静电增强纤维层的荷尘特怔

本文根据实验发现，假定粉尘均匀地沉积在纤维层中各纤维的表面上，从而，建立了荷尘纤维当量直径和荷尘纤维层当量充填率的数学模型。     

纤维滤坐设备气流组织彩式试验研究

纺织车间散发出的尘埃为混合性尘,内含大量有回用价值易燃的纤维尘绒和对人体危害较大的小粒径无机粉尘。因而纺织厂对滤尘设备性能要求不仅仅是过滤效率,同时要求滤尘设备将根据纤维尘绒回用价值分级回收和具有可靠的防火防爆性能。近几年国内外对纤维滤尘设备的研究都已注意进入滤尘设备的气流流径滤料的形式不仅影响过滤效率,而且对纤维尘的分级回收和防火性能有明显的影影。为此本文对国内外现有纤维滤尘设备的气流组织形式进行測试和试验研究,提出纤维滤尘设备的最佳气流组织形式。     

静电增强纤维层的荷尘特征

静电增强纤维除尘技术是控制呼吸性粉尘危害的有效技术。本文根据实验发现，假定粉尘均匀地沉积在纤维层中各纤维的表面上，从而，建立了荷尘纤维当量直径和荷尘纤维层当量充填率的数学模型。为了检验这些数学模型而进行了一系列实验．实验结果表明：在荷尘状态下，静电增强纤维层的除尘过程具有深床型过滤、深床型和浅床型复合过滤，以及随机构流三个阶段特征。在深床型过滤阶段，实验结果与本文建立的数学模型吻合很好。     

物料自由下落过程产尘率影响因素分析

本文通过改变接触面的方法,将总产尘分为下落过程中随气流逃逸的一次尘和与接触面碰撞过程中产生的二次尘两部分,用实验的方法,研究了两组不同粒径分布的物料在下落高度、出流流量变化时,一次尘、二次尘、总产尘的变化规律。实验结果表明,不同粒径分布的物料其产尘情况差异较大,两组物料随下落高度及出流口径的变化趋势一致。一次产尘率、二次产尘率、总产尘率均随下落高度的增大而增大,随出流口径的增大而减小。     

放射性厂房不同送风过滤器组合对排风过滤器寿命的影响

通过建立放射性厂房颗粒物浓度平衡模型,分析了排风系统净化过滤器容尘负荷的主要影响因素.实测了6种空气过滤器组合对6个粒径区间粒子的过滤效率,并根据实测效率计算了各空气过滤器组合对试验尘、实测大气尘中粒径≥0.3μm颗粒物的计重过滤效率.分析了某核电厂废物暂存库送风系统不同的空气过滤器组合对排风系统净化过滤器容尘负荷和寿...     

碎石最大粒径对纤维混凝土强度的影响

通过不同碎石最大粒径纤维混凝土强度的试验分析。介绍了碎石最大粒径对三种常用纤维混凝土强度的影响规律，指出纤维混凝土是一种新型材料，具有广阔的发展前景。     

地面狭缝通风系统对屋尘空间分布及作用效果的影响研究

屋尘包含真菌的孢子和尘螨的尸体、粪便等,它们会引起哮喘和非特异性过敏疾病。本研究通过实验和CFD数值模拟研究地面狭缝通风系统对屋尘空间分布及作用效果的影响。考虑到屋尘通常沉降于地面,通风系统的送风口设置在天花板中心,狭缝状排风口位于墙壁和地面交界处。在实验研究中,使用核黄素粉体代替屋尘,对于粒径在0.5～3.0μm的屋尘粒子,实验值和计算值表现出良好的相似度。通风系统运行前,由于重力沉降的影响,不同粒径的屋尘粒子表现出平滑的沉降曲线;通风系统运行后,屋尘粒子的沉降率比系统运行前更快。系统运转2h后,屋尘浓度大幅降低。     

气溶胶粒径计数法检测空气过滤器效率的探讨

介绍了国内现行空气过滤器效率的标准检测方法——大气尘计数法,指出了该效率检测方法的优缺点。详细介绍了当前欧、美等国家空气过滤器效率的标准检测方法—气溶胶粒径计数法,并从试验用气溶胶、检测仪器和效率标识三个方面对欧、美的效率检测方法进行了详细的分析比较。列出了气溶胶粒径计数法较大气尘计数法的优越性,进而提出了用气溶胶粒径计数法来检测空气过滤器效率的观点。并详细说明了用气溶胶粒径计数法检测空气过滤器效率的操作方法。     

纺织厂粉尘爆炸预防技术措施

所谓粉尘，是指悬浮于空气中的微细尘粒。纺织厂粉尘多数为纤维的各种成份的混合物，还含有动植物性粒屑、细菌、灰尘等各种污染物，粒度范围广，尘粒形态复杂。粉尘爆炸必须具备三个要素：粉尘本身易燃，有足够的氧气及火源。纺织厂尘室内的棉尘、麻尘、针织起绒形成的绒尘及各种成份的尘埃，均是可燃性粉尘，并在尘窒和风管中呈悬浮状态。因此，纺织厂的尘室都存在着极大的火灾爆炸危险，一旦遇有火源．随时都有发生爆炸的可能。1987年3月15日，     

静电增强纤维层压力损失的计算

许多研究者对纤维层的压力损失进行了大量的研究，并取得了良好的结果。不过，这些研究均是假定气流为小雷诺数流，即展流。然而静电增强纤维层常常在大雷诺流中运行．本文给出了大雷诺数流场中单位长度纤维上无量纲流体阻力的定义式，并用类比法求得了无量纲流体阻力和纤难层压力损失的计算式。根据质量守衡定律，本文还定量分析了静电增强纤维层在荷尘状态下的特征。最后，用实验证实了这些研究结果．     

Influence of fibrous additives on properties of aerated autoclaved concrete forming mixtures and strength characteristics of products

The influence of fibrous additives of non-hydrophilized and hydrophilized carbon, polypropene, basalt and kaoline fibre on properties of aerated autoclaved concrete (AAC) forming mixture, as well as on properties of final product was investigated.All these fibrous additives, both non-hydrophilized and hydrophilized, have effect on fluidity and swelling of forming mixtures and increase plastic strength. Along with growing content of each fibrous additive within limits from 0.1% to 0.4% of mass of solid components, the fluidity and swelling of forming mixtures decreases, while the plastic strength increases.All investigated fibrous additives, both hydrophilized and non-hydrophilized, increase the compression- and flexural strengths of AAC. The optimal content of all fibrous additives to be added for obtaining of greatest compression- and flexural strengths is 0.3% counting of dry material in the forming mixture. By capacity to increase the compression- and binding strengths, the fibrous additives may be lined up in the following order: carbon fibre > polypropene fibre > basalt fibre > kaoline fibre. All fibrous additives increase flexural strength more than that of compression. Hydrophilized fibres increase compression- and flexural strengths of concrete more than the respective non-hydrophilized ones.Basing on the results of investigations performed as to fibre-reinforced AAC structure by scanning electron microscope, as well as on the results of earlier performed investigations with fibres used for reinforcement to find out their chemical resistance to treatment of them in the autoclave by alkaline solutions, the pH value of which corresponds to that of hardening alkaline binding medium of concretes, the influence of properties of fibrous additives on efficiency of reinforcement was explained.     

聚丙烯纤维网混凝土低温抗裂性能分析

为了改善混凝土低温抗裂抗冲击性能,在混凝土中加入聚丙烯纤维网。本文通过对聚丙烯纤维网混凝土低温抗裂性能理论分析和对不同掺量聚丙烯纤维混凝土低温状态下试验指标比较分析,从而得出不同掺量对混凝土各种性能的不同影响。     

无机纤维状绝热材料在土木工程中的应用

根据无机纤维状保温隔热材料的特性和功能,分析其在特定的领域所能发挥的作用及施工工艺,实践证明:无机纤维状保温隔热材料可以提高工业和民用建筑的保温隔热性能,降低能耗,既能满足人们对建筑物的舒适性和健康性要求,又能满足人们对于工业建筑低耗能的要求。     

On the filtration of fibrous aerosols

Basic processes occurring during the filtration of fibrous aerosols are discussed. Using aerosols containing very fine asbestos fibers, the filtration efficiencies of some analytical filters — Nuclepore, Millipore and fiber filters — were investigated. The collection efficiences were determined by electron microscopy and radiolabeled asbestos fibers and were found to depend upon the pore size of the filter and on the form of the fiber of the respective aerosols. The collection efficiencies were found to lie in the range 40–99.9%.A special problem discussed concerns the orientation of fibrous particles in the vicinity of the entrances to pores in the filter.     

纤维束过滤技术处理微污染水源水的中试研究

采用纤维柬过滤技术与均质滤料过滤技术处理某石化水厂的微污染源水。结果表明,纤维柬过滤技术比均质滤料过滤技术对浊度、色度的去除效果更好。纤维柬过滤在滤速为15m／h时,出水浊度最低可达0．2NTU以下,色度为10倍,过滤周期为36h;在滤速为20m／h时,出水浊度仍能达到0．3NTU以下,且过滤周期可达到24h。均质滤料过滤在滤速为8m／h时,出水浊度最低只能达到0．3NTU,色度为15倍,过滤周期为24h。纤维柬过滤技术具有阻力小、滤速快的特点,对中小水厂改扩建有积极的推广价值。     

Study on transient heat transfer through multilayer thermal insulation: Numerical analysis and experimental investigation

This paper reports on a numerical and experimental study of heat transfer phenomena through two different multilayer fibrous insulations for building applications. The investigated samples were composed of different layers of fibrous materials and aluminium foils, placed between one or two air gaps in the vertical dimension. An experimental apparatus (a guarded hot box) has been used to measure heat transfer through the samples, while a finite volume numerical model combined radiation/conduction heat transfer was developed to predict the temperature distribution and heat transfer in such insulation systems comprised of the materials separated by multiple reflective foils. The model takes into account the coupling between the solid conduction of the fibrous system and the gaseous conduction and radiation. The radiation heat transfer through the insulation system has been modelled via the two flux approximation. The numerical results were compared with the experimental data from the guarded hot box for model validation, as well as to assess the effectiveness of the reflective foils in changing the resistance of the insulations. The comparative verification of the model showed that the numerical results were consistent with the experimental data through the environmental conditions under examination.     

128 层螺旋 CT 三期动态增强在鉴别高分化肝癌和局灶性结节增生中的价值

目的：探讨128层螺旋CT三期动态增强在鉴别高分化肝癌（WHCC）和局灶性结节增生（FNH）中的诊断价值。方法分析41例肝脏占位病变患者（其中20例 WHCC为 WHCC组、21例 FNH 为 FNH 组）128层螺旋CT三期动态增强扫描图像,观察有无假包膜、有无肝硬化、有无肿块纤维瘢痕;测量病灶大小、病灶平扫 CT值、平扫值与正常肝脏的 CT比值、动态增强的峰值、动态峰值与肝脏比值、动脉期 CT值（AP 值）、静脉期 CT 值（VP值）、延时期CT值（DP值）。结果假包膜：WHCC组12例,FNH组0例;中央纤维瘢痕：WHCC组0例,FNH组8例;肝硬化：WHCC组7例,FNH组1例。WHCC组年龄大于 FNH 组[（58．40±0．29）岁比（41．20±0．46）岁, P＜0．01]。WHCC组较 FNH 组的平扫 CT值（42．90±1．76比51．33±1．26）、动态增强峰值（94．74±4．49比116．74±4．25）、峰值与肝脏比值（1．30±0．72比1．63±0．59,）、AP值（74．10±4．15比102．71±4．10）、VP 值（84．05±4．62比107．05±3．76）、DP值（78．70±2．99比95．24±3．35）显著降低（均P＜0．01）。结论假包膜为WHCC固有特征,中央纤维瘢痕为 FNH 常见特征。三期动态增强扫描年龄、平扫 CT 值、动态增强的峰值、AP值、VP值、DP值对 WHCC和 FNH的检出和鉴别诊断有一定价值。     

Macro- and microscopic in-situ observation of gas bubbles and sludge particles in a biogas tower reactor

Macroscopic and microscopic in-situ observation of particles and gas bubbles are used to get precise impressions of the hydrodynamical characteristics of a biologically active suspension. Moreover, values of in-situ velocities and particle densities can be gained by using these methods. The suspended anaerobic sludge revealed an extensive fibrous structure ('fur') on its surface. The observed microfibers have a profound influence on the settling/flotation behavior of the particles because they increase the effective particle volume, they may trap gas bubbles and they favor agglomeration. The biomass particles do not appear as single spherical objects but due to its fibrous structure on the outside as strongly interacting mass. The compressibility of the bubbles which are entrapped in the sludge agglomerates results in a pressure-dependent density of the sludge particles.     

Fibrous Tectonics

Living nature is characterised by ubiquitous and all-pervading diversity. Over the course of evolution, highly differentiated and infinitely varied systems have emerged in biology. Given the vast range of natural variation, it may come as a surprise that almost all load-bearing biological structures are fibrous composites. Guest-Editor Achim Menges , Director of the Institute for Computational Design (ICD), and Jan Knippers , Director of the Institute of Building Structures and Structural Design (ITKE), both at the University of Stuttgart, have conducted several research projects exploring how the principles of biological fibre systems can be transferred to architecture. Based on advanced design computation, simulation and robotic fabrication, these explorations not only open up a new approach to fibre-reinforced composite structures, but also enable the discovery of novel fibrous tectonics.     

The fire hazard of fibrous glass ducts—An evaluation

A series of fifty-seven fire tests was conducted to evaluate the significance of the combustible components of compositions used in the manufacture of fibrous glass ducts and to evaluate the fire spread potential of such ducts. These tests established that fibrous glass ducts are products of low combustibility comparable to several other products of low combustibility which are commonly classed as noncombustible, that with severe fire exposure much in excess of the available heat in the products themselves they can be made to burn, and that the likelihood of fire spread through the ducts to other areas is remote. Factory Mutual Research Corporation Note: Based on Factory Mutual Research Corp. Laboratory Report No. 15985 by J. A. Wilson, prepared for the National Insulation Manufacturers Association, Mr. Capron is currently employed by the Inland Steel Company.