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Influence of ash composition on the sintering behavior during pressurized combustion and gasification process

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第3期13卷 230-238页

作者： Ni-jie JING Qin-hui WANG Yu-kun YANG Le-ming CHENG Zhong-yang LUO ke-fa.CEN State key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.

关键词： Ash composition Sintering temperature X-ray diffractometer (XRD) Field emission scanning electron microscope/energy dispersive X-ray spectrometer (FE-SEM/EDS)

HNCO hydrolysis performance in urea-water solution thermohydrolysis process with and without catalysts

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第11期11卷 849-856页

作者： Zhen-chao CHEN Wei-juan YANG Jun-hu ZHOU Hong-kun LV Jian-zhong LIU ke-fa.CEN State key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

The thermolysis of urea-water solution and its product, HNCO hydrolysis is investigated in a dual-reactor system. For the thermal decomposition below about 1073 K, the main products are ammonia (NH3) and isocyanic acid (HNCO) whereas at higher temperatures the oxidation processes take effect and the products include a low concentration of nitric oxide (NO) and nitrous oxide (N2O). The gas HNCO is quite stable and a high yield of HNCO is observed. The ratio of NH3 to HNCO increases from approximately 1.2 to 1.7 with the temperature. The chemical analysis shows that H radical is in fa.or of HNCO hydrolysis by instigating the reaction HNCO+H·→·NH2+CO and high temperature has positive effect on H radical. The hydrolysis of HNCO over an alumina catalyst made using a sol-gel process (designated as γ-Al2O3) is investigated. The conversion of HNCO is high even at the high space velocities (6×105 h-1) and low temperatures (393–673 K) in the tests with catalysts, which enhances HNCO hydrolysis and raises the ratio of NH3 to HNCO to approximately 100. The pure γ-Al2O3 shows a better catalytic performance than CuO/γ-Al2O3. The addition of CuO not only reduces the surfa.e area but also decreases the Lewis acid sites which are recognized to have a positive effect on the catalytic activity. The apparent activation energy of the hydrolysis reaction amounts to about 25 kJ/mol in 393–473 K while 13 kJ/mol over 473 K. The overall hydrolysis reaction rate on catalysts is mainly determined by external and internal mass-transfer limitations.

关键词： Urea-water solution Sol-gel method γ-Al2O3 HNCO hydrolysis

Study on pyrolysis and gasification of wood in MSW

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Journal of Environmental Sciences 2006年第2期18卷 407-415页

作者： NI Ming-jiang XIAO Gang CHI Yong YAN Jian-hua MIAO Qi ZHU Wen-li CEN ke-fa Institute for Thermal Power Engineering State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

In order to develop municipal solid waste（MSW） pyrolysis/gasification and melting technology with low emission and high efficiency, it was planed that all the main components in MSW and some typical kinds of MSW were pyrolyzed/gasified to propose an expert system for raw MSW. In this paper, wood, which was a prevalent component in MSW, was pyrolyzed and gasified in fluidized-bed reactors at different apparent excess air ratios （EARs）, temperatures and fluidizing velocities. For pyrolysis, with tem- perature increasing from 400℃ to 700℃, the yield of pyrolysis char decreased while that of pyrolysis gas increased （in this paper respectively from 28% to 20% and from 10% to 35%）, and when temperature was 500℃, the yield of pyrolysis tar reached the highest, up to 38% in this paper. It was the optimum for gasification when temperature was 600℃ and apparent EAR was 0.4. Under the experimental conditions of this paper, gasification efficiency achieved 73%, lower heat value（LHV） reached 5800 kJ/（Nm^3） and yield of syngas was 2.01 Nm^3/kg. Lower fluidizing velocity was useful to upgrade gasification efficiency and LHV of syngas for wood gasification. Based on the results, the reactive courses and mechanism were analyzed respectively for wood pyrolysis and gasification.

关键词： wood pyrolysis gasification municipal solid waste(MSW)

A new species of the genus Micropeplus Latreille(Coleoptera: Staphylinidae: Micropeplinae) from China

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Zoological Systematics 2014年第3期39卷 445-448页

作者： fa.ke Zheng Yu-Jie Li Xiang-Hui Yan Life Science College China West Normal University

A new species of the genus Micropeplus Latreille is described under the name of M. songi sp. nov. Color photos of habitus, head, pronotum, elytra, wing, metastemum, the 3rd to 7th tergites of abdomen, the 8th stemite,... 详细信息

关键词： Staphylinidae Micropeplinae Micropeplus new species China.

Blockade of Na^+/H^+ exchanger type 3 causes intracellular acidification and hyperexcitability via inhibition of pH-sensitive K^+ channels in chemosensitive respiratory neurons of the dorsal vagal nucleus in rats

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Neuroscience Bulletin 2014年第1期30卷 43-52页

作者： Jing Zhang Hui Peng Sigrid C.Veasey Jing Ma Guang-fa.Wang ke-Wei Wang Department of Respiratory and Critical Care Medicine Peking University First Hospital Departments of Neurobiology and Molecular and Cellular Pharmacology Peking University Health Science Center Center for Sleep and Circadian Neurobiology University of Pennsylvania School of Medicine Department of Medicine University of Pennsylvania School of Medicine

Extracellular pH （pHe） and intracellular pH （pHi） are important fa.tors for the excitability of chemosensitive central respiratory neurons that play an important role in respiration and obstructive sleep apnea. It has been proposed that inhibition of central Na^＋/ H^＋ exchanger 3 （NHE-3）, a key pHi regulator in the brainstem, decreases the pH, leading to membrane depolarization for the maintenance of respiration. However, how intracellular pH affects the neuronal excitability of respiratory neurons remains largely unknown. In this study, we showed that NHE-3 mRNA is widely distributed in respiration-related neurons of the rat brainstem, including the dorsal vagal nucleus （DVN）. Whole-cell patch clamp recordings from DVN neurons in brain slices revealed that the standing outward current （Iso） through pH-sensitive K^＋ channels was inhibited in the presence of the specific NHE-3 inhibitor AVE0657 that decreased the pHi. Exposure of DVN neurons to an acidified PIle and AVE0657 （5 μmol/L） resulted in a stronger effect on firing rate and Iso than acidified pHe alone. Taken together, our results showed that intracellular acidification by blocking NHE-3 results in inhibition of a pH- sensitive K^＋ current, leading to synergistic excitation of chemosensitive DVN neurons for the regulation of respiration.

关键词： Na^+/H^+ exchange potassium channel dorsal vagal nucleus in situ hybridization respiration

Determination of aniline in environmental water samples by alternating-current oscillopolarographic titration

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Chinese Chemical Letters 2007年第6期18卷 730-733页

作者： Jun Ping Xiao Qing Xiang Zhou Xiao ke Tian Hua Hua Bai Xian fa.Su Department of Chemistry University of Science and Technology Beijing Beijing 100083 China School of Chemistry and Environmental Sciences Henan Normal University Henan Key Laboratory for Environmental Pollution Control Xinxiang 453007 China

A new method for the determination of aniline in environmental water based on oscillopolarographic titration was presented in this paper. Several fa.tors including the kind, concentration, and volume of acid, the dosage of potassium bromide, the temperature and concentration of concomitant substances were investigated in detail. The experimental results indicated that this method was simple, rapid, and sensitive. The linear range was 8.367 × 10(?4) to 2.789 × 10(?2) mol L(?1), the relative standard deviation (R.S.D.) was lower than 0.96%, and the spiked recoveries of aniline in environmental water samples were in the range of 99.4–106.9% under the optimal conditions. The results indicated that the present method could be used as an alternative method for aniline determination in realworld water samples.

关键词： Alternating-current oscillopolarographic titration Aniline Potassium bromide

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河南董寨再引入朱鹮种群的巢址分布特征

动物学杂志 2024年第1期59卷 11-18页

作者：黄华王科黄治学蔡德靖刘进法朱家贵席学博王代平河南信阳罗山县董寨国家级自然保护区管理局罗山464236 中国科学院动物研究所动物生态与保护生物学院重点实验室北京100101

为了解再引入朱鹮(Nipponia nippon)种群的分布与扩张情况,本研究对董寨再引入朱鹮野外种群的繁殖巢址进行了调查研究。在2014到2022年间,共调查统计了84个野化放飞朱鹮及其后代的繁殖巢址,使用圆形分布法分析了巢址与放飞点的相对方位... 详细信息

为了解再引入朱鹮(Nipponia nippon)种群的分布与扩张情况,本研究对董寨再引入朱鹮野外种群的繁殖巢址进行了调查研究。在2014到2022年间,共调查统计了84个野化放飞朱鹮及其后代的繁殖巢址,使用圆形分布法分析了巢址与放飞点的相对方位和集中程度,并根据全部巢址的空间分布,使用固定核空间方法计算得到巢区(95%巢址所在区域)与核心巢区(50%巢址所在区域)的分布范围和面积。将巢址图层、土地覆盖图层以及数字高程模型叠加,观察朱鹮巢址选择的生境偏好,并使用单样本t检验判断了巢址平均海拔与巢区海拔间的差异。结果显示,繁殖巢址与放飞点平均距离(平均值±标准差)(12.82±14.11)km(n=84),平均方位角(平均值±标准差)为(138.99±82.44)°(瑞利检验:Z=10.60,P<0.01)。核心巢区与巢区面积分别为74.43 km^(2)和549.66 km^(2)。巢址平均海拔(平均值±标准差)(103±43)m,显著低于巢区内平均海拔(t=﹣5.48,df=83,P<0.01)。巢址的分布主要位于水稻田和森林的交界区域。逐年繁殖区域分布图显示,繁殖区域基本朝向西北-东南方向扩张,与圆形分布分析结果一致。本研究描述了董寨再引入朱鹮种群繁殖巢址的分布特征与扩张趋势,可以为野外朱鹮潜在繁殖地和栖息地的保护提供参考,优化保护工作中的人力物力资源配置。

关键词：朱鹮再引入繁殖巢址分布区河南董寨

Emission and drying kinetics of paper mill sludge during contact drying process

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第11期10卷 1670-1677页

作者： Wen-yi DENG Xiao-dong LI Jian-hua YAN Fei WANG Sheng-yong LU Yong CHI ke-fa.CEN State key Laboratory of Clean Energy Utilization Institute for Thermal Power Engineering Zhejiang University Hangzhou 310027 China

The emission and contact drying kinetics of the paper mill sludge (PMS) were studied through experiments carried out in a paddle dryer. To get a better understanding of its drying mechanism, a penetration model developed by Tsotsas and Schlünder (1986) was used to simulate the drying kinetics of the PMS. The result indicated that this kinetics could be divided into three phases: pasty, lumpy and granular phases, and could be successfully simulated by the penetration model as the related sludge parameters were integrated into the model. The emission rate curves of the volatile compounds (VCs) were interrelated to the drying rate curve of the PMS, especially for volatile fa.ty acids (Vfa.) and ammonia in this study.

关键词： Contact drying Emission Paper mill sludge (PMS) Paddle dryer

Coupled extension and thickness-twist vibrations of lateral field excited AT-cut quartz plates

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Acta Mechanica Sinica 2014年第1期30卷 67-72页

作者： Ting-Feng Ma Rong-Xing Wu Ji Wang Jian-ke Du Li-Li Yuan fa.Peng Yu Chao Xie Piezoelectric Device Laboratory School of Mechanical Engineering & MechanicsNingbo University Department of Architectural Engineering Ningbo Polytechnic State key Lab of Crystal Materials and Institute of Crystal Materials Shandong University

In this paper, the coupled extension and thickness- twist vibrations are studied for AT-cut quartz plates under Lateral Field Excitation （LFE） with variations along the x1- direction. Mindlin＇s two-dimensional equations are used for anisotropic crystal plates. Both free and electrically forced vibrations are considered. Important vibration characteristics are obtained, including dispersion relations, frequency spectra, and motional capacitances. It is shown that, to avoid the effects of the couplings between extension and thickness-twist vibrations, a series of discrete values of the length/thickness ratio of the crystal plate need to be excluded. The results are of fundamental significance for the design of LFE resonators and sensors.

关键词： Lateral field excitation - Resonators Quartz Thickness-twist vibrations