal temperature for reburning is about 1300 ℃ and fuel-rich stoichiometric ratio is essential; coal fineness can slightly enhance the reburning ability. The temperature window for ammonia injection is about 700 ℃～1100 ℃. CO can improve the NH3 ability at lower temperature. During advanced reburning, 72.9% NO reduction was measured. To achieve more than 70% NO reduction, Selective Non-catalytic NOx Reduction (SNCR) should need NH3/NO stoichiometric ratio larger than 5, while advanced reburning only uses common dose of ammonia as in conventional SNCR technology. Mechanism study shows the oxidization of CO can improve the decomposition of H2O, which will rich the radical pools igniting the whole reactions at lower temperatures. 相似文献
12.
Quantum chemical simulation was used to investigate the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process. Both NO-char and NO-Na/K reactions were considered as three-step processes in this calculation. Based on geometry optimizations made using the UB3LYP/6-31G（d） method, the activation energies of NO-char and NO-Na/K reactions were calculated using the QCISD（T）/6-311G（d, p） method; Results showed that the activation energy of the NO-Na/K reaction （107.9/82.0 kJ/mol） was much lower than that of the NO-char reaction （245.1 kJ/mol）. The reactions of NaO/KO and Na2O/K2O reduced by char were also studied, and their thermodynamics were calculated using the UB3LYP/6-31G（d） method; Results showed that both Na and K can be refreshed easily and rapidly by char at high temperature during the coal reburning process. Based on the calculations and analyses, the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process was clarified. 相似文献
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陈峰 《宁德师专学报(自然科学版)》2007,19(4):407-409
利用二乙酰基二氢二甲基吡啶（DDL）在412nm处具有最大吸光度,运用汉茨（Hantzsch）反应对甲醛所表现出来的良好特性,采用气体分析法测定样品中甲醛的含量进而分析新装修后居室的污染情况,结果表明,气体分析法是一种快速便捷的测定新装修后居室的甲醛含量的方法,其灵敏度高. 相似文献
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超细粉体的制备方法 总被引：4，自引：0，他引：4
徐羽展 《浙江教育学院学报》2005,(5):53-59
超细粉体具有一些普通物质所不具备的特性,其中纳米材料具有广泛的应用价值.综述了纳米材料的主要制备方法,包括固相法(机械粉碎法、固相反应法)、液相法(沉淀法、水热法、微乳液法、溶胶凝胶法、水解法、溶剂蒸发法、电化学法)和气相法(气体中蒸发法、气相化学反应法、溅射法、流动油面上真空沉积法、金属蒸气合成法)等.简要讨论了各种制备方法的进展. 相似文献
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1IntroductionNickel-based alloys containing 20 -30 wt % Mo isknown to be essential for corrosion resistance in re-ducing media[1],especially for resistance to HCl at alltemperatures and concentrations[2]. However , uponexposure to elevated temperatures in the range of600 -800 ℃,these alloys suffer an al most completeloss of roomtemperature ductility as a result of long-range ordering (LRO) to Ni4Mo .It is considered thatthe loss of ductility mainly results from the environ-mental embrittle… 相似文献
18.
利用分形维数定量表征催化剂的形状不规则程度 ,对其中进行的气 -固相催化反应进行了分析计算 .计算结果表明 ,催化剂的形状越不规则 ,催化剂的外表面分形维数越高 ,在相同反应条件下 ,催化剂的利用率越高 .同时给出了适用于形状不规则催化剂的通用 Thiele模数 .计算结果还表明 ,分形维数只影响通用 Thiele模数的数值 ,但在相同的通用Thiele模数下 ,催化剂具有相同的效率因子 相似文献
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The fracture behavior of disordered and ordered Ni4Mo alloy was investigated by tensile tests in hydrogen gas or during hydrogen charging. The results show that the ductility of the disordered alloy decreased slightly with the hydrogen pressure increasing, while that of the ordered alloy decreased rapidly with the hydrogen pressure increasing. However, the ductility of both disordered and ordered alloys reduced similarly seriously with the charging current density increasing. Therefore, the mechanism of order-induced embrittlement of Ni4 Mo alloy in hydrogen gas is supposed to be that atomic order accelerates the kinetics of the catalytic reaction for the dissociation of molecular H2 into atomic H. 相似文献
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To understand the absorption mechanism of nitrogen dioxide into a sodium sulfide solution, a stirred tank reactor with a plane gas-liquid interface was used to measure the chemical absorption rate of diluted nitrogen dioxide into sodium sulfide solution. The absorption rates under various experimental conditions were measured and the effects of experimental conditions on nitrogen dioxide absorption rate were discussed. The results show that, in the range of this study, nitrogen dioxide absorption rate increases with increasing sodium sulfide concentration, nitrogen dioxide inlet concentration, and flue gas flow rate, but decreases with increasing reaction temperature and oxygen content in flue gas. 相似文献