农产品安全追溯系统的云计算技术性能提升设计

农业生产及环境的信息采集是农业信息系统的重要环节,无线传感器网络以它的低成本、无线传输等优势广泛应用于农产品安全追溯的信息采集中。由于无线传感器网络长年不间断信息采集的积累,数据库的大信息量及网站用户高访问量将对网站服务器造成高负载的压力,这将导致网站的响应速度大大降低。采用高存储、高负载处理性能云计算计算技术,能提高网站访问的响应速度,提高网站的访问性能。该文设计了基于私有云的农产品安全追溯网站,研究了Hill-Climbing搜索算法优化云平台配置及MapReduce对大数据的并行计算,提高了私有云上的农产品安全追溯系统的性能。通过将网站系统迁移至私有云的前后的比较试验,说明将网站系统迁移至私有云后各方面性能得到较大提升,网站访问响应速度提高了33%。     

图书馆网站评估分析系统设计与实现

采用定量分析的方法,利用计算机技术制作了一个图书馆网站评估分析系统。该系统作为高职院校图书馆网站建设的评估工具,增强了我国图书馆网站建设评估的可操作性。     

探析电路精品课网站的改造

采用ASP.NET和Dreamweaver对电路精品课网站进行开发。电路精品课网站的优化是动态地对文章、图片、公告、留言、视频等信息进行管理,主要包括各种信息的浏览、发布等管理功能。管理员可以对网站各类信息的添加和删除等操作,同时管理员还可对网站系统进行更新和维护,确保网站系统正常运行。     

《中国农业气象》在线投稿系统开通启示

为了贯彻国家信息化发展战略,提升专业化服务水平,提高工作效率,使您能够更为方便快捷地投稿与查询相关信息,《中国农业气象》在线投稿系统已于2011年10月开通试运行。今后,作者可通过网站投稿并查询稿件处理进程,审稿专家可实现网上审稿,读者可通过网站阅读下载本刊已发表论文的全文。欢迎大家积极投稿。在线投稿系统的网址为:http://zgnyqx.ieda.org.cn,投稿前您需先进行注册,具体注册方法如下:(1)登录《中国农业气象》网站主页-点击左侧作者登录,进入投稿系统页面。(2)点击新用户注册,填写个人信息后,点击完成,您就可以使用您申请的用户名和密码进入在线投稿系统进行投稿和查询了。(3)初次注册可能需要花费一定时间,但注册成功后,投稿和查询可节约大量时间和精力,而且今后投稿无     

山东金农信息网的建设

详细介绍了＂山东金农信息网＂新版的设计方案、网站系统建设流程和网站技术特点。     

植被系统受干扰效应分析与建设方略

 植被系统受到干扰后,会出现弹性极限与塑性极限。在弹性极限以下的轻度干扰,植被系统受力后产生的应变可以通过植被本身的自组织能力得以自我修复;中度干扰、严重干扰的应力介于弹性极限与塑性极限之间,其应变可通过人力与自然力的综合作用来加以恢复;剧烈干扰的应力在塑性极限或断裂点以上,系统完全崩溃,需要通过人力重新建造。植被保护是植被恢复、重建的保证。在持续干扰条件撤除后,植被系统将自行或在适度人为措施干预下进入自然演替序列。     

涉农企业网络信息化技术集成与应用研究

本文主要介绍了采用ASP与ACCESS数据库技术设计的涉农企业网站及后台管理系统开发工具,可为涉农企业建立网站并进行管理维护,重点介绍了实现技术和应用功能。     

《中国农业信息》在线投稿系统开通启事

为了方便作者能够更为方便快捷地投稿与查询相关信息,经过一段时间的技术开发及在线调试,《中国农业信息》在线投稿系统于9月1日开通试运行。在线投稿系统主要包括投稿与查询系统、编辑加工系统、专家远程审稿系统3部分。今后,作者可通过网站投稿并查询稿件处理情况,审稿专家可实现网上审稿．读者可通过网站阅读本刊已发表的论文。欢迎大家积极参与测试及投稿,     

基于角色访问控制在农业科研单位网站中的应用

根据农业科研单位网站院所两级管理人员的权限需求分析,将基于角色访问控制应用在网站后台管理用户权限分配系统中,并限制用户＂操作所有信息＂和＂仅操作自己的信息＂,满足了不同层次管理人员权限分配的要求。     

双塔小流域生态系统健康评价

以凌源市双塔小流域为对象,采用层次分析法对双塔小流域综合治理后生态经济系统健康状况进行评价,定量分析双塔小流域历经10 a的综合治理生态经济系统恢复发展过程。结果表明,双塔小流域经过10 a左右的治理恢复,生态系统健康指数由2006年的0.174 2提高到2016年的0.844 2,实现生态健康、经济活跃。     

Automated sample cleanup for pesticide multiresidue analysis. III. Evaluation of complete system for screening subtolerance residues in vegetables

An automated continuous flow sample cleanup system intended for rapid screening of foods for pesticide residues in fresh and processed vegetables has been developed. Recovery and precision data for 8 pesticides in each of 3 crops are compared for the automated and manual procedures. Average recovery for samples fortified with pesticides between 0.026 and 0.277 ppm was 98% for the automated system and 92% for the manual procedure. Average coefficient of variation was 6.6% for the automated system and 4.2% for the manual procedure. In another evaluation, the automated system gave an average recovery of 95% for 12 pesticides commonly found in imported foods; the manual procedure gave an average recovery of 91%. Thus, the results obtained so far indicate that the automated system for sample cleanup gives results comparable to those obtained by manual procedures.     

Valuable Metal Recovery During the Bioremediation of Acidic Mine Drainage Using Sulfate Reducing Straw Bioremediation System

Recovery of valuable metals from acidic mine drainage (AMD) during bioremediation using straw bioremediation system was investigated, with observation of efficient metal recovery. The recovery loading rates of Cu and Zn were 46.19?±?6.13 and 43.86?±?6.76?mg?m^?3?h^?1, respectively. More than 97.0% of Cu and more than 87.0% of Zn were recovered from AMD during bioremediation. The recovery loading rate of Cu increased by 4.54?mg?m^?3?h^?1 for each 1?mg?L^?1 increase in influent concentration while that of Zn increased by 4.08?mg?m^?3?h^?1. Heavy metal toxic effect on the metal recovery in the straw bioremediation system could be neglected in most cases. Low pH could severely decrease recovery rate of Zn, while it had no influence on that of Cu. The recovery loading rate of Zn decreased by almost 70% when the influent pH decreased from 7.0 to 3.0. Cu could be recovered efficiently even at a short hydraulic residence time (HRT) of 18?h, while Zn could only be efficiently recovered at a relatively long HRT of 80?h, indicating that selective metal recovery might be achieved with relatively short HRT and bioreactor process optimization. These findings suggested the feasibility of using sulfate-reducing straw bioremediation system to recover valuable metals during bioremediation of AMD.     

畜舍热交换芯体-风机热回收通风系统的热回收效果

热回收通风作为一种节能的通风换气方式,可缓解畜舍保温能耗与通风的矛盾。然而民用一体式热回收通风系统在畜舍中直接应用时存在通风量小、单位通风量的设备造价高等问题。该研究设计了适用于畜舍的新型节能热回收通风系统,并研究该热回收通风系统在以下3种不同配置条件下的热回收效果,探究该系统在畜舍中的较佳运行条件:板翅式热交换芯体配置不同迎面风速的热回收效果;新风依次经过2个串联连接的板翅式热交换芯体后的热回收效果;优化了板式热交换芯体与噪声小、风量大的轴流风机的参数配比后的热回收效果。结果表明:在舍内外温差为12.08℃,芯体配置迎面风速分别为1.05和0.86 m/s时,新风温度经过板翅式热交换芯体后分别升高了1.93和2.79℃,显热回收效率、热回收负荷和能效比分别为35.88%和43.63%、0.16和0.19 kW,1.37和1.61,两者显热回收效率均未达到冬季65%的节能标准。在舍内外温差为10.49℃时,新风依次经过串联的2个板翅式热回收芯体,经过第1次热交换后新风温度升高2.59℃,显热回收效率为52.11%,热回收负荷及能效比分别为0.39 kW,3.26;新风经过第2次热交换芯体时热回收作用甚微。优化板式热交换芯体与风机配比后,在舍内外温差为12.12℃,迎面风速为4 m/s时,新风温度升高8.23℃,显热回收效率为69.9%,能效比为8.0,达到了冬季节能标准。从该研究热回收效果看,第3种配置参数条件平衡了热回收效率及通风需求的关系,可满足畜舍大通风量及节能的需求。     

生物质好氧发酵热生产与回收利用研究进展

好氧发酵是目前有机固体废弃物处理的一种有效手段。人们对于好氧发酵的研究主要集中在高效有机肥的获取上,但发酵过程产生的热能不容忽视。发酵热作为一种“零碳”能源,可代替传统化石能源应用于加温供暖、生物干化等领域,助力实现“碳达峰、碳中和”。为将生物质能高效转化为热能利用,人们对发酵热回收利用进行了研究,但是没有将热生产、热回收和热利用三个阶段进行系统联系,导致热回收工艺效率不高。该文主要阐述了好氧发酵产热原理,并从菌剂、原料理化性质和发酵工艺三个方面对发酵热生产的影响进行了探讨,总结了现有热回收利用系统,最后对生物质好氧发酵热生产与回收利用系统的发展方向进行展望,以期为生物质发酵热能利用提供支持。     

玉米收获机茎秆堆放装置设计

机械化整秆回收可提高玉米茎秆回收效率、降低回收成本,是玉米茎秆综合开发利用的一个重要环节。在现有玉米收获机械化技术的基础上,开发了玉米茎秆堆放装置,采用铣切刀、搅龙和压送器等部件将玉米茎秆割下、切断并条铺成行,然后由安装在玉米收获机后下方的搂草机构将其集成草堆。堆放装置采用机电液一体化技术,操作人员可通过调节旋钮,方便地改变玉米茎秆的堆间距,机具在地头转向时,操作人员可以通过操作相应按键,方便地控制搂草过程的启、停。试验表明：该玉米收获机茎秆堆放装置工作安全、可靠,与传统的收获相比,玉米茎秆整秆回收效率可提高50%以上。该装置的设计,为玉米茎秆回收和高效生态化利用创造了条件。     

Modelling the turnover of 15N-labelled fertilizer and cover crop in soil and its recovery by maize

The rate at which available nitrogen (N) is released from organic materials in soil is often measured by applying ¹⁵N and following its recovery by the growing crop. However, the turnover of labelled N in soil modifies the ratio of labelled to unlabelled available N and thereby affects the uptake of ¹⁵N by plants. The recovery of labelled N by maize was measured in a field experiment under three management systems, with one ¹⁵N‐labelled input in each: (1) conventional, with fertilizer side dressing, (2) low input, with vetch as a cover crop and fertilizer side dressing, and (3) organic, with vetch and composted manure. The NCSOIL model, which simulates C and N turnover in soil, was modified to include relevant processes related to the maize crop, and used to estimate the decomposition rate constant of vetch in the field by optimizing the simulated dynamics of labelled N uptake by maize against the measured results. A large input of C from mineralizable soil organic matter and root deposition was necessary to account for the recovery of fertilizer N by maize. Optimization of labelled N recovery in the low input system resulted in two optional rate constants for the decomposition of vetch: rapid decomposition (0.4 day^?1) of a labile vetch pool (49% of total vetch N), or slow decomposition (0.008 day^?1) of a single vetch pool. In the simulated organic system, where manure and vetch were incorporated at the same time, only a rapid decomposition of the labile component of vetch accounted well for the recovery of vetch N by maize. The prolonged recycling of N mineralized from the vetch, and its mixing with fertilizer side dressing in the low input system, reduced the recovery of vetch N even though it was mineralized rapidly. This demonstrates the difficulty in assessing the availability of N from organic materials.     

Single-Stage Short-Duration Tempering of Corn for Dry-Milling

Pilot-scale dry-milling runs were conducted to study the feasibility of using a short-duration single-stage tempering procedure for the tempering-degerminating system, instead of the 17.8–21.5 hr of conventional three-stage tempering procedures reported in the scientific literature. Using a Beall degerminator No. 0, pilot-scale dry-milling experiments were conducted at 10 tempering levels: 0, 5, 10, 15, 30, 45, 60, 120, 180, and 240 min. Variation in moisture content of through- and tail-stock fractions, degerminator throughput, ratio of tail- to through-stock, yields of different sized grits from tail- and through-stock fractions, and the recovery of germ and pericarp were used to compare tempering periods. A decrease in the milling action was observed for tempering durations >30 min. A tempering period of 15 min gave the highest grit recovery and a 30-min tempering period resulted in the highest germ and pericarp recovery. Based on these results, it was concluded that short tempering periods of 10–30 min as compared to 17.8–21.5 hr could be used for the tempering-degerminator system.     

吉兰泰盐湖防护体系地表蚀积特征

采用矩阵式插钎法对盐湖防护体系不同防护功能区地表进行野外观测,探究吉兰泰盐湖防护体系地表蚀积特征。结果表明：吉兰泰盐湖防护体系不同防护功能区地表蚀积月际变化呈现明显的波动性。流沙固阻带、封沙育草带主要以风蚀为主,防风阻沙带和盐湖防护林带主要以风积为主。地表沉积物质由外向内趋于细化。流动阻沙带和封沙育草带粒度组成主要以细砂和中砂为主;防风阻沙带和盐湖防护林带粒度组成主要以极细砂和细砂为主。盐湖防护体系表层沉积物平均粒径Φ值、分选系数、峰态和偏度分别为1.66～3.32,0.99～2.91,1.23～2.05和-0.08～-0.89。表层沉积物平均粒径、分选系数、偏度、峰态随着盐湖防护体系由外向内逐渐增加。总体看来,盐湖防护体系营建使地表沉积物趋于细化,有利于土壤细粒物质沉积,对地表起到一定保护作用。     

An overview: recycling nutrients from crop residues for space applications

Without some form of regenerative life support system, long duration space habitation or travel will be limited severely by the prohibitive costs of resupplying air, water, and food from Earth. Components under consideration for inclusion in a regenerative life support system are based on either physicochemical or biological processes. Physicochemical systems would use filtration and elemental phase changes to convert waste materials into usable products, while biological systems would use higher plants and bioreactors to supply crew needs. Neither a purely biological nor strictly a physicochemical approach can supply all crew needs, thus, the best each approach can offer will be combined into a hybrid regenerative life support system. Researchers at Kennedy Space Center (KSC) Advanced Life Support Breadboard Project have taken the lead on bioregenerative aspects of space life support. The major focus has been on utilization of higher plants for production of food, oxygen, and clean water. However, a key to any regenerative life support system is recycling and recovery of resources (wastes). In keeping with the emphasis at KSC on bioregenerative systems and with the focus on plants, this paper focuses on research with biologically-based options for resource recovery from inedible crop residues.     

An Overview: Recycling Nutrients from Crop Residues For Space Applications

Without some form of regenerative life support system, long duration space habitation or travel will be limited severely by the prohibitive costs of resupplying air, water, and food from Earth. Components under consideration for inclusion in a regenerative life support system are based on either physicochemical or biological processes. Physicochemical systems would use filtration and elemental phase changes to convert waste materials into usable products, while biological systems would use higher plants and bioreactors to supply crew needs. Neither a purely biological nor strictly a physicochemical approach can supply all crew needs, thus, the best each approach can offer will be combined into a hybrid regenerative life support system. Researchers at Kennedy Space Center (KSC) Advanced Life Support Breadboard Project have taken the lead on bioregenerative aspects of space life support. The major focus has been on utilization of higher plants for production of food, oxygen, and clean water. However, a key to any regenerative life support system is recycling and recovery of resources (wastes). In keeping with the emphasis at KSC on bioregenerative systems and with the focus on plants, this paper focuses on research with biologically-based options for resource recovery from inedible crop residues.