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小型建筑的暖通空调系统

暖通空调 1993年第1期22卷 54-56页

作者： Gary a.smith 郭兴荣

本文所说的小型建筑,是指建筑面积一般在2300m^2以下的零售商店、办公楼、教堂、剧院、餐馆以及服务性建筑等。在美国,这类建筑就有350万座以上。

关键词：小型建筑采暖通风空气调节系统

The Effect of Signal Propagation Delay on the Measured Vibration in Planetary Gearboxes

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Journal of Dynamics, Monitoring and Diagnostics 2022年第1期1卷 9-18页

作者： Marc Hilbert Wade a.smith Robert B.Randall LIACS Leiden UniversityRapenburg 702311 EZLeidenThe Netherlands School of Mechanical and Manufacturing Engineering University of New South WalesUNSWSydneyNSW2052Australia

Modulation of the gear mesh vibration is a major field of research for the condition monitoring of planetary *** modulation creates sidebands around the gearmesh frequency in the vibration spectrum,and the distribution of these sidebands has been researched in numerous *** publications on the subject assume that the effect of the time varying signal propagation delay between the main vibration source–the gear mesh point(s)–and the(usually fixed)transducer can be *** paper investigates the validity of this *** do so,a planetary gearbox with a transducer mounted on the(fixed)ring gear is studied,and the effect of the propagation delay is modelled as a phase modulation of the gear mesh *** expressions are then derived for the distribution and strength of the modulation sidebands,and these expressions are applied to quantify the effect of the propagation delay on five industrial *** results show that the amplitude of the sidebands is negligible and would not interfere with condition assessment based on analysis of the modulation of the gear mesh frequency,and thus the propagation delay can be neglected for practical purposes.

关键词： gear diagnostics phase modulation planetary gearbox propagation delay

Should prostate-specific antigen velocity be abandoned？

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Asian Journal of Andrology 2011年第3期13卷 359-360页

作者： stacy Loeb H Ballentine Carter Brady Urological Institute Johns Hopkins Medical Institutions Baltimore MD 21287 USA

Prostate-specific antigen （PSA） is the most widely used biomarker for prostate cancer, but may also be elevated in non-malignant conditions such as benign prostatic hyperplasia. Studies in the early 1990s suggested that rapid increases in PSA over time--a concept known as PSA velocity （PSAV）--may be useful to distinguish prostate cancer from the generally slower rise in PSA that may be seen in benign conditions.

关键词： Physical sciences Atomic and molecular physics

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地面对晴空大气热辐射结构的影响

气象学报 1991年第2期49卷 215-221页

作者：王鹏举周秀骥 Eric a.smith 施蕾国家气象局气象科学研究院美国佛罗里达州立大学气象系

本文利用1987年美国FIFE资料及1986年6月TIPMEX资料,并利用大气长、短波一维辐射传输数值模式,计算了晴空大气状态下地面辐射参数(地面热辐射温度、地表反照率等)对大气长波冷却率、短波加热率廓线的影响。结果表明,地球表面对大气边界... 详细信息

本文利用1987年美国FIFE资料及1986年6月TIPMEX资料,并利用大气长、短波一维辐射传输数值模式,计算了晴空大气状态下地面辐射参数(地面热辐射温度、地表反照率等)对大气长波冷却率、短波加热率廓线的影响。结果表明,地球表面对大气边界层内的热辐射结构影响很大,特别是在高原地区这种影响尤其显著。

关键词：地面晴空大气热辐射结构

Estimating the Yield Loss of Winter Wheat from Drought in the United States Southern Plains Region as Influenced by El Niño-Southern Oscillation (ENSO)

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Agricultural Sciences 2024年第9期15卷 1018-1034页

作者： Prem Woli Gerald R. smith Charles R. Long Francis M. Rouquette, Jr. Texas A&M AgriLife Research Center Overton USA

Wheat (Triticum aestivum L.) production is a major economic activity in most regional and rural areas in the Southern Plains, a semi-arid region of the United States. This region is vulnerable to drought and is projected to experience a drier climate in the future. Since the interannual variability in climate in this region is linked to an ocean-atmospheric phenomenon, called El Niño-Southern Oscillation (ENSO), droughts in this region may be associated with ENSO. Droughts that occur during the critical growth phases of wheat can be extremely costly. However, the losses due to an impending drought can be minimized through mitigation measures if it is predicted in advance. Predicting the yield loss from an imminent drought is crucial for stakeholders. One of the reliable ways for such prediction is using a plant physiology-based agricultural drought index, such as Agricultural Reference Index for Drought (ARID). This study developed ENSO phase-specific, ARID-based models for predicting the drought-induced yield loss for winter wheat in this region by accounting for its phenological phase-specific sensitivity to drought. The reasonable values of the drought sensitivity coefficients of the yield model for each ENSO phase (El Niño, La Niña, or Neutral) indicated that the yield models reflected reasonably well the phenomena of water stress decreasing the winter wheat yields in this region during different ENSO phases. The values of various goodness-of-fit measures used, including the Nash-Sutcliffe Index (0.54 to 0.67), the Willmott Index (0.82 to 0.89), and the percentage error (20 to 26), indicated that the yield models performed fairly well at predicting the ENSO phase-specific loss of wheat yields from drought. This yield model may be useful for predicting yield loss from drought and scheduling irrigation allocation based on the phenological phase-specific sensitivity to drought as impacted by ENSO.

关键词： ARID Drought Drought Index ENSO El Niño Growth-Stage Model Phenological-Phase Prediction Semi-Arid Wheat Yield Loss

Isolated Lumbar Extension Resistance Training Is Effective at Improving Extension Power and Disability in Subjects with Diagnosed Lumbar Multifidus Dysfunction

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Open Journal of Therapy and Rehabilitation 2024年第3期12卷 245-255页

作者： William Roger Peters James Thomas Ernest smith Mario Guiseppe Zotti Adam Leslie Lincoln Benjamin James Enser Faculty of Medicine & Health Sciences Bond University Queensland Australia Back Neck Clinic Bundall Queensland Australia Kieser Australia Bundall Queensland Australia

Background: Lumbar multifidus dysfunction is a prevalent cause of disability in individuals with lower back pain. Previous research highlights the benefits of isolated lumbar extension training for non-specific lower back pain, however, studies examining its efficacy in lumbar multifidus dysfunction are lacking. Objective: To evaluate the effectiveness of isolated lumbar extension resistance training on disability and strength in individuals with lumbar multifidus dysfunction. Methods: Subjects underwent a physiotherapy led structured rehabilitation program incorporating isolated lumbar extension. Sessions were conducted twice weekly targeting momentary muscular failure with time under load 90 - 120 seconds and progressions aimed at 5 - 10 lbs increments. Outcomes were assessed using the Oswestry Disability Index and lumbar extension strength testing at baseline and after 12 weeks, with statistical analysis using t-test and chi-squared 2 × 2. Results: Forty-five subjects (24 male, 21 female) with a median age of 48 completed the intervention. Improvements were noted in Oswestry Disability Index scores (median pre: 24, post: 15) and maximal lumbar extension strength (median pre: 122 lb, post: 186 lb), with p ≤ 0.05. Overall, 89% showed improvement in disability scores, 67% moved to a better disability category, and 51% saw at least a 50% increase in strength. No significant gender differences were observed. Conclusions: Isolated lumbar extension resistance training is effective at improving extension power and disability in subjects with lumbar multifidus dysfunction.

关键词： Low Back Pain Multifidus Muscle Strength Rehabilitation Resistance Training

The subcutaneous implantable cardioverter defibrillator—— review of the recent data

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Journal of Geriatric Cardiology 2018年第3期15卷 222-228页

作者： stacy B Westerman Mikhael El-Chami Emory University School of Medicine Atlanta USA Division of Cardiology Section of Electrophysiology Emory University School of Medicine Atlanta USA

The subcutaneous implantable cardioverter defibrillators （SICD） is an altemative to the transvenous ICD for the prevention of sudden cardiac death （SCD）. Multiple studies have shown that the SICD is safe and effective in treating ventricular arrhythmias. While earlier stud- ies mainly enrolled younger patients with channelopathies, more recent reports included patients with ＂typical＂ indications for ICD therapy for the prevention of SCD. In this review we summarize the data available to date on the SICD while highlighting its pros and cons.

关键词： Inappropriate shocks Subcutaneous ICD Sudden Cardiac death Transvenous ICD

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猫眼草化学成分研究

中药材 2015年第3期38卷 514-517页

作者：刘超孙会王维婷孙金月 Mark a.smith 山东省农业科学院农产品研究所山东济南250100 山东诚创医药技术开发有限公司山东济南250101 National Research Council Canada Saskatoon SK Canada

目的:研究大戟科植物猫眼草的化学成分。方法:运用硅胶、Sephadex LH-20、MCI等色谱进行分离纯化,通过红外光谱、紫外光谱、质谱、核磁共振等现代波谱学方法进行结构鉴定。结果:从猫眼草乙酸乙酯和正丁醇部位中分离得到了12个化合物,分... 详细信息

目的:研究大戟科植物猫眼草的化学成分。方法:运用硅胶、Sephadex LH-20、MCI等色谱进行分离纯化,通过红外光谱、紫外光谱、质谱、核磁共振等现代波谱学方法进行结构鉴定。结果:从猫眼草乙酸乙酯和正丁醇部位中分离得到了12个化合物,分别鉴定为:3β-羟基-7β-甲氧基-5-豆甾烯(1)、3β,22β-二羟基-7β-甲氧基-5-豆甾烯(2)、灰绿曲霉酰胺(3)、2,5-二羟基-4-甲氧基菲(4)、对羟基苯甲酸(5)、3-甲氧基-4-羟基苯甲酸(6)、灯盏花苷C(7)、5,7,4'-三羟基双氢黄酮(8)、山柰酚(9)、槲皮素(10)、科罗索酸(11)、金合欢素(12)。结论:除化合物9、10外,其余化合物均为首次从该植物中分离得到。

关键词：猫眼草大戟科豆甾烯槲皮素科罗索酸

Efficient Vision Transformers for Autonomous Off-Road Perception Systems

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Journal of Computer and Communications 2024年第9期12卷 188-207页

作者： Max H. Faykus III Adam Pickeral Ethan Marquez Melissa C. smith Jon C. Calhoun Holcombe Department of Electrical and Computer Engineering Clemson University Clemson SC USA

The development of autonomous vehicles has become one of the greatest research endeavors in recent years. These vehicles rely on many complex systems working in tandem to make decisions. For practical use and safety reasons, these systems must not only be accurate, but also quickly detect changes in the surrounding environment. In autonomous vehicle research, the environment perception system is one of the key components of development. Environment perception systems allow the vehicle to understand its surroundings. This is done by using cameras, light detection and ranging (LiDAR), with other sensor systems and modalities. Deep learning computer vision algorithms have been shown to be the strongest tool for translating camera data into accurate and safe traversability decisions regarding the environment surrounding a vehicle. In order for a vehicle to safely traverse an area in real time, these computer vision algorithms must be accurate and have low latency. While much research has studied autonomous driving for traversing well-structured urban environments, limited research exists evaluating perception system improvements in off-road settings. This research aims to investigate the adaptability of several existing deep-learning architectures for semantic segmentation in off-road environments. Previous studies of two Convolutional Neural Network (CNN) architectures are included for comparison with new evaluation of Vision Transformer (ViT) architectures for semantic segmentation. Our results demonstrate viability of ViT architectures for off-road perception systems, having a strong segmentation accuracy, lower inference speed and memory footprint compared to previous results with CNN architectures.

关键词： Semantic Segmentation Off-Road Vision Transformers CNNs Autonomous Driving