岭西电网经济分析     

洪宝棣  刘保国 《内蒙古农业大学学报(自然科学版)》2004,25(4):79-83

本文对岭西电网的经济运行调整进行了分析、总结。并应用《岭西电网经济运行计算》系统的计算结果，提出了岭西电网的经济运行调整办法。  相似文献   

电导法测定林木种子活力的研究   总被引：4，自引：0，他引：4  

郑郁善 《福建林学院学报》1989,9(2):199-202

本文研究了林木种子电导法测定条件和测定电导率或相对电导率,通过回归分析建立电导率或相对电导率与种子活力指数的相关方程,找出了电导法测定林木种子活力的方法。  相似文献   

小麦雪霉叶枯病产量损失的初步研究     

康业斌  商鸿生  王树权 《河南科技大学学报(农学版)》1996,(1)

人工接种试验结果表明,雪腐格氏霉(Gerlachia nivalis)引起的小麦成株期叶枯、鞘枯和穗腐,鞘枯使小麦穗粒重减少2.1％～27.1％,千粒重降低9.5％～16.9％;穗腐使小麦穗粒重减少9.6～33.9％,千粒重降低7.8％～17.9％;鞘枯—穗腐复合症状使穗粒重减少10.2％～55.2％,千粒重下降9.5％～14.8％;叶斑—鞘枯—穗腐使穗粒重减少11.7％～47.1％,千粒重下降12.1％～18.3％。  相似文献   

发动机排气系统噪声的实验分析   总被引：1，自引：1，他引：0  

王斌  吴锦武  陈志军  李佩林 《农机化研究》2004,(4):233-235

以某车型配备491发动机为例,采用实验对发动机上安装和未安装排气系统时的噪声进行了比较,同时得出了在不同频率范围排气噪声对整车噪声的影响.  相似文献   

杉木林地套种绿肥筛选初报   总被引：4，自引：1，他引：3  

马祥庆  何智英 《福建林学院学报》1992,12(3):343-346

收集了三十种绿肥,在杉木当年造林地上进行套种试验,根据其生长状况、生物量、覆盖度及对杉木生长的影响,把供试绿肥分成三类,初步筛选出羽扁豆、决明豆、日木草为适宜杉木林地种植的林用绿肥。同时对今后林用绿肥的选择提出了有益的建议。  相似文献   

Evaluation of Wheat (Triticum aestivum) and Legume Intercropping Under 1:1 and 2:1 Row-replacement Series System     

P. Banik 《Journal of Agronomy and Crop Science》1996,176(5):289-294

A field experiment was conducted during the winter season of 1992–93 and 1993–94 at Agricultural Experimental Farm, Giridih, Bihar to evaluate the intercropping systems of legumes, gram ( Cicer arietinum L.), pea ( Pisum sativum ) and lentil ( Lens culinaris ) with wheat ( Triticum aestivum ) in 1:1 and 2:1 'row replacement series'. Intercropping systems were assessed on the basis of new indices termed as actual yield loss (AYL) and intercropping advantage (IA). This paper highlights the comparative effectiveness of evaluating the intercropping systems through the existing intercropping indices like LER, RCC, aggressivity. The indices AYL and IA seem to be more appropriate particularly when per plant yield is considered. Intercropping reduced the yield of component crops compared with respective pure stands. Wheat + pea in 1:1 row replacement series gave the highest wheat yield equivalent value (3.02 t ha⁻¹) followed by wheat + lentil (2.91 tha⁻¹). When the actual sown proportion was considered wheat + lentil (1:1) resulted in maximum AYL (+0.610) and IA (+0.279) values. This treatment also gave the maximum monetary advantage (Rs 5985.45 ha⁻¹).  相似文献   

秦皇岛装船原油管道能耗指标测算     

汪冈伟  宋建河  赵晓智  肖明 《油气储运》2002,21(10):41-44

针对秦皇岛原油装船线装船量急剧下降的情况，从分析油电消耗着手，推导出油电指标的测算公式，探讨成本与装船计划的关系。确定了维持成本运行的最低年装船量，并提出了相应降低能耗的措施。  相似文献   

Long-term application of animal slurries to grassland alters soil cation balance     

P.N.C. Murphy  R.J. Stevens  P. Christie 《Soil Use and Management》2005,21(2):240-244

Abstract. Soil samples from a 32-year grassland field experiment were taken from 0–5, 5–10, and 10–15 cm soil depths in February 2002. Plots received annual treatments of unamended control, mineral fertilizer, three rates of pig slurry and three rates of cow slurry, each with six replicates. Samples were analysed for cation exchange capacity (CEC), exchangeable cations (Na⁺, K⁺, Ca²⁺, Mg²⁺), pH and Olsen P. Exchangeable sodium percentage (ESP) was calculated as a sodicity indicator. Mean ESP was generally greater for slurry treatments than the control, with a trend of increasing ESP with application rate. This was particularly marked for cow slurry. At 0–5 cm depth ESP increased from 1.18 in the control to 1.75 at the highest rate of pig slurry and 5.60 at the highest rate of cow slurry. Similar trends were shown for CEC, exchangeable Na⁺, K⁺ and Mg²⁺, Ca²⁺ and Olsen P. The build-up of soil P due to slurry applications, together with this combination of physical and chemical factors, may increase the risk of P loss to surface waters, particularly from soils receiving high rates of cow slurry.  相似文献   

基于网络技术的电力系统通信及调度方案设计     

逄志刚  李踊鹿  王立舒 《农机化研究》2004,(4):214-215

电力网络传输距离长、覆盖面广，利用电力网络实现通信和控制具有很大的发展潜力。为此,介绍了网络技术的发展及特点，并结合电力系统自身的优势，对电力系统通信方案进行了设计。  相似文献   

微波电路电测及其计算方法     

付世民  房维龙 《油气储运》1994,13(4):38-42

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  相似文献