本研究以饲料桑新品种‘川饲桑1号’(Morus alba cv.Chuansisang-1)为试验材料,采用二因素随机区组设计连续3年(2016-2018)对不同刈割高度(H_(1):70 cm,H_(2):90 cm,H_(3):110 cm)和施氮量(N1:138 kg N·hm^(-2),N2:207 kg N·h...本研究以饲料桑新品种‘川饲桑1号’(Morus alba cv.Chuansisang-1)为试验材料,采用二因素随机区组设计连续3年(2016-2018)对不同刈割高度(H_(1):70 cm,H_(2):90 cm,H_(3):110 cm)和施氮量(N1:138 kg N·hm^(-2),N2:207 kg N·hm^(-2),N3:276 kg N·hm^(-2))下的饲草产量、植物学特性及营养品质进行测定,并对其饲用价值进行综合评价,以期为饲料桑的推广利用提供数据支撑。结果表明,随着年限的增加各处理下饲草产量逐年递增,且均以H2N3处理最高。刈割高度与施氮量对饲料桑产量、植物学特性和营养品质均有影响。其中,刈割高度是影响饲料桑植物学特性的主要因素,两者交互作用对饲草产量、单枝重及各营养指标影响显著(P<0.05)。在相同刈割高度下,鲜、干草产量和中性洗涤纤维均以N_(3)处理最高,粗蛋白含量随施氮量的增加先增加后减小。在相同氮肥用量下,H_(2)处理下的大部分饲草产量、主枝叶片数、单株重最大,中性洗涤纤维和酸性洗涤纤维含量整体随刈割高度的增加而增大。粗蛋白和粗灰分含量整体在H_(2)高度下最高,粗脂肪含量随刈割高度增加呈先升高后降低的趋势。以隶属函数法对‘川饲桑1号’的饲用价值进行综合评价可知,在刈割高度为90 cm、施氮量为276 kg N·hm^(-2)时其饲用价值最高。展开更多
A series of laboratory investigations are conducted to analyze the effect of flocculant type on the spatial morphology and microstructural characteristics of flocs during the flocculation and settling of tailings.Four...A series of laboratory investigations are conducted to analyze the effect of flocculant type on the spatial morphology and microstructural characteristics of flocs during the flocculation and settling of tailings.Four flocculant types(i.e.,ZYZ,JYC-2,ZYD,and JYC-1)are considered in this study.The fractal characteristics and internal structures of tailings flocs with different flocculant types and settlement heights are analyzed by conducting scanning electron microscopy and X-ray micro-computed tomography scanning experiments based on the fractal theory.Results show that unclassified tailings flocs are irregular clusters with fractal characteristics,and the flocculation effect of the four flocculant types has the following trend:ZYZ>JYC-2>ZYD>JYC-1.The size and average grayscale value of tailings flocs decrease with the increase in settlement height.The average grayscale values at the top and bottom are 144 and 103,respectively.The settlement height remarkably affects the pore distribution pattern,as reflected in the constructed three-dimensional pore model of tailings flocs.The top part of flocs has relatively good penetration,whereas the bottom part of flocs has mostly dispersed pores.The number of pores increases exponentially with the increase in settlement height.By contrast,the size of pores initially increases and subsequently decreases with the increase in settlement height.展开更多
Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, wh...Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.展开更多
In this paper, we propose the novel method of complex least squares adjustment （CLSA） to invert vegetation height accurately using single-baseline polarimetric synthetic aperture radar interferometry （PollnSAR） da...In this paper, we propose the novel method of complex least squares adjustment （CLSA） to invert vegetation height accurately using single-baseline polarimetric synthetic aperture radar interferometry （PollnSAR） data. CLSA basically estimates both volume-only coherence and ground phase directly without assuming that the ground-to-volume amplitude radio of a particular polarization channel （e.g., HV） is less than -10 dB, as in the three-stage method. In addition, CLSA can effectively limit errors in interferometric complex coherence, which may translate directly into erroneous ground-phase and volume-only coherence estimations. The proposed CLSA method is validated with BioSAR2008 P-band E-SAR and L-band SIR-C PollnSAR data. Its results are then compared with those of the traditional three-stage method and with external data. It implies that the CLSA method is much more robust than the three-stage method.展开更多
文摘本研究以饲料桑新品种‘川饲桑1号’(Morus alba cv.Chuansisang-1)为试验材料,采用二因素随机区组设计连续3年(2016-2018)对不同刈割高度(H_(1):70 cm,H_(2):90 cm,H_(3):110 cm)和施氮量(N1:138 kg N·hm^(-2),N2:207 kg N·hm^(-2),N3:276 kg N·hm^(-2))下的饲草产量、植物学特性及营养品质进行测定,并对其饲用价值进行综合评价,以期为饲料桑的推广利用提供数据支撑。结果表明,随着年限的增加各处理下饲草产量逐年递增,且均以H2N3处理最高。刈割高度与施氮量对饲料桑产量、植物学特性和营养品质均有影响。其中,刈割高度是影响饲料桑植物学特性的主要因素,两者交互作用对饲草产量、单枝重及各营养指标影响显著(P<0.05)。在相同刈割高度下,鲜、干草产量和中性洗涤纤维均以N_(3)处理最高,粗蛋白含量随施氮量的增加先增加后减小。在相同氮肥用量下,H_(2)处理下的大部分饲草产量、主枝叶片数、单株重最大,中性洗涤纤维和酸性洗涤纤维含量整体随刈割高度的增加而增大。粗蛋白和粗灰分含量整体在H_(2)高度下最高,粗脂肪含量随刈割高度增加呈先升高后降低的趋势。以隶属函数法对‘川饲桑1号’的饲用价值进行综合评价可知,在刈割高度为90 cm、施氮量为276 kg N·hm^(-2)时其饲用价值最高。
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51974012 and 51804017)the National Key Research and Development Program of China(No.2018YFC0604602)+1 种基金the Fundamental Research Funds for the Central Universities,China(No.FRF-BD-19-005A)the Opening Fund of State Key Laboratory of Nonlinear Mechanics(No.LNM202009).
文摘A series of laboratory investigations are conducted to analyze the effect of flocculant type on the spatial morphology and microstructural characteristics of flocs during the flocculation and settling of tailings.Four flocculant types(i.e.,ZYZ,JYC-2,ZYD,and JYC-1)are considered in this study.The fractal characteristics and internal structures of tailings flocs with different flocculant types and settlement heights are analyzed by conducting scanning electron microscopy and X-ray micro-computed tomography scanning experiments based on the fractal theory.Results show that unclassified tailings flocs are irregular clusters with fractal characteristics,and the flocculation effect of the four flocculant types has the following trend:ZYZ>JYC-2>ZYD>JYC-1.The size and average grayscale value of tailings flocs decrease with the increase in settlement height.The average grayscale values at the top and bottom are 144 and 103,respectively.The settlement height remarkably affects the pore distribution pattern,as reflected in the constructed three-dimensional pore model of tailings flocs.The top part of flocs has relatively good penetration,whereas the bottom part of flocs has mostly dispersed pores.The number of pores increases exponentially with the increase in settlement height.By contrast,the size of pores initially increases and subsequently decreases with the increase in settlement height.
文摘Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.
基金supported by the National Basic Research Program of China(Grant No.2013CB733303)National Natural Science Foundation of China(Grant Nos.41274010,41371335)supported by PA-SB ESA EO Project Campaign of"Development of methods for Forest Biophysical Parameters Inversion Using POLIn SAR Data"(Grant No.ID.14655)
文摘In this paper, we propose the novel method of complex least squares adjustment （CLSA） to invert vegetation height accurately using single-baseline polarimetric synthetic aperture radar interferometry （PollnSAR） data. CLSA basically estimates both volume-only coherence and ground phase directly without assuming that the ground-to-volume amplitude radio of a particular polarization channel （e.g., HV） is less than -10 dB, as in the three-stage method. In addition, CLSA can effectively limit errors in interferometric complex coherence, which may translate directly into erroneous ground-phase and volume-only coherence estimations. The proposed CLSA method is validated with BioSAR2008 P-band E-SAR and L-band SIR-C PollnSAR data. Its results are then compared with those of the traditional three-stage method and with external data. It implies that the CLSA method is much more robust than the three-stage method.
