井下无定向导线测量

本文介绍了井下无定向导线测量方法及解算步骤。     

OTS全站仪在竖井、斜井定向测量中的应用

为在井下控制测量中利用OTS全站仪方便、快捷、精度高的作业优势,通过制作棱镜挂钩对点器、将仪器中心标定在全站仪提手上的方式,解决了仪器棱镜点位对中问题.分别介绍了OTS全站仪用于竖井和斜井定向测量的四种测量方法,可按全站仪的三种测量模式进行,解决了传统定向测量中的技术缺陷.     

“几何定向法”在井下导线测量中的应用

本文讨论了一种新的井下导线测量方法－几何定向法，并结合井下巷道实际情况，对这种方法的布设方案，精度以及与支导线测量的比较，作了详细的研究与分析。说明了这种方法的可靠性与实用性。     

某煤矿矿山贯通测量优化分析

某煤矿在日常生产中曾多次发生矿车和皮带设备磨损严重、连接装置断裂等跑车事故,经事故分析后发现,该事故发生的主要原因为煤矿贯通测量工艺落后、工艺精度差。针对这一问题,提出采用陀螺定向、全站仪高程测量以及GNSS定位技术相结合的测量方法,以改进测量精度,并建立相应的GNSS地表控制网与高程控制网,对平面导线、高程测量以及陀螺定向进行工艺改进。经试验表明,优化测量工艺后,解决了贯通测量工艺及其精度问题,提高了该煤矿的生产效率。     

矿山井下单一无定向导线应用分析

小铁山矿井下采用单一无定向导线的测量方法,同采用闭合导线的测量方法相比,精度上虽然稍有偏差,但实用性很强,且能满足矿山的生产需要,经过几年的实际应用和补充完善,取得了省时、快捷、准确的效果。     

激光垂准仪竖井定向的测量实践

介绍了通过高精度激光垂准仪投点,利用瞄直法进行矿山竖井定向测量实践。表述了瞄直法在矿山竖井定向的测量过程及实际操作过程中应该注意的事项。应用实践表明,激光垂准仪竖井定向是一种快捷、高效,并能完全满足矿山生产精度要求的测量方法。     

单井定向测量方案设计

定向问题的分析研究,是每一个矿山测量工作者的重大课题之一,本文叙述了矿山单井定向测量方案设计及单井定向测量精度估算与分析等内容。     

全站仪后方交会法在倾斜天溜井测量中的应用

矿井定向是矿井测量的重要组成部分。传统矿井定向方法包括1井定向、2井定向和陀螺定向。由于矿井本身的原因或由于仪器设备不足的原因,这些方法都有一定的局限性。在矿房法采矿工艺中,倾斜天溜井众多,联系测量任务繁重,为解决矿房法施工中联系测量的难题,探讨了全站仪后方交会法在倾斜天溜井中进行联系测量的可行性。     

无定向导线的平差和坐标计算的应用

就无定向导线在甘肃武都地区实际应用中的测量公式推导及精度分析进行探讨。     

特殊无定向导线法

本文介绍的方法，解决了以往的无定向导线和支导线所不能解决的问题，成功地在互不通视的两点间布设控制点。     

The direct activating effect of a nonapeptide neurohormone (vasotocin) on the thyroid and interrenal glands of sturgeons in in-vitro experiments

An in-vitro effect of nonapeptide neurohormone vasotocin on thyroid and interrenal glands was studied in hybrid of Siberian and Lena sturgeons [correction of salmons] at light microscopy level using morphometric method. At a concentration of 0.1 and 1 nmol/l vasotocin was shown to exert undirectional stimulating effect on the thyroid and interrenal gland functions. In the presence of vasotocin at a concentration of 1 nmol/l in culture media the activity of glands is even more pronounced than under the influence of adenohypophyseal hormones, adrenocorticotropic (8 x 10 ng/ml) and thyrotropic (5 ng/ml).     

Matrix crack spacing in brittle matrix composites

A model describing the evolution of matrix cracks in undirectional continuous fiber, brittle matrix composites is developed. The approach involves calculation off the steady state strain energy release rate available for crack extension in terms of the constituent properties, the applied stress and the distances to the neighboring cracks. Interactions between cracks are found to occur when the crack spacing falls below twice the slip length. The model provides an analytical solution to the crack spacing for periodic arrays of cracks. Comparisons are conducted with predictions derived from computer simulations of random cracking. The effects of the matrix flaw density are briefly considered.     

Acute effects of N-methyl-N'-nitro-N-nitrosoguanidine on canine gastric mucosa

The electrophysiological effects of the chemical gastric carcinogen N-methyl-N'-nitro-N-nitrosoquanidine (MNNG) were determined in an in vivo chambered canine stomach and in an in vitro canine gastric mucosal preparation. In the in vivo stomach, the topical application of 2.5 mg MNNG/ml decreased the transmural electrical potential difference, and the systemic blood pressure was essentially unchanged. In the in vitro preparation, exposure of the mucosal side of the isolated canine gastric mucosa to 0.25 and 2.5 mg MNNG/ml for 1 hour sequentially or exposure of the serosal side to 2.5 mg MNNG/ml for 2 hours inhibited net Na+ and Cl- fluxes. With longer duration, the undirectional fluxes of Na+ and Cl- increased, indicating an increase in permeability. These findings suggested that inhibition of active transport in the gastric mucosa may have an important function in the gastric carcinogenicity of MNNG.     

Out-of-Plane Strengthening of Masonry Walls with Reinforced Composites

This paper presents an investigation into the effectiveness of using fiber-reinforced composite overlays to strengthen existing unreinforced masonry walls to resist out-of-plane static loads. A total of fifteen wall panels [1,200 × 1,800 × 200 mm (4 ft × 6 ft × 8 in.)] were tested. Twelve panels were assembled with fiber-reinforcing systems attached to the tension side, and the remaining three control walls were left without any external reinforcement. Two configurations of external reinforcement were evaluated. The first reinforcement configuration consisted of two layers of fiber-reinforced plastic webbing and the second consisted of vertical and horizontal bands of undirectional fiber composites. The three wall specimens without external reinforcement were tested to evaluate the change in the system strength and behavior with application of the external reinforcing systems. In addition to the two fiber configurations, the testing program also evaluated two methods of surface preparation of the walls, sand blasting, and wire brush. All specimens were thoroughly washed by water jet, 48 hours prior to application of the fiber-reinforcing systems. Three specimens were tested for each variable. A uniformly distributed lateral load was applied to each panel using the procedures described in the ASTM Standard E-72 Test Method (airbag). Failure loads, strains in the external reinforcement (FRP), out-of-plane deformations, and failure modes were recorded. Recommendations on the usefulness of the proposed technique as a means of strengthening masonry walls for out-of-plane loads are presented. In general, flexural strength of masonry walls can be increased if the shear failure is controlled.     

Uric acid permeability coefficient in the rat papillary collecting duct

1. While it is believed that the mammalian distal nephron is not involved in uric acid transport, this has not been directly evaluated. Nevertheless, some studies are consistent with significant distal nephron transport. 2. As uric acid transport in man may be similar to the rat, undirectional uric acid permeability was evaluated by perfusion of the isolated rat papillary collecting duct. 3. Uric acid permeability was 0.61 +/- 0.04 micron/s, which was similar to sodium permeability (0.66 +/- 0.05 micron/s) but was less than chloride permeability (0.93 +/- 0.07 micron/s) and markedly less than water permeability (4.81 +/- 0.21 micron/s). Uric acid permeability was not changed following the addition of a maximal antidiuretic concentration of arginine vasopressin (200 microU/mL), nor was it changed by altering the uric acid concentration in the perfusate and bath. 4. These results demonstrate that the papillary collecting duct is permeable to uric acid. The coefficient of transport is sufficiently low and insensitive to arginine vasopressin and uric acid concentrations to suggest that any transport that occurs is probably passive and only of minor physiological significance.     

Rapid characterization of mutations in amplified human hprt cDNA by polyacrylamide gel electrophoresis

Local cerebral serotonin synthesis capacity was measured with alpha-[C-11]methyl-L-tryptophan ([C-11]AMT) in normal adult human brain (n = 10; five males, five females; age range, 18-38 years, mean 28.3 years) by using positron emission tomography (PET). [C-11]AMT is an analog of tryptophan, the precursor for serotonin synthesis, and is converted to alpha-[C-11]methyl-serotonin ([C-11]AM-5HT), which is trapped in serotonergic neurons because [C-11]AM-5HT is not degraded by monoamine oxidase. Kinetic analysis of [C-11] activity in brain after injection of [C-11]AMT confirmed the presence of a compartment with unidirectional uptake that represented approximately 40% of the activity in the brain at 50 min after tracer administration. The undirectional rate constant K, which represents the uptake of [C-11]AMT from the plasma to brain tissue followed by the synthesis and physiologic trapping of [C-11]AM-5HT, was calculated using the Patlak graphic approach on a pixel-by-pixel basis, thus creating parametric images. The rank order of K values for different brain regions corresponded well to the regional concentrations of serotonin in human brain (P < .0001). High serotonin synthesis capacity values were measured in putamen, caudate, thalamus, and hippocampus. Among cortical regions, the highest values were measured in the rectal gyrus of the inferior frontal lobe, followed by transverse temporal gyrus; anterior and posterior cingulate gyrus; middle, superior, and inferior temporal gyri; parietal cortex; occipital cortex, in descending order. Values in women were 10-20% higher (P < .05, MANOVA) throughout the brain than those measured in men. Differences in the serotonin synthesis capacity between men and women measured in this study may reflect gender differences of importance to both normal and pathologic behavior. This study demonstrates the suitability of [C-11]AMT as a tracer for PET scanning of serotonin synthesis capacity in human brain and provides normal adult values for future comparison with patient groups.     

高炉风口回旋区深度直接测量方法的研究

高炉风口回旋区深度是高炉实现最佳冶炼的重要参数之一。简要介绍了回旋区深度理论建模计算、经验公式计算的研究及不足,同时介绍了炉芯取样、风口探针、激光雷达、微波雷达等几种风口回旋区深度直接测量技术的测量原理及应用现状。通过对各种直接测量技术的分类讨论和优劣对比,得出微波测量是1种较为有效的回旋区深度测量方法。在完善各种回旋区深度直接测量方法的同时,建议结合CCD成像等其它监测系统同步完成风口多项指标的测量。     

电子皮带秤准确性的影响因素及控制措施

介绍了皮带秤在贸易计量中的应用,通过对焦炭计量数据的实时分析,分析出影响皮带秤测量精度因素包括皮带跑偏、托辊的磨损及环境影响等。通过在电桥上增加可调电位器,提高了皮带秤的测量精度,实物校验达到了预期效果,运行稳定、计量准确,值得在贸易计量中推广应用。     

Examiner expectancy effects in the measurement of pressure pain thresholds

The ascending Method of Limits, used for the determination of pressure pain thresholds (PPT), is not a psychophysically robust method. The present study sought to determine if the examiner's expectancy, based on whether the measurement site was clinically 'painful' or 'non-painful', would bias the obtained PPT values. Twenty-eight patients with facial or temporal area pain served as subjects, and in each subject, a pain site and a control site were identified and marked. According to a randomization schedule, the pain and control sites were correctly marked in half of the subjects and were mis-labeled in the other half, thereby controlling the examiner's knowledge of a site and thus the examiner's expectancy of what the PPT should be. Two examiners, shown to be reliable with each other in both pre-clinical and post-clinical reliability studies, were blind to the true purpose of the study and to the marking procedures. Each examiner made one PPT measurement at each marked site in a counterbalanced measurement order. Manipulating the examiner's prior knowledge of the measurement site's characteristics significantly lowered the obtained PPT values for control sites but did not significantly alter the PPT at the clinically painful sites. Nevertheless, the pain sites still had significantly lower PPTs than did control sites. We conclude that: (i) PPTs at pain sites are robust to a major source of measurement bias associated with the ascending Method of Limits; (ii) measurement order and knowledge of measurement site characteristics can influence obtained PPT; and (iii) the common protocol in which the examiner monitors the amount of pressure during PPT measurement in order to control the force application rate may serve as a mechanism that can bias the obtained values.     

Conditional Assessment of Flow Measurement Accuracy

A study conducted by the Utah Water Research Laboratory assessed the accuracies of a wide variety of flow measurement devices currently in service. During the study, a wide variety of flow measurement devices, including flumes, weirs, and rated sections in open channel systems, were evaluated; magnetic and ultrasonic meters in closed-conduit systems were also tested. The specified design accuracies for each device are presented. Actual flow measurements were determined at 70 sites and were compared with the theoretical discharges of each device. Comparison of actual and theoretical flow indicates that only 33% of the measurement devices tested currently measure flow within manufacturer-designed specifications. Field data is presented, and possible reasons for the flow measurement errors and their corrections are discussed.