高压水射流清洗技术的探讨

高压水射流清洗技术在高压清洗机基础上，配套进给机构和三维旋转喷头，其垂直进给、倾斜、旋转和曲臂功能使得清洗效果更为理想。对于小直径容器及各类管道的内壁清洗则采用二维旋转喷头，可实现对管道内外壁的同步清洗。     

Experiments of the Self-excited Oscillation Pulsed Jet Nozzle

The self-excited oscillation pulsed jet nozzle which proposed makes the continuous jet transform into pulsed jet . Comparing with general continuous jet, the pulsed jet has a higher peak of pressure and larger volume of erosion , therefore it increases the effective distance off of the jet under the same conditions. The laboratory and industry experiments of the Self-excited oscillation pulsed jet nozzle are introduced in the report.     

依兰县省级重点生态林的生态区位特征及保护的意义

根据依兰县的自然地理概况及特点,论述了依兰县省级国家重点公益林生态区的森林资源状况,阐明重点公益林培育的目的、经营方法及保护意义。     

An anatomical study to evaluate the risk of pulpar exposure during mechanical widening of equine cheek teeth diastemata and 'bit seating'

Reasons for performing study: Cheek teeth (CT) diastemata are a major equine dental disorder that can be treated by mechanically widening the diastemata. There is limited anatomical knowledge of the spatial relationships of the individual pulps to the adjacent interproximal surfaces; on the risks of exposing the 6th pulp horn when performing the clinically unproven ‘bit seating’ procedure on Triadan 06s. Objectives: To describe the anatomical relationships between the occlusal and interproximal surfaces of CT and the adjacent pulp horns; and between the 6th pulp horn and the occlusal and rostral surfaces of Triadan 06s. Methods: The CT from 30 skulls of horses subjected to euthanasia for non‐dental reasons were sectioned to expose the rostrally and caudally situated pulp horns to allow the anatomical relationships between the pulp horns and the occlusal and interproximal aspects of the CT to be assessed. Results: Pulp horns were mean ± s.d. of 5.74 ± 1.45 (range 1.3–10.8 mm) from the nearest interproximal surface, with 5.3% of pulp horns being <3.5 mm from the interproximal surface. In contrast to expectations, pulps tended to became closer to the interproximal surface (and also to the occlusal surface) with increasing age. Teeth with physiologically tall clinical crowns, and also those in the Triadan 09 position had pulps that were closer to the interproximal surfaces than the remaining CT. The more caudally situated pulp horns, i.e. in particular, the 4th maxillary and 5th mandibular pulp horns were closer to the interproximal surfaces than the remaining pulp horns and these pulp horns also had the thinnest sub‐occlusal secondary dentine. Pulps that were close to the interproximal surface were also found to be close to the occlusal surface of the CT. Conclusions and potential relevance: While diastema widening is theoretically safe between the majority of CT, a small proportion of pulp horns are only 1.3 mm from an interproximal surface and others lie just 1.6 mm beneath the occlusal surface, and such pulps are at risk of pulpar exposure and to thermal injury during this procedure. The risk of pulpar exposure increases when dental tissue is removed from the caudal aspects of CT.     

Preliminary study of jointed snaffle vs. crossunder bitless bridles: Quantified comparison of behaviour in four horses

The study tested the null hypothesis that if a horse is ridden in a snaffle bridle and then a crossunder bitless bridle, there will be no change in its behaviour. It was predicted that there would be change and that behaviour would improve when bitless. Four horses, none of which had ever been ridden in a crossunder bitless bridle, were ridden through two 4 min, exercise tests, first bitted then bitless. An independent judge marked the 27 phases of each test on a 10 point scale and comments and scores were recorded on a video soundtrack. The results refuted the null hypothesis and upheld the predictions. Mean score, when bitted, was 37%; and through the first 4 min of being bitless, 64%. A binomial probability distribution suggested that the results were significantly different from random effects. All 4 horses accepted the crossunder bitless bridle without hesitation. Further studies are warranted and it is hoped that others will build on this new field of investigation. The authors are of the opinion that the bit can be a welfare and safety problem for both horse and horseman. Equestrian organisations that currently mandate use of the bit for competitions are urged to review their rules.     

用FPGA实现的位同步电路

位同步电路在现代通信中占有重要地位.根据数字信号特点,设计了超前-滞后全数字锁相环,采用现场可编程逻辑器件(FPGA)进行了集成处理,并通过了系统仿真和下载测试.测试结果表明,该设计方法能比较准确地恢复位同步信号,并适合在不同的传输速率下工作.     

不同疏花留果方式对红色梨32号果实品质影响的研究

本试验主要研究红梨32号果实生产过程中的最佳疏花留果的方法。以红梨32号为试材,采用不同果实序位的留果方式以及不同疏花疏果的方法,在红梨32号的开花期、结果期以及果实成熟期,开展了相关研究。结果表明：在一个结果枝上,1-6号果位上每个果位留果一个以及每个果位上不进行疏花蔬果,平均单果重、平均果实纵径以及果面果锈面积差异性显著,2、3、4号果位的果型端正,无生理落果现象;同时,一结果枝上同时保留2、3和4号果位的花朵,每朵花序留2个果,平均单果重最重,达284.45g,较其他留果方式差异性明显,果形指数为0.878,此处理方法有明显的果实增重作用,在实际生产过程中,对梨树合理的果位留果具有重要的指导意义。     

Adaptive bit allocation algorithm in an orphogonal frequency division multiplexing system of cognitive radio

An orphogonal frequency division multiplexing(OFDM) based cognitive radio architecture was designed to meet the transmission requirements of a cognitive radio system. After finishing the allocation of subtransmission, and keeping BER within the limit that ensures service quality, an adaptive bit allocation method was proposed to allocate the bit and energy of subtransmission dynamically. The total power for launching needed reached its minimum (or SNR per bit reached its maximum). Compared with the fixed bit allocation method, the proposed method is simpler, decreases the system transmission power, and has better BER performance.     

VBR Coding Algorithm Based on Wavelet Transform

The introduction of the asynchronous transfer mode(ATM) concept has significantly influenced the coding theory.According to the characteristics of the ATM network,using the advantages based on the wavelet transform,how to apply the wavelet transform to plane separation and how to apply VBR coding to the layered data are discussed.The results of experiment are described respectively.     

计算机图像处理技术在异色羽绒分选中的应用

为了解决异色羽绒的自动分选问题,实现异色羽绒的自动识别和自动提取的目的,提出了一种基于数字图像处理技术的机器视觉分选方法。该文对视觉识别中的窗口处理、图像分割以及面积和重心的计算做了介绍;分析了图像分割最佳阈值的计算方法,讨论了异色羽绒提取的信号控制方式;介绍了异色羽绒自动分选机的实验运行结果及其应用前景。