20kg连续铸造机常见故障分析及其处理方法

介绍了20kg连续铸造机的主要构成及作用,分析了铸造机运行过程中的常见故障及其原因,提出了故障的处理方法。     

预制块铝液溜槽的结构设计、制作与应用

本文简述了铝液溜槽在20 kg连续铸造机组运行中的作用以及现行铝液溜槽砌筑工艺的缺点,提出了用预制块实现铝液溜槽的砌筑工艺,并针对20 kg连续铸造机组进行了铝液溜槽的模具设计、预制块的制作、养护、干燥及组装,总结出了预制块铝液溜槽的优点.     

20kg铝锭连续铸造机组技术改造

介绍了改造恢复20kg铝锭连续铸造机组中采取的技术改进措施。     

20kg铝锭连续铸造机打击装置的改进

分析了20kg铝锭连续铸造机打击装置存在的问题以及对铸造生产和铸模使用寿命的影响,提出并实施了一种新型打击装置,取得了良好效果。     

20kg铝锭连续铸造机自动堆垛系统的改进

针对20kg铝锭连续铸造机原控制系统存在的问题,介绍改进情况。     

20kg铝锭连续铸造机组中铝锭脱模敲击装置的设计与应用

分析20kg铝锭连续铸造机组在生产使用过程中运行不连续、铝锭不脱铸模问题，设计并制作了铝锭脱模敲击装置。     

200kA铸造冷却水设备改造的经济分析

铝锭铸造机组是铝冶炼企业形成最终产品的重要工艺设备,设备的平稳运行和充分发挥机械效率,是保障日常生产需求与最终产品外观质量的基本条件。本文针对连城分公司200 kA铸造车间20 kg铝锭连续铸造机组循环水设施和铝锭连续铸造机组主体部分存在的问题和局部设计改造进行了论述与经济分析。通过对ATZJ2-20/16-Ⅱ.20 kg铝锭铸造机组的进一步优化改进,使日常生产中铝锭脱模率由设备改造前的20%左右,提升到了设备改造后的98%以上,生产过程中铝锭脱模率低、产品外观质量有缺陷的"瓶颈"问题得到了解决,在人力、财力、物力、电力方面节省了开支,同时企业经过工艺设备的优化改进,提高了水资源的再循环利用,进一步完善了企业节能减排工作目标,降低了铝锭的生产成本。     

铸造机链条滚轮滑动原因的分析及改进

20kg连续铸造机是中铝青海分公司第一电解铝厂生产重熔铝锭的主要设备,其铸模的输送装置为链条结构形式滚子链,滚轮在链条的传动过程中的运动形式为滚动.但由于铸模轴结构设计及摩擦润滑方式的不正确,导致链条运动摩擦阻力增大,链条易产生瞬间的抖动使铝锭表面产生较大的波纹和飞边,影响铝锭表面质量.从铸模轴结构和摩擦与润滑的角度分析了20kg连续铸造机链条滚轮滑动原因,并提出了改进措施.     

20kg铝锭铸造机组脱模的研究

针对目前20kg铝锭铸造机组生产中脱模率低的问题,对影响脱模的因素进行了全面的分析,提出了多项改进措施,通过实践证明,脱模率达到了99%以上,另外推导出了脱模机构动力学方程。     

20kg铝锭连续铸造机不脱模检测报警及二次打击系统设计安装

分析了20 kg铝锭连续铸造机存在的问题,设计安装了不脱模检测报警及二次打击系统。该系统能对铝锭出现未脱模时及时报警,并对不脱模铝锭进行精确打击。本系统可安装在铸造机的有限空间内,具有结构紧凑、设计精巧和自动化程度、运行的可靠性、安全性高的特点。     

本雅明眼中机械复制时代的文艺审美特征

20世纪初是继19世纪资本主义高速发展后西方文艺从古典向现代递变的时期，此期的文艺作品生产者、文艺作品以及文艺作品接受者较前代有了极大的转变。本雅明目睹了这种变化，并对各种文艺现象进行研究，提出了此期文艺审美的特征。     

On the stability of d .

In signal detection theory, the index d -sub(s) is commonly believed to be a more stable measure of discrimination than d ' when the slope of the receiver operating characteristic varies across conditions. The basis for this is examined, and a model is developed that appears to explain both the stability of d -sub(s) and the variation in the slope of the receiver operating characteristic, which may be found when the prior probability of the signal is varied. The model rests on the assumption that sequential influences may affect criterion variance. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of telemetric techniques for use in studies of the electrical activity of the brain

A telemetry system has been designed to transmit two channels of wideband activity (0.2 Hz-2.5 KHz) recorded from high-impedance microelectrodes in the brains of free-moving cats. Thus, both unit activity and slow-wave field activity are accessible without disruption of the animals' behavior. In addition, circuitry is described that conditions the receiver signals, that dicriminates valid subcarrier signals from receiver noise and that automatically aborts data output in the absence of discriminable subcarrier. This receiver signal processing circuitry thus assures the fidelity of the decoded subcarrier, greatly facilitates further machine processing of the data and frees the experimenter from having to continuously monitor the receiver signals to subjectively edit out noisy data.     

Surgical therapy for pulmonary aspergillosis in immunocompromised patients

OBJECTIVE: The objective of our study was to compare child abuse detection using screen-film radiographs and their digitized images displayed on a computer workstation. MATERIALS AND METHODS: Skeletal surveys of 20 consecutive child abuse patients whose abuse was clinically proven by a combination of history, physical and radiographic findings, and social work history, and 20 consecutive control subjects were evaluated. Three radiologists rated both the screen-film radiographs (400-speed, double-emulsion film) and their digitized images displayed on a workstation (2K x 2K resolution) using a six-point ordinal scale for suspicion of child abuse, fracture detection, and image quality. The rating response was analyzed using multiobserver-multicase receiver operating characteristic analysis of variance. The McNemar test was used to evaluate differences between imaging techniques and between diagnoses made using each imaging technique and clinically proven child abuse. RESULTS: The area under the receiver operating characteristic curve for screen-film radiographs was 0.934+/-0.025 and for digitized images was 0.922+/-0.013. This difference was not significant (p = .658); however, two observers significantly underestimated the child abuse diagnosis with digitized images (p = .02). In a review of the false-negative child abuse diagnoses, observers failed to recognize characteristic metaphyseal fractures (10 observations) and rib fractures (five observations) on digitized images that had been recognized on screen-film radiographs. Mean image quality was rated significantly lower (p < .0001) and interpretation time was significantly longer (75 sec; p < .001) for the digitized images than for screen-film radiographs. CONCLUSION: The characteristic types of fractures that were not identified on the digitized images, lower image quality, and longer interpretation time raise concern that digitized images may not be adequate for interpretation of suspected child abuse.     

Specificity of the BvgAS and EvgAS phosphorelay is mediated by the C-terminal HPt domains of the sensor proteins

Despite the presence of highly conserved signalling modules, significant cross-communication between different two-component systems has only rarely been observed. Domain swapping and the characterization of liberated signalling modules enabled us to characterize in vitro the protein domains that mediate specificity and are responsible for the high fidelity in the phosphorelay of the unorthodox Bvg and Evg two-component systems. Under equimolar conditions, significant in vitro phosphorylation of purified BvgA and EvgA proteins was only obtained by their histidine kinases, BvgS and EvgS respectively. One hybrid histidine kinase consisting of the BvgS transmitter and HPt domains and of the EvgS receiver domain (BvgS-TO-EvgS-R) was able to phosphorylate BvgA but not EvgA. In contrast, the hybrid protein consisting of the BvgS transmitter and the EvgS receiver and HPt domains (BvgS-T-EvgS-RO) was unable to phosphorylate BvgA but efficiently phosphorylated EvgA. These results demonstrate that the C-terminal HPt domains of the sensor proteins endow the unorthodox two-component systems with a high specificity for the corresponding regulator protein. In the case of the response regulators, the receiver but not the output domains contribute to the specific interaction with the histidine kinases, because a hybrid protein consisting of the EvgA receiver and the BvgA output domain could only be phosphorylated by the EvgS protein.     

A biotelemetry system for monitoring heart rates in unrestrained ungulates

An EKG telemetry system has been designed for use on free-living ungulates. An FM transmitter with a battery life of 2 +/-0.5 months and a range of 2-6 km is mounted on the back of the animal by means of an adjustable harness. The EKG signal is detected by subdermal electrodes overlying the sternum and transmitted to an FM receiver equipped with a frequency down-converter. The output of the receiver is the modulated audio carrier which is recorded on magnetic tape. The EKG waveform is recovered from the tape-recorded signal using an FM demodulator connected to a strip chart recorder.     

Pleiotropic phenotypes caused by genetic ablation of the receiver module of the Agrobacterium tumefaciens VirA protein

The VirA protein of Agrobacterium tumefaciens is a transmembrane sensory kinase that phosphorylates the VirG response regulator in response to chemical signals released from plant wound sites. VirA contains both a two-component kinase module and, at its carboxyl terminus, a receiver module. We previously provided evidence that this receiver module inhibited the activity of the kinase module and that inhibition might be neutralized by phosphorylation. In this report, we provide additional evidence for this model by showing that overexpressing the receiver module in trans can restore low-level basal activity to a VirA mutant protein lacking the receiver module. We also show that ablation of the receiver module restores activity to the inactive VirA (delta324-413) mutant, which has a deletion within a region designated the linker module. This indicates that deletion of the linker module does not denature the kinase module, but rather locks the kinase into a phenotypically inactive conformation, and that this inactivity requires the receiver module. These data provide genetic evidence that the kinase and receiver modules of VirA attain their native conformations autonomously. The receiver module also restricts the variety of phenolic compounds that have stimulatory activity, since removal of this module causes otherwise nonstimulatory phenolic compounds such as 4-hydroxyacetophenone to stimulate vir gene expression.     

Comparison of several patterns of communication.

Studied amount of material recalled by 10 undergraduates in each of 4 patterns of communication: (a) a "receiver" listening to 1 "transmitter," (b) "receiver" listening to 2 "transmitters" and speaking simultaneously, (c) "receiver" talking while listening to 1 "transmitter," and (d) receiver talking and listening to 2 simultaneous "transmitters." Statistically significant results favored the "receiver" who listened to 1 rather than 2 transmitters and listened rather than talked and listened. A significant interaction also occurred. Information retained by the "receiver" from each of the 2 simultaneous "transmitters" was compared. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflict, receiver bias and the evolution of signal form

In a model, conflicts of interest between communicating individuals are shown to have an important influence on the cost and form of signals that evolve. Two types of conflict are considered: competition between senders to obtain a response from the receiver, and conflict between the sender and the receiver. The receiver system is modelled as an artificial neural network whose 'resistance' to signals is represented as a motivational factor that varies independently of the signal. Biases in the receiver system act as the selective force on signals, causing them to become more costly and conspicuous as the intensity of conflict increases. There is some evidence that competition between senders and sender-receiver conflict may have qualitatively different outcomes. We give examples of some situations to which the model might be applied and point out some predictions that could be tested empirically.