摘要：An experiment was conducted to investigate the requirement of nonphytate phosphorus（nPP） and efficacy of a genetically engineered yeast phytase（PHY A） for Lingnan yellow broilers from 22-to 42-d-old age.A total of 1 320 1-d-old male chicks were randomly divided into 11 dietary treatment groups,which consisted of 4 replicate floor pens with 30 birds per *** control group（treatment 1） was fed with basal diet of nPP 0.08% without dicalcium phosphate or phytase *** levels of nPP were 0.16,0.24,0.32,0.40,0.48,and 0.56%,respectively,for treatments 2 to 7,through addition of dicalcium phosphate（chemistry grade） to the basal *** of treatments 8 to 11 were supplemented with PHY A at 200,400 and 600 U kg-1,a commercial phytase product（PHY B） at 400 U kg-1 level,*** birds in 0.32-0.56% nPP groups gained more than those of the other groups（P0.05）.The nPP supplementation significantly improved feed intake（P0.05）.The feed gain ratio was significantly decreased by 0.40% nPP diet compared to the control birds（P0.05）.The level of 0.48% nPP was required for optimum tibia *** additions of PHY A at 400 and 600 U kg-1 level and PHY B all significantly improved ADG（P0.05）,ADFI（P0.05）,and dry defatted tibia weight（P0.05）.Similarly,the percentage of tibia ash was increased by 600 U kg-1 PHY A supplementation（P0.05）.The requirement of nPP for maximal ADG and highest percentage tibia ash both was 0.40%.The phosphorus equivalency value of PHY A was estimated as 685 U kg-1 for male yellow broilers of 22-to 42-d-old age.

摘要：Maize(Zea mays L.) stands prominently as one of the major cereal crops in china as well as in the rest of the ***,predicting the growth and yield of maize for large areas through yield components under high-yielding environments will help in understanding the process of yield formation and yield potential under different environmental *** accurate early assessment of yield requires accuracy in the formation process of yield components as *** order to formulate the quantitative design for high yields of maize in china,yield performance parameters of quantitative design for high grain yields were evaluated in this study,by utilizing the yield performance equation with normalization of planting *** density was evaluated by parameters including the maximum leaf area index and the maximum leaf area per *** showed that the variation of the maximum leaf area per plant with varying plant density conformed to the Reciprocal Model,which proved to have excellent prediction with root mean square error(RMSE) value of 5.95%.Yield model estimation depicted that the best optimal maximum leaf area per plant was 0.63 times the potential maximum leaf area per plant of *** performance parameters for different yield levels were quantitatively designed based on the yield performance *** validation of the yield performance model by simulating high yields of spring maize in the Inner Mongolia Autonomous Region and Jilin Province,china,and summer maize in Shandong Province,the yield performance equation showed excellent prediction with the satisfactory mean RMSE value(7.72%) of all the *** present study provides theoretical support for the formulation of quantitative design for sustainable high yield of maize in china,through consideration of planting density normalization in the yield prediction process,providing there is no water and nutrient limitation.

摘要：Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium （Se） concen- trations. A long-term （over 20 years） experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North china Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments： 1） organic compost （OC）, 2） half organic compost plus half N-P-K chemical fertilizers （OC ＋ NPK）, 3） N-P-K fertilizers （NPK）, 4） N-P fertilizers （NP）, 5） P-K fertilizers （PK）, 6） N-K fertilizers （NK）, and 7） an un-amended control. Soil samples from the surface （20 cm） were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments （149 ± 8 beg kg-1） were higher than those in the soil samples collected in 1989 at the beginning of the experiment （112 4- 4 beg kg-1）, and decreased in the order of OC 〉 OC ＋ NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction （50.06%± 3.94%） was the dominant form of Se in the soil, followed by the residual fraction （24.12% ± 2.89%）, exchangeable fraction （15.09% ± 4.34%） and Fe-Mn oxides fraction （10.73%±4.04%）. With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer （0-20 cm） were mainly related to soil organic carbon （SOC）, although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC ＋ NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food （100 μg kg·1]. Additionallv. Se concentrations in

摘要：本文研究了一种基于PID的排种器电驱控制系统,取消了播种机采用地轮和链条驱动的方式,提高了播种机的播种质量和作业速度。采用PID算法控制排种盘转速,在目标转速与当前转速差异较大时,加入PID积分分离算法,以减少转速的超调量。通过整定后的PID参数为:K_p=16、K_i=0.05、K_d=36,在其排种盘转速范围为0~24 r/min时,响应时间、超调量、稳态误差分别为0.4秒,1.56%和0.75%。试验结果表明,在12 km/h的高速播种作业条件下,采用该电驱控制系统的排种器排种单粒率仍然可达到98.4%,其重播率和漏播率小于1%。采用本文研究的基于PID算法的排种控制系统可以获得良好的排种质量和更高的排种速度,使排种器更适宜高速精量播种。

摘要：为解决大蒜机械化收获时损伤率与损失率较高的问题,结合大蒜物理特性和种植模式,该研究设计了一种双行手扶式大蒜联合收获机,主要由挖掘装置,矫正装置,夹持装置,切割装置,收集装置等组成,可一次完成大蒜的挖掘,姿态矫正,夹持输送,茎根切割,低损收集等作业工序。为提高大蒜收获作业质量,采用Box-Behnken中心组合试验方法,以前进速度、挖掘深度、链条距离为试验因素,以损伤率和损失率为评价指标,进行参数优化试验。建立各影响因素与指标之间的回归数学模型,分析各因素对响应值的交互影响,获得最优参数组合为:前进速度0.51 m/s、挖掘深度97.2 mm、链条距离7.6 mm,对应的损伤率、损失率分别为0.65%、1.28%,对优化结果进行验证试验,试验结果表明在最优参数组合下,损伤率为0.63%、损失率为1.25%,各评价指标与预测值均很接近。研究结果可为大蒜联合收获机进一步完善结构设计和工作参数优化提供参考。

摘要：针对传统马铃薯种薯切块机存在的切块均匀性差、不便于直接进行播种的问题,设计了一种安装在马铃薯种薯切块机上的分级装置。对分级装置的结构和工作原理进行了阐述,通过力学分析和运动分析确定了分级装置分级辊拨轮各部分的结构参数。选取分级辊组组数、分级辊组转速、上料量为试验因素,分级精度为试验指标进行正交试验,并用Design-Expert 8.0.6软件对试验结果进行分析,确定较优参数组合为分级辊组组数为7,分级辊组转速为110 r/min,上料量为40 t/h,并对较优参数组合进行了验证试验,验证试验结果表明在较优参数组合下的分级精度为98.7%,能够满足分级要求,该研究提供了一种用于马铃薯种薯切块机上的高效率、高分级精度的分级装置。

摘要：为深入开展半喂入式花生摘果装置作业机理、结构参数和作业参数优化等研究,设计了自动喂秧平台、控制系统、参数调节系统和保鲜库,选配高速摄像系统,并与已有试验台进行技术集成,研制成半喂入式花生摘果试验台。该试验台具备关键参数调节和采集、作业过程图像获取和植株保鲜等功能,主要包括机架、自动喂秧平台、夹持输送装置、摘果装置、控制系统、传感器、变频电机和高速摄影系统等。试验台的主要技术指标为:摘果辊长度500,800,1 000 mm,摘果辊直径160,200,240 mm,摘果辊后端中心与夹持输送链的距离100~150 mm,摘果辊的转速200~1 000 r/min,夹持输送链的速度0.5~2.5 m/s。在试验台上,对前期尚未涉及的供给株数、链辊夹角等因素、摘果辊功耗等进行了试验研究,开展了摘果过程高速摄影试验研究。结果表明:供给株数对未摘净率和破碎率影响较大;链辊夹角对未摘净损失影响较大,对破碎率影响较小;摘果功耗随着供给株数的增大呈递增规律;高速摄像系统能够揭示摘果叶片与花生果系的作用过程、果秧分离行为和内在机理。该半喂入式花生摘果试验台可为进一步深入开展摘果作业机理研究提供参考。

摘要：The aim of this study was to optimize the conditions for the extraction of low-abundance proteins（LAPs） and the removal of abundant proteins（APs; β-conglycinin and glycinin） from soybean *** factor and orthogonal experiments were designed to determine the effects of four factors（isopropanol concentration, total extraction time, ultrasonic power, and ultrasonic time） on protein concentration in isopropanol *** in the isopropanol supernatant and the cold acetone precipitate of isopropanol were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDS-PAGE） and matrix-assisted laser desorption/ionization-time of flight mass spectrometry（MALDI-TOF-MS）.The results showed that the optimal conditions were 50% isopropanol, ultrasonic pretreatment for 15 min at 350 W, and a total extraction time of 1 *** these conditions, the protein concentration in the isopropanol extracts reached 0.8081 g/*** LAPs were detected, including β-amylase, soybean agglutinin, soybean trypsin inhibitor, fumarylacetoacetase-like, phospholipase D alpha 1-like, oleosin, and even some unknown soybean *** soybean APs（β-conglycinin and glycinin） were not *** method may be useful for discovering new soybean proteins and extracting enough LAPs of soybean to allow further studies of their physiological effects on animals without the influence of APs.

摘要：为促进微生物预处理方法在提高玉米秸秆高效厌氧消化产甲烷方面的应用效果,该文研究了由黑曲霉(Aspergillus)、木霉(Trichoderma)、草酸青霉(Penicillium)和白腐真菌组成的复合微生物菌系HK-4,对玉米秸秆预处理及厌氧消化产气性能的影响。将复合微生物菌系加入到粒径为0.7~1 cm玉米秸秆中,在28℃恒温条件下190 r/min震荡培养15 d,测得纤维素、半纤维素和木质素的降解率分别可达64.52%、51.06%和3.89%。使用经HK-4处理过的玉米秸秆,用于沼气生产,发酵32 d,复合微生物菌系组共产生7364 m L气体,比未处理组提高了27.4%;预处理4 d,复合微生物处理组甲烷体积分数即可提升到40%以上,之后20 d在45%~53%之间波动,而未经HK-4处理过的玉米秸秆,甲烷体积分数在第6天才稳定到36.7%。

摘要：为探究施肥多因子耦合对黄瓜产量、品质、肥料利用率等方面的综合调控,获取适宜的基质栽培营养液配方。以‘博耐526’黄瓜为试材,通过四因素(N、K、Ca、Mg)五水平(1/2)二次正交旋转组合设计,共23个处理,利用四元二次回归分析建立了N、K、Ca、Mg对黄瓜产量品质综合评分的回归模型,分析了双因素与三因素耦合效应对黄瓜产量品质综合评分的影响。结果表明,各因素对黄瓜产量品质综合评分的影响程度由大到小依次为氮、钾、钙、镁,黄瓜产量品质综合评分随各因素的增加均呈现先增加后减小的趋势。N-K和N-Ca的耦合效应显著(P0.05);N-K耦合效应对黄瓜产量和品质综合得分的影响为负,而N-Ca耦合效应为正。同时建立了黄瓜产量品质综合评分、氮、钾和钙利用率的多目标优化模型,利用遗传算法对该模型进行模拟寻优,得到优化的氮,钾,钙和镁浓度分别为14.83、6.89、3.55和4.17 mmol/L。在此条件下,黄瓜的单株产量、可溶性蛋白、维生素C和可溶性总糖含量分别比山崎黄瓜专用配方处理显着提高了21.07%,40.91%,53.33%和11.48%,有机酸和硝酸盐含量比山崎黄瓜专用配方处理显著降低,此结果可为基质栽培黄瓜高产优质和营养液科学管理提供指导依据。