机修配件储备模型及其库存量的控制

为保证机械系统的正常运行,为满足机修作业的需求,必须设立配件库。本文用数理统计的方法,以模型论、库存论为指导,建立配件储备数学模型,解决配件库存量的控制问题,从而获得最佳经济效益。     

烟草及烟草制品中硝酸盐/亚硝酸盐流动分析模块的建立

[目的]组建流动分析模块,并用于检测烟草中硝酸盐/亚硝酸盐的含量。[方法]收集可用材料、配件组装模块,然后对样品以及标准物质进行检测,确定其重复性、回收率、检测限,以验证模块可用性。[结果]通过反复改进组装模块,对多个烟草样品硝酸盐/亚硝酸盐含量分别测定多次,测定模块重复性,结果RSD〈2.92%;向样品中加入标准溶液测定回收率,回收率为97.2%～104.9%。[结论]组装模块能够满足烟草及烟草制品中硝酸盐/亚硝酸盐含量检测需要,节省了新购仪器的费用,同时提高了现有仪器的使用率。     

农村沼气配件使用的常见问题与对策

通过对农村沼气配件产品使用情况的实地检查,总结了农村主要沼气配件使用中常见的问题,分析了产生问题的主要原因,提出了加快沼气配件产品产业化、市场化进程和加快沼气配件产品技术标准体系建设以及建立质量安全监管机制的对策建议。     

云南新犁温室工程有限公司

1、温室大棚设计、制作、安装施工。 2、温室各种配件资材销售。 3、移动苗床、遮阳等配套设施制安。     

农机维修配件简易识别方法

正一、假冒伪劣配件常见特征假:假产品的标识不全,"三无"产品居多。有严重的超差和损坏:配件尺寸、形状或位置超差,或有划痕、开裂、残缺不全以及严重锈蚀等。冒:冒用正规厂家的注册商标、合格证和包装。这类产品一般制作精良,但在选材、加工工艺上存在偷工减料现象。如不按技术要求进行切削加工、热处理以及未按正确的方法进行连接等。伪:伪造商标、合格证和包装,用廉价的、易加工的材料代替原设计要求的材料,以次充好,以假充真,最常见的有用普通灰铸铁     

农机维修配件简易识别方法

一、假冒伪劣配件常见特征假:假产品的标识不全,"三无"产品居多。有严重的超差和损坏:配件尺寸、形状或位置超差,或有划痕、开裂、残缺不全以及严重锈蚀等。冒:冒用正规厂家的注册商标、合格证和包装。这类产品一般制作精良,但在选材、加工工艺上存在偷工减料现象。如不按技术要求进行切削加工、热处理以及未按正确的方法进行连接等。伪:伪造商标、合格证和包装,用廉价的、易加工的材料代替原设计要求的材料,以次充好,以假充真,最常见的有用普通灰铸铁     

家庭组合盆栽制作工艺

从选题构思、花卉选择、盆器选择、布局设计、上盆、装饰配件材料、题名等方面介绍了家庭组合盆栽制作工艺,以期为园艺爱好者提供参考。     

农机节油方法与技巧

要选择动力性好、作业性能稳定、适应性好、机具结构及设计合理、技术成熟、调整维修方便、配件市场充足、具有良好的市场售后服务的机型。     

完美在于细节——谈高校图书馆建筑中洗手间的细节考虑

高校图书馆建筑中的洗手间,要注重细节上的考虑,要从设计、施工、洁具、材料、配件上的诸多环节上追求完美、避免不足、不留遗憾,从而造就一座精品工程,服务于读者。     

铁路客车电气火险防控对策

通过分析电气绝缘、配件质量、作业标准等造成铁路客车火险的三个方面问题,对铁路客车火险防控提出了提高生产工艺落实能力、把好配件装车质量关、加强乘务作业管理三方面的具体措施。     

Variable-rate lime application in Louisiana sugarcane production systems

Precision agriculture may offer sugarcane growers a management system that decreases costs and maximizes profits, while minimizing any potential negative environmental impact. The utility of variable-rate (VR) lime application in the initial production year (plant cane) of a 3-year sugarcane crop cycle was investigated at three locations planted to the cultivar LCP 85–384 for a total of nine site-years. A conventional, uniform-rate (UR) lime application method was compared to a VR application method and a no-lime control. Prior to lime application, soil samples (0–200 mm) were taken on a 0.4 ha grid to produce VR application maps. Soil samples were also taken after each crop of the 3-year production cycle to determine effects of lime application on soil properties. The combined results showed that neither the UR nor VR lime application method consistently improved cane or sugar yields over the no-lime control. Cane and sugar yields at Naquin Farms (NF) were increased with both the UR and VR methods, with the UR method having a slight advantage. At St. Louis Plantation (SLP), only the VR method in the first-ratoon crop increased cane and sugar yields and there were no yield differences due to lime application at Ellendale Plantation (EP). At NF and SLP, application of lime in the plant-cane crop increased soil pH and available phosphorus over the 3-year production cycle. At EP, lime application did not influence any of the soil properties measured. The failure to get a yield response from lime application at SLP and EP may have been due to the fact that fertility levels at planting were already greater than those at NF and the nitrogen fertilizer rates used by the grower at EP were higher than those at either SLP or NF. This may have obscured any positive yield effects that would be realized from increased nutrient availability. It is also possible that multiple VR lime applications will be required over a number of crop cycles to stabilize soil pH levels before a consistent positive effect on cane and sugar yields is observed with VR application. This possibility will be investigated in future studies.     

直径1422mm、压力12MPa、钢级X80管道输气方案可行性

为了满足超大输量天然气的输送工艺要求,采用大直径、高压力、高钢级管道是发展趋势。通过分析,对于300×108~500×108 m3/a输量要求,推荐采用直径1 422 mm、压力12 MPa、钢级X80管道输气方案。基于对相关钢厂、管厂、阀门厂和施工建设单位等30余家企业的深度调研,从板卷生产、宽厚板生产、螺旋管生产、直缝管生产、弯管及管件生产、阀门生产供应、运输能力等方面,论证了1 422 mm/12 MPa/X80方案的可行性,结果表明该方案总体可行。该方案可以减少输气管道的建设数量,节省建设时间,减少占地和投资,便于今后运营管理。(图4,表10,参7)     

玉米大斑病菌的胞外黑色素种类及影响其产量的因素

【目的】对玉米大斑病菌胞外黑色素的种类进行确定,探索影响玉米大斑病菌野生型菌株胞外黑色素产量的因素。【方法】利用酸碱沉淀法提取玉米大斑病菌01-23（野生型）菌株和1,3,8-三羟基萘还原酶（3HNR）基因缺失突变菌株ΔSt3hnr-3的胞外黑色素,采用红外光谱分析确定黑色素的种类。通过在培养基中添加不同的物质,确定影响胞外黑色素产量的因素。【结果】玉米大斑病菌胞外黑色素不同于DHN黑色素,2种黑色素的理化性质相似,溶解于热碱溶液,且与FeCl3反应产生沉淀。在振荡培养条件下,加入酪氨酸和三环唑分别使胞外黑色素的产量提高了2倍和1.5倍,而Cu2+浓度低于0.5 μmol•L-1利于胞外黑色素的合成,反之则表现抑制作用;pH值为6时较利于对胞外黑色素分泌。【结论】玉米大斑病菌胞外黑色素为DOPA黑色素类型,酪氨酸和三环唑对胞外黑色素的产生具有明显促进作用。     

用回归-马氏链法预测我国油气的近期产量

精确的预测石油及天然气的产量对国家能源决策有着重要的作用,可为决策者提供理论依据,根据回归和马氏链的基本原理,并考虑其各自的特点,构造出预测我国石油及天然气产量的回归-马氏链预测方法,该方法可以优势互补,使得预测结果更加合理可靠.     

井冈霉素的提纯和含量测定研究

[目的]对井冈霉素原药进行提纯,并测定其含量,以用于井冈霉素生产中的质量控制。[方法]选用混合溶剂对62%井冈霉素原药进行重结晶;利用苯酚-硫酸比色法对其含量进行测定,并研究了不同测定条件对含量测定结果的影响。[结果]经过重结晶后的样品,其纯度提高至97.7%。苯酚-硫酸比色法测定井冈霉素含量的最佳条件为：对照品为无水葡萄糖;5%苯酚溶液1.0 ml,浓硫酸用量5.0 ml,反应后静置20 min,检测波长490 nm;葡萄糖标准曲线的相关系数（R2）为0.9939;平均加标回收率为99.72%,RSD为0.3628%。[结论]重结晶法可以很好的完成井冈霉素的精制;硫酸？苯酚比色法用于测定井冈霉素的含量,操作简单,准确度高,可靠性强,可以在工业化生产中推广应用。     

基于改进灰色关联度法的河北省粮食波动影响因素研究

 【目的】定量分析河北粮食产量波动成因,为全省乃至国家粮食安全生产提供科学的理论和方法支撑。【方法】综合运用EMD和剩余法剥离河北省粮食产量及其各影响因素波动量,并采用一种灰色关联与两两比较判断矩阵有机融合的改进灰色关联方法定量分析河北省粮食产量波动影响因素的影响度。【结果】影响河北省粮食产量波动的各要素时序特征为：自然资源各指标波动振幅在-113.43—34.38;政策经济支持能力各指标振幅在-34.59—31.79,波动强度较大;固定资产投资累计各指标振幅在-17.17—10.52,波动强度较小;可变要素投入各指标波动振幅均在-11.39—9.16。粮食产量波动主控因素为：成灾面积、有效灌溉面积、粮食作物播种面积、支援农业生产及农业事业费用、降水量、化肥施用量等六指标,影响度分别为：19.08%、17.80%、12.84%、11.03%、10.28%、7.79%、7.28%,总影响度达78.82%。【结论】提出的改进灰色关联度方法弥补了传统灰色关联度方法只能定性排序的不足,能够客观真实地反映河北省粮食产量波动的主控因素,为定量化研究变量影响因素影响度提供了新方法。     

Monitoring of swarming sounds in bee hives for early detection of the swarming period

Beekeeping, known as one of the oldest forms of agriculture, in its complexity requires control for honey production with what modern technology can offer. Honey is included in animal production implying that farmers have interest in big productions according to the best blooming time, the presence of parasites, the genetic strain of his bees and the swarming periods of the honeybees (queen and her workers leaving the hive).This last fact has a big economic interest for the beekeeper as swarming means honey loss since bees start collecting the honey to migrate. Here for a method that enables the prediction of the swarming is required to prevent the queen from leaving the hives. In this experiment an acoustic method based on labelling of sounds is proposed to predict the swarming period. Three hives were monitored during 270 h. The microphones were sited inside the hives together with a temperature and humidity sensor. The sounds were recorded with a sample rate of 2 kHz, and analyzed via Matlab and Cool Edit Pro. During this period 9 swarming activities occurred. Swarming is indicated by an increase in the power spectral density at about 110 Hz; approaching to swarm the sound augmented in amplitude and frequency to 300 Hz, occasionally a rapid change occurred from 150 Hz to 500 Hz. Another finding indicating the initiation of a swarming period is the raise in temperature from 33 °C to 35 °C until the actual time of swarming when the temperature starts dropping to 32 °C. With more activity, ventilation from bee wings causes drop of temperature. Less information comes from the correlation between sound and humidity since this parameter is too much influenced by the external conditions and no significant variation occurred according to a swarm. This increase of temperature, together with the changes in acoustical features of the sound recorded in the hive, may be used as a predictor for swarming of the bees to reduce honey loss.     

克乌成品油管道工程设计

介绍了克－乌成品油管道工程的概况,输油工艺设计,主要工艺设计计算方法、主要设备与阀件的选型、线路工程情况及整个管道的自动化系统。     

农业保险费率和保费的计算方法研究

为合理确定农业保险费率和保费,本研究根据保险收支平衡原理,提出县级农业保险费率和保费的动态计算方法。该方法根据历年县级作物单产、种植面积和承保年的种植面积,可计算出相应承保产量或保障水平所需收缴的保费率和保费。并以东北三省水稻生产为例,以前3年单产平均值为标准产量,按标准产量100%的保障水平承保,在计算各县水稻产量保险费率和保费的基础上,运用Mapinfo7.0软件绘制保险费率和保费的空间分布图。结果表明:1)该方法输入因子简单,可操作性强,计算结果可动态输出,选择不同产量保障水平计算相应的保险费率和保费,有助于实现农业保险费率和保费的公平性和增加透明度。2)东北179个县(市)水稻产量纯保费率在0～36.21%,县域间保费率差异大,保费率空间分布分散,因此农业保险应以县域进行承保。3)东北179个县(市)水稻应采用的产量保险费率平均为10.1%,略高于美国、加拿大、摩洛哥、日本和印度等现行作物产量的保险费8%～9%,以上各国政府还按农业保费率的40%～60%给予补贴,表明我国农业保险费率需要政府提供补贴。4)在农业保险业务中应该考虑多因素而不能简单地以产量的高低来评估风险,不能认为高产区风险低而收取较低保...     

吉林省白山市八道江水文站旱限水位(流量)确定

通过对吉林省白山市八道江水文站旱限水位确定方法的探讨,分析确定了八道江水文站旱限水位,该指标是确定八道江干旱预警等级的重要指标,是启动抗旱应急响应级别的重要依据,对抗旱工作提供了依据,指导农业生产发展具有十分重要的意义。