测距仪

Based on the principle of current meter measurement, this article makes analysis on the influence of measured discharge by measurement distance and width error caused by hydrometric cableway counter.

从流速仪测流的原理，分析由水文缆道计数器而产生的测距、测宽误差对实测流量的影响，进一步说明水文缆道计数器率定与比测的必要性，并结合实际提出缆道计数器率定前实测流量的校正方法。

This study thoroughly inspects reciprocal method and leap-frog method of EDM trigonometric leveling along with relationship between EDM height, ellipsoid height, and orthometric height. An experimental area with 200m, 400m and 600m span intervals were set up with vertical angle error ±1.5〞and EDM error ±（2mm+2×10-6×Smm）.

本研究规划实验区实地针对200m、400m、600m三种测段长，采用之全测站仪之垂直角中误差为±1.5〞，测距中误差为±（2mm+2×10-6×Smm），进行EDM三角高程测量，并对测量方法及观测成果精度进行分析，实际探讨短距离EDM三角高程代替水准测量的可能性。

Based on the test of practical measure of laser water-level gauge, the error is less than 0.6mm in the measure range less than 5 meters. Compared with other field water-level measure apparatuses in common use, the precision of laser water-level gauge has obvious improvement. And this gauge can also be applied to physical modeling experiment in river engineering.

4研制开发的激光水位仪经实测检验，在5米测距范围内，测量误差小于0.6mm，比常用的野外水位观测仪器的精度有明显的提高，该仪器亦可用于河工模型试验的水位测量。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。