HOESCH型压滤机在赵庄选煤厂的应用

在赵庄矿选煤厂处理的原煤中，13—0mm粒级末煤含量高（67．23％）、0．5～0mm粒级的原生煤泥含量大（11．79％）。为提高煤泥水系统的处理能力，设计中选用了德国OUTOKUMPU公司生产的HOESCH 40S-1516／19V M50PP／PP型压滤机来处理细煤泥。本文介绍了该设备的主要技术特征、特点和实际应用的效果。     

Stability analysis of chatter vibration for a thin-wall cylindrical workpiece

The vibration characteristics and the vibration direction angle between the beam mode and shell mode of the three-jaw clamped thin-wall cylindrical workpiece will change according to the relative position of the cutting tool to the chucking jaws. This will induce parametric vibration and cause the chatter characteristics of a thin-wall cylindrical workpiece to become more complicated than those of a solid workpiece. In this study, the three-jaw clamped thin-wall cylindrical workpiece was considered as a parametrically excited vibration system. Initially, the relationship between the parametric vibration and the workpiece system structure was investigated, and then the equivalent stability cutting depth of the thin-wall cylindrical workpiece was analyzed by a numerical calculation method. When the three-jaw clamped thin-wall cylindrical workpiece was considered as a parametric vibration system, the analytical results were consistent with the experimental results.     

Early results of AV sequential pacing on left ventricular outflow obstruction after Senning procedure

Dual chamber pacing was shown to decrease left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy 30 years ago. We report early results of AV sequential pacing from the LV apex in a patient with transposition of the great arteries who is post-Senning procedure. LVOT obstruction resulted from septal deviation and systolic anterior motion of the mitral valve. Pacing was indicated for sinus node dysfunction. AV sequential pacing with a short optimal AV interval of 60 ms demonstrated a 45% reduction in the degree of LVOT obstruction. This article suggests that LVOT obstruction after the Senning procedure can be palliated by asynchronous septal contraction induced by AV sequential pacing, even if the activation is from LV apex, and avoid or postpone surgery in selected situations.     

AGN 191976: a novel thromboxane A2-mimetic with ocular hypotensive properties

The possible subdivision of thromboxane A2-sensitive (TP) receptors is currently a controversial subject. We report herein on a novel thromboxane A2 mimetic, AGN 191976, which has almost identical pharmacological activity to the well-characterized prostaglandin H2/thromboxane A2 (PGH2/TxA2) mimetic U-46619, but its effects on intraocular pressure are quite distinct from U-46619. Prostanoid receptor activity was determined in vitro using different smooth muscle assays and platelets. Intraocular pressure was measured tonometrically in ocular normotensive Beagle dogs and Cynomolgus monkeys. Conjunctival microvascular permeability was determined in guinea pigs. Despite closely resembling U-46619 as a potent and selective TP receptor agonist, AGN 191976 was a potent ocular hypotensive in dogs and monkeys whereas U-46619 did not lower IOP in either species. The ocular hypotensive effect of AGN 191976 in dogs was attenuated by pretreatment with the TP receptor antagonist SQ 29548. Thus, the ocular hypotensive effects of AGN 191976 are consistent with TP receptor stimulation. Both TxA2-mimetics caused plasma leakage in the guinea pig conjunctiva. The disparate activities of U-46619 and AGN 191976 in our studies suggest the existence of heterogeneous populations of TP-receptors in the eye.     

Detection of dimension sets in engineering drawings

This correspondence presents a system for detecting dimension sets in engineering drawings that are drawn to ANSI drafting standards. A new rule-based text/graphics separation algorithm and a model-based procedure for detecting arrowheads in any orientation have been developed. Arrowhead tracking and search methods are used to extract leaders, tails, and witness lines from segmented images containing only graphics. Text blocks and feature control frames extracted from the segmented images are than associated with their corresponding leaders to obtain complete dimension sets. Experimental results are presented     

Thermo-oxidative degradation of poly(ethylene glycol)/poly( -lactic acid) blends

The thermo-oxidative degradation of poly(ethylene glycol)/poly( -lactic acid) (PEG/PLLA) blends was studied by infra-red spectroscopy (IR), differential scanning calorimetry (DSC), gel permeation chromatography (GPC) and thermogravimetry (TGA). The thermo-oxidative degradation of PEG occurred after a period time of aging in air at 80 °C. The mechanism of thermo-oxidative degradation of PEG was found to be the random chain scission of the main chain. As PEG blending with PLLA, the existence of PLLA appeared to enhance the thermo-oxidative degradation of PEG. The enhancement of thermo-oxidative degradation increased first and then decreased with the increase of PLLA. The results could be attributed to the ease of abstraction of the carboxylic hydrogen (–COOH) of PLLA, which enhanced the thermo-oxidative degradation of PEG. Also, the dilution effect of PLLA on the concentration of free radicals was an important factor of the thermo-oxidative degradation.     

Fatigue crack growth behavior of Sn-Pb and Sn-based lead-free solders

Solder alloys of lead-rich composition have been commonly used as joining materials in electronic package. However, because of environmental concerns, lead-free solders will replace lead-rich solders more and more in the future. The fatigue characteristics of the solders used are most important in assessing the reliability of joints in electronic packaging. In the present study, the fatigue crack growth (FCG) behavior of a wide variety of solders of both lead-rich and lead-free types has been investigated under a range of mean stresses and frequencies. Both time dependent and time independent (cyclic dependent) behaviors were observed. In the cyclic dependent crack growth regime, the FCG rates could be expressed as a function of either ΔK_eff or ΔJ. Further, the lead-free solders were found to have a higher resistance to FCG than did the lead-rich solders. In the time dependent crack growth regime, the FCG rates were found to be a function of C∗. The point of transition between time dependent and time independent behavior was found to depend on the homologous temperature and strength of the alloys.     

An investigation into the effects of probing and wire bonding stress on the reliability of BOAC

This work describes two types of low stress bonding over active circuit (BOAC) structures applying a finite element analysis. The advantage of improving the chip area utility of the BOAC design is approximately 150–180 μm for each dimension. A 0.13 μm 2 Mb high-speed SRAM with fluorinated silicate glass (FSG) low-k dielectric was combined with these two BOAC structures as the test vehicles to evaluate the impact of the probing and wire bonding stress on the reliability. Initially, a cantilevered probe card was applied to probe the BOAC pads using the typical and the worse probing conditions. Before and after the circuits probing (CP1 and CP2) the experimental results were compared, including the 2 Mb high-speed SRAM yield and wafer bit map data. The difference between the CP1 and CP2 results were negligible for all probing split cells. Next, the cross-section of the BOAC pad under the probing area was investigated following the worst probing condition. In addition, the BOAC pads evaluate the bondability, including the use of ball shear, wire pull and cratering tests. Moreover, all BOAC packaging samples underwent reliability tests, including HTOL, TCT, TST, and HTST. All the bondability and reliability tests passed the criteria for both proposed BOAC structures. Finally, the immunity level of both proposed BOAC pads, for ESD-HBM (human body mode) and ESD-MM (machine mode), differed slightly from the normal pads. No performance degradation was detected. Accordingly, this work shows that both proposed BOAC structures can be used to improve the active chip area utility or save the chip area.     

Effects of Na2CO3 and NaOH on Pasting Properties of Selected Native Cereal Starches

ABSTRACT: Using a Rapid Visco Analyzer (RVA), it was revealed that 2 alkalizing agents (Na2CO3 and NaOH) had a far larger effect on pasting properties of nonwaxy starches (wheat, corn, rice) compared with their effect on waxy starches (waxy corn and waxy rice). It was hypothesized that the alkalizing agents have a greater propensity to attack the amorphous regions of the nonwaxy starch granules, thereby causing increased leaching of amylose molecules and possibly also some hydrolysis of starch chains. As a result, the RVA pasting profile of a nonwaxy starch, in the presence of alkali, was drastically altered to one that more closely resembled that of its waxy counterpart without added alkali.     

Robust and efficient image alignment based on relative gradient matching.

In this paper, we present a robust image alignment algorithm based on matching of relative gradient maps. This algorithm consists of two stages; namely, a learning-based approximate pattern search and an iterative energy-minimization procedure for matching relative image gradient. The first stage finds some candidate poses of the pattern from the image through a fast nearest-neighbor search of the best match of the relative gradient features computed from training database of feature vectors, which are obtained from the synthesis of the geometrically transformed template image with the transformation parameters uniformly sampled from a given transformation parameter space. Subsequently, the candidate poses are further verified and refined by matching the relative gradient images through an iterative energy- minimization procedure. This approach based on the matching of relative gradients is robust against nonuniform illumination variations. Experimental results on both simulated and real images are shown to demonstrate superior efficiency and robustness of the proposed algorithm over the conventional normalized correlation method.