半导体消雷器在县级电力系统中的应用

取代传统避雷针的一种新型防雷装置——半导体消雷器已经问世。本文根据半导体消雷器的性能特征,以电力系统为应用领域,提出了将半导体消雷器组成联合保护网带的方法,总结了运用半导体消雷器的实际经验。     

进一步加强西藏自治区的小水电建设

在整理和分析西藏自治区40年小水电建设资料的基础上,着重总结了小水电建设和管理中存在的主要问题,并就今后如何搞好西藏的小水电建设提出了建议。     

微机交流采样系统的研制

交流电量测量是水电站自动化中的基本环节。文章作者在湖南省嘉禾县调塘水电站实现微机监控系统中研制了基于8098单片机的交流采样,通过初步调试证明:用微机来直接采集交流电量可使系统结构得以简化,采集数据稳定性及精度均较高,便于现场调试,可以充分利用8098芯片的功能,满足中小型电站测量要求,具有实用价值。     

Evaluation of the Penman-Monteith model for estimating soybean evapotranspiration

The Penman-Monteith model with a variable surface canopy resistance (r_cv) was evaluated to estimate hourly and daily crop evapotranspiration (ET_c) over a soybean canopy for different soil water status and atmospheric conditions. The hourly values of r_cv were computed as a function of environmental variables (air temperature, vapor pressure deficit, net radiation) and a normalized soil water factor (F), which varies between 0 (wilting point, _WP) and 1 (field capacity, _FC). The performance of the Penman-Monteith model (ET_PM) was evaluated using hourly and daily values of ET_c obtained from the combined aerodynamic method (ET_R). On an hourly basis, the overall standard error of estimate (SEE) and the absolute relative error (ARE) were 0.06 mm h^–1 (41 W m^–2) and 4.2%, respectively. On a daily basis, the SEE was 0.47 mm day^–1 and the ARE was 2.5%. The largest disagreements between ET_PM and ET_R were observed, on the hourly scale, under the combined influence of windy and dry atmospheric conditions. However, this did not affect daily estimates, since nighttime underestimations cancelled out daytime overestimations. Thus, daily performances of the Penman-Monteith model were good under soil water contents ranging from 0.31 to 0.2 (_FC and _WP being 0.33 and 0.17, respectively) and LAI ranging from 0.3 to 4.0. For this validation period, calculated values of r_cv and F ranged between 44 s m^–1 and 551 s m^–1 and between 0.19 and 0.88, respectively.Communicated by R. Evans     

Stable resistance against the leaf miner <Emphasis Type="Italic">Leucoptera coffeella</Emphasis> expressed by genetically transformed <Emphasis Type="Italic">Coffea canephora</Emphasis> in a pluriannual field experiment in French Guiana

Summary A pluriannual field trial of transgenic clones of Coffea canephora (the Robusta coffee tree) transformed for resistance to the lepidopteran coffee leaf miner Leucoptera coffeella was installed in French Guiana. Fifty-eight transformed clones produced by transformation of the C. canephora clone 126 were planted. They were harbouring the pEF1α constitutive promoter of Arabidopsis thaliana controlling either the Bacillus thuringiensis native gene for the cry1Ac insecticidal protein (eight clones) or a synthetic cry1Ac gene (53 clones). The vectors for the transformation were a strain of the bacterium Agrobacterium tumefaciens and one of Agrobacterium rhizogenes. The transformed clones were generally independent, presenting different integration patterns of the genetic construct. Four randomly distributed groups of five plants per transformed clone were planted along with 60 untransformed control trees. Over a 4-year period after plantation six releases of L. coffeella were performed. Mines on the leaves are the marks of larvae development and were counted on plants. A majority of the independent transformed clones harbouring the synthetic gene and transformed by the strain of A. tumefaciens displayed constantly much less mines than the control, therefore expressing a stable resistance. The need for complementary research is presented.     

Application of digital photogrammetry to measure distribution of tree postions

The application of digital photogrammetry to measure distribution of tree positions with stereo image couple is introduced in detail, and the procedure of stereo vision applied in forestry environment is explored. Nonlinear error in measure model is adopted in the camera calibration; the interactive correlation matching is used under constraint of epipolar line and edge of tree detected by Canny operator. Results prove that application of digital photogrammetry technology to measure distribution of tree positions can meet demand of precision in experimental conditions.     

The relationship between water intake rates,paddy ponding depth,and farmers’ water management techniques

Japanese farmers manage their irrigation water based on their past experiences and preferences, considering such factors as weather and available water (hereafter defined as empirical water management). They elaborately control the intake and drainage rates of their own paddy fields to maintain optimal ponding depths. But these well-managed systems will drastically change because of the decreasing number of farmers. Therefore, it is necessary to clarify if the optimal ponding depth will be maintained within the limits of traditionally-allowed water intake rate from the main river. The first objective of this study was the quantification of actual water use in the paddy fields, resulting from the farmers water management on the basis of their experience. The significance of the present water intake rate under empirical water management was studied for a paddy field command area of about 230 ha. Water intake rates and the water requirements of the whole area were investigated by measuring the flow rate at 17 points of irrigation and drainage canals. Characteristics of the farmers empirical water management were investigated by measuring the hourly changes in inflow and outflow rates for a sub-area using an automatic measurement system, and an inferential method of determining water management patterns for the paddy fields was proposed. The newly-proposed inferential method was introduced in the tank model, which expresses the characteristics of water management in the command area. The Shuffled Complex Evolution Algorithm (SCE-UA) method was used for optimizing the model parameters. It was proven that the model accuracy improved when the farmers empirical water management was taken into account. The optimal amount of water to be applied to the command area was quantified by the simulation. The second objective was to predict the effect of the decreasing number of farmers on future water use conditions. The simulated result indicates the difficulty of maintaining optimal ponding depth for the whole command area when the farmers empirical water management is not maintained. In other words, results indicated that efficient water use requires an automatic water management system or a new pipeline system to replace the farmers present empirical water management.     

Incorporation of Maize Gluten in Supplementary Feed and its Impact on Growth and Flesh Quality of Some Carps

Maize gluten (a byproduct from the starch industry) was used at four different levels (5, 10, 15 and 20% w/w) replacing the fish meal, a component of supplementary diet, under a semi-intensive culture system. The impact of different diets on the physico-chemical parameters of water, growth and flesh quality of catla, Catla catla; rohu, Labeo rohita; and mrigal, Cirrhina mrigala was studied. Growth in terms of body weight gain was highest when fed a diet having 5% maize gluten (replacing fish meal at 25% level) for all the fish species. However, incorporation of maize gluten at higher levels led to decline in growth, since maize gluten is deficient in essential amino acids like methionine, lysine and threonine, etc. The flesh quality in terms of total protein, total lipid, total sugar, moisture and total ash was also determined at the termination of the experiment to see whether there was any significant variation with the incorporation of maize gluten or not.     

The effects of vitamin E on non-specific immune response of the juvenile soft-shelled turtle <Emphasis Type="Italic">Pelodiscus sinensis</Emphasis>

ABSTRACT:   This study was conducted to determine the effect of dietary vitamin E supplements on non-specific immune responses in juvenile soft-shelled turtles. Turtles were fed diets supplemented with vitamin E at 0 (control), 50, 250, 500, 1000 and 5000 mg/kg, respectively, for 4 weeks. Results showed that blood cell phagocytosis and serum bactericidal activity were significantly improved in turtles from two diets (250 and 500 mg/kg vitamin E supplementation), while had no significant improvement in turtles from the three remaining diets (50, 1000 and 5000 mg/kg vitamin E supplementation) when compared to turtles from the control group. Serum bacteriolytic activity in turtles from diets with 50, 250, 500 and 1000 mg/kg vitamin E supplementation were higher than activity levels quantified for the control group, but no significant difference was observed between the 5000 mg/kg vitamin E supplementation diet and the control diet. The results suggest that vitamin E has an upper and lower threshold for improving non-specific immune function in soft-shelled turtles, and the optimal supplementation may be between 250 and 500 mg/kg.     

Ribotyping of Indian Isolates of <Emphasis Type="Italic">Pasteurella multocida</Emphasis> Based on 16S and 23S rRNA Genes

The applicability of ribotyping based on 16S and 23S rRNA was evaluated for molecular epidemiological studies. Forty-eight isolates of Pasteurella multocida isolated from different hosts and geographical locations and one reference isolate were ribotyped. Only four ribotypes were found. All the isolates including reference isolate from wild carnivores had the same ribotype, though they had different serotypes. The isolate from a tiger had one band in addition to the bands present in the major ribotype. The isolates from lions represented two ribotypes; of these ribotypes, one (r2) had an additional band of 3.6 kbp, which was absent in all other ribotypes. The second ribotype (r4) from a lion had one band missing (6 kbp) that was present in the other ribotypes. These isolates were further typed using ERIC-PCR and REP-PCR. With ERIC-PCR and REP-PCR, higher D values of 0.83 and 0.89 were obtained. The current study revealed that ribotyping is not a very efficient typing tool for use in molecular epidemiology for differentiation of isolates.