模外装饰自动换膜机构设计

基于模外装饰工艺原理,对模外装饰自动换膜机构进行了详细设计,其中包含抚平轮和夹紧轮部分、机构固定部分、机架部分和裁刀部分。抚平轮和夹紧轮部分由抚平轮、夹紧轮、轴承、轴承套和摇杆等组成;机构固定部分由电机、压块、压块杆、轴承盖和摇杆等组成,机架部分由滚动导轨副、底板、滚珠丝杆副、步进电机、滚筒支架等组成;裁刀部分由侧板、导向杆、滑块和驱动电机组成。该套模外装饰自动换膜机构能够满足设计要求和实际需要。     

Lipoprotein(a): Nonhuman primate models

Lipoprotein(a) [Lp(a)] is a low density lipoprotein which has apo(a) disulfide-linked to apoB100. Apo(a) has recently been shown to have a striking homology with plasminogen, a knowledge that has stimulated a lot of interest in the mechanism of atherogenicity and thrombogenicity of this lipoprotein particle. Several studies have documented the presence of Lp(a) in nonhuman primates with particular reference to the rhesus monkeys and baboons. The Lp(a) of rhesus monkey is structurally very similar to that of humans, except for the absence of kringle V and the amino acid composition of the catalytic region. The Lp(a) of nonhuman primates, like their human counterparts, exhibit a wide range of interindividual plasma levels and also a wide size polymorphism of apo(a). Nonhuman primates appear to represent a good model for the study of the structure and biology of Lp(a).     

Generalized Orowan-Petch Plot for Brittle Fracture

The fracture of brittle solids is considered to be based on a defect configuration consisting of a stress concentrator, in our case a hemispherical pore, and a starter crack, in our case either a semicircular crack, a circular crack, or a circumferential crack. Computation of the stress field, application of the relevant weight functions, and an averaging scheme based on the assumption of a virtual crack increment provides stress intensity factors for all defect configurations considered. A normalization scheme yields a generalized version of the Orowan-Petch plot in the form of a normalized strength to normalized defect size relationship.     

Monitoring the oxidative modification of lipoprotein(a) by capillary zone electrophoresis

Lipoprotein(a) [Lp(a)] is a recognized risk factor for atherosclerotic cardiovascular disease. It is made of a lipoprotein particle containing apoB100 linked by a single disulfide bridge to apolipoprotein(a), a glycosylated protein with a variable mass. Some authors suggest that oxidative modification could explain the contribution of Lp(a) in the development of atheromatous lesions in a comparable way to low‐density lipoproteins (LDL). Recently, the use of capillary electrophoresis to measure the variations in the relative electrophoretic mobility (REM) of LDL subjected to copper oxidation has been proposed. The aim of this work is to employ this method also to monitor the copper‐induced oxidative modification of Lp(a). Migration of Lp(a) was monitored by absorption at 200 nm in a 50 mmol/L tricine, 100 mmol/L methylglucamine, pH 9.7 run buffer. Contrary to the conventional slab gel methods, our procedure provides a rapid and reproducible means to measure the electrophoretic mobility of Lp(a) (migration time <10 min with a CV% <0.5).     

Gravity draining of a yield-stress fluid through an orifice

We study the draining of a yield-stress fluid from a vertical vessel having a hole or a tube at its bottom. In order to understand the basic process we first study the problem with a Newtonian fluid and show that the flow characteristics can be very well described by assuming that the flow is analogous to that through a straight conduit of given length. For a yield-stress fluid draining through a hole the behaviour is different: the flow stops when the pressure drop across the orifice falls to a finite value which increases as the yield stress of the fluid increases or the hole radius R decreases. All the data collapse onto a master curve when plotted in terms of dimensionless numbers involving a characteristic length which is a function of R. We deduce an empirical model for the flow characteristics in such a case. When a length of tube is added after the hole we show that the characteristics of the flow are similar to those for flow through a straight conduit with an equivalent length equal to the tube length plus a fixed additional length.     

GENERAL LINEAR PROCESSES:A PROPERTY OF THE EMPIRICAL PROCESS APPLIED TO DENSITY AND MODE ESTIMATION

Abstract. General linear processes do not usually satisfy strong mixing conditions. Therefore, we investigate the empirical process based on samples from such a general linear process by using a truncation argument and derive a local fluctuation inequality. It is well known that such a fluctuation inequality is of basic importance in the study of the empirical process. Here it is applied to obtain a rate of almost sure (a.s.) convergence for certain density estimators in the supremum norm. This extends a local result obtained by Chanda. As a direct corollary a rate of a.s. convergence for a mode estimator is obtained.     

Successful utilization of lyophilized lipoprotein(a) as a biological reagent

Lipoprotein(a) [Lp(a)] represents a class of lipoprotein particles having as a protein moiety apoB-100 linked by a single disulfide bond to apolipoprotein(a) [apo(a)], a multikringle structure with a high degree of homology with plasminogen. A recognized feature of Lp(a) is its instability on storage caused by attendant protein and lipid modifications that affect the structural, functional, and immunological properties of this lipoprotein. Here we present data showing that, under appropriate conditions of cryopreservation, Lp(a) retains the properties of the freshly isolated product, and we provide examples supporting the stability of this cryopreserved product as a primary standard in immunoassay settings and in cell culture systems.     

Effects of catalyst and vehicle in coal liquefaction

Experiments have been carried out, using a semi-batch reactor equipped with a consecutive sampling device, to clarify the effects of catalysts and vehicles in the coal liquefaction process. The results show that a vehicle has a significant effect during preheating, unlike a catalyst which is not effective at this stage. A catalyst is more effective in promoting liquefaction under reaction conditions of 450°C and ≈ 20 MPa than is a vehicle. A vehicle higher in hydrogen donation increases the yield of oil even if a catalyst is present, providing a multiplier effect. In the development of a direct coal liquefaction process, therefore, selection of a vehicle is as important as that of a catalyst.     

Simulation of the vapor explosion of tin and aluminum oxide fragments in water

The vapor explosion process involves an explosive phase change from a thin liquid film into a vapor with a dramatic change in material properties across a high-pressure shock wave. The energy released during the explosion process can reach a level of chemical explosions associated with detonating high explosives. Because no fuel-air chemical reaction is needed for initiating a vapor explosion, the process can be considered as a green reaction that generates zero pollutants. However, the phase change that accompanies a thousand-fold increase in the vapor volume during the rapid film evaporation is a natural consequence of a sudden change in density across the phase front; this feature closely resembles the process of blast wave generation. The high-pressure vapor produced without a chemical reaction expands as a spherical wave at a uniform velocity predicted through the Rankine-Hugoniot shock conditions. In this paper, a new methodology based on a simple shock wave and a phase field theory is proposed to formulate the vapor explosion process.     

Metabolization of the Polycyclic Aromatic Hydrocarbon Benzo( A )Pyrene by a Non-White Rot Fungus ( Fusarium Solani ) in a Batch Reactor

To investigate metabolization of benzo[ a ]pyrene (B a P), a high-molecular-weight polycyclic aromatic hydrocarbon consisting of five aromatic rings, by a Deuteromycete Fusarium solani , a culture with [7,10- 14 C]benzo[ a ]pyrene was carried out in a batch fermentor under cometabolic conditions. In spite of drastic culture conditions with a high load of B a P (302 mg in a 1.6 liters), analysis of the growth and substrate depletion kinetics showed a classical pattern. The evolution of 14 CO 2 release demonstrated that B a P mineralization by the non-white rot fungus F. solani occurred rapidly at early stages of fermentation (15 hr) during the germination process. At the end of fermentation, 1.2% of the B a P was evolved as 14 CO 2 and 5.3% was incorporated in biomass. B a P metabolization was also confirmed by isolating metabolic products, extracted from mycelia and identified as 1,6-benzo[ a ]pyrene quinone and 3,6-benzo[ a ]pyrene quinone, by mass and ultraviolet (UV) spectroscopic analyses.     

Treatment for improving flame retardancy of wool and minimizing toxic gas evolution in burning

A treatment involving formaldehyde, a reducing agent, and a boron-containing compound of a wool shag carpet imparted to it a flame-retardancy effect that was effective after the seventh but not the eighth shampoo. This treatment also decreased the concentration of carbon monoxide and hydrocyanic acid generated in the products of combustion by at least a factor of 2. Analogous treatment of a wool flannel fabric produced a 15–22% sample area shrinkage and imparted a flame-retardancy effect that was still effective after a 2-hr cold water rinse.     

Thermal conductivity of polymer filled with carbon materials: Effect of conductive particle chains on thermal conductivity

Thermal and electric conductivities of polyethylene and poly(vinyl chloride) filled with carbon materials over a wide range are measured in order to study the effect of formed conductive particle chains on thermal conductivities of the composites. With increase of content of carbon particles, the amount of formed conductive chains exponentially increases and the conductive chains tend largely to increase thermal conductivity of a composite. Some models proposed to predict thermal conductivity of a composite in a two-phase system could not be applied to the system with high volume content of particles. In this study, a new thermal conduction model is proposed to correctly predict thermal conductivity of a composite which contains various amounts of particles ranging from a small content, to the region in which conductive chains largely effect a thermal conductivity of a composite. Thermal conductivity of a polymer filled with high volume content of particles largely decreased with a rise in temperature. This phenomenon can be referred to as a PTC phenomenon in thermal resistance.     

Analysis of the process of the countercurrent cyclic chromatography

Cyclic countercurrent chromatography, a new method of liquid chromatography, has been considered. A mathematical model of a cyclic process has been developed. Each cycle consists of two half-periods, i.e., a half-period of the motion of a light phase (a heavy phase plays a role of an immobile phase) and a half-period of the motion of a heavy phase (a light phase plays a role of an immobile phase). Sampling is introduced in the form of a pulse into the average zone of a system of sequentially connected equilibrium steps into the half-period of the motion of the light phase of the initial process cycle. Analytical dependences for calculating the cyclic processes of the countercurrent chromatography have been derived. The experiment and the theory are correlated, and satisfactory agreement between the experimental results and computational investigations has been established.     

Templating of crystallization and shear-induced self-assembly of single-wall carbon nanotubes in a polymer-nanocomposite

We report the appearance of a novel self-assembling of a fraction of single-wall carbon nanotubes (SWCNT) within a SWCNT-polymer nanocomposite subjected to flow fields upon injection molding processing. By combining X-ray diffraction and Raman spectroscopy techniques, both working on a microfocus fashion, we probe that a fraction of the thinnest SWCNT self-assembles into a rectangular lattice in the sample regions where the shear stress induces the highest levels of nanotube aggregation. Additionally, we demonstrate that a modest amount in weight of nanotubes is enough to template the morphology of crystallization during flow providing a method to obtain a highly desirable fiber-like morphology.     

A fryer design with constant specific surface area

The specific surface area (surface area/volume) of a traditional frying vessel with a rectangular profile increases as the oil level decreases. In order to maintain a constant specific surface area of frying oil regardless of oil consumption, a special fryer was designed and constructed. The specific surface area of a frying vessel having a linear-inclined profile (Valentine batch fryer) deviated from a constant value by a maximum of 7.5%. The specific surface area of a frying vessel with an exponentially curved profile maintained a constant specific surface area even though the oil level varied.     

Effect of packing density and adsorption parameters on the throughput of a thermal compressor

Vapour adsorption refrigeration systems (VAdS) have the advantage of scalability over a wide range of capacities ranging from a few watts to several kilowatts. In the first instance, the design of a system requires the characteristics of the adsorbate–adsorbent pair. Invariably, the void volume in the adsorbent reduces the throughput of the thermal compressor in a manner similar to the clearance volume in a reciprocating compressor. This paper presents a study of the activated carbon +HFC-134a (1,1,1,2-tetrafluoroethane) system as a possible pair for a typical refrigeration application. The aim of this study is to unfold the nexus between the adsorption parameters, achievable packing densities of charcoal and throughput of a thermal compressor. It is shown that for a thermal compressor, the adsorbent should not only have a high surface area, but should also be able to provide a high packing density. Given the adsorption characteristics of an adsorbent–adsorbate pair and the operating conditions, this paper discloses a method for the calculation of the minimum packing density necessary for an effective throughput of a thermal compressor.     

Non-Destructive Reliability Analysis of a Bridgewire Fuze Head

In this paper a novel method to determine the reliability of a bridgewire fuze head is proposed. It is assumed that a bridgewire will respond positively to a current pulse if the bridgewire temperature exceeds a critical value as a result of the pulse. To calculate the bridgewire temperature the distributions of four thermal parameters that characterize the electrothermal response of a bridgewire fuze head are used. Preliminary results indicate that this novel approach is in agreement with classical methods. Furthermore, one needs to test a limited amount of items and only a fraction of the tested items is destroyed.     

Fireclay mortar with a casting binder as a plasticizing additive

A composition of a fireclay mortar with a casting binder as a plasticizing additive is described. Results of a study of the properties of a mortar of grade MSh39 with a composite plasticizing agent (soda ash+LST) and a casting binder are presented. It is established that use of a casting binder in the composition of a fireclay mortar increases the adhesion between the mortar and the refractory, decreases the thickness of the joint, and simplifies the production process of the mortar. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 2, pp. 35–36, February, 1998.     

A Wavelet-Based Test for Stationarity

We develop a test for stationarity of a time series against the alternative of a time-varying covariance structure. Using localized versions of the periodogram, we obtain empirical versions of a reasonable notion of a time-varying spectral density. Coefficients with respect to a Haar wavelet series expansion of such a time-varying periodogram are an indicator of whether there is some deviation from covariance stationarity. We propose a test based on the limit distribution of these empirical coefficients.     

Filamentary extrusion of microcellular polymers using a rapid decompressive element

An extrusion process for manufacturing microcellular plastics is presented. In the past, microcellular structures have been produced in batch processes by using a thermodynamic instability of a polymer/gas system. In order to utilize such a thermodynamic instability in a continuous extrusion process, a large amount of gas must be dissolved quickly in a molten plastic flowing in the machine, and a rapid drop in the gas solubility must be induced in the flowing polymer/gas solution. Since the solubility of a gas in a polymer is a sensitive function of pressure, a thermodynamic instability for producing a microcellular structure can be induced by rapidly lowering the pressure. This paper presents a means for continuously forming the polymer/gas solution at an industrial processing rate and a means of nucleating microcells in the polymer/gas solution using a nozzle. Finally, a process model for controlling the cell morphology is presented by identifying the key parameters that control microcellular foaming in a continuous process. The experimental results agree with theoretical analyses, confirming the fact that the processing pressure strongly affects the microcellular foaming process through its effects on the amount of gas dissolved in the polymer and the magnitude of the pressure drop in the nucleation device.