Analysis of Grain Storage Security Countermeasures under the New Normal Condition with "Grain Storage Technology" as the Core

Grain storage security is big issue related to national economy and the people＇s livelihood, as well as one of the most important strategic requirements in China. Under the background of grain supply-side structural reform, this paper analyzed the grain storage security countermeasures under the new normal conditions with ＂grain storage technology＂, one of the national grain security strategies of China during the 13th Five-year Plan, as the guiding ideology, from the perspectives of scientific technologies, policy supports, government supports and talent construction, so as to provide supports for the storage enterprises with vulnerable technological links. In addition, the food security issues discussed in this paper could be a helping hand in improving people＇s living quality, enhancing grain storage ecological quality, promoting grain green storage quality security, and be of important and profound strategic significance to enhance the macro-control capability of the government, maintain social stability and people＇s health.

Influence of broken kernels content on soybean quality during storage

Although it is recognized that the post-harvest system is most responsible for the loss of soybean quality,the real impact of this loss is still unknown.Brazilian regulation allows 15%and 30%of broken soybean for group I and group II(quality groups),respectively.However,the industry is not informed about the loss in the quality parameters of soybeans and its impacts during long-term storage.Therefore,the objective was to evaluate the effect of the breakage kernel percentage of soybean stored for 12 months.Content of 15% of breakage kernels did not affect soybean quality.However,content of 30% of breakage kernels affected significantly soybean quality,which was evidenced by the increase of up to 75% in moldy soybeans,72% in acidity,50% in leached solids,27% in electrical conductivity,and the decrease of up to 12% in soluble protein,6.4% in germination and 3.5% in thousand kernel weight after 8 months of storage.Although the legislation establishes a percentage limit,it is recommended to store soybeans with up to 15% breakage kernels.On the contrary,values higher than that can cause a significant reduction in soybean quality,resulting in commercial losses.

The Current Situation and Development of Grain Storage Technologies and Facilities for Chinese Farmers

In China, the quantity of farmer＇s grain storage covers about 40% of the total grain yield every year. While, the losses of farms＇ grain storage are up to 8%, which is due to the lack of grain storage facility and technology. The losses of farmer＇s grain storage could reach nearly 20 million tons every year. In this paper, the current situation and development of grain storage technology and facility for Chinese farmers were presented. And a series of policy and research work for reducing the losses of farms＇ grain storage was introduced. The large scale farmers are now developing quickly in China, the new storage warehouse and mechanized facility should be developed adaptively. So, the new storage technology and policy to meet the need of large scale farmers were also introduced in this paper.

Grain Hermetic Storage Adoption in Northern Uganda: Awareness, Use, and the Constraints to Technology Adoption

Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage losses. In Uganda, HSTs were first introduced in 2012. However, its use among farming households remains low today. Data were collected from 306 smallholder farmers from four districts of Northern Uganda using a pre-tested semi-structured questionnaire to understand their knowledge, use, and constraints to the adoption of hermetic storage. A multivariate Logit regression model was used to find the significance of the factors affecting adoption. Results showed low awareness and use of hermetic storage among smallholder farmers. Only 53.3% of the interviewed farmers were aware of the use of hermetic storage for grain storage. The SuperGrain bag was the most known form of hermetic storage (35.3%), followed by the Purdue Improved Crop Storage (PICS) bag (34.9%), metallic silo (15.5%), and plastic silo (14.4%). Hermetic storage use was even lower as only 17.6% of the surveyed farmers were using one or more forms of hermetic storage to store their grains. Insect pest management without chemical insecticides was the main reason (83.1%) for hermetic storage use. About 75.5% of those aware of hermetic storage had received training in the technology. Hermetic storage use in farming households led to improved food availability, household income, and nutrition. Lack of local availability (50.2%), high costs (37.8%), and inadequate knowledge (6.9%) were the main constraints hindering the adoption of hermetic storage in Northern Uganda. The logit regression models showed that only training in hermetic storage significantly (p = 0.002) affected farmers’ decision to adopt hermetic storage. Understanding the factors that constrain the adoption of HSTs could provide policymakers with important information to initiate and design policies and programs aimed at reducing crop storage losses.

Change in Grain-Size Composition of Lignite under Cyclic Freezing-Thawing and Wetting-Drying

The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to repeated freezing-thawing and wetting-drying, which determines the possibility of changing their grain-size composition and structure. Experimental studies in laboratory conditions on the influence of cyclic freezing-thawing (FTC) and wetting-drying (WDC) on the quality indicators of lignites have been carried out, their granulometric (fractional) composition has been studied. Freezing-thawing cycle conditions are as follows (FTC): minimum exposure temperature: -20°C;maximum: +5°C;relative humidity: 30%;number of processing cycles: 3. Wetting-drying cycles are as follows (WDC): drying temperatures are +20, +40, +60, +80°C, drying time 90 minutes, the coals are further subjected to rain (soaking) for a period of water saturation to humidity of 30% - 40% and dry again. The number of wetting-drying cycles is 3 times. The tests have revealed the destructive effects of FTC and WDC on the samples of lower metamorphic grade coal, and the cycles of wet-dry lead to the much higher yield of fine sizes (-6+0;-13+0 mm) than the cycles of freeze-thaw. Furthermore, it is found that the increase in the yield of fines depends on the heating temperature: coal disintegration proceeds more intensively at a higher temperature of drying.

Effects of Different Tillage Systems on Soil Properties,Root Growth,Grain Yield,and Water Use Efficiency of Winter Wheat (Triticum aestivum L.) in Arid Northwest China

Studies on root development, soil physical properties, grain yield, and water-use efficiency are important for identifying suitable soil management practices for sustainable crop production. A field experiment was conducted from 2006 through 2008 in arid northwestern China to determine the effects of four tillage systems on soil properties, root development, water-use efficiency, and grain yield of winter wheat （Triticum aestivum L.）. The cultivar Fan 13 was grown under four tillage systems：conventional tillage （CT） without wheat stubble, no-tillage without wheat stubble mulching （NT）, no-tillage with wheat stubble standing （NTSS）, and no-tillage with wheat stubble mulching （NTS）. The soil bulk density （BD） under CT system increased gradually from sowing to harvest, but that in NT, NTSS, and NTS systems had little change. Compared to the CT system, the NTSS and NTS systems improved total soil water storage （0-150 cm） by 6.1-9.6 and 10.5- 15.3% before sowing, and by 2.2-8.9 and 13.0-15.1% after harvest, respectively. The NTSS and NTS systems also increased mean dry root weight density （DRWD） as compared to CT system. The NTS system significantly improved water-use efficiency by 17.2-17.5% and crop yield by 15.6-16.8%, and the NTSS system improved that by 7.8-9.6 and 7.0-12.8%, respectively, compared with the CT system. Our results suggested that Chinese farmers should consider adopting conservation tillage practices in arid northwestern China because of benefits to soil bulk density, water storage, root system, and winter wheat yield.

Effects of hexanal fumigation on fungal spoilage and grain quality of stored wheat

The prevention of fungal spoilage is an essential consideration in wheat storage.Recent studies have revealed that volatile organic compounds(VOCs),possibly with natural fungicidal properties,could be produced from stored wheat grains.In this study,the antifungal effect of hexanal,a main component of VOCs from stored wheat,against spoilage fungi on agar plate and in high-moisture wheat grains were investigated via the gas fumigation method.And the impact of hexanal fumigation on grain quality was evaluated through analysis of the malondialdehyde content,fatty acid values,germination percentages and vigor of 16%and 18%moisture wheat grains fumigated with 1.66,2.49,and 3.31 mmol/L hexanal vapor.The results of in vitro antifungal experiments on agar plates revealed that the minimum inhibitory concentration and minimum fungicidal(fatal)concentration of hexanal against the five fungi were 4–14 folds and 4–7 folds lower than those of propionic acid,respectively.The fungal spoilage of high-moisture wheat grains inoculated with pure fungal spores and with naturally occurring fungi could be completely inhibited by 1.66 mmol/L hexanal vapor.During 5-week storage of high-moisture wheat grains fumigated with 1.66,2.49,and 3.31 mmol/L hexanal vapor,the malondialdehyde content in high-moisture wheat grains did not change significantly in all samples,and fatty acid values were slightly higher in 18%moisture wheat than in 16%moisture wheat.The germination percentages and vigor of wheat samples decreased with increased hexanal vapor concentrations and moisture content.These results indicated that hexanal fumigation could be used as an alternative chemical control method to prevent the fungal spoilage of postharvest wheat.

Laboratory Assessment of Diatomaceous Earth against Several Stored-Grain Pests of Sorghum

A wide range of insect pests attacks stored sorghum grains and the significant damage in grain weight loss and negative impact on the nutritional values of sorghum are caused with the activities of these pests. The insecticides, especially from organophosphate group （OP）, are still used to prevent damage of sorghum grains during storage period. One of the possible replacements for OP and other synthetic insecticides is a natural and safe diatomaceous earth （DE）. The primary objectives of this study was conducting the laboratory experiments with enhanced DE Protect-lt on Sitophilus oryzae （L.）, Rhyzopertha dominica （Fab.） and Tribolium castaneum （Herbst.） to find out the effective concentrations and to determine the effect of applicable concentration of DE on bulk density （test weight） of sorghum grains. The effect of Protect-it on bulk density was measured at 1,000 ppm. After the exposure of S. oryzae, R. dominica and T castaneum to treated grains during 13 days, lethal dosis that causes 90% mortality （LD90） were 811 ppm, 1,102 ppm and 1,244 ppm, respectively. After exposure of 8 days the concentration of 1,000 ppm generated the mortality ofS. oryzae 100% and for R. dominica and T.castaneum for over 99%. The same concentration had a minimal effect on the reduction of sorghum bulk density （for 1.95% only）.

Mining the Change of the Quality of Stored Grain

The quality of grain changes continually during its storage, including the change of its physical characteristics and physiological characteristics. This paper presents an approach to predict the change of the quality of stored grain with data mining technology. Logistic Regression, Decision Tree and Muitilayer Perceptron are applied to predict the change of the grains＇ quality control index and to obtain the grains＇ quality change probability. The grain sampling with higher probability can be processed earlier.

有土斯有粮:高标准农田建设提高了粮食单产吗?

作为“藏粮于地,藏粮于技”战略的重要政策实践,高标准农田建设被期待能够有效实现粮食增产和更好保障国家粮食安全。基于27个省(市、自治区)的面板数据,探索了高标准农田建设对粮食单产的影响及其可能机制。研究发现:(1)高标准农田建设能显著提高粮食单产。替换核心变量、进行非参数估计和考虑内生性的稳健性检验,均证实上述发现可信。(2)机制验证表明,高标准农田建设主要通过提升规模经营、促进技术进步和降低生产风险三大路径来提高粮食单产。(3)异质性分析发现,高标准农田建设对起伏度较小地形、粮食主产区、较发达地区的粮食单产促进效应更大。研究结果表明高标准农田建设确实是夯实粮食安全根基的重要举措,需扎实推进新一轮高标准农田建设工作。

昆虫对低氧环境的适应性机制研究进展

昆虫需要利用氧气进行有氧呼吸,产生能量,维持正常的生命活动。在储藏环境中,可以利用气调技术控制环境中氧气的占比,以达到防治害虫的目的。然而害虫低氧适应性的发展为这项技术的推广和应用带来挑战。文章围绕低氧对昆虫生长发育、生命活动、生理功能的影响,以及昆虫适应低氧环境的补偿性策略,包括内在调控机制,生物学特性调节,代谢网络重构,基因调控等方面进行了综述。以期为害虫低氧适应性的产生机制提供新的研究线索,为绿色储粮技术的研究及发展提供参考。

粮仓能源桩系统绿色储粮技术应用研究

简化粮食入库后全周期控温供冷储粮流程,提出满仓主动降温与夏季粮仓热平衡2种供冷方案。通过理论公式计算2种方案下的供冷量需求,并利用有限元模拟软件计算得出能源桩换热量,由此设计可满足上部粮仓供冷需求的能源桩运行方案。结果表明:在1万t储粮规模下,粮仓能源桩储粮技术可满足2种供冷方案下的能源需求,对比谷物冷却机与地源热泵储粮,其初期投入成本更低;对比空调储粮,其初期投入成本增加,但能源桩储粮技术可利用绿色清洁能源,储粮能耗最低。

储粮信息系统弱密码增强多重散列保护方法研究

使用弱密码是计算机信息系统安全的重要漏洞,在粮食储藏信息化应用中亦是如此。单纯的哈希散列加密算法对弱密码存在明显局限性。结合粮库软件系统应用实际,本文提出以哈希散列算法为基础,混入盐值和引入高进制映射等进行增强处理,多次复用散列运算的弱密码保护方法。验证分析表明,方法增加了弱密码的加密值强度,阻断了字典攻击或彩虹表攻击,实现了对弱密码传递和存储的有效保护,且复杂度较低,程序实现难度低,运算耗时均值约2.5ms,对用户无感。方法用于粮食储藏信息化建设管理,可提供良好的安全保障。

不同储粮工况下柱承式立筒仓结构动力特性

柱承式立筒仓广泛应用于国家粮食储备,不同储粮工况对其结构动力特性影响显著。为揭示粮食散体对柱承式立筒仓动力特性的影响规律,结合某实际柱承式立筒仓设计制作了缩尺比例为1/25的有机玻璃筒仓模型,在空仓、半仓、3/4仓和满仓4种储粮状态下,进行了振动台模态试验、有限元数值分析和自振频率理论计算。结果表明:不同储粮工况对柱承式立筒仓试验模型的固有频率影响显著,随储粮状态变化,固有频率减小幅度较大,应在结构设计中加以考虑;空仓状态下阻尼比最小,满仓状态比空仓增大42.65%,仓内原有储粮越多,阻尼比增值越大,减震耗能效果越明显;有限元模型一阶固有频率与试验值平均误差为5.1%,所建有限元模型较为合理,为结构动力响应分析及结构设计提供一种合理的数值模拟方法;简化的三质点串联多自由度的弹性动力模型较为准确计算柱承式立筒仓在4种储粮工况下的固有频率,试验值与理论值平均误差为5.6%。研究结果可为柱承式立筒仓结构动力特性计算提供参考,为其抗震性能设计提供理论基础和试验依据。

我国粮食仓储设施建设与经济发展耦合协调的时空演化分析

利用2006—2020年中国31个省级行政区面板数据,在分析我国粮食仓储设施建设综合水平的基础上,对粮食仓储设施建设与经济发展耦合协调的时空演变特征进行研究,得出以下结论:在研究期内,我国粮食仓储设施建设综合评价值波动上升,空间上呈东高西低态势;粮食仓储设施建设与经济发展的耦合协调度偏低,呈上升-下降-上升趋势;耦合协调度的空间关联性自2009年开始逐渐显著,空间集聚程度呈北高南低的态势,空间演变格局具有向东北方向移动的集聚态势。根据研究结论,建议未来因地制宜提升不同省份粮食仓储设施建设与经济发展的协调匹配程度,以高耦合协调度地区带动周边地区发展,实现全国范围内粮食仓储设施建设与经济发展的协调进步。

收储制度市场化改革能提升玉米生产效率吗?——基于玉米主产区247地级市数据实证分析

党的十九大要求,加快推动粮食收储制度改革,保障国家粮食安全。党的二十大进一步指出,全方位夯实粮食安全根基,确保中国人的饭碗牢牢端在自己手里。收储制度市场化改革能否有效激发市场机制作用、提升粮食生产效率,对稳定国内粮食供给、保障国家粮食安全具有重要影响。利用2011-2020年玉米主产区247地级市面板数据,构建DID模型和中介效应模型,基于市场扭曲和市场风险双重视角分析收储制度改革对玉米全要素生产率的影响,并探讨其影响机制。结果表明:(1)收储制度改革对东北三省一区玉米全要素生产率总体呈现正向影响,但是随着改革的深入,全要素生产率增长幅度呈现波动变化;(2)收储制度改革的影响存在较大区域差异性,改革对于内蒙古和黑龙江两地呈现较为明显正向影响,尤其是对该地区第一、第四和第五积温带区域影响最为显著,而对吉林和辽宁两省影响并不明显;(3)收储制度改革通过缓解市场扭曲和加剧市场风险两条路径影响玉米全要素生产率,其中市场扭曲的缓解有助于提升玉米全要素生产率,而市场风险的加剧则减缓了玉米全要素生产率的增长。政府应该关注收储制度改革后玉米生产效率,充分发挥市场机制功能,同时配套抗风险、防波动稳定机制,以确保玉米生产高质量发展,保障国家粮食安全。

半地下双层浅圆仓静态储粮温度场的数值分析

粮食温度是影响储粮安全的最重要因素之一,为揭示半地下双层浅圆仓的储粮温度场分布规律,本文建立了地上浅圆仓和地下仓的粮堆数学分析模型,并通过现场实验结果验证了模型的有效性。以此为基础建立了半地下双层浅圆仓数值模型,分析低温入粮后静态储藏1年期间的粮堆温度场变化规律。结果表明:半地下双层浅圆仓地上层靠近仓壁2 m内的粮温受外界气温影响变化明显,温度范围在10.62~27.37℃,地下层粮温常年处在准低温状态,平均温度不超过地下恒温区温度17℃;入冬时地上层粮堆在距仓壁1~3 m之间会短期形成一个热量聚集区,导致近仓壁处粮堆温差较大,随后外围区温度缓慢降低,形成“热心冷皮”;仓壁的保温隔热措施可有效减小气温对粮温的影响,地上层夏季最高粮温较未做保温的地上浅圆仓低3.86℃左右。研究结果可为半地下双层浅圆仓的推广应用提供技术支持。

新工科背景下“粮油贮运学”课程改革与实践

新工科发展建设要求食品专业培养既有专业知识又具有创新意识和能力的综合人才。以“粮油贮运学”课程为例,从优化课程目标和教学内容、改进教学手段、丰富实践教学环节及建立科学合理的课程考核评价体系等方面进行了课程改革和建设。课程改革将理论与实践教学的有机结合,提高了学生参与度和学习主动性,有利于培养学生创新意识和创新能力,提升学生解决实际问题的能力。

民营粮食收购企业供应链融资模式选择的影响因素研究

论文针对东北三省中小民营粮食收购企业存在融资难的问题,选取东北三省中小民营粮食收购企业收储供应链为研究对象,首先,通过问卷调查得出:一是这类企业选择供应链融资模式频率由小到大依次为“应收账款类融资模式”“信用类融资模式”“存货类融资模式”;二是在下游购销企业主导的粮食收储供应链金融中,以其自身资质向中小民营粮食收购企业提供担保的意愿不高;三是中小民营粮食收购企业认为政商关系总体在合格以上。其次,运用多变量Probit模型,得出供应链融资模式选择影响机理:贷款期限对信用类融资模式选择有显著的正向影响,政府对这类企业的服务水平正向影响着存货类融资模式选择。最后,得出政策启示:政府应提高服务水平精准到选择存货类融资模式的企业,通过优质中小企业梯度培育政策鼓励中小民营粮食收购企业兼并,鼓励银行扩大资产负债率的融资条件到8%—20%。

一种粮仓能源桩绿色储粮原理科普教具设计

为进一步做好研究性教学工作,一方面结合粮食仓储行业“碳中和”目标的实现,创新地将能源桩技术首次应用于粮仓结构,设计了一种粮仓能源桩绿色储粮系统;另一方面,针对粮仓能源桩绿色储粮系统教学难点,从外观应用、技术科普及信息反馈3个方面,采用3D打印技术设计配套科普教具,利用科普教具直观演绎粮仓系统组成、能量传递机理等,给予学生不同的教学体验,使学生在学习基础知识点的同时,开拓视野,提高创新思维。