联合收获机喂入量模糊控制系统研究     

尤惠媛  卢文涛 《西北农林科技大学学报(自然科学版)》2015,43(5):229-234

【目的】设计喂入量模糊控制系统,为提高联合收获机收获效益提供支撑。【方法】采用油压力传感器检测喂入量,根据滚筒扭矩与行走速度之间的关系,建立喂入量模型。设计模糊控制器并在MATLAB下进行仿真,利用PLC建立模糊控制系统,通过电控静液压系统控制行走速度来调整喂入量,并以新疆-3稻麦联合收获机为试验机型,进行喂入量自动控制田间试验。【结果】基于模糊控制系统调整后的联合收获机损失率小于1.2%,破碎率小于1.0%,损失率和破碎率均与经验丰富的驾驶员手动控制结果基本持平,符合国标要求。在作物密度不均匀的区域进行试验,指令喂入量取2kg/s时计算平均喂入量为2.04kg/s;指令喂入量取3kg/s时计算平均喂入量为3.08kg/s,喂入量能稳定控制在±10%的范围以内。【结论】联合收获机喂入量模糊控制系统稳定可靠,能提高收获效益。  相似文献   

豆粕和膨化大豆粉对鲤鱼生长及其肌肉营养成分的影响     

邢秀苹  杨欢欢  韦庆勇 《西北农林科技大学学报(自然科学版)》2015,43(12):13-17,28

【目的】研究豆粕和膨化大豆粉对鲤鱼生长、饲料利用及肌肉营养成分的影响,为优化鲤鱼人工配合饲料提供依据。【方法】分别利用豆粕和膨化大豆粉替代约60%(质量分数)的鱼粉,以全鱼粉为对照,配制成3种等氮(粗蛋白含量为360g/kg)、等能(总能为15.2 MJ/kg)的半精制饲料,在室内单循环控温养殖系统中对初始体质量为(27.25±0.09)g的鲤鱼进行8周饲养试验。饲养试验结束后测算鲤鱼生长和饲料利用相关指标及肌肉营养成分含量。【结果】豆粕组和膨化大豆粉组鲤鱼的增重率和特定生长率与对照组相比显著降低(P0.05),而饲料效率、蛋白质效率、肥满度、肝体比和脏体比与对照组无显著差异(P0.05)。豆粕组鲤鱼肌肉中粗蛋白含量显著低于对照组(P0.05),水分含量显著高于对照组(P0.05);膨化大豆粉组鲤鱼肌肉中粗蛋白和水分含量与对照组无显著差异(P0.05);不同大豆蛋白源对鲤鱼肌肉粗灰分和粗脂肪含量的影响不显著(P0.05)。【结论】在本试验条件下,综合考虑鲤鱼的生长、饲料利用和肌肉营养成分因素,相同鱼粉替代水平下膨化大豆粉的替代效果优于豆粕。  相似文献   

蚕豆秸秆综合利用研究进展     

徐晓俞  李爱萍  吴凌云  陈均  郑开斌 《福建农业学报》2015,(2)

蚕豆秸秆富含蛋白质等营养成分,相比其他农作物秸秆具有较高的利用价值。利用蚕豆秸秆作为肥料还田,可提高土壤肥力,提升作物产量;作为食用菌的生物基质,可提高其产量;通过化学或生物学方法处理的蚕豆秸秆,是猪、羊、牛、鹅等家畜的高营养饲料;蚕豆秸秆作为一种可再生资源,可用于生产氢气、甲烷等清洁能源,还能制备活性炭。本文介绍了蚕豆秸秆在农业、畜牧业等方面的开发利用情况,旨在为其科学利用提供参考依据。最后对蚕豆秸秆的未来研究方向提出建议。  相似文献   

94 GHz Vlasov准光模式变换器的设计     

王康佳 《河北北方学院学报(自然科学版)》2015,(3):6-10

利用几何光学理论分析Vlasov辐射器的辐射原理,依据原理并结合基于矢量绕射理论的StrattonChu公式编写数值计算软件。设计出TE6,2模94GHz准光模式变换器,并使用Feko三维仿真电磁软件对准光模式变换系统进行仿真分析。仿真结果表明系统的总效率达到94.2%,矢量高斯含量达92%。  相似文献   

Effect of feeding some plant foods as source of dietary fibre on biological utilisation of diet in rats     

V. Agarwal  B. M. Chauhan 《Plant foods for human nutrition (Dordrecht, Netherlands)》1989,39(2):161-167

Isoproteinous diets containing 1% cholesterol and 10% fibre derived from plant foods namely,peepalbanti (Ficus religiosa),barbanti (Ficus bengalensis),gullar (Ficus glomerata),teent (Capparis decidua) andkhejri beans (Prsopsis cineria) or pure cellulose, were fed to rats for 40 days. Effect of incorporation of these whole plant parts on feed intake, weight gain, feed efficiency ratio (FER), dry matter digestibility (DMD) and true protein digestibility (TPD) in weanling rats was studied. Their inclusion did not affect the weight gain significantly whereas all other parameters were influenced to a varying extent. Foods rich in lignin had relatively lower FER, DMD and TPD whereas cellulose and pectin rich foods had higher DMD and TPD.  相似文献   

PORK PRODUCTION SYSTEMS IN CHINA: A REVIEW OF THEIR DEVELOPMENT,CHALLENGES AND PROSPECTS IN GREEN PRODUCTION     

Shuai ZHANG  Xin WU  Dandan HAN  Yong HOU  Jianzhuang TAN  Sung Woo KIM  Defa LI  Yulong YIN  Junjun WANG 《农业科学与工程前沿(英文版)》2021,8(1):15

•Large-scale industrial pork production enterprises are preferred in China in the future.•Challenges to green pork production include emissions, feed shortage and residues.•Potential solutions to green production include precise feeding and manure recycling.This paper reviews the changes in pork production in China, the largest pork producing and consuming nation in the world. The pork sector in China has changed dramatically since the 1990s, with large-scale intensive pork production systems replacing the former, exclusively family-based pork production systems. Modern breeding, feeding, vaccinating, and management technologies are widely used now. However, smallholders still account for a large proportion of the total production. The intensification and specialization of the pork sector is expected to continue in the future, but there is increasing awareness and pressure to develop more environmentally-sustainable production systems. The relative shortage of domestically produced feed, the low utilization efficiency of feed ingredients, the large emissions of nitrogen and phosphorus to the environment, the high use of antibiotics, and the presence of residual metals in manures are very large challenges for the pork sector nowadays. To solve these problems, techniques including new feed resource utilization, precise feeding, low-protein diets, alternatives to antibiotics and increased manure recycling are all important topics and research directions today. With new techniques and management approaches, it is possible to build more sustainable pork production systems in China.  相似文献   

The influence of xylanase on the fermentability,digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs     

Amy L Petry  Nichole F Huntley  Michael R Bedford  John F Patience 《Journal of animal science》2021,99(7)

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. A total of 3 replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF + 100 mg xylanase/kg (HF + XY [Econase XT 25P; AB Vista, Marlborough, UK]) providing 16,000 birch xylan units/kg; and HF + 50 mg arabinoxylan-oligosaccharide (AXOS) product/kg (HF + AX [XOS 35A; Shandong Longlive Biotechnology, Shandong, China]) providing AXOS with 3–7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P < 0.01). Relative to HF, HF + XY improved the AID of GE, CP, and NDF (P < 0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P < 0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P = 0.031). Relative to HF, HF + XY improved cecal disappearance of DM (162 vs. 98 g; P = 0.008) and NDF (44 vs. 13 g; P < 0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P < 0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF + XY decreased ileal viscosity compared with HF (P < 0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.  相似文献   

延安市1999-2008年植被恢复的成效分析     

张小勇  卫海燕 《水土保持通报》2013,33(2):218-220,225

延安市1999年被确定为退耕还林示范地区,迄今实施退耕还林工程已10余年,研究和监测退耕前后植被覆盖变化就成为退耕还林工程的重要任务之一.选取了SPOT/VGT NDVI数据,借助Erdas和ArcGIS平台,利用一元趋势线模型和植被覆盖度模型对延安市1998-2008年间植被的动态变化进行了分析.结果表明:(1)延安市10a间大部分地区植被恢复情况良好,植被指数明显改善的地区占总面积的21.27％,中度改善地区占61.46％.(2)延安市植被覆盖率呈现为南高北低,该市平均覆盖度为0.519 8.(3)0°～35°坡度之间明显改善和中度改善的面积比例均超过了各自面积的75％,其中15°～25°坡度明显改善面积比例最高,占总面积的35.8％.  相似文献   

抗疲劳中药复方制剂的安全性毒理学试验     

吴永魁  李乾学  张祚新  柳巨雄  陈巍  胡仲明 《吉林农业大学学报》2008,30(1):93-97

采用小鼠经口急性毒性试验、小鼠骨髓微核试验、精子畸形试验和大鼠30 d喂养试验,检测抗疲劳中药复方制剂的急性毒性、致突变性和亚慢性毒性。结果表明:抗疲劳中药复方制剂对小鼠急性经口LD50>15 g/kg;3个剂量组微核率为0.16%~0.20%,精子畸形率2.70%~2.94%,与阴性对照组比均无显著差异。给予中药复方制剂后,各剂量组大鼠生长发育良好。第15 d检查,中、高剂量组大鼠平均红细胞体积(MCV)高于对照组,血清球蛋白(GLOB)含量低于对照组,其它指标与对照组比较无显著差异;第30 d检查,各剂量组血液葡萄糖(GLU)含量高于对照组,中、高剂量组GLOB和肌酐(CRE)含量也高于对照组,其它指标均在正常范围内,与对照组差异不显著;主要脏器系数及病理组织学检查未见明显异常。以上结果表明抗疲劳中药复方制剂属于实际无毒类,无致突变性,部分检测指标的改变可能与机体代谢状况和抗疲劳机制形成有关。  相似文献   

巴什拜羊春季牧食行为研究   总被引：1，自引：0，他引：1  

刘武军  余雄  李建华  王旭光  赵福宾  马杰  赵泽 《新疆农业科学》2008,45(1):180-183

对巴什拜羊春季牧食行为进行24 h 的连续观测表明,巴什拜羊昼夜牧食行为活动节律:采食时间263.3±11.2 min,反刍时间298.7±56.0 min,睡眠时间255.6±37.1 min,运动时间391.4±4.6 min,静立时间231±17.0 min.巴什拜羊的日反刍周期数7.22±0.56次,每周期持续时间35.52±5.98 min,全天总食团数265.62±7.40个,每食团咀嚼时间31.31±2.17 min,采食前进速度3.8±1.0 m/s,采食速度60.9±6.3口/s.全天总食团数265.62±7.40个,每食团咀嚼时间31.31±2.17 min,每个食团咀嚼次数42.69±5.67次,与一般绵羊全天逆呕食团及每个食团咀嚼次数差异很大,这可能与巴什拜羊消化机能强有关.巴什拜羊的前进中的采食速度较快.说明草场退化严重以及巴什拜羊的牧食能力较强.  相似文献