作物设施栽培基质消毒机的设计与研究

根据土壤高温蒸汽消毒原理,结合作物设施栽培的农艺要求,设计制造了一种自走式作物栽培基质蒸汽消毒机。利用Solid Works软件分析了消毒机的基本工作原理、总体结构组成及关键零部件设计,对各零部件结构图与装配图进行绘制并对重要工作部件进行了强度校核和运动轨迹分析;通过有限元软件ANSYS针对消毒机的抛土机构等开展静力学及模态的研究;依靠样机采用正交实验方法完成了田间性能试验,验证其设计的合理性与可行性。结果表明:设计的消毒机结构简单、操作简便,在减轻劳动强度的同时缩短了消毒时间,有利于提高设施栽培作物的产量和质量,为后续小型育苗基质消毒机械的设计提供了参考。     

二月兰在园林中的应用价值

二月兰是一种优良的早春地被植物,具有广阔的发展前景。文章主要阐述了二月兰的生态特征及观赏价值,介绍了其在园林绿化中的应用和优势,同时阐述了二月兰的推广价值。     

超声波对航煤中微生物的杀灭效果实验

航空煤油的微生物污染已经成为国际航空界普遍关注的问题.以超声波发生器为灭菌设备,以污染航空煤油的微生物为指示菌,研究超声波及超声波与紫外线协同作用的杀菌效果.实验结果表明:超声波灭菌存在最佳频率,超声波频率为28 kHz时,其对微生物的杀灭效果最好,超声波频率为59 kHz时,其对微生物的杀灭效果最差;同时灭菌率随培养...     

中药活性成分皂苷免疫作用的研究进展

皂苷一种从中药中提取出来的三萜类化合物,具有广泛的生理活性。本文从皂苷对机体非特异性免疫、特异性免疫的增强作用以及抗肿瘤活性、作为佐剂等的研究进展方面进行了综述。     

基于层次分析法建立规模猪场非洲猪瘟风险评估模型

为确定规模猪场非洲猪瘟(ASF)传入和传播的风险因子,应用层次分析法(AHP),构建半定量评估模型,对规模猪场引发ASF疫情的风险因子重要程度进行排序;以农业农村部下发的《非洲猪瘟疫情应急实施方案(2020年版)》等技术规范及集约化猪场防疫标准为依据,通过查阅文献资料、专家咨询的方式,建立了由目标层、准则层、评价要素层...     

薰衣草叶片高频再生体系的建立

 以薰衣草叶片为外植体进行了离体再生研究。结果表明: 叶片愈伤组织诱导最佳的培养基是MS + 2,4-D 0.1 mg/L + 6-BA 0.5 mg/L, 诱导率高达100%; 液体悬浮—固体培养芽分化率达92.5% , 芽数/愈伤组织达6.6; 正交试验筛选出芽增殖最佳培养基为MS +NAA 2.0 mg/L + 6-BA 0.5 mg/L + IAA 1.0 mg/L, 其增殖系数高达8.7; 在芽增殖培养基上可直接生根, 生根率达100%。     

Experiments analysis on the influence induced by parameters of nature gas huff and puff in foamy oil reservoir

Foamy oil phenomenon of heavy oil reservoirs gradually disappears in the latter period of solution gas drive, which causes the decrease of oil development. Based on the formation of secondary foamy oil by gas injection, foamy oil unconventional experiments and pressure depletion tests are conducted to reveal the characteristics of the foamy oil and analyze the applicability of various types of foamy oil reservoir simulation models. Evaluation of improving oil recovery by nature gas huff and puff is conducted and the influence of injection and production parameters is studied. The study shows that foamy oil exists quasi bubble point which decreases with the decrease of time. The foamy oil compression coefficient is in the range of 10～0.012 MPa -1, which is higher than that of the conventional crude oil. Foamy oil model of six components is the most suitable model for the foamy oil reservoir. There is optimal gas injection and soak time for nature gas huff and puff. Increasing the gas injection speed, gas injection pressure and fluid production rate will improve the performance of nature gas huff and puff. Increasing the speed that dissolved and injected gas change into disperse gas is very important during the solution gas drive and gas injection process.     

顺序输送管道调度计划编制的影响因素分析

在编制成品油顺序输送管道调度计划时,需要着重考虑管道的能耗、压力波动和混油等因素,以指导管道的安全和经济运行。对这些因素进行了分析,以兰成渝成品油管道为例,探讨了调度计划的变化对下游混油量的影响。     

农村宅基地代码编制规则研究与应用以安达市吉星岗镇吉星村为例

【目的】 建立统一的农村宅基地代码编制规则是开展农村宅基地信息化管理的基础性工作。【方法】 在吸收、消化国内外相关编码的基础上,文章将宅基地所有权人、农户、宅基地、宅基地使用权人和农民房屋作为农村宅基地编码内容,提出了相应的代码结构、编码方法和赋码规则,并以安达市吉星岗镇吉星村为例,对编码进行了应用。【结果】 （1）各编码内容体现了农村宅基地的权利要素构成,符合农村宅基地基础信息调查工作的实际需要;（2）各编码内容以行政区划编码为基础,符合国家行政管理原则,能够与其它相关编码体系进行有效衔接,有助于农村宅基地信息的交换和共享;（3）以宅基地所有权人为基础进行统一编码,能够很好地反映各编码内容之间的内在关系,有利于农村宅基地信息化管理。【结论】 研究对提高农业农村行政主管部门工作效率和促进农村宅基地管理信息化建设具有十分重要的理论和实践意义。     

SUSTAINABLE NITROGEN MANAGEMENT INDEX: DEFINITION,GLOBAL ASSESSMENT AND POTENTIAL IMPROVEMENTS

● A composite N management index is proposed to measure agriculture sustainability. ● Nitrogen management has been moving towards sustainability targets globally. ● The improvement was achieved mainly by yield increase, while Nitrogen Use Efficiency (NUE) stagnated. ● No country achieved both yield and NUE targets and spatial variation is large. ● Region-specific yield targets can be used to supplement the standard Sustainable Nitrogen Management Index (SNMI). To represent the sustainability of nitrogen management in the Sustainable Development Goals indicator framework, this paper proposes a sustainable nitrogen management index (SNMI). This index combines the performance in N crop yield and N use efficiency (NUE), thereby accounting for the need for both food production and environmental protection. Applying SNMI to countries around the world, the results showed improvement in the overall sustainability of crop N management over the past four decades, but this improvement has been mainly achieved by crop yield increase, while global NUE has improved only slightly. SNMI values vary largely among countries, and this variation has increased since the 1970s, implying different levels of success, even failure, in improving N management for countries around the world. In the standard SNMI assessment, the reference NUE was defined as 1.0 (considered an ideal NUE) and the reference yield was defined as 90 kg·ha⁻¹·yr⁻¹ N (considering a globally averaged yield target for meeting food demand in 2050). A sensitivity test that replaced the reference NUE of 1.0 with more realistic NUE targets of 0.8 or 0.9 showed overall reduction in SNMI values (i.e., improved performance), but little change in the ranking among countries. In another test that replaced the universal reference yield with region-specific attainable yield, SNMI values declined (i.e., improved performance) for most countries in Africa and West Asia, whereas they increased for many countries in Europe and South America. The index can be improved by further investigation of approaches for setting region-specific yield targets and high-quality data on crop yield potentials. Overall, SNMI offers promise for a simple and transparent approach to assess progress of countries toward sustainable N management with a single indicator.