Effects of Ultrasound/Dilute H_2 SO_4 Pretreatment on Cellulase Activity of Corn Straw Liquid Fermentation

[ Objective] The aim was to study pretreatment of ultrasound enhancing dilute H2SO4 on cellulase activity of corn straw liquid fermentation and explore the pretretment＇ s optimal conditions. [ Method ] By using orthogonal test, the pretretment of ultrasound enhancing dilute H2SO4 on corn straw was studied, then straw was fermented as the sole carbon source. Finally, the cellulase activity in extracellular fermentation broth was determined. [Result] The results showed that cellulase activity in extracellular broth was greatest under the conditions of acid bath time 3 h, acid concentration 3.5%, ultrasonic power 150 W, and ultrasonic time 5 h. They were FPA 15.82 U/ml, Cx 39.9 U/ml, 13-Giu 55.94 U/ml respectively. [ Conclusion] Under the above conditions, extracellular cellulase production has a high stability.

Effect of Sludge from Different Sources on Solid Anaerobic Digestion of Corn Straw

[Objective] The aim was to study on effect of sludge from different sources on biogas yield efficiency through anaerobic digestion of corn straw. [Method] The present research studied on daily biogas yield and the accumulated biogas amount through anaerobic digestion of corn straw and sludges from four sources. [Result] The accumulated biogas yields produced from sludges in four sources from high to low were granular sludge, river sediments, concentrated sludge and filtered sludge. The first one proved the highest at 3.73 and 56.29 L/kg VS in daily biogas yield and the accumulated biogas. [Conclusion] The research laid foundation for full utilization of straw, improvement of energy utilization and sustainable development.

Production of Biotechnology Fulvic Acid from Fermented Corn Straw by Microbial Community LCM9 and Its Application Effect

[Objective] The aim was to evaluate the feasibility of biotechnology fulvic acid produced by microbial community LCM9 by the use of corn straws as substrate and its application effect.[Method]Microbial community was obtained from the nature samples,and corn straws were used as fermentation substrate.The yield of biotechnology fulvic acid and its application effect was evaluated.[Result]The yield of biotechnology fulvic acid was up to 15.7% when the water content was 75.0% and fermented after 7 d using corn straws as the only source of nutrition.After 500 mg/kg of biotechnology fulvic acid was added for 5 d,the root length and bud length could be increased by 59.1% and 97.1%,respectively.[Conclusion]A higher yield of biotechnology fulvic acid could be obtained by the method in this experiment and the product could enhance the growth of wheat seedlings.

Corn straw return can increase labile soil organic carbon fractions and improve water-stable aggregates in Haplic Cambisol

Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA).Moreover,the labile SOC fractions play an important role in OC turnover and sequestration.The aims of this study were to determine how different corn straw returning modes affect the contents of labile SOC fractions and OC associated with WSA.Corn straw was returned in the following depths:(1)on undisturbed soil surface(NTS),(2)in the 0–10 cm soil depth(MTS),(3)in the 0–20 cm soil depth(CTS),and(4)no corn straw applied(CK).After five years(2014–2018),soil was sampled in the 0–20 and 20–40 cm depths to measure the water-extractable organic C(WEOC),permanganate oxidizable C(KMnO4-C),light fraction organic C(LFOC),and WSA fractions.The results showed that compared with CK,corn straw amended soils(NTS,MTS and CTS)increased SOC content by 11.55%–16.58%,WEOC by 41.38%–51.42%,KMnO4-C and LFOC by 29.84%–34.09%and 56.68%–65.36%in the 0–40 cm soil depth.The LFOC and KMnO4-C were proved to be the most sensitive fractions to different corn straw returning modes.Compared with CK,soils amended with corn straw increased mean weight diameter by 24.24%–40.48%in the 0–20 cm soil depth.The NTS and MTS preserved more than 60.00%of OC in macro-aggregates compared with CK.No significant difference was found in corn yield across all corn straw returning modes throughout the study period,indicating that adoption of NTS and MTS would increase SOC content and improve soil structure,and would not decline crop production.

Recycling of Secondary Aluminum Dross to Fabricate Porous <i>γ</i>-Al₂O₃Assisted by Corn Straw as Biotemplate

In the aluminum industry, secondary aluminum dross (SAD) is an inevitable solid residue, which usually contains 30 - 70 wt% Al2O3. In this work, Al(OH)3 was extracted from SAD through acid-leaching and alkali purification process. The as-obtained Al(OH)3 precipitation then was calcinated to synthesize porous γ-Al2O3 assisting by an agricultural waste biomass-corn straw as biotemplate. Effects of H2SO4 concentration, reaction temperature and time on the recovery of SAD were investigated. Furthermore, the dependence of calcination temperature on specific surface area, pore volume and content of porous γ-Al2O3 was analyzed. X-ray diffraction (XRD) and X-ray fluorescence (XRF) were used to inspect the phase compositions and their contents, respectively. Scanning electron microscopy (SEM) was employed to analyze the morphologies of the sintered porous γ-Al2O3. It was found that the highest recycle rate of aluminum from SAD was obtained under optimum conditions of 80&#176;C, acid concentration of 1.6 mol/l, and reaction time of 5 h by acid process. The porous γ-Al2O3 with specific surface area, 261.22 m2/g and average pore diameter, 52.64 nm, was obtained under calcination at 850&#176;C through mixing the as-obtained Al(OH)3 precipitation and corn straw.

The Importance of Three Protozoa in Corn Straw Decomposition and Nutrient Transformation

Three typical soil protozoa of Bodo edax, Colpoda cucullus and Amoeba proteus were inoculated into the soil amended with corn straw. The soils were then incubated at 25℃ for 60 days. It was found that the protozoa, particularly Bodo edax, significantly reduced soil microbial biomass C. However, the decomposition of corn straw was accelerated by the protozoa. Colpoda cucullus significantly enhanced soil available P content, but Amoeba proteus decreased soil available P content. Colpoda cucullus and Bodo edax did not obviously influence NH4+-N and NO3--N contents. In contrast, Amoeba proteus significantly increased both NH4+-N and NO3--N contents.

Effects of Straw Returning with Different Tillage Patterns on Corn Yield and Nitrogen Utilization

To explore the effects of farming methods,straw returning and their interaction on corn yield and nitrogen utilization,the experiment was conducted for two consecutive years from 2016 to 2017 at the Xiangyang Experimental Base of Northeast Agricultural University in Heilongjiang Province of China.The method of combining farming with straw returning was used and six treatments as rotary tillage(R)+no straw returning(K),rotary tillage(R)+straw returning(S),tillage(T)+no straw returning(K),tillage(T)+straw returning(S),tillage(T)+subsoiling(D)+no straw returning(K)and tillage(T)+subsoiling(D)+straw returning(S)were set to study the effects of different tillage methods and straw returning on corn yield and nitrogen accumulation and utilization.The corn yield,nitrogen accumulation,nitrogen transport,grain weight and dry matter accumulation of tillage(T)+subsoiling(D)and tillage(T)were significantly higher than those of rotary tillage(R)treatment.Meanwhile,the corn yield,nitrogen accumulation and dry matter accumulation of TD treatment were significantly higher than those of T treatment;the corn yield,dry matter accumulation,kernel weight,nitrogen dry matter production efficiency and nitrogen grain production efficiency of S treatment were significantly higher than those of K treatment.Among the treatments,the yield,nitrogen accumulation and utilization efficiency of TDS,TS and TDK were the highest.The yield,nitrogen accumulation and nitrogen transport of TDS were significantly higher than those of TS.In 2016,TDS production increased by 7.30%and 8.20%compared with TS;and TDS nitrogen accumulation increased by 6.78%and 9.50%compared with TS,while the yield and nitrogen grain production efficiency were significantly higher than those of TDK.Therefore,under the conditions of this experiment,on the basis of straw returning,tillage+subsoiling was the suitable farming method.

Effect of Sweet Corn Straw Returning to the Field on Soil Fertility, Yield and Benefit

It is an important way for realizing sustainable development of sweet corn production to stabilize and improve soil fertility of cultivated land in sweet corn production region.Through the test of sweet corn straw directly returning to the field after 6seasons for 3years,the results showed that continuous single application of chemical fertilizer is not conducive to the stability of soil fertility and yield improvement,and implementation of straw returning could receive fertility,improve soil acidic conditions,and enhance the yield of sweet corn.Compared with before the test,the single application of chemical fertilizer increased soil available phosphorus,while the contents of soil organic matter,available nitrogen and available potassium decreased by 1.08,1.18 and 2.47mg/kg respectively,and the soil pH decreased by 0.15.Under the same fertilizer conditions,organic matter contents of single and double-season straw returning increased by 0.71 and 1.29g/kg,available nitrogen increased by 17.15 and 28.27mg/kg,available phosphorus increased by 0.96 and 1.73mg/kg,available potassium increased by 2.41 and 5.92mg/kg,the soil pH increased by 0.16 and 0.2.Compared with the single application of chemical fertilizer,the average yields of single and double-season straw returning increased by 7.5%and 11.8%,and their average income increased by 87.3and 117.1yuan of per mu(667m^2)respectively.

Effects of Agitating Intensity on Anaerobic Digestion Performance of Corn Straw Silage

Anaerobic fermentation can increase biomass energy use efficiency of crop straws and realize win-win of energy and environment.This paper explored the biogas generation performance of anaerobic digestion of cow dung liquid as nitrogen source in three different levels of stirring intensity at 30℃ constant temperature condition. Through p H value,biogas production,chemical oxygen demand( COD),methane content,volatile fatty acid( VFA),principal component analysis( PCA) and modified Gompertz model,effects of agitating intensity on anaerobic digestion performance of corn straw silage were evaluated. Results indicate that the COD removal rate of three agitating intensity levels is higher than 85%,and p H value is about 6.5; the cumulative biogas production after 20 days is 2h > 4h > 1h of agitating; in the49 th day,the biogas production is 1.9 Lat 30 min /2h,1.7 L at 30 min /4 h,and 1. 6 Lat 30 min / h; the maximum biogas production rate is 30 min /2h > 30 min /4h > 30 min / h; and the maximum methane production rate is 30 min /4h > 30 min /2h > 30 min / h; in the same energy consumption,the biogas production at 30 min /4h is higher than 1h. In conclusion,overall analysis of energy consumption and economic factors indicate that 30 min /4 h agitating intensity is more suitable for straw biogas fermentation project. This study is expected to provide theoretical foundation for biogas fermentation project.

Effect of goethite on anaerobic co-digestion process of corn straw and algae biomass

1 Introduction Recently the demand for fossil fuel has grown significantly with the rapid development of the Chinese economy.Renewable energy was developed to replace traditional fossil fuels,which would decrease the

寒地玉米秸秆力学特性研究

为了合理利用玉米秸秆这种生物质资源,采集了寒地整株玉米秸秆,结合自制试验装置,利用电子万能试验机等设备,测试了整株玉米秸秆不同直径部位在相同加载速率下有节段径向和轴向压缩及无节段抗弯的力学性能。对试验数据进行了拟合,建立了相关数学模型,结果表明:当直径小于20mm时,轴向压缩实验中直径对压力影响并不明显,直径达到25mm左右时影响开始显现,直径大于29mm后影响非常显著;径向压缩时,离秸秆顶端较近的几节直径与压力近似线性相关,但随着直径的增加径向压力并不是均值上升,具有一定的离散性。抗弯试验中,在初始阶段压力在某一范围内上下波动,直径对压力影响并不显著;当直径大于23mm后,所需压力值显著增加;当直径大于30mm之后,直径对压力的影响产生了较为明显的波动性。试验数据真实可靠,拟合结果具有较强的可参考性,可为更好地开发利用秸秆资源及优化秸秆收获装置结构提供理论依据。

玉米秸秆与金针菇菌糠不同混合比例对发酵全混合日粮营养品质和霉菌毒素含量的影响

[目的]研究以玉米秸秆和金针菇菌糠作为粗饲料加工调制肉牛发酵全混合日粮(fermented total mixed ration,FTMR)时二者的最佳配比,为菌糠等副产物高值化利用提供技术支撑。[方法]设置7个不同比例的粗饲料混合处理组,玉米秸秆与金针菇菌糠的比例分别为8∶2(T1组)、7∶3(T2组)、6∶4(T3组)、5∶5(T4组)、4∶6(T5组)、3∶7(T6组)、2∶8(T7组),再以精粗比为4∶6(鲜重)添加肉牛精料补充料,混合均匀后加工制成全混合日粮(total mixed ration,TMR);将不同处理组的TMR样品装入青贮袋,压实密封后抽真空,遮光保存于室内,自然发酵60 d制成FTMR;分别测定并比较TMR和FTMR的营养组分含量和霉菌毒素含量,同时,测定FTMR的发酵参数,确定最优配比。[结果]①随着玉米秸秆与金针菇菌糠配比降低,TMR的DM含量呈逐渐降低趋势,CP含量呈逐渐增加趋势,NDF和ADF含量总体呈逐渐增加趋势,EE含量呈波动性变化。②随着玉米秸秆与金针菇菌糠配比降低,FTMR的DM含量呈逐渐下降趋势,与发酵前相比,T4组的DM损失率最低;T3组和T4组FTMR的CP含量显著(P<0.05)高于其他组,与发酵前相比,T3组与T4组FTMR的CP含量增加;各组FTMR的EE含量差异不显著(P>0.05),与发酵前相比,T1组~T4组FTMR的EE含量下降,T5组~T7组增加;T1组~T5组FTMR的NDF含量显著(P<0.05)低于T6组和T7组,T3组NDF含量最低,与发酵前相比,T3组和T5组FTMR的NDF含量下降;T1组~T5组FTMR的ADF含量显著(P<0.05)低于T6组和T7组,与发酵前相比,T4组和T5组ADF含量下降。③各组FTMR样品均产生酸香味,发酵品质良好;T3组FTMR的pH值最低,显著(P<0.05)低于其余各组,T4组的pH值也较低;随着玉米秸秆与金针菇菌糠配比降低,FTMR的LA含量呈先增加后降低趋势,T4组含量最高,T3组次之,二者均显著(P<0.05)高于其余各组;随着玉米秸秆与金针菇菌糠配比降低,FTMR的AA含量呈先增加后降低趋势,T5组含量最高,T4组和T3组次之;各组FTMR样品均检测到微量的PA,组间差异不显著(P>0.05);T6组和T7组FTMR样品检测到微量的BA,其余各组均未检出;T3组FTMR的AN/TN比值最低,除T6组和T7组AN/TN比值超过10%外,其余各组均小于10%。各组TMR样品以及各组FTMR样品中AFB1、ZEN、OTA含量组间差异均不显著(P>0.05),参考《饲料卫生标准》(GB 13078—2017),发酵前后样品中霉菌毒素均未超过阈值。④主效应分析结果表明,发酵处理显著(P<0.05)降低了TMR的AFB1和ZEN含量,玉米秸秆和金针菇菌糠混合比例处理以及发酵和混合比例组合效应对发酵前后样品的AFB1和ZEN含量无显著(P>0.05)影响;发酵处理、玉米秸秆和金针菇菌糠混合比例处理、发酵和混合比例组合效应对发酵前后样品的OTA含量无显著(P>0.05)影响。[结论]综合营养组分和霉菌毒素含量以及发酵品质分析,采用玉米秸秆混合金针菇菌糠调制FTMR的方式能高效保存利用秸秆和菌糠等副产物,二者以6∶4(T3组)或5∶5(T4组)配比时效果较好。

混合比例、菌剂和压实密度对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响

本试验旨在研究混合比例、菌剂和压实密度对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响。试验分为2部分,试验1研究混合比例和菌剂对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响。将玉米秸秆和花生秧按5个混合比例(4∶0、3∶1、2∶2、1∶3、0∶4)进行混合,每个比例下设4个组,分别为对照组(CON组,喷洒无菌生理盐水)、植物乳杆菌组(LP组,喷洒1×10^(6)CFU/g植物乳杆菌)、粪肠球菌组(EF组,喷洒1×10^(6)CFU/g粪肠球菌)、植物乳杆菌+粪肠球菌组(LP+EF组,喷洒5×10^(5)CFU/g植物乳杆菌+5×10^(5)CFU/g粪肠球菌),每组3个重复,厌氧发酵60 d。试验2研究压实密度和菌剂对玉米秸秆和花生秧混合青贮发酵品质和营养价值的影响。将玉米秸秆和花生秧按3∶1比例混合后,按不同压实密度(300、450、600 kg/m^(3))进行发酵,每个压实密度下设4个组(同试验1),每组3个重复,厌氧发酵60 d。试验1结果表明:1)随着花生秧比例的提高,有机物、中性洗涤纤维和水溶性碳水化合物含量显著降低(P<0.05),粗蛋白质含量显著升高(P<0.05)。与对照组相比,EF和LP+EF组的中性洗涤纤维含量显著降低(P<0.05),EF组的氨态氮含量显著降低(P<0.05)。2)混合比例对乳酸菌和霉菌数量无显著影响(P>0.05)。与对照组相比,LP、EF和LP+EF组的乳酸菌数量显著升高(P<0.05),LP+EF组的霉菌数量显著降低(P<0.05)。3)混合比例为2∶2组的玉米赤霉烯酮含量显著高于其他各组(P<0.05),混合比例为3∶1和2∶2组的赭曲霉毒素含量显著低于混合比例为4∶0组(P<0.05)。与对照组相比,LP+EF组的玉米赤霉烯酮含量显著降低(P<0.05)。4)混合比例为2∶2组的pH显著高于其他各组(P<0.05),混合比例为3∶1组的乳酸含量显著高于混合比例为2∶2组(P<0.05),混合比例为3∶1组的乙酸含量显著低于其他各组(P<0.05),混合比例为3∶1组的丁酸含量显著低于混合比例为4∶0组(P<0.05)。与对照组相比,LP+EF组的pH显著降低(P<0.05),乳酸含量显著升高(P<0.05);EF组的乙酸含量显著降低(P<0.05)。试验2结果表明:1)压实密度为600 kg/m^(3)组的有机物、粗蛋白质含量显著低于压实密度为300 kg/m^(3)组(P<0.05),水溶性碳水化合物含量显著高于其他各组(P<0.05);随着压实密度的增加,氨态氮含量显著降低(P<0.05)。与对照组相比,EF组的有机物含量显著升高(P<0.05),LP+EF组的粗蛋白质含量显著升高(P<0.05)。2)压实密度对乳酸菌和霉菌数量无显著影响(P>0.05)。与对照组相比,LP和LP+EF组的乳酸菌数量显著升高(P<0.05),LP、EF和LP+EF组的霉菌数量显著降低(P<0.05)。3)压实密度为450和600 kg/m^(3)组的玉米赤霉烯酮和伏马毒素含量显著高于压实密度为300 kg/m^(3)组(P<0.05)。与对照组相比,LP+EF组的玉米赤霉烯酮含量显著降低(P<0.05)。4)压实密度对pH无显著影响(P>0.05)。压实密度为600 kg/m^(3)组的乳酸含量显著高于压实密度为300 kg/m^(3)组(P<0.05),压实密度为300 kg/m^(3)组的乙酸和丁酸含量显著高于其他各组(P<0.05)。综合各项指标,推荐玉米秸秆和花生秧混合青贮的适宜混合比例为3∶1,菌剂为植物乳杆菌和粪肠球菌联合添加,压实密度为450~600 kg/m^(3)。

玉米秸秆压缩特性试验研究

为了更好地利用玉米秸秆这种生物质材料,同时为设计和优化秸秆收获、打捆、切割等装置结构提供一定的技术参数,对寒地玉米秸秆进行了压缩试验。设计了三因素三水平的正交试验,并结合自制试验装置,利用万能试验机、数显鼓风干燥箱等设备对玉米秸秆进行了有节段的径向和轴向压缩试验,测得了基于不同部位、不同速度、不同含水率三因素在不同水平组合下的破坏力的大小,获得因素的显著性影响程度及最优水平组合。试验结果表明:玉米秸秆轴向压缩破坏力为0.726~3.271 kN,R值为0.586~1.527,F值为7.093~38.742;玉米秸秆径向压缩破坏力为0.370~2.297 kN,R值为0.382~0.921,F值为9.096~22.183。分析得出:各因素对试验指标影响极显著的是秸秆部位,加载速度和含水率次之;最优水平组合为秸秆部位为上、加载速度为10 mm/min、含水率为最低,且径向压缩所需破坏力小于轴向压缩所需破坏力。

油菜秸秆和玉米青贮混贮对发酵品质和瘤胃发酵特性的影响

试验旨在研究油菜秸秆和玉米青贮混贮后的发酵品质,并结合体外模拟瘤胃发酵试验评估其饲用价值。试验选用风干油菜秸秆和新鲜的玉米青贮进行混贮,油菜秸秆与玉米青贮混合比例为2∶1(干物质基础),混合物含水量为60%。取一部分混合物作为对照组,剩余部分装入发酵桶(5 L)中进行发酵,作为混贮组。每组3个重复。在发酵49 d后开封取样,进行发酵品质评定和体外模拟瘤胃发酵试验。结果发现:油菜秸秆和玉米青贮混贮达到优良发酵饲草等级,显著降低了中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)(P≤0.05)。油菜秸秆和玉米青贮混贮后显著提高了体外模拟瘤胃发酵的干物质降解率(DMD)、中性洗涤纤维降解率(NDFD)、总挥发性脂肪酸(TVFA)浓度和微生物蛋白(MCP)产量(P≤0.05),显著降低了乙丙比和甲烷产量(P≤0.05)。研究结果表明:油菜秸秆和玉米青贮混贮能够取得较好的饲草发酵品质,提高体外模拟瘤胃发酵的纤维降解率及TVFA浓度,促进瘤胃发酵模式向丙酸生成型转变,同时减少甲烷产量。是一种能够提高油菜秸秆饲用价值的有效发酵方式。

大豆玉米带状种植模式下玉米摘穗机设计与试验

针对丘陵山区大豆玉米带状种植模式的玉米果穗收获有机难用、无机可用的现状,设计一款自走式小型玉米摘穗机。该机采用纵卧式摘穗辊实现果穗摘取,并通过输送装置收集装袋;采用“Y”型布局的L型小甩刀实现茎秆粉碎。对摘穗过程进行动力学分析、对粉碎过程进行静力学分析,确定其核心装置设计参数并进行样机试制。以茎秆粉碎长度合格率、果穗损失率、籽粒破碎率为试验指标进行田间试验,来验证该机设计的合理性。试验表明:在生产率为0.8 hm^(2)/d、果穗籽粒含水率为26.38%、茎秆含水量为71.25%的条件下进行试验,茎秆粉碎长度合格率为92.4%、果穗损失率为2.06%、籽粒破碎率为0.61%。该机设计各项指标符合国家相关标准,能够满足丘陵山地地区玉米机械化收获需求。

玉米秸秆穰叶对肉羊生长性能、养分表观消化率、血清生化指标及免疫指标的影响

试验旨在研究玉米秸秆穰叶对肉羊生长性能、养分表观消化率及血清生化指标的影响。选取健康状况较好、体重(30.0±3.0)kg的母羊30只,按体重相近原则,随机分为2组,每组3个重复,每个重复5只羊。对照组以整株玉米秸秆作为粗饲料,试验组以玉米秸秆穰叶作为粗饲料,试验组和对照组精料一致。预试期10 d,正式试验期90 d。结果显示,与对照组相比,试验组肉羊的平均日增重提高了10.58%,平均日干物质采食量提高了1.01%,料重比降低了8.66%。试验组肉羊对饲粮中干物质、粗蛋白、粗脂肪、中性洗涤纤维、酸性洗涤纤维、钙及磷的表观消化率分别比对照组提高了6.52%、8.69%、9.43%、8.17%、8.43%、5.87%和6.51%。试验组肉羊血清中总蛋白含量、球蛋白含量及碱性磷酸酶活性分别比对照组提高了3.41%、10.70%和12.42%,尿素氮含量降低了5.00%。试验组肉羊血清中免疫球蛋白A、免疫球蛋白M、免疫球蛋白G、补体C3和补体C分别比对照组提高了5.89%、7.90%、7.58%、6.95%和2.66%。研究表明,与整株玉米秸秆相比,玉米秸秆穰叶是草食家畜的一种优质粗饲料。

玉米秸秆焦油制备生物沥青的性能研究

随着大规模高等级公路建设和养护维修工程的不断推进,沥青材料的需求量逐渐攀升。随着化石资源的消耗,寻找一种能够替代石油沥青的材料已成为道路工程领域的迫切需求。本文以玉米秸秆焦油为原料,对其进行树脂化处理,制备生物沥青。基于BOX-Behnken响应面分析,以树脂得率为评价指标,确定了树脂合成的最佳工艺条件为:酚醛摩尔比为0.8,反应时间为125 min,秸秆焦油添加量为10%。结果表明:随着树脂化产物的增加,生物沥青的针入度也随之增大,且均高于70#石油沥青。B-PF生物沥青延度随掺量增加呈先升高后降低趋势;但H-PF生物沥青延度随掺量的增大而减小。提高生物沥青掺量可使软化点降低。H-PF生物沥青在10%掺量下延度及软化点低于70#石油沥青,而掺量达到20%时,所制备的生物沥青的软化点和延度皆低于70#石油沥青。

玉米秸秆高扰低阻深松铲设计与试验

东北垄作区玉米秸秆还田条件下,针对秸秆较多时易使深松铲和后续机具堵塞、耕作阻力增加等问题,基于深松切割根茬一侧时土壤、根茬状态对秸秆的作用进行深松铲优化,设计了一种可减小深松阻力、提高秸秆扰动的深松铲。根据离散元仿真深松作业中切割根茬一侧时秸秆力矩波动段峰值时刻的秸秆受力方向和秸秆位置,对深松铲刃口曲线进行设计和优化。选取深松铲平均耕作阻力、秸秆水平侧向扰动距离为试验指标,进行二因素五水平中心组合试验,并得到深松铲各参数最优组合,即深松铲入土角23.91°、深松铲刃角32.01°。由仿真验证试验可知:深松铲的平均耕作阻力和理论值相比增大0.65%,秸秆扰动距离和理论值相比减小2.95%,仿真试验值与理论值差异较小,验证了设计思路的可行性。在最优参数下,与圆弧深松铲、折线深松铲进行田间对比试验,结果表明:平均耕作阻力减小7.43%和29.36%,油耗减少16.19%和31.93%,秸秆水平侧向扰动距离分别增大65.42%和减小3%。所设计的深松铲平均耕作阻力和油耗小且对秸秆扰动大,可为深松铲设计与优化提供参考。

中小型青贮玉米收获机械研究现状及发展趋势

随着牛、羊等草食性牲畜的快速发展,畜牧业对青贮玉米饲料的需求持续增长,我国青贮玉米的种植规模也在不断扩大。由于我国耕地类型和地块面积差异较大,青贮玉米的收获需要多种类型的作业机械。为促进玉米青贮收获机械的研发和应用,从畜牧产业适度规模发展的需要和当前我国分段收获与直接收获并存的现实情况出发,采用分作业环节的方式,针对青贮玉米收获机械的共性关键技术:秸秆切割、秸秆切碎揉丝、玉米籽粒破碎、青贮打捆包膜等,分析青贮玉米收获机械生产中的常用结构和最新研究现状。介绍青贮玉米收获机械的研发应用情况,从青贮作业环节中分析总结出存在秸秆切割与粉碎理论研究较少、各装置作业质量研究不足、整机适应性不强等共性问题。提出加强刀具与秸秆互作机理的研究、作业质量的研究、整机适应性的研究,使中小型青贮玉米收获机械在不同规模和作业需求下具有更好的作业性能、作业质量和综合生产效率。