Light Simplified Foxtail Millet Cultivation Technique Adopting Furrow Sowing beside Plastic Film Covering Micro-ridges

In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with the characteristics of low instable yield, manual thinning and weeding, high labor intensity, and labor and time saving, Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated furrow sowing beside plastic film covering micro-ridges, simplified cultivation and mechanized production, forming the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges. This study introduced the technique points of the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges, including preparation before sowing,sowing, attached agricultural machines, field management, harvest and residual film recovery.

Effects of film-stalk spaced dual mulching system on corn growth and yield

Film-stalk spaced dual mulching is a new type of cultivation measure that is increasingly highlighted in semi-arid areas in China.Despite its potential,there is limited understanding of how different mulching materials affect both soil quality and crop yield in these areas.To address this gap,we conducted a two-year(2020-2021)field experiment in central China to explore the yield-enhancing mechanisms and assess the impact of various mulching materials on soil and corn yield.The experiment comprised six treatments,i.e.,plastic film-whole stalk spaced mulching in fall(PSF),plastic film-whole stalk spaced mulching in spring(PSS),black and silver plastic film-whole stalk spaced mulching in spring(BPSS),biodegradable film-whole stalk spaced mulching in spring(BSS),liquid film-whole stalk spaced mulching in spring(LSS),and non-mulching cultivation(CK).Results revealed that BPSS demonstrated the most significant yield increase,surpassing CK by a notable 10.0%and other mulching treatments by 2.4%-5.9%.The efficacy of BPSS lied in its provision of favorable hydrothermal conditions for corn cultivation,particularly during hot season.Its cooling effect facilitated the establishment of optimal temperature conditions relative to transparent mulching,leading to higher root growth indices(e.g.,length and surface area),as well as higher leaf photosynthetic rate and dry matter accumulation per plant.Additionally,BPSS maintained higher average soil moisture content within 0-100 cm depth compared with biodegradable mulching and liquid mulching.As a result,BPSS increased activities of urease,catalase,and alkaline phosphatase,as well as the diversity and abundance of soil bacteria and fungi in the rhizosphere zone of corn,facilitating nutrient accessibility by the plant.These findings suggest that selecting appropriate mulching materials is crucial for optimizing corn production in drought-prone areas,highlighting the potential of BPSS cultivation.

Simulation Experiment of Air Temperature Variation in Multi-film Covering at Night

In order to provide theoretical basis and data support for improving the production mode of covering,this study investigated the nighttime air temperature formed by multiple layers of films with tunnel sheds and small tunnel sheds as trial subjects.The experiment was carried out in four tunnel sheds with 0 or 2 small tunnel sheds covered by 0,1,2 and 3 layers of films,respectively in Jinan,Shandong Province in winter of 2018.The nighttime air temperatures of tunnel sheds and small tunnel sheds formed by 1,2,3 and 4 layers of plastic film were measured and analyzed to simulate the temperature environment of early-spring season.The results showed that there were little differences between the nighttime air temperatures inside the tunnel sheds which was installed 0-3-layer small tunnel sheds inside,and there were uncertainty in the values of the air temperatures inside and outside the tunnel sheds;and the nighttime temperature conditions were constantly improved with the number of plastic film layers increasing under the conditions of this study.The analysis indicated that the mechanism of raising the temperature surrounded by plastic film was not only due to its own thermal parameter (thermal conductivity).MATLAB fitting analysis results showed that the increment of nighttime temperature in multi-film coverings became smaller with the number of film layers increasing.In this study,the number of layers in multi-film covering should not exceed 5 layers.

Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro

BACKGROUND The treatment of difficult common bile duct stones(CBDS)remains a big challenge around the world.Biliary stenting is a widely accepted rescue method in patients with failed stone extraction under endoscopic retrograde cholangiopancreatography.Fully covered self-expanding metal stent(FCSEMS)has gained increasing attention in the management of difficult CBDS.AIM To manufacture a drug-eluting FCSEMS,which can achieve controlled release of stone-dissolving agents and speed up the dissolution of CBDS.METHODS Customized covered nitinol stents were adopted.Sodium cholate(SC)and disodium ethylene diamine tetraacetic acid(EDTA disodium,EDTA for short)were used as stone-dissolving agents.Three different types of drug-eluting stents were manufactured by dip coating(Stent I),coaxial electrospinning(Stent II),and dip coating combined with electrospinning(Stent III),respectively.The drugrelease behavior and stone-dissolving efficacy of these stents were evaluated in vitro to sort out the best manufacturing method.And the selected stonedissolving stents were further put into porcine CBD to evaluate their biosecurity.RESULTS Stent I and Stent II had obvious burst release of drugs in the first 5 d while Stent III presented controlled and sustainable drug release for 30 d.In still buffer,the final stone mass-loss rate of each group was 5.19%±0.69%for naked FCSEMS,20.37%±2.13%for Stent I,24.57%±1.45%for Stent II,and 33.72%±0.67%for Stent III.In flowing bile,the final stone mass-loss rate of each group was 5.87%±0.25%for naked FCSEMS,6.36%±0.48%for Stent I,6.38%±0.37%for Stent II,and 8.15%±0.27%for Stent III.Stent III caused the most stone mass-loss no matter in still buffer or in flowing bile,which was significantly higher than those of other groups(P<0.05).In vivo,Stent III made no difference from naked FCSEMS in serological analysis(P>0.05)and histopathological examination(P>0.05).CONCLUSION The novel SC and EDTA-eluting FCSEMS is efficient in diminishing CBDS in vitro.When conventional endoscopic techniques fail to remove difficult CBDS,SC and EDTA-eluting FCSEMS implantation may be considered a promising alternative.

STUDIES ON TUNG OIL COATED REGENERATED CELLULOSE FILMS WITH WATERRESISTANCE

Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.

复合材料薄膜盖结构与功能一体化设计

目的解决传统硬质泡沫塑料易碎盖存在的承压能力不足、冲破性能不稳定、不能有效防潮控湿、电磁兼容性差等缺陷。方法以某型导弹武器系统发射筒密封盖为主要应用对象开展薄膜盖设计,主要包括总体结构设计、零部件设计、功能设计及仿真验证。结果薄膜盖经密封、承压、冲破、电磁兼容等性能考核,均满足装备贮存使用要求,冲破盖体所受的最大峰值冲击力可稳定保持在1200~1600 N。结论建立了薄膜盖结构与功能一体化设计方法,可满足在研型号对新型密封盖的设计需求,并为新型号弹箭发射筒大尺寸密封盖的顺利研制提供技术储备。

干旱地区不同颜色覆膜对土壤水热及茴香产量的影响

以“民勤2号”茴香为试材,采用大田随机区组设计方法,设置无覆盖(NM)、黑色地膜覆盖(BM)、透明地膜覆盖(TM)3个试验处理,测定了干旱区不同颜色覆膜下茴香农田土壤的含水量、温度、株高及产量,通过比较测定数据探究不同颜色覆膜对土壤水热及茴香产量的影响,以期为该地区茴香覆膜栽培技术应用提供参考依据。结果表明:覆膜可以提高茴香全生育期及不同土层土壤含水量,BM显著高于其他处理;不同生育期茴香农田土壤温度及不同生育期0~100 cm土层的土壤温度均表现为覆膜处理高于无覆膜处理,且BM>TM>NM;茴香株高、产量试验均表现为覆膜处理高于无覆膜处理,且BM增加效果最为显著。综上,覆黑色地膜在提高土壤含水量和土壤温度、增加茴香产量方面具有重要作用。

内嵌式基质开沟覆膜一体机设计与试验

为解决新疆南疆地区设施农业温室大棚内作业空间狭窄、缺乏高效作业的开沟覆膜一体机问题,设计一款内嵌式基质开沟覆膜一体机。该机具由机架、开沟覆膜机构、动力机构、梯形镇压机构、覆基质机构等组成,内嵌式基质开沟覆膜一体机作业可一次性完成开沟、覆膜、定型、覆土和排基质等多项作业。通过EDEM仿真软件对单一切土开沟刀和切抛组合式开沟刀进行开沟仿真模拟,并进行田间试验验证。结果表明,单一切土开沟刀在开沟过程中所受到的阻力平均值为329 N,切抛组合式开沟刀在开沟过程中所受到的阻力平均值为338 N左右,切抛组合式开沟刀提高作业质量且开沟阻力并未明显增加。该机具开沟深度为30 cm、开沟深度稳定性为87.1%、开沟后碎土率为92.4%。可为干旱偏远地区设施农业温室大棚内机械作业提供技术参考。

生物降解地膜水蒸气透过量试验中不同条件对结果的影响

生物降解地膜相比传统聚乙烯地膜,水蒸气透过量要大。因此,研究影响生物降解地膜水蒸气透过量因素就很重要。本文通过对2种不同厚度的样品分别进行不同称量时间间隔的水蒸气透过量测定,并利用GB/T 35795—2017《全生物降解农用地面覆盖薄膜》水蒸气透过量检验指标和GB/T 1037—2021《塑料薄膜与薄片透水蒸汽性能测定杯式增重与减重法》规定的测试方法,以恒温恒湿箱增重法为试验方法研究了称量时间间隔对水蒸气透过量的影响关系。结果表明:1)厚度对地膜的水蒸气透过量有影响,随着厚度的增加,水蒸气透过率会减少;2)水蒸气透过量测试过程中,称量时间间隔会影响结果准确性,在满足GB/T 1037—2021中要求的干燥剂吸湿总量不超过10%的前提下,称量时间间隔与结果呈负相关性。

秸秆深埋配施硫酸铝对西辽河平原地区苏打盐碱土水盐运移的影响

为探索秸秆深埋和硫酸铝改良剂配施交互作用对苏打盐碱地水盐运移的影响,在通辽市科尔沁左翼中旗开展覆膜滴灌下不同硫酸铝用量与秸秆深埋的田间试验,以甜菜为指示作物,常规处理为对照(CK),在有无秸秆深埋(A、B)的条件下分别设置4水平硫酸铝添加量(30、60、90、120 g/m^(2)),揭示硫酸铝用量、秸秆深埋与土壤含水率、盐分的相关关系,提出覆膜滴灌及秸秆深埋下适宜的硫酸铝用量。结果显示,未添加秸秆处理中B3处理0~50 cm土体平均含水率最高(23.8%),比CK高8.2%,且平均含盐量最低(1.69 g/kg),比CK低12.6%;添加秸秆处理中A3处理0~50 cm土体平均含水率最高(26.6%),比B3处理高2.8%,平均含盐量也最低(1.57 g/kg),比B3处理低19%,且平均积盐率最低,比B3处理降低7.6%;A3处理在10~20和20~30 cm处土壤含水率均显著高于B3处理(P<0.05),在0~10和20~30 cm处土壤含盐量较B3处理显著降低(P<0.05);A3处理0~30 cm各土层均有脱盐趋势,达到显著水平(P<0.05),平均脱盐率11.5%;硫酸铝和秸秆深埋交互作用与土壤含水率呈极显著正相关(0.808),与土壤含盐量呈显著负相关(-0.564)。秸秆深埋和硫酸铝改良剂综合作用可有效降低土壤pH值0.53~0.94,缓解土壤碱化度20.5%~21.9%。覆膜滴灌及秸秆深埋下硫酸铝用量在72~104 g/m^(2)为适宜当地的推荐用量。研究结果可为西辽河平原地区盐碱土壤改良提供理论依据。

覆膜种植措施对垄作农地土壤优先流空间异质性的影响

为进一步针对垄作田间农业生产制定高效的需水用肥策略提供科学支撑,将野外染色示踪试验和室内土柱水分入渗实验相结合,利用图像形态学解析、模拟入渗分析、熵权分析和灰色系统理论分析等方法,对垄作覆膜和垄作(对照)种植措施下的农地土壤优先流空间异质性特征进行分析,阐明覆膜种植措施下的垄作农地土壤优先流空间分布及其运动变化规律,揭示覆膜种植措施影响下的优先流与垄作田间土壤水分运动过程的作用关系。结果表明:在相同外部供水条件下,垄作覆膜种植农地的水分集中分布在0~10 cm土壤表层,随着土壤深度的增加分布范围逐渐缩小,其土壤染色复杂程度随着土壤深度的增加先增大后减少。而垄作种植农地在10~30 cm土壤深度范围内的水分分布出现显著的指状优先流分化现象。同时,垄作覆膜农地土壤达到饱和状态的时间是垄作农地的1.36倍,其单位时间内的平均土柱水流出流量(质量流率为0.20 g/s)显著(P<0.05)小于垄作农地(质量流率为0.35 g/s),土壤优先流程度相较更高,土壤属性中饱和导水率对优先流程度影响最大。垄作覆膜种植措施相较垄作在一定程度上能够进一步降低农地土壤空间内优先流的发生及其分布,减少水分向土壤深层渗漏,起到一定程度的蓄水保墒作用。

青贮玉米光合特性及产量对全膜覆盖不同滴灌量的响应

为探讨全膜覆盖下滴灌量对河西灌区青贮玉米光合特性及产量的影响,以甘肃省河西灌区W_(1)(节水30%)、W_(2)(节水20%)、W_(3)(节水10%)、W_(4)(传统灌水)4种滴灌处理下青贮玉米为研究对象,分析不同滴灌处理下青贮玉米关键生育期光合生理特性、水分利用效率及产量的变化特征。结果表明:①除拔节期外,W_(3)、W_(4)处理下青贮玉米叶片净光合速率(P_(n))、蒸腾速率(T_(r))和气孔导度(G_(s))均显著高于W_(1)和W_(2)处理(P<0.05),而W_(3)和W_(4)处理间无显著差异。②抽雄期至成熟期,W_(1)、W_(2)处理下青贮玉米叶片光合水分利用效率(WUE)显著高于W_(3)和W_(4)处理(P<0.05),但拔节期内,W_(3)处理下青贮玉米WUE显著高于其他处理。③在不同生育期、不同滴灌处理下,青贮玉米叶片的P_(n)、T_(r)、G_(s)和胞间CO_(2)浓度(C_(i))都呈现明显的光合日变化特征;W_(3)、W_(4)处理下各光合特征的日变化幅度、峰高、峰值与W_(1)和W_(2)处理之间存在显著差异(P<0.05)。④与W_(1)和W_(2)处理相比,W_(3)和W_(4)处理显著增加青贮玉米茎重、穗重及生物产量(P<0.05),但相对于W_(3)处理而言,W_(4)处理对青贮玉米产量及其构成因素的影响并不显著。综合青贮玉米产量与光合特性、水分利用效率的表现,在全膜覆盖的传统施肥条件下,滴灌量在5535 m^(3)/hm^(2)时青贮玉米的产量最佳。

Simulation of temperature distribution in double-row potato ridges mulched with plastic film covered with soil

In Northwest China,potatoes are cultivated on double-rows of each ridge which is mulched with plastic film,and the film is covered with some of soil.While effective in retaining soil moisture,this technique can render the potato seedlings prone to be burned if they are not released from the plastic film in time.In this study,the model of convective heat transfer of potato ridge under solar radiation and atmospheric radiation is established by the Fluent software.The processes of the heat transfer of potato ridge was simulated for a certain day,and the temperature distribution in the potato ridge was monitored over time.The temperature distribution of soil in the growth layer of potato plants was analyzed under different thickness and widths of the covering soil on the film.The results showed that with the increase of covering soil thickness and width,the time for soil at different depth to reach the peak-temperature was delayed,and the daily temperature change of soil where the different depths layer of potato plants growth was reduced.At that time,a binary regression equation of offset temperature was constructed by using the Response Surface Method.The best parameter combination for covering soil on the plastic film is a thickness of 50 mm and a width of 280 mm in the cold and arid areas of Northwest China.However,the offset temperature(PT)first decreased and then almost remained unchanged with the increase of covering soil thickness.Considering the operational efficiency and power consumption of soil covering devices in the field,the unchanged width of the covering soil is 200 mm.The field experiments have shown that a 50 mm thick of soil covering is beneficial for the growth of potato plants and a 200 mm width of soil covering is beneficial for the growth of potato plants.The height of potato plants was 21 cm,and the natural emergence rate of potatoes was 95.8%on June 9,2024.The environment of soil covered could provide theoretical support for the mechanized planting of potatoes.

基于隶属函数法对不同材料膜覆盖花生影响评价

利用隶属函数法对不同材料膜覆盖下的花生生长影响进行了评价,结果表明,形态学方面,塑料地膜覆盖效果最优,纤维黑色纸膜次之,对照(无覆盖)最差;光合方面,液态生物降解膜覆盖效果最优,粉剂生物降解膜次之,对照最差;水分利用方面,粉剂生物降解膜覆盖效果最优,液态生物降解膜次之,对照最差;产量方面,粉剂生物降解膜效果最佳,塑料地膜和液态生物降解膜次之,对照亦最差。隶属函数法可以解决同类间不同指标所得的结论不一致的矛盾,可以准确反映出不同材料膜覆盖对花生生长的影响。

2M-2覆膜机的设计与试验

随着农用机械与机具的普及,对应覆膜播种机和覆膜移栽机的机具越来越多,覆膜机的作业质量直接影响覆膜播种机出苗率和覆膜移栽机秧苗的成活率。通过对覆膜机各关键部件的设计研究,针对覆膜过程中影响覆膜质量的关键问题进行设计计算,确定覆膜机关键参数,并进行现场试验,铺膜效果高于国标要求,解决了麦间套种铺膜作业有机难用的难题。

空调座盖塑件模内装饰成型工艺与模具设计

针对空调座盖采用塑件模内装饰(IMD)方式进行成型的要求,为其设计了一种基于高压成型3D膜片镶件的IMD成型工艺用于该塑件的成型。工艺中,IMD塑件的保护层3D膜片镶件使用0.25 mm聚甲基丙烯酸甲酯(PMMA)薄膜高压压制+真空吸附3D成型,内衬使用聚碳酸酯/丙烯腈-丁二烯-苯乙烯共聚物(PC/ABS)合金注塑成型。所设计的IMD工艺路径包括9道工序。其中3D膜片镶件高压成型模具为一种模具闭合后具备膜片上表面高压压制和下表面真空吸附能力的双作用成型凸模,对应的高压成型工艺参数为:成型压力(35±1)Kg/保压时间(7.0±1)s/模具温度183℃。内衬的注塑成型中,内衬注塑模具为一种两板式单浇口热流道倒装模具,3D膜片镶件在型腔镶件内的定位依靠2个定模限位滑块进行定位,塑件的脱模由倒装模具动模内设置的2个油缸驱动推板及其上的10个斜顶和14根顶针共同顶出来实现。运用CAE软件Moldflow中“重叠注塑”分析序列对内衬的注塑成型进行了内衬/3D膜片镶件之间的重叠注塑成型仿真优化分析,优化结果为:内衬模腔注塑时,热浇口直径取Ø4 mm,模温79℃,熔料温度260℃,注塑压力90 MPa,保压分4段保压,分别为40 MPa-2 s/30 MPa-2 s/15 MPa-2 s/10 MPa-1.5 s。

基于刚柔流耦合的水稻覆膜插秧机破膜装置设计

针对现有水稻覆膜插秧机无破膜装置或破膜装置结构不合理导致伤根率高等问题,设计了一种水稻覆膜插秧机破膜装置,以有限元方法建立了破膜插秧作业的刚柔流耦合模型。分析了各试验因素对评价指标的影响,并进行了多目标优化;获得了破膜装置最优结构和工作参数组合,并通过台架试验进行验证。研究可为水稻覆膜插秧机破膜装置结构优化和水田覆膜复杂作业环境下的可视化互作分析提供理论依据和技术支持。

跨越式膜上对行覆土装置设计与覆土性能研究

针对西北寒旱区马铃薯全膜覆盖种行覆土栽培农艺要求,研制一种跨越式膜上对行覆土装置。解析跨越式提土装置和侧向对行覆土装置作业机理,确定了各个部件的核心作业参数。运用离散单元法(DEM)进行了对行覆土仿真试验,结合Box-Behnken试验设计原理,采用三因素三水平响应曲面法,建立了覆土宽度和覆土厚度的回归模型,优化得到跨越式膜上对行覆土装置的最优作业参数组合为螺旋输土器转速135 r·min^(-1),覆土器开口长度100 mm,覆土器离地高度为233 mm。田间试验表明,设计的跨越式对行覆土装置满足马铃薯种植农艺要求,马铃薯幼苗自然出苗率达到92.5%,同时烧苗率为7%。

垄上破膜覆土一体机设计与仿真

针对贵州省铜仁市植烟区膜后打孔投苗移栽方式存在的烟苗根部覆土不足、苗株周围易长草问题,设计了一款适合于铜仁市植烟区烟叶生产的乘坐式垄上破膜覆土一体机。该机由增程式发电机、铅酸电池组、行走装置、取土运土装置、破膜覆土装置、控制面板、机架及驾驶位等组成。利用Solidworks软件建立了双曲柄多连杆鸭嘴破膜覆土机构虚拟样机模型,经模型简化导入ADAMS中进行仿真分析,得到其运动轨迹和X、Y方向位移与时间变化曲线。结果表明,设计的双曲柄多连杆鸭嘴破膜覆土机构满足55 cm定株距破膜和作业效率0.067 hm^(2)/h的要求,验证了其结构选择和参数设计的合理性。该机能够代替人工膜上覆土作业、降低作业成本、提高覆土效率,具有推广使用价值。

不同细度重质碳酸钙在PVC压延膜中的应用研究

分析了两种矿种制备出的不同细度重质碳酸钙(南召1号~8号和连州1号~5号)的性能指标,研究了这些不同细度重质碳酸钙粉体应用于PVC压延膜对其白度、拉伸强度、耐热性能与遮盖性能的影响。研究结果发现:从南召1号到8号,粉体的粒径在逐渐变小,粒径分布逐渐变窄,白度和吸油值均在逐渐增加;连州1号到5号粉体具有类似的变化规律。南召1号至8号粉体随着粉体白度和细度的提升,其应用于PVC压延膜的白度、拉伸强度、耐热性和遮盖力性能都在明显提升,其中,5号以上的产品填充PVC压延膜可以获得较好的综合性能,7号具有最佳的综合性能。连州1号至5号填充PVC压延膜,白度变化不大,拉伸强度增大,耐热性能和遮盖性能逐渐变好,其中,3号以上的产品均可获得较好的综合性能,5号具有最佳的综合性能。