Development of two telemetry-based systems for monitoring the feeding behaviour of Atlantic salmon (Salmo salar L.) in aquaculture sea-cages

Two novel acoustic transmitter tags intended to reflect feeding behaviours in farmed Atlantic salmon (Salmo salar L.) were developed and tested in this study. Using information from the literature and video recordings of feeding salmon, measurements of swimming depth and motion (acceleration) were identified as two promising sensing principles on which to base the tag development. Video footage and laboratory studies were used to develop corresponding algorithms that translated depth and acceleration measurements into compound parameters reflecting the different aspects that discern feeding activity from other activities. Field tests performed in a sea-farm were used to verify the functionality of the tags, and indicated that both tag types had potential in distinguishing between feeding and non-feeding behaviour. Additionally, both depth- and acceleration-based tags were seen to have applications to fish monitoring and farm management beyond that of observing feeding in salmon, in giving recordings of the vertical swimming behaviour of fish over extended periods of time as well as indications of the activity changes of fish due to external influences. These results suggest that fish telemetry using sensor-based transmitter tags could represent a useful tool in future fish farm management.     

花生在保护栽培条件下的就地加代研究

１９９２～１９９７ 年在开封利用温室栽培等保护措施，采用“越冬加代”和“当年两代”的方式进行试验。共用花生材料９９ 份，全部收获种子，成功率１００％ 。加代当代反季节种植出苗率８６．５％ ，繁殖倍数２０．７。加代下代正常季节种植出苗率９１．６％ 。评价了４ 种加代方式的特点     

链刀前置式开沟机的起步加速特性

根据力学原理，建立了开沟机起步加速瞬间的运动方程，在获得其前后轮接地载荷垢基础上，对开沟机的稳定性问题进行了讨论，对整机稳定设计提供了理论依据。     

施肥对连翘增产效果韵试验研究

通过连翘施肥期、施肥量、激素微肥3个对比试验结果表明，施肥对连翘增产产生一定效果，不同施肥期以花期施肥效果好，增产182．2％；不同施肥量以施中量肥为宜，增产574％；施激素微肥以花期喷施硼液效果最佳，增产254％。     

Study of force distribution in the citrus tree canopy during harvest using a continuous canopy shaker

Mechanical harvesting is increasingly being employed in the citrus industry of Florida because of the faster and efficient harvesting it provides with comparatively lower cost when compared to manual harvesting. Continuous canopy shakers are the only mechanical harvesters commercially used in Florida. The main concerns regarding the use of these machines are damage to tree and detrimental effect on next year yield. Because of these concerns, only a very low percentage (6-7%) of the acreage is being harvested mechanically. To improve these machines and address the growers’ concerns, experiments were conducted to study the force and acceleration distribution on the tree branches and fruits. The acceleration was measured at different locations in the canopy using tri-axis accelerometers attached to the branch and data was recorded using ZigBee^® transceivers. The distribution of force and acceleration along an individual branch in trees of two different sizes were studied at three different tine angles and frequencies of the shaker. Both distributions were modeled using the Curve Fitting Toolbox™ of Matlab^®. The results suggested that the force was higher for the fruits inside the canopy than the ones at the edges. It was also observed that the maximum force required to remove the fruit mechanically was only 18% of the traditionally measured fruit detachment force. The force along the branch was found to be Gaussian in nature and the acceleration along the branch was found to be exponential.     

水稻应用酿热物抗低温育苗技术研究

通过酿热物抗低温育苗,观察酿热物育苗对水稻生长发育及产量和效益的影响,结果表明,在水稻生产上应用酿热物抗低温育苗,对水稻的秧苗素质、生育进程、提高苗床温度以及不同生育期水稻干物质积累、产量等有一定的促进作用。     

Application of Wavelet Filtering to Analyze Acceleration-Time Curves of Horses Trotted on Different Surfaces

The objective of the present study was to illustrate the possibilities of wavelet filtering to denoise hoof-acceleration data measured on different surfaces. Further, three variables from the time-domain acceleration signal and two variables from the single-sided amplitude spectrum of the Fourier-transformed signal were statistically analyzed to detect the differences between the riding surfaces as well as to compare the results of the different variables. For data recording, six Warmblood horses were trotted on five different riding surfaces. The recorded acceleration data were smoothed by wavelet filtering on three levels by using the Haar wavelet as well as the fourth-order Daubechies wavelet. The hoof’s landing phase was extracted from the acceleration signal by a special algorithm and analyzed because of to its significance with regard to the injury risk of a horse. More accurate hoof’s landing phases could be detected by the algorithm in the first and second approximations of both wavelet-filtered signals than in the original signal. The dissected hoof’s landing phases were used to calculate the aforementioned variables. The statistical analysis showed similar results within the variables of the time-domain signal and within the variables of the single-sided amplitude spectrum. The least square means of the original signal and the first and second approximation of both wavelet-filtered signals were on a similar level. In conclusion, it was shown that wavelet filtering is a suitable method to denoise acceleration-time curves. Further, the results of the five variables showed that the insertion of time- and frequency-domain variables was significant in the analysis of the acceleration data.     

农业水利建设中黄土边坡抗震分析

地震过程中,地震力的方向是不定的,仅考虑水平的地震力对黄土边坡的影响,具有明显的不足。利用地震角的影响,把地震力分解到潜在滑动面的法线和切线方向,计算相应的地震力,对黄土边坡在地震力作用下的安全性进行比较研究,对黄土边坡抗震设计具有一定的指导意义。     

稳态加载工况(ASM)测试程序运行试验

在系统试验前期准备的基础上,对ASM系统进行运行试验,得出试验结果。系统软件完全根据ASM工况要求设计。系统在软件抗干扰设计中采用了数字滤波技术,从软件方面保证了数据采集的精确性。该软件系统综合了VB串口通讯技术、VB数据库接口技术、SQL Sever2000数据库存储技术、网络技术、数据库远程存储和读取技术。从本系统运行情况判断,系统控制灵活、运行稳定,数据采集精确,完全满足ASM工况测试需求。     

加快农村教育事业发展的若干思考

农村全面建设小康社会根本在于提高农民素质,关键是要加快发展农村教育事业。长期以来农村教育结构单一,片面追求升学率,职业教育和成人教育薄弱,缺乏以农村为特色的普及型教育,忽视回乡参加生产劳动的大批中学毕业生对生产知识和技术的需要,制约了农业科技的发展和农业结构的调整,减弱了农业竞争力,影响了农村剩余劳动力的转移。提出要加强政府对农村教育投资力度,建立对教育经费使用监督和激励机制,加强政府对家庭教育支出的诱导和激励,调整农村中学专业的专业设置和加强农村实用技术培训,加快农村人口向城镇转移等措施来促进农村教育事业发展。