期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
花生秧作为肉用绵羊单一粗饲料有效能值的测定与估测 被引量:15
1
作者 赵明明 马涛 +6 位作者 赵江波 邓凯东 肖怡 马俊南 毛建红 贾鹏 刁其玉 《动物营养学报》 CAS CSCD 北大核心 2017年第11期4162-4170,共9页
本试验旨在用套算法和插值法测定与估测肉用绵羊花生秧有效能值,确定替代法中饲粮中适宜花生秧替代比例,为单一秸秆饲料有效能值的测定与估测提供方法学上的参考。选用体重为(45.00±1.96)kg的体况良好的杜泊×小尾寒羊F1肉用... 本试验旨在用套算法和插值法测定与估测肉用绵羊花生秧有效能值,确定替代法中饲粮中适宜花生秧替代比例,为单一秸秆饲料有效能值的测定与估测提供方法学上的参考。选用体重为(45.00±1.96)kg的体况良好的杜泊×小尾寒羊F1肉用成年羯羊54只,采用随机区组设计,分为9组,饲粮分别为基础饲粮、全花生秧饲粮和分别以10%、20%、30%、40%、50%、60%、70%花生秧替代基础饲粮的试验饲粮,每组6个重复,每个重复1只羊。预试期10 d,正试期9 d,其中气体代谢试验3 d,消化代谢试验6 d。结果表明:1)全花生秧饲粮组花生秧干物质(DM)表观消化率与20%、30%、40%组间差异不显著(P>0.05),显著高于其他各组(P<0.05)。全花生秧饲粮组花生秧有机物(OM)表观消化率与20%组差异不显著(P>0.05),但显著高于其他各组(P<0.05)。全花生秧饲粮组花生秧总能(GE)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、粗脂肪(EE)表观消化率显著高于10%组(P<0.05),粗蛋白质(CP)表观消化率显著低于10%组(P<0.05),与其他各组间差异不显著(P>0.05)。2)花生秧消化能(DE)、代谢能(ME)均具有相同的规律,即全花生秧饲粮组DE、ME(8.57、6.69 MJ/kg DM)与20%(8.22、6.58 M J/kg DM)、30%(8.02、6.50 M J/kg DM)、40%组(8.10、6.52 M J/kg DM)差异不显著(P>0.05),但显著高于其他组(P<0.05)。3)插值法求得花生秧M E"真值"为6.62 M J/kg DM,接近于套算法得到的花生秧ME。综合得出,套算法可以用于肉用绵羊估测花生秧(单一粗饲料)的DE和M E;用套算法测定花生秧秸秆类粗饲料有效能值,其在饲粮中的适宜替代比例为20%~40%。 展开更多
关键词 肉羊 能量估测 代谢能 套算法 花生秧 有效能值
下载PDF
生长肥育猪营养需求模式试验 被引量:7
2
作者 余德谦 林映才 +5 位作者 蒋宗勇 杨晓建 张振斌 杨立彬 谯仕彦 李德发 《养猪》 2002年第2期3-6,共4页
本试验设置三个营养水平验证 2 0~ 3 5kg、3 5~ 60kg和 60~ 90kg三个阶段杜×大×长肉猪的营养需求。试验结果表明 ,三个阶段各组的采食量无显著差异 (p >0 .0 5 )。三个阶段高能组和中能组的日增重极显著 (p <0 0 1 ... 本试验设置三个营养水平验证 2 0~ 3 5kg、3 5~ 60kg和 60~ 90kg三个阶段杜×大×长肉猪的营养需求。试验结果表明 ,三个阶段各组的采食量无显著差异 (p >0 .0 5 )。三个阶段高能组和中能组的日增重极显著 (p <0 0 1 )或显著 (p <0 .0 5 )高于低能组 ,饲料转化率均极显著 (p <0 0 1 )或显著 (p <0 0 5 )优于低能组。在 2 0~ 3 5kg阶段 ,高能组和中能组的日增重差异不显著 (p >0 .0 5 ) ,但料重比的差异极显著 (p <0 .0 1 )。在 3 5~ 60kg阶段 ,高能组和中能组的日增重和料重比差异均不显著 (p >0 0 5 )。在 60~ 90kg阶段 ,高能组和中能组的日增重和料重比差异均显著 (p <0 .0 5 )。同时 ,用超声波测膘仪测量了猪的膘厚和眼肌深度 ,推算出胴体无脂瘦肉日增重。在 2 0~ 60kg阶段 ,高能组和中能组极显著高于低能组 (p <0 .0 1 ) ,高能组显著高于中能组 (p <0 .0 5 )。在 60~ 90kg阶段 ,高能组和中能组极显著高于低能组 (p <0 .0 1 ) ,高能组和中能组差异不显著 (p >0 .0 5 )。在 2 0~ 90kg整个试验过程 ,高能组和中能组极显著高于低能组 (p <0 .0 1 ) ,高能组和中能组差异不显著 (p >0 .0 5 )。试验的结果显示NRC(1 998)模型估测值基本符合我国瘦肉型肉猪生长需要 ,具有一定的实用价值 ,但对? 展开更多
关键词 生长模式试验 采食量 瘦肉型 肉猪 能量估测 肥育猪 营养需求
下载PDF
基于几何聚类映射采样机制的无线传感网超宽带传输算法 被引量:3
3
作者 刘东旭 《长春工程学院学报(自然科学版)》 2022年第1期115-119,共5页
为解决无线传感网超宽带传输领域存在的传输性能不高、拥塞控制能力较差等不足,提出了一种基于几何聚类映射采样机制的无线传感网超宽带传输算法。首先,根据无线传感网信道存在的频率干涉特性,采取并发正交传输及周期采样方式对传输数... 为解决无线传感网超宽带传输领域存在的传输性能不高、拥塞控制能力较差等不足,提出了一种基于几何聚类映射采样机制的无线传感网超宽带传输算法。首先,根据无线传感网信道存在的频率干涉特性,采取并发正交传输及周期采样方式对传输数据予以正交处理,以增强节点及链路的网络传输性能,提升超宽带传输质量;随后,基于能量估测机制提出了功率阈值稳定方法,利用最低功率模型对运行不稳定的节点及时进行休眠处理,降低因节点失效而导致数据拥塞的概率,以改善网络的拥塞控制性能。仿真实验结果表明:与当前无线传感网超宽带传输领域常用的基于NMF和2-SVD-QR混合矩阵分解的WSN优化传输算法和基于SWIPT机制的WSN节能传输算法相比,所提算法具有网络传输带宽较高及累计拥塞发生频次较低的特点,实际部署价值较高。 展开更多
关键词 无线传感网 超宽带 频率干涉 正交传输 能量估测 功率稳定 节点休眠
下载PDF
Experiences in using gas dispersion measurements to evaluate metallurgical performance of scavenger cleaner and recleaner circuit at Vale's Thompson Mill 被引量:1
4
作者 刘洪均 张炜 孙春宝 《Journal of Central South University》 SCIE EI CAS 2014年第10期3955-3962,共8页
The performance of a flotation circuit is largely the result of the operator's response to visual clues. This includes manipulation of the gas input and how it is distributed to cells in a bank. A new gas dispersi... The performance of a flotation circuit is largely the result of the operator's response to visual clues. This includes manipulation of the gas input and how it is distributed to cells in a bank. A new gas dispersion technology was presented which was conducted to perform characterization tests in Outokumpu 30 m3 and 50 m3 flotation cells installed at Thompson Vale's concentrator, and subsequent data analysis. The experimental program was designed to establish "as-found" baseline conditions for each cell of the two-parallel banks in the scavenger-cleaner and recleaner circuit, to select and characterize one typical cell in the two banks with either different frother concentrations or different air flow rates, and establish what variables can be manipulated in future characterization work. A three-parameter model was developed in order to link the bubble size and frother concentration. This relationship can be used to correlate gas dispersion change to improved metallurgical performance. 展开更多
关键词 bubble size bubble size distribution bubble surface area flux gas dispersion
下载PDF
Estimates of global M_2 internal tide energy fluxes using TOPEX/POSEIDON altimeter data
5
作者 张艳伟 梁鑫峰 +1 位作者 田纪伟 杨丽芬 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第1期129-134,共6页
TOPEX/POSEIDON altimeter data from October 1992 to June 2002 are used to calculate the global barotropic M2 tidal currents using long-term tidal harmonic analysis. The tides calculated agree well with ADCP data obtain... TOPEX/POSEIDON altimeter data from October 1992 to June 2002 are used to calculate the global barotropic M2 tidal currents using long-term tidal harmonic analysis. The tides calculated agree well with ADCP data obtained from the South China Sea (SCS). The maximum tide velocities along the semi-major axis and semi-minor axis can be computed from the tidal ellipse. The global distribution of M2 internal tide vertical energy flux from the sea bottom is calculated based on a linear internal wave generation model. The global vertical energy flux of M2 internal tide is 0.96 TW, with 0.36 TW in the Pacific, 0.31 TW in the Atlantic and 0.29 TW in the Indian Ocean, obtained in this study. The total horizontal energy flux of M2 internal tide radiating into the open ocean from the lateral boundaries is 0.13 TW, with 0.06 TW in the Pacific, 0.04TW in the Atlantic, and 0.03 TW in the Indian Ocean. The result shows that the principal lunar semi-diurnal tide Me provides enough energy to maintain the large-scale thermohaline circulation of the ocean. 展开更多
关键词 TOPEX/POSEIDON altimeter M2 internal tide vertical energy flux horizontal energy flux
下载PDF
Investigation of Key Parameters for 3-D Dredging Plume Model Validation
6
作者 Junsheng Jiang 《Journal of Shipping and Ocean Engineering》 2014年第5期129-139,共11页
Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental... Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental impact assessment of the proposed dredging, particularly those associated with suspended sediments and sedimentation. Model validation and performance are still not resolved because of the difficulty of site measurements and the understanding of the parameters used in the model. This paper presents a 3-D dredging plume model based on the MIKE3 software package to investigate parameters which affect the model performances. As a result of lack of site data for the public domain uses, the model scenarios are designed artificially for sensitive runs to identify the key parameters affecting plume behaviours. The factors include dredging spill rates using different dredging methods, equipment and sediment settling velocities. The influence of wave and wind effects combined with tidal forces on the sediment re-suspended rates and the advection/dispersion scales are also assessed. 展开更多
关键词 3-D dredging plume model settling velocity sediment measurement.
下载PDF
Image reconstruction of a neutron scatter camera 被引量:1
7
作者 ZHANG XianPeng ZHANG Mei +10 位作者 SHENG Lang ZHANG ZhongBing LI Kui Nian PENG BoDong ZHANG XiaoDong OUYANG XiaoPing LIU Jun LIU JinLiang CHEN Liang ZHU Jie HE ChaHui 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第1期149-155,共7页
Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discriminat... Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discrimination ability, and wide field of view. However, using the direct projection method, the angular resolution of this camera is limited by uncertainties in the energies estimated from pulse height and time of flight measurements. In this study, we established an eight-element neutron scatter camera and conducted the experiment with a ^(252)Cf neutron source. The results show that it has an angular resolution better than 8°(1s) and a detection efficiency of approximately 2.6′10-4. Using maximum likelihood expectation maximization method, the image artifact was eliminated, and the angular resolution was improved. We proposed an average scattering angle method to estimate the scattering energy of neutrons and Compton gamma rays. As such, we can obtain a recognizable image and energy spectrum of the source with some degradation of energy and image resolutions. Finally, a newly measured light response function based on the MPD^(-4) device was used for image reconstruction. Although we did not obtain a better result than that of the standard light response function, we have observed the effects of light response function on image reconstruction. 展开更多
关键词 neutron scatter camera ^(252)Cf neutron source energy reconstruction image reconstruction maximum likelihood expectation maximization time of flight light response function
原文传递
Analysis of internal tidal characteristics in the layer above 450 m from acoustic Doppler current profiler observations in the Luzon Strait 被引量:4
8
作者 LIAO GuangHong YUAN YaoChu +4 位作者 Kaneko ARATA YANG ChengHao CHEN Hong Taniguchi NAOKAZU Gohda NORIAKI 《Science China Earth Sciences》 SCIE EI CAS 2011年第7期1078-1094,共17页
The characteristics of internal tides in the upper layer of the Luzon Strait are investigated on the basis of direct-observation current data recorded on April 25 and September 26, 2008 by an acoustic Doppler current ... The characteristics of internal tides in the upper layer of the Luzon Strait are investigated on the basis of direct-observation current data recorded on April 25 and September 26, 2008 by an acoustic Doppler current profiler. Spectral analysis and energy estimation show that the diurnals and semidiurnals carry most of the energy of internal tides. Values of the depth-integrated total energy E for the three frequency bands of diurnal, semidiurnal, and high frequencies are 31, 6.9, and 3.4 kJ. m, respectively. Near-inertial peaks are only present in the baroclinic component. The behavior of typical tidal frequencies (i.e., O1, K1, M2, MK3, and M4) and the near-inertial frequency is basically consistent with linear internal wave theory, which predicts E+(ω)/E_(ω)=(ω-f)2/(ω+f)2 at depths above 66 m, while not all prominent tidal components coincide well with the relation of the linear internal wave field at other depths. Examinations of depth structures of the baroclinic tides and temporal variations show that the surface tides and internal tides are both of mixed type, having diurnal inequality and spring-neap fortnight periods. The K1 and O1 tides have comparable cross- and along-shelf components, while the M2 and S2 tides propagate toward the shelf in the northern South China Sea as wave beams. The amplitude and phase of internal tides vary with time, but M2 and S2 tides appear to have structures dominated by the first mode, while the K1 and O1 tides resemble second-mode structures. The minor to major axis ratios are close to expected values of flω in the thermocline. 展开更多
关键词 current observation acoustic Doppler current prof'fler internal tides internal waves Luzon Strait
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部