木材干燥应力连续监测方法的研究

本文在卡普法的基础上，提出了木材干燥应力连续监测方法，并设计了所需的配套装置。该方法采用涡流传感器对干燥过程中卡普片的矢高进行连续测试，同时通过计算机自动采集、存储数据。结果表明：矢高与干燥时间存在精密的相关性，它们之间的相关系数大部分达到0．99以上，从而实现了木材干燥应力的自动与连续监测。     

杜仲研究的历史,现状和展望

本文讨论了杜仲研究的历史和现状，并根据现在研究的成果和存在的问题，对将来应该开展的研究课题提出了一些建议。     

Application of acoustic Doppler current profiler combined with a scientific echo sounder for krill Euphausia pacifica density estimation

ABSTRACT:   An application of the acoustic Doppler current profiler (ADCP, 153.6 kHz) in combination with a scientific echo sounder (EK60, 38 and 200 kHz) was investigated to estimate the density of krill Euphausia pacifica . The acoustic backscattering strength from sound scattering layers was compared with biomass estimates from midwater trawls. Euphausia pacifica was targeted among mixed species populations in the sound scattering layer in the offshore Funka Bay area of Hokkaido, Japan. The frequency characteristics of acoustic backscattering by krill were calculated using a distorted wave Born approximation scattering model at three frequencies. Krill aggregations identified from the EK60 data were extracted as the mean volume backscattering strength difference between two frequencies. They were then used to identify similar aggregations in the ADCP data by matching observation times and depths for the two methods, which were applied simultaneously. Results from the comparison of the mean volume backscattering strength and the density calculated from the ADCP and EK60 showed that ADCP can be used to measure density and spatial–temporal distribution of krill aggregations. Current speed and direction at the study site were found to be 16.1 cm/s and 187.0°, respectively, and krill speed and direction (including the current component) were found to be 19.8 cm/s and 172.2°, respectively. Based on the ADCP data, the net speed and direction of the krill aggregations were found to be 5.9 cm/s and 128.0°, respectively.     

微波电路电测及其计算方法

从实际工程的角度出发，对电路电测方法进行了论述。在微通信工程中，需要获得障碍物的位置和高度，最合理的天线高度组合和障碍物绕射损耗等参数，为此论述了微波电路电测方法及技术要求。在大庆－秦皇岛输油管道通信工程中采用了Ａ，Ｂ测试法进行测试，得到高度－损耗曲线。这种曲线给出相对自由空间接收电平与收，发天线高度之间的关系。在测试所得的高度－损耗曲线与断面图相结合的基础上，由绕射损耗计算公式推出了几种常见障碍     

继电保护用电流互感器的暂态特性数字仿真及电磁优化设计

本文在分析CT的暂态特性及其动态磁化过程的基础上,建立了计及铁芯饱和、局部磁滞回环、动态剩磁影响的CT单、复励磁暂态过程数字仿真模型,提出了继电保护用P、TPX、TPY、TPz级CT的电磁优化设计方法,编制了计算机程序,用于CT的电磁优化设计及数字仿真分析.     

湖南马尾松遗传改良现状与策略

在叙述湖南马尾松20多年来于马尾松群体遗传改良、马尾松优良家系定向选择、马尾松基因资源收集与种子园营建等方面所取得成绩的基础上，探讨了目前马尾松遗传改良所存在的问题，提出了今后一段时期湖南马尾松遗传改良策略。     

油罐阻油切水阀启动过程的研究

本文对油罐本安型阻油切水阀研制过程中的几个技术关键之一￣二次启动进行了较详细的力学分析，研究了阻油切水阀的启动过程，分析了启动过程中液体在静止和流动两种情况下对浮球工作的影响，提出了启动机构方案。     

Repeat patient testing shows promise as a quality control method for veterinary hematology testing

Background

Repeat patient testing‐based quality control (RPT‐QC) is a potential method for veterinary laboratories (eg, that have a limited budget for quality commercial control material [QCM] or that wish to use material with a species‐specific matrix).

Objectives

To determine whether total error (TE_a), probability of error detection (Ped), and probability of false rejection (Pfr) similar to that achievable with QC materials can be controlled using RPT‐QC

Methods

Control limits (WBC, RBC, HGB, HCT, MCV, and PLT) for the Advia 120 (n = 23) and scil Vet ABC (n = 22) were calculated using data from normal canine specimens from a routine caseload. Specimens were measured at accession and again after 24 hours. Control limits were validated using 23 additional canine specimens tested similarly. Achievable TEa, Ped, and Pfr were investigated using the Westgard EZRules3 and compared to those achievable with commercial QCM.

Results

Theoretical performance of RPT‐QC and commercial QCM‐QC are similar for 1‐3s with both n = 1 and 1‐3s with n = 2 for all measurands and both instruments. Achievable TE_a values for RPT‐QC were close to ASVCP recommendations for most measurands; exceptions were PLT (both instruments) and WBC (scil Vet ABC).

Conclusions

Repeat patient testing‐based quality control advantages include a species‐specific matrix, low‐cost, and absence of QC material deterioration over time (since a fresh specimen is used each day). A potential disadvantage is daily access to normal canine specimens. A challenge is determining control limits, which has a subjective element. Further study is needed to confirm actual RPT‐QC performance and to determine if RPT‐QC with abnormal patient specimens is feasible.     

Water circulation induced by mechanical aerators in a rectangular vessel for shrimp aquaculture

A water streamer was designed for the purpose of enhancing cost-efficient circulation between the water surface and bottom of shrimp aquaculture ponds. We took direct measurements of the water current field induced by the designed aerator in a large rectangular reservoir of dimensions (L)50 × (W)19 × (D)1.3 m³ and compared the results with those of a standard Taiwanese paddle-wheel aerator. Vertical circulation between the surface and the bottom induced by the paddle wheel aerator was less than that by the designed aerator. Furthermore, the paddle-wheel aerator consumed more electric power than the designed aerator. The structures of water current induced by the two aerators are elucidated, and the advantages and disadvantages of the aerators are discussed.Auxiliary employment of the designed aerators may contribute to delivery of high DO water throughout the pond, which is more efficient than a paddle wheel aerator.