n维非线性Chaffe-Infante方程的孤立波解

考虑n维非线性Chaffe-Infante方程。首先,利用直接假设法,给出了一类二阶常系数非线性微分方程的一组实的显式精确解。接着,仍然用直接假设法,并利用前面的结果,得到了n维非线性Chaffe-Infante方程的十个新的实的孤立波解。

Aerodynamic Characteristics Calculation and Diffusion Law Analysis of Rectangular-Chaff Clouds Under Airflow

To calculate the diffusion law of chaff cloud launched by aircraft,taking rectangular chaff as an example,the diffusion model of chaff cloud is established in this paper.Firstly,the coordinate systems of chaff are defined and the motion model of chaff is established.The motion model mainly includes chaff motion equation and rotation equation,which are obtained by combining the aerodynamic moment and aerodynamic damping.Then,the influence of multi-chaff aerodynamic interference on the movement of chaff is analyzed.Finally,considering the influence of overlap area between chaffs and chaff spacing on the aerodynamic coefficients,the multi-chaff motion model is obtained,and the simulation results are compared with the test results to verify the credibility of the model.

Evaluation of Methane Yield on Mesophilic-Dry Anaerobic Digestion of Piggery Manure Mixed with Chaff for Agricultural Area

A mesophilic-dry anaerobic digestion process is valid in treating high-concentration substrates containing low moisture content. It has merits of lower wastewater discharge and lower heat capacity required in maintaining reactor temperature as compared with a thermophilic-wet anaerobic digestion process. In fact, chaff can be easily obtained in farming areas and used as a mixture substrate as one of bulking agents for controlling moisture and supplying carbon. For this reason, this study applies the chaff to improve livestock manure, which contains high moisture content and is discharged from domestic pig farms. This study aims at verifying its feasibility for improving methane production efficiency on a basis of BMP (Biochemical Methane Potential) assay obtained through a series of experiments. Finding results were methane gas production and gas production per volatile solid (VS) added, and methane gas production among biogas production were increased as the chaff added in the piggery manure was increased. According to experimental results for improving the methane production efficiency, mixture of the chaff and the piggery manure played an important role in controlling the moisture content and improving the methane gas production rate, and also verified its feasibility in the mesophilic-dry anaerobic digestion process indicating relatively less difficulty for operation and management.

Chaff Jamming Recognition of Radar

A modified chaff jamming recognition method of radar is investigated using grey relational analysis（ GRA） based on the difference in echo correlation characteristics between a complex rigid target and chaff cloud in time domain. Slice method（ SM）,a novel modeling approach,is proposed to construct an electromagnetic scattering model of chaff cloud in a scenario with slowly moving platform that is targeted. The diffusion characteristics and echo characteristics of the chaff cloud are analyzed. The GRA of a real target and chaff cloud shows that the adjacent return waves have a good correlation for the target but a weak correlation for chaff cloud. Since the correlation degree of chaff cloud＇s echo is far lower than that of a complex rigid target＇s,the chaff jamming can be identified by setting a reasonable threshold. Simulation results are presented to verify the effectiveness of this method.

Evaluation for Success Probability of Chaff Centroid Jamming

As the chaff centroid jamming can introduce the guiding error of the anti-warship missile's seeker and decrease its hitting probability,a new quantitative analysis method and a mathematic model are proposed in this paper to evaluate the success jamming probability.By using this method,the optimal decision scheme of chaff centroid jamming in different threat situations can be found,and also the success probability of this scheme can be calculated quantitatively.Thus,the operation rules of the centroid jamming and the tactical approach for increasing the success probability can be determined.

Theoretical analysis of polarization recognition between chaff cloud and ship

Aimed at the difficulty in finding an efficient method to depress and recognize chaff in both time and frequency domain,this paper tries to recognize chaff and target such as warship in polarization domain under the theoretical analysis of the polarization scattering cross section of chaff.In order to find target more exactly,non-linear polarization transformation and polarization smoothness are applied to process the polarization information of chaff and ship target.The resulting recognition is proved to be effective by simulation.

茴香秸秆和秕壳对育肥羊生长性能及羊肉膻味的影响

为了充分利用茴香秸秆和秕壳,减少浪费及其对环境的污染,将采集的茴香秸秆、秕壳与玉米秸秆等比例混合,用不同方法处理后作为粗饲料饲喂湖羊羔羊,研究茴香秸秆和秕壳对羔羊的采食量、日增重、F/G及羊肉中脂肪酸含量的影响。结果表明,复合微生物菌系发酵处理的茴香秸秆和秕壳可显著提高育肥羊采食量、日增重,降低F/G(P<0.05),可在一定程度上降低羊肉膻味。

雌雄配比和种植密度对单雌性工业大麻籽糠产量的影响

以单雌性工业大麻云麻雌1号作为对象,研究不同雌雄配比(雄株比例为10%、20%和30%)种植模式下种植密度(5210、10420、15630株/hm^(2))对麻籽和麻糠产量的影响,进而探讨单雌性工业大麻用于籽糠兼用的生产模式。结果表明,在同一雌雄比例下,种植密度越大,麻籽、麻糠、麻秆及大麻二酚(CBD)理论产量越高;在最大种植密度15630株/hm^(2)下,20%雄株率下的麻籽、麻糠、麻秆及CBD理论产量均高于10%和30%雄株率的产量,其麻籽产量为5738.02 kg/hm^(2),麻糠产量为6087.14 kg/hm^(2),麻秆产量为9396.35 kg/hm^(2),CBD理论产量127.58 kg/hm^(2)。在单雌性工业大麻云麻雌1号籽糠生产实践中,建议配置花期一致的20%左右雄株,保证授粉充足,实现麻籽和麻糠丰产。

添加比例及青贮天数对统糠和紫花苜蓿混合青贮品质的影响

本研究以统糠和紫花苜蓿为青贮原料,进行不同比例的统糠(0、15%、20%、25%、30%)与紫花苜蓿的混合青贮,于青贮0、3、5、7、15、30 d测定混合青贮发酵品质、营养品质和有氧稳定性。结果表明:与不添加统糠的对照相比,添加统糠的所有处理组乳酸、乙酸含量显著降低(P<0.05),pH值、丙酸含量、丁酸含量降低但差异不显著,氨态氮/总氮有所提高但差异不显著,添加统糠间接促进了同型乳酸菌发酵,提高了青贮的发酵品质;除添加30%处理组外,其他统糠添加处理组有氧稳定性显著提高(P<0.05)。添加统糠的所有处理组粗蛋白、可溶性碳水化合物含量显著降低(P<0.05),干物质、粗灰分、中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素、纤维素和半纤维素含量显著提高(P<0.05),混合青贮的营养品质降低。与青贮原料相比,青贮30 d后干物质、pH值、可溶性碳水化合物、半纤维素含量显著降低,粗蛋白、粗灰分、酸性洗涤纤维、乳酸、乙酸含量显著上升(P<0.05),丁酸仅在青贮3 d时检出。采用一元线性回归分析青贮天数和统糠添加比例与各指标之间的关系,结果表明统糠添加量在15%~30%区间内,混合青贮的发酵指标和营养指标遵循回归预测模型,可针对不同动物营养需求进行科学配比。通过主成分分析提取指标,隶属函数综合评价表明,统糠与紫花苜蓿的配比为25∶75时混合青贮饲料品质最佳。

Experimental and numerical study of chaff cloud kinetic performance under impact of high speed airflow

To solve the kinetic and diffusion problem of surface-type infrared decoy, multi-chaff kinetic models are established and chaff cloud holistic kinetic performance are analyzed under the impact of high speed airflow in this work. Chaffs rotate rapidly during the motion under the impact of high speed airflow. The rotation speed is correlated with lift, position of pressure center and aerodynamic damping. Computational Fluid Dynamics(CFD) is used to compute the aerodynamic coefficients of chaff. It is found that there exists serious aerodynamic interference which mainly relates to the overlapping area and distance among chaffs during the diffusion of chaff cloud. The chaff wind tunnel test and rocket sled experiment are carried out to verify the credibility of the models in this work. Then, the variation of chaff cloud expectation and extremum are analyzed to achieve the holistic kinetic and diffusing performance of chaff cloud. Simulation results demonstrate that the chaffs diffuse rapidly under the impact of high speed airflow and chaff cloud can be formed rapidly within 0.5 s. The shape of the chaff cloud is similar to cone that forms a certain angle with the horizontal plane and most chaffs focus on the second half.

基于灰狼算法的箔条幕干扰构设方法研究

海战场环境中,箔条幕自卫干扰构设前由于未充分考虑风向、风速等因素,容易导致干扰失败,且无定量化的布放模型。针对此问题,提出一种新的箔条幕干扰构设方法。基于箔条幕干扰机理分析,构建干扰场景模型,具体包含导弹运动模型、舰船运动模型和箔条幕形态模型;综合考虑干扰有效性和资源损耗性,提出采用灰狼算法进行箔条幕干扰构设方案求取的思路,建立相应约束条件(遮蔽有效性约束条件、质心拖引有效性约束条件和干扰能力约束条件)、目标函数和补弹策略,且采用Logistic混沌映射和反向学习策略改进灰狼算法。最终通过仿真案例分析得出以下结论:所提出的箔条幕干扰构设方法寻优速率快,可保证整个对抗过程中舰艇始终能够进行有效自卫干扰。初始时刻构设的箔条幕轴线基本与弹目轴垂直,而箔条幕质心基本处于弹目轴线附近。风向与风速对自卫干扰效果影响较小,初始弹目距离主要影响箔条弹用量,初始反舰导弹攻击方向对自卫干扰效果影响较为明显。当从舰艇尾向进行攻击时,干扰效果最好;相反,从舰艇艏向进行攻击时,干扰效果最差。

基于布谷鸟搜索算法的机动化箔条幕布放方法研究

雷达导引头采用动目标显示、边搜索边跟踪等抗干扰技术,导致传统质心、冲淡、幕墙式箔条干扰方法干扰效能降低。对此,提出一种机动化箔条幕布放方法,通过无人机和舰船协同布放箔条弹,使幕墙能量质心随时间不断移动,保证舰船在有效时间内成功逃离雷达波束。首先,基于机动化箔条幕干扰机理,构建箔条幕布放模型,具体包括雷达导引头运动模型、舰船运动模型、箔条幕形态模型和箔条幕运动模型。随后,根据机动化箔条幕模型求解特点,确定采用布谷鸟搜索算法求取布放方案;据此提出总体求解思路,并构建布放效能条件(目标函数与约束条件);采用Logistic混沌机制改进布谷鸟搜索算法,建立补弹策略。最终,通过仿真案例对机动化箔条幕布放模型的有效性进行分析验证。结果表明,与常规箔条幕布放方法相比,机动化箔条幕布放方法能够有效减小舰船逃逸时间,降低箔条弹消耗量,同时具备较强的应对不同风速风向的能力。

基于机器视觉的谷糙分离检测方法

[目的]解决传统的谷糙分离机存在的人工检测精度差的问题,提高生产效率。[方法]提出了一种基于机器视觉的图像检测方法,通过不同图像算法的多级式递进融合,实现对谷糙的特征识别与分离。对采集到的图像进行ROI区域选定,并利用Retinex算法进行图像增强;使用Otsu算法对图像进行分割,再利用中值滤波与形态学相结合去除图像噪声;采用改进的Canny算法对二值图像进行边缘特征检测,结合Hough变换提取谷糙图像轮廓的位置信息;最后应用卡尔曼滤波对位置信息进行状态估计,得到分离位置最佳预测值的同时,减小位置偏移误差。[结果]系统的检测平均误差为3.14 mm,相比较滤波前减少1.82 mm,滤波误差平均标准差为0.8 mm。[结论]该方法能够有效检测谷糙特征信息并提高分离精度。

打顶和喷施乙烯利对工业大麻籽粒和麻糠产量的影响

为探究提高雌雄异株工业大麻品种籽粒和麻糠产量的农艺措施,以云麻8号为试验材料,开展大田试验研究开花前打顶和喷施乙烯利处理(0、100、200、400 mg/L)对籽粒和麻糠产量的影响。结果表明,打顶处理会导致雌株的籽粒和麻糠产量下降。喷施乙烯利显著增加了雌株数量,雌雄株数比值由1.04提高到1.60。随喷施乙烯利浓度的增加,雌株的籽粒和麻糠产量均先升高后降低。喷施200 mg/L乙烯利溶液的雌株籽粒和麻糠产量最高,分别为2158.4 kg/hm^(2)和1978.4 kg/hm^(2),较0 mg/L处理分别增加了50.8%和28.5%,较400 mg/L处理分别高283.5 kg/hm^(2)和549.0 kg/hm^(2)。喷施乙烯利还会导致部分雄株分化出雌花并结实,喷施400 mg/L乙烯利时雄株籽粒产量最高,达到910.5 kg/hm^(2),但雄株麻糠产量在喷施200 mg/L乙烯利时最高,为427.5 kg/hm^(2)。综合雌株和雄株的产量,喷施400 mg/L乙烯利的籽粒产量最高,喷施200 mg/L乙烯利的麻糠产量最高。

平菇菌糠部分替代全株青贮玉米对育肥期肉用山羊生长性能、表观消化率及屠宰性能的影响

本试验主要研究以平菇菌糠部分替代全株青贮玉米对育肥期肉用山羊生长性能、表观消化率及屠宰性能的影响。试验选取体重相近(15.46±1.24)kg、2月龄的健康青山羊60只,采取单因素随机分组试验设计,按照添加平菇菌糠替代全株青贮玉米的不同比例将试验羊分成5个组,分别为对照组饲喂基础日粮,不添加平菇菌糠、5%组饲喂添加5%平菇菌糠的基础饲粮、10%组饲喂添加10%平菇菌糠的基础日粮、15%组饲喂添加15%平菇菌糠的基础日粮、20%组饲喂添加20%平菇菌糠的基础日粮,每组12只,每组3个重复,每个重复4只羊。预试期7 d,正试期90 d。结果显示,在平均日增重指标方面,1~30 d,20%组显著高于对照组和50%组(P<0.05);31~60 d,5%组显著高于15%、20%组(P<0.05);60~90 d,15%组、20%组显著高于对照组、5%组、10%组(P<0.05);1~90 d,15%组、20%组显著高于对照组和5%组(P<0.05)。各组干物质采食量无差异显著性(是无差异显著性还是无显著差异性?),但有升高的趋势;在料重比指标方面,1~30 d,20%组显著低于对照组和5%组(P<0.05),31~60 d,15%组、20%组显著高于5%组(P<0.05);1~90 d,20%组显著低于对照组和5%组(P<0.05)。20%组干物质、有机物和粗蛋白质表观消化率高于其它各组,显著高于5%组(P<0.05)。20%组屠宰率高于其它各组,显著高于对照组(P<0.05)。综上可见,在本试验条件下,在日粮中添加平菇菌糠替代青贮玉米秸秆可以改善育肥期肉用山羊生产性能、提高营养物质表观消化率及屠宰率,综合分析比较,以添加20%的平菇菌糠效果最佳,切实可行。

发酵金针菇菌糠对关中奶山羊产奶性能、营养物质表观消化率及瘤胃发酵参数的影响

试验旨在研究发酵金针菇菌糠对关中奶山羊产奶性能、营养物质表观消化率及瘤胃发酵参数的影响。选取体重、年龄、胎次及产奶量相近的健康关中奶山羊75只,随机分为5组,每组3个重复,每个重复5只羊。各组奶山羊分别饲喂添加0(对照组)、20%、25%、30%、35%发酵金针菇菌糠的日粮。预试期15 d,正式试验期60 d。结果显示,30%组奶山羊的平均日产奶量显著高于其他组(P<0.05)。30%组奶山羊的干物质(DM)、粗蛋白质(CP)、粗脂肪(EE)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)表观消化率显著高于对照组、20%组(P<0.05)。30%组奶山羊瘤胃pH值显著低于对照组、20%组、25%组(P<0.05),与35%组差异不显著(P>0.05)。与对照组相比,20%组、25%组、30%组、35%组奶山羊氨态氮含量分别提高了23.04%、37.40%、46.86%、47.27%。研究表明,在饲粮中添加30%发酵金针菇菌糠可以提高关中奶山羊产奶性能,促进机体对营养物质的消化吸收,改善瘤胃发酵状况。

针对时空统计特性的箔条云半实物射频仿真

本文针对箔条云半实物射频仿真(Radio Frequency Simulation System,RFSS)中的关键问题进行研究,给出了对箔条云进行半实物射频仿真时的三元组的馈电系数的计算公式.与对点目标的仿真不同,对箔条云的仿真更注重其散射场统计特性的复现.箔条云的空间随机分布和随机运动特性,表现为其回波的空间相关性和时间相关性.本文通过三元组馈电系数之间的相关性来仿真箔条云散射回波的空间相关性;通过差分重心公式的横向平移、径向相移以及时域滤波来仿真箔条云散射回波的时间相关性.数值模拟结果验证了所给出的箔条云射频仿真方法的有效性.这些工作为箔条云的半实物射频仿真提供了理论基础和分析框架.

不同食用菌菌糠中微生物的群落结构

食用菌菌糠是食用菌栽培过程中收获子实体后剩下的栽培基质,随着食用菌产业的发展,食用菌菌糠数量越来越多,菌糠中微生物群落结构的研究未见相关报道。本试验中以不同食用菌菌糠为材料,采用高通量测序的方法对平菇、香菇、金针菇、杏鲍菇菌糠中的细菌、真菌群落进行了分析。结果表明,所有菌糠样品细菌群落在门水平上的优势群落为变形菌门和厚壁菌门,从属水平来看,未分类的细菌群落占优势;所有菌糠样品真菌群落在门水平上的优势群落为子囊菌门和担子菌门,从属水平来看,优势属为食用菌自身所在属。

无线电引信抗箔条干扰综述

首先简要叙述了箔条干扰的发展状况。然后对无线电引信抗箔条干扰方法的研究现状进行了综述,介绍了基于频谱展宽、极化特征、多普勒差异、回波信号特征、距离像、稀疏表示等抗箔条干扰方法。最后总结了无线电引信抗箔条干扰技术面临的问题,并对其发展前景作了展望。