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101.
回转式干馏炉内影响颗粒混合运动因素的数值分析 总被引:3,自引:1,他引:3
以水平回转式干馏炉为研究对象,采用离散单元法(discrete element method,DEM)建立颗粒运动模型,接触模型采用Hertz无滑动接触模型,分别对在其内设置不同形式抄板(直角抄板﹑弯抄板和直抄板)的混合效果和混合规律进行了数值研究。将大小颗粒间接触数与颗粒间接触总数之比定义为混合质量,并以此来衡量混合程度,同时分析抄板形式及转速对混合质量的影响。研究结果表明,干馏炉内设抄板时,混合趋于稳定的时间较短,抄板形式对混合质量的影响较小;随着转速的降低,混合质量曲线越平缓,波动幅度越小。研究结果对干馏炉的设计和优化具有一定的指导作用。 相似文献
102.
为了解决目前主流的基于WS-security的面向服务安全框架中的安全脆弱性问题,保证面向服务架构中Web服务的安全,通过采用将安全语句封装在SAML断言语句块中,创建SAMI认证声明及进行SAML授权等为服务响应模块提供安全断言,并通过网络层和服务层的安全实现来保证Web服务的安全和实现用户的单点登录等. 相似文献
103.
Let A be a real matrix or a sign pattern of order n. N-(A) denotes the number of negative entries in A. In 1972 R DeMarr and A Steger conjectured: If A is a real matrix of order n such that A2≤0, then N_(A2)≤(n-1)2 1. Now the conjecture is proved to be true when A is reducible or a matrix of order n≤3 and some sufficient conditions for N_(A2)≤(n-1)2 1 are given. It is also proved that N_(A2)≤n2-4n 5 when A is a reducible combinatorially symmetric sign pattern such that A2≤0, and the extreme sign patterns are characterized. 相似文献
104.
为适应城市对国防、治安、反恐、消防等需求,一些新建的超高层建筑在顶层设置了圆形直升机停机坪。通过具体工程设计实例,介绍了超高层建筑屋顶直升机停机坪灯光信号、灯光照明等电气设计,以对类似新建超高层建筑停机坪电气设计提供参考。 相似文献
105.
对比了二价和三价铁及其复合药剂对城市污水处理厂除磷效果,研究了搅拌条件对除磷效率的影响,同时研究了混凝后不同形态磷的变化情况。研究结果显示,原始混合液中颗粒态磷、无机溶解态和有机溶解态的磷分别为2.63、0.99、0.28 mg/L。三价铁化学除磷效果最佳,复合药剂次之。当复合混凝剂投加量达到污泥体积0.15%时,TP的去除效率达到最高,之后会随着混凝剂投加量的增加而降低。水力剪切过程对化学除磷效果影响较大,随着搅拌速率的提高,混凝效率逐渐提高,转速达到200 rpm时TP去除率达到最大。 相似文献
106.
中国传统绘画中的建筑形象及表现手法 总被引:1,自引:0,他引:1
靳超 《北京建筑工程学院学报》2002,18(2):40-46
本文着重论述了中国传统绘画中(主要是界画与壁画)建筑形象及表现手法,通过对部分代表性作品的分析,阐述传统绘画中建筑形象与画面意境和精神内涵的有机结合以及建筑形象的表现样式. 相似文献
107.
The article presents an analysis of a large-scale survey with the aim of understanding differences in the open, interactive and distributed nature of external innovation relations amongst firms belonging to different industrial knowledge bases. The thesis is that the source of critical innovation relevant knowledge differs between industrial knowledge bases, making the character and the need of openness contingent on these specificities. Accordingly, we anticipate that we will observe systematic variations in how industries access and combine innovation-related external knowledge. In our analyses we attempt to address a gap in the literature by examining how industrial knowledge bases affect the recombination of knowledge by analysing the different extents, forms (formal and informal) and geography of inbound open innovation. The article illustrates that features and structures of inbound open innovation align, to a large extent, with the industries' knowledge bases and that there is a interplay between an industry's knowledge base, the internal organisation of innovation processes and the channels and geography of inbound open innovation. 相似文献
108.
Intrinsic Fluorescence of the Active and the Inactive Functional Forms of Human Thymidylate Synthase
Dr. Simone Vitiello Dr. Monica Caselli Dr. Giorgia Pavesi Dr. Matteo Santucci Dr. Stefania Ferrari Prof. Maria Paola Costi Prof. Glauco Ponterini 《Chembiochem : a European journal of chemical biology》2021,22(10):1800-1810
The observables associated with protein intrinsic fluorescence – spectra, time decays, anisotropies – offer opportunities to monitor in real time and non-invasively a protein‘s functional form and its interchange with other forms with different functions. We employed these observables to sketch the fluorometric profiles of two functional forms of human thymidylate synthase (hTS), a homodimeric enzyme crucial for cell proliferation and thus targeted by anticancer drugs. The protein takes an active and an inactive form. Stabilization of the latter by peptides that, unlike classical hTS inhibitors, bind it at the monomer/monomer interface offers an alternative inhibition mechanism that promises to avoid the onset of drug resistance in anticancer therapy. The fluorescence features depicted herein can be used as tools to identify and quantify each of the two protein forms in solution, thus making it possible to investigate the kinetic and thermodynamic aspects of the active/inactive conformational interchange. Two examples of fluorometrically monitored interconversion kinetics are provided. 相似文献
109.
We use one-variable Loewner techniques to compute polynomial-parametric models for MIMO systems from vector-exponential data gathered at various points in the parameter space. Instrumental in our approach are the connections between vector-exponential modelling via bilinear differential forms and the Loewner framework. 相似文献
110.
AbstractObjectives were to study mechanical properties of various solid forms of paracetamol and relate to their crystal structures. Paracetamol form I (PRA), its cocrystals with oxalic acid (PRA-OXA) and 4,4-bipyridine (PRA-BPY) and hydrochloride salt (PRA-HCL) were selected. Cocrystals and salt were scaled-up using rational crystallization methods. The resulting materials were subjected to different solid-state characterizations. The powders were sieved and 90–360?µm sieve fraction was considered. These powders were examined by scanning electron microscopy (SEM) and densities were determined. Tablets were made at applied pressures of 35–180?MPa under controlled conditions and the tablet height, diameter and hardness were measured. Tensile strength and porosity of the tablets were estimated using well known models. Crystal structures of these systems were visualized and slip planes were identified. Cocrystal and salt of PRA were physically pure. Sieved powders had comparable morphologies and particle size. The apparent and theoretical densities of powders were similar, but no clear trends were observed. The tensile strengths of these compacts were increased with increasing pressure whereas tabletability decreased in the order oxalic acid?>?PRA-HCL?≈?PRA-OXA?>?BPY?>?PRA-BPY. Tablet tensile strength decreases exponentially with increasing porosity with the exception of PRY-BPY and BPY. Slip plane prediction based on attachment energies may not be independently considered. However, it was possible to explain the improved mechanical properties of powders based on the crystal structure. Cocrystallization and salt formation have introduced structural features that are responsible for improved tableting properties of PRA. 相似文献