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1.
综合流动和传热的废轮胎回转窑热解模型   总被引:1,自引:0,他引:1  
废轮胎在回转窑内的热解主要受到气-固相流动、传质和传热及化学反应动力参数等因素的影响。在对回转窑 内固体颗粒运动、传热传质进行分析的基础上,结合对轮胎热解反应动力学的研究,发展了综合流动、传热的废轮胎回转 窑热解模型,可计算得到回转窑内热解的温度分布、物料转化率、产物得率等。模型计算结果与试验结果吻合较好。  相似文献   

2.
李群祥  杨金龙 《物理学报》1999,48(6):1086-1094
利用第一性原理的离散变分局域密度泛函方法,采用团簇模型(Si34H36-W11)来模拟STM操纵(Si111)-7*7表面顶角吸附原子的过程,通过分析在进行原子操纵过程中体系的能量与电子云密度分布来研究针尖和外电场的作用。  相似文献   

3.
本文利用一维圆柱等离子体输运编码(TRANPY),编制了模拟锯齿振荡的大型编码(SAWMOD)。对锯齿振荡的研究,我们选用了两种具有代表性的理论模型:重联模型和湍流模型,后者特别适用于低qa放电的锯齿特性研究。重联模型的锯齿振荡是由于磁力线的完全重联引起的,而湍流模型的锯齿振荡是因为微观湍流或磁力线的随机化而产生的。最后,我们将HL─1装置的一次典型高密放电的参数代入(SAWMOD)编码,运算结果表明,重联模型和湍流模型均能解释实验观测的锯齿现象,理论模拟与实验结果符合较好。  相似文献   

4.
微波溶样火焰和石墨炉原子吸收法测定样品中的金属元素   总被引:4,自引:1,他引:3  
本文采用全聚四氟乙烯高压消化弹结合微波溶样技术消化食物,植物和河流沉积物样品,用火焰和石墨炉子原子吸收法测定了样品中的Cu,Zn,Fe,Mn,Ca,Mg,Pb,Se,Cr和Mo讨论了混合酸及消化时间等因素对不同样品的影响,将此法用于标准物质大米粉(G BW08502),猪肝(GBW08551),甘蓝(GBW08504)和河流沉积物(GBW08301)的分析,得到了满意的结果。  相似文献   

5.
本文利用一维圆柱等离子体输运编码(TRANPY),编制了模拟锯齿振荡的大型编码(SAWMOD)。对锯齿振荡的研究,我们选用了两种具有代表性的理论模型:重联模型和湍流模型,后者特别适用于低qa放电的锯齿特性研究。重联模型的锯齿振荡是由于磁力线的完全重联引起的,而湍流模型的锯齿振荡是因为微观湍流或磁力线的随机化而产生的。最后,我们将HL-1装置的一次典型高密放电的参数代入(SAWMOD)编码,运算结果  相似文献   

6.
气固两相混合层流场双向耦合的数值研究   总被引:5,自引:0,他引:5  
采用双向耦合模型对有涡配对的二维气固两相混合展数值模拟,在考虑颗粒对流场反作用基础上进一步对颗粒间通过流体的相互作用进行分析。流场用拟谱方法求解,颗粒用颗粒轨道模型跟踪。结果发现,流场中大涡卷起和配对仍居主导地位;颗粒St数为O(0.1)~O(1)时,颗粒减弱了流场雷诺应力强度,加快涡量扩散; St数为O(1)时,颗粒分布极不均匀,主要集中在渴的边缘.  相似文献   

7.
模拟危险废物颗粒回转窑内运动特性试验研究   总被引:5,自引:0,他引:5  
危险废弃物在回转窑内的运动特性研究是危险废弃物处理处置研究的一部分,本文分析了影响危险废弃物在回转窑内运动特性的主要因素,并采用模拟危险废物颗粒,通过实验的方法研究了回转窑倾角、转速、给料率对物料停留时间、填充率和体积流率的影响。  相似文献   

8.
DSM-LPDF两相湍流模型及旋流两相流动的模拟   总被引:2,自引:0,他引:2  
本文由流体-颗粒速度的拉氏联合概率密度函数(PDF)输运方程出发,用Simonin建议的Langevin模型封闭颗粒所遇到流体瞬时速度的条件期望项,并用Monte Carlo方法直接求解 PDF输运方程,将其和求解流体雷诺应力方程模型的有限差分方法结合,建立了雷诺应力-拉氏PDF(DSM-LPDF,简称DL)两相湍流模型.用此模型模拟了旋流数为0.47的突扩旋流气粒两相流动,并与文献中PDPA实验和用类似于单相流动湍流模型封闭方法的时平均统一二阶矩(USM)模型的预报进行了对比.  相似文献   

9.
MS^2-4(M=Mo、W、V等)阴离子由于灵活多样的配位方式可形成特殊的构造单元而被广泛应用于分子设计中,本文对含有MS^2-4及1,10-phenanthroline的混配金属配合物Zn(phen)2WS4和Zn(phen)2MoS4的晶体进行红外光谱和拉曼光谱的研究并讨论了谱学与结构的关系。  相似文献   

10.
丝光沸石的Monte Carlo研究 Ⅰ,原粉丝光沸石的硅,铝分布   总被引:1,自引:0,他引:1  
丝光沸石原粉样品骨架上硅、铝原子占据是不违反Loewenstein's rule。而且Al-Al彼此次最近邻回避的随机分布。基于这个设想模型,Model-2的Monte Carlo计算所得到的Si-Al近邻分布{Si(n-Al)}相对于未考虑Al-Al次最近邻回避原则的Model-1或二项分布模型计算与^29Si MASNMR实验观测有较好的符合。根据Model-2我们也计算了Al-Al次邻分布{  相似文献   

11.
Chaos synchronization and message transmission of a mutually coupled system consisting of two semiconductor lasers (SLs) and a partially transparent mirror (PTM) in between are investigated theoretically. Analytical results show that two types of chaos synchronization schemes, named as isochronal synchronization (IS) and leader/laggard synchronization (LLS), can be achieved by adjusting the reflectivity and position of PTM. By establishing SIMULINK model, numerical simulations illustrate that as the PTM is positioned at the center of two lasers, IS is available when the reflectivity of PTM is moderate. The LLS is achieved when the reflectivity of PTM equals to 0.5, which means feedback strength equals to coupling strength. Its lag time is just determined by the difference of feedback delay time. The investigations of mutual chaos pass filtering (MCPF) effects and the secure chaotic communication simulations indicate that IS allows real-time bidirectional message transmission on a public-channel, while LLS can achieve higher security chaotic communication by using its lag time as cryptography key. The demonstrated system can be used as a rudiment of array chaos communications system.  相似文献   

12.
Two vertical-cavity surface-emitting lasers(VCSELs) are mutually coupled through a partially transparent mirror (PTM) placed in the pathway. The PTM plays the role of external mirror,which controls the feedback strength and coupling strength.We numerically simulate this system by establishing a visible SIMULINK model.The results demonstrate that the anticipation synchronization is achieved and it can tolerate some extent frequency detuning.Moreover,the system shows similar chaos-pass filtering effect on unidirectionally coupled system even both VCSELs are modulated.This system allows simultaneously bidirectional secure message transmission on public channels.  相似文献   

13.
微生物接种堆肥胡敏酸三维荧光特性研究   总被引:2,自引:0,他引:2  
为提高堆肥效率,试验采用接种微生物堆肥技术,通过对堆肥样品中胡敏酸三维荧光光谱特性进行动态分析,探讨了微生物接种对堆肥腐殖化进程的影响。在堆肥初期,胡敏酸只产生一个类富里酸荧光峰(peak a,Ex/Em为330/440)。在堆肥的336 h,与对照(RUNck)相比,接种微生物堆肥(RUNmic)胡敏酸三维荧光光谱中类富里酸特征峰(peak a,Ex/Em约为350/440)荧光强度明显减少,而类胡敏酸荧光峰(peak b,Ex/Em约为390/470)强度则略有增加;并且peak a和peak b对应的激发、发射波长均有一定程度的红移。胡敏酸元素分析表明,堆肥336 h,RUNck胡敏酸分子中C/H和O/C依次增加9.68%和10.91%;RUNmic中胡敏酸C/H和O/C依次增加了11.11%和20.37%,表明RUNmic中胡敏酸分子缩合度明显。以上结果证实,接种微生物可明加快堆肥腐殖化进程,进而提高堆肥效率。  相似文献   

14.
城市生活垃圾流化床焚烧时PCDD/Fs排放特性的研究   总被引:7,自引:0,他引:7  
城市生活垃圾焚烧处理已逐渐在我国推广应用.垃圾焚烧所产生的二恶英污染问题日益被人们所关注,浙江大学基于我国城市生活垃圾的特点(高水份、多组份、低热值等),成功开发了异重流化床焚烧技术并应用于一座 150 t/d垃圾流化床焚烧锅炉.木文首先介绍了二恶英的分析方法,其次在小型流化床上进行了PCDD/Fs的生成机理试验、在此基础上,对150t/d垃圾焚烧炉烟气中二恶英排放进行了分析,实验结果将指导焚烧炉优化运行并为进一步研究打下坚实基础。  相似文献   

15.
《Current Applied Physics》2018,18(11):1218-1224
Pressure-dependent structural and morphological changes of two amphibole minerals, tremolite and actinolite, were investigated up to 7.0 GPa using synchrotron X-ray powder diffraction underthree different pressure transmission media (PTM): water (W), CO2 and silicone oil (SI). The elastic response of tremolite and actinolite are found to be dependent on the PTM used. When using water (W) as PTM, tremolite and actinolite show normal volume contractions with bulk moduli of 74(1) and 78(1) GPa, respectively. When using CO2 as PTM, we observe the formation of calcite from tremolite above 3.8(1) GPa, whereas actinolite did not show any carbonation reaction. Under silicone oil PTM, we observe modulated volume contraction behaviors in both samples, compared to water and CO2 PTM, with bulk moduli in the order of 90(1) and 94(4) GPa for tremolite and actinolite, respectively.  相似文献   

16.

One hundred consumers evaluated three types of set yoghurt made from: 100% pressure treated milk (PTM; 600 MPa for 15 min), 100% heat treated milk (HTM; 85 °C for 20 min) and a mixture containing 10% PTM and 90% HTM. There was no significant difference between appearance liking or texture liking of the three yoghurt types, though the texture score of PTM yoghurt and mixed milk yoghurt were both higher than HTM yoghurt. Creaminess score for PTM yoghurt was significantly higher than for HTM yoghurt; mixed milk yoghurt was significantly different from HTM yoghurt but not from PTM yoghurt. Concerning taste liking, PTM yoghurt scored significantly less than mixed milk yoghurt, with HTM yoghurt between these two. 57% of consumers preferred the HTM to PTM yoghurt, giving taste as their main criteria; those preferring PTM yoghurt based their choice on texture. Rheological assessments showed differences in gel structure, which justify consumer texture and creaminess choices.  相似文献   

17.
Q. Wei  P. X. Zhang  D. Y. Zhang  J. H. Zhou 《Pramana》2009,73(6):1087-1094
The EPR spectra for VO2+ in CaO-Al2O3-SiO2 system are calculated using complete diagonalization method (CDM) and perturbation theory method (PTM). The calculated results are in good agreement with the observed values. By comparing the calculated results by CDM and PTM in a wide range of crystal field parameters, the validity of the PTM formulas has been studied. It is shown that, the PTM formulas are reasonable and reliable in a wide range of CF parameters.  相似文献   

18.
Simulations of bubble entrainment into a stationary Gaussian vortex are performed by using the combined particle tracking method (PTM) and boundary element method (BEM). Before the bubble is captured by the vortex core, oscillation and migration of the quasi-spherical nucleus are solved by using improved RP equation and the momentum theorem in the Lagrangian reference frame simultaneously, and the trajectory of the nucleus presents a kind of reduced helix shape. After captured by the vortex core, the bubble grows immediately and moves and deforms along the vortex core axis. The non-spherical evolution and deformation of the bubble is simulated by adopting a mixed Eulerian-Lagrangian method. The output of quasi-spherical stage is taken as the input of non-spherical stage, and all the behaviors of the entrained bubble can be simulated such as inception, motion, deformation and split. Numerical results agree well with published experimental data. On this basis, the influences of various factors such as viscosity, surface tension, buoyancy are studied systemically. Hopefully the results from this paper would provide some insight into the control on vortex bubble entrainment.  相似文献   

19.
Optoelectronic tweezers uses optically induced dielectrophoretic (DEP) force for manipulating cells in aqueous solution, which has shown potential applications in biology and tissue engineering among other possibilities. To effectively design the optoelectronic tweezers (OETs) chip, detailed knowledge about the behavior of cells in response to DEP force in an aqueous layer is needed. In this paper, the trajectories of an SMMC-77721 cell, simulated as a rigid dielectric sphere, in the induced electric field of optical trapping are studied using both an Arbitrary Lagrangian-Eulerian (ALE) method and a particle-tracing method (PTM) available within the COMSOL multiphysics software platform. Because the ALE method involves solving the distorted electric field around the cell and taking a full account of the Maxwell stress tensor (MST), it is expected to provide more accurate predictions about the spherical cell velocity than PTM that involves dipole moment approximation. Our ALE results show noticeably greater cell velocity than that predicted by the classical DEP expression based on dipole moment approximation. The ALE model can help gain new insights for analyzing cell motions in aqueous solution under sophisticated optical spot patterns.  相似文献   

20.
垃圾焚烧灰渣的熔融物理化学特性分析   总被引:4,自引:0,他引:4  
对垃圾焚烧灰渣的熔融物理化学特性研究,为合理应用和发展垃圾焚烧技术以及对灰渣的熔化处理和有效利用提供基础。本研究对目前运行的不同垃圾焚烧技术进行灰渣采样,系统分析垃圾灰渣的熔融物理化学特性的变化和相互关系,并给出灰渣流动温度和软化温度的拟合公式,并对垃圾焚烧技术及灰渣处理提出建议。  相似文献   

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