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Search Results: 1 - 10 of 279243 matches for " 李纪鹏 "
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黑龙江省玉米产业发展策略
The Development Strategies of Maize Industry in Hei-longjiang Province
 [PDF]

胡洪林, 刘清海, 夏艳龙, 张阔, , 庭锋, 高锦荣
Hans Journal of Agricultural Sciences (HJAS) , 2013, DOI: 10.12677/HJAS.2013.33011
Abstract: 黑龙江省玉米单产增长缓慢,收获时籽粒水分含量高,粮食流通产业不健全导致玉米种植业效益低,本文对此提出了应对策略:1) 实现玉米生产全程机械化;2) 基于全程机械化确定品种熟期标准化;3) 构建黑龙江省现代粮食流通产业。
In Heilongjiang Province, the slow growth of maize per unit area yield, high moisture content of grain at the harvest and distemperedness of the grain circulation industry contribute to the low efficiency of maize planting industry. And this paper proposed coping strategies: 1) Realizing full mechanization in maize production; 2) Confirming mature period of standardization based on the whole process of mechanization; 3) Constructing the modern grain circulation industry in Heilongjiang Province.



NiO/Al体系绝热温度的数值计算与试验验证
宋月,江涛,裴 军,文文
复合材料学报 , 2010,
Abstract: 根据热力学基本原理,通过计算机编程,对NiO/Al体系的绝热温度进行了数值计算。结果表明,预热温度低于2790K时,体系绝热温度即为产物Ni的沸点温度(3156K),对体系进行预热仅仅是提高产物Ni的蒸发量;同时,研究表明,稀释剂Al2O3粉末的添加量在一定的范围内对体系的绝热温度没有影响,这些温度与生成物的相变温度相对应。
恒壁温条件下水平管内气固两相对流传热
成雷,菊香,,涂善东
华东理工大学学报 , 2011,
Abstract: 对恒壁温加热条件下水平管内空气-煤粉混合物的两相对流传热进行了数值模拟和试验研究。数值模拟结果表明:壁面总传热量和壁面与固体粉末间的传热量都随着固相颗粒直径的增大而减少、随着煤粉体积率的增大而增大,而固相颗粒直径和煤粉体积率对壁面与气体间的传热量的影响不大;对流传热的Nusselt数(Nu)随着Reynold数(Rem)的增大而增大,且大Rem时的增大趋势更快;对流传热的Nu随煤粉体积率基本成线性变化。根据数值模拟提出的恒壁温条件下气固两相对流传热Nu的关联式,与试验结果具有较好的一致性。
含锡铁素体不锈钢的开发及性能研究
,,姜周华,方勇
东北大学学报:自然科学版 , 2014, DOI: 10.3969/j.issn.1005-3026.2014.09.014
Abstract: 基于新型含锡铁素体不锈钢,采用冶金反应平衡对其冶炼过程进行实验室条件下的研究,对其室温力学性能、耐腐蚀性能进行了研究,同时分析Sn对铁素体不锈钢基体的微观结构的影响规律,分析脱氧夹杂物的形貌和成分演变.研究结果表明,尽管锡的熔点极低,其收得率较高,锡在硫化物周围的富集现象明显;含锡铁素体不锈钢性能优于SUS430不锈钢,具有较好的塑形和强度,可满足深冲加工性能的要求,而耐腐蚀性能明显优于SUS430铁素体不锈钢,可部分代替其在生产中的应用.
特殊线性群(37)3L和 (11)32L的最短共轭类刻画
余大,金宝,,张良才
重庆师范大学学报(自然科学版) , 2015, DOI: 10.11721/cqnuj20150529
Abstract: 利用群的数量特征刻画有限单群很有意义。利用群的阶及最短共轭类长刻画了素因子个数为6和7的两个有限非交换单群。证明了特殊线性群(37)3L和(11)32L是可用群的阶及最短共轭类长来刻画的。
铝热剂燃烧合成Y_3Al_5O_(12)块体材料传热过程的模拟与验证
文文,宋月,江涛,冯媛媛
硅酸盐学报 , 2010,
Abstract: 采用自蔓延合成技术制备了钇铝石榴石(Y3Al5O12,YAG)陶瓷块体材料。利用ANSYS软件的瞬态热分析功能,对压块传热和传质过程进行了模拟与实验验证;在此基础上,结合压块燃烧过程温度场的模拟结果,对铝热剂燃烧合成YAG块体的相结构形成过程进行了分析研究,对不同点燃方式下(区域点火、面点火)压块传热过程进行了模拟。研究表明模拟结果与实验结果吻合较好,从而验证了该模拟方法及物性参数选择的可靠性;淬熄后压块不同区域内的组织结构和成分分布存在较大差异,表明自蔓延燃烧合成YAG材料过程中,压块的传热、传质及点火方式对燃烧速度及物相的形成具有显著影响。
应用于采空区失稳预报的声发射差量比指标
, 张红军, 欧阳治华,
金属矿山 , 2014,
Abstract: 鄂东地区中小型矿山数量众多,采空区失稳事故频发,实现采空区准确有效的预警预报已成为鄂东地区重点研究内容之一。结合鄂东地区声发射监测应用现状,提出差量比指标,该指标综合考虑了一段期间声发射大事件、总事件及能率3项参数,有效减少外界干扰、地质条件不同及采空区结构差异造成的声发射监测参数波动影响。通过对比采空区岩体失稳声发射参数累计值的变化,得出了对应的声发射差量比指标的一般变化规律及失稳前兆特征,利用声发射差量比指标,不仅能合理有效分析采空区稳定性状态,还能简单准确地根据差值比前兆特征对采空区失稳时间进行预测。将声发射差值比指标应用于鄂东地区普民铁矿采空区稳定性分析,预测评判结果与现场实际情况一致,说明该指标评判方法具有一定的适用性和合理性。
含锡不锈钢溶质偏析模型计算
,,姜周华,何盼
- , 2015, DOI: 10.12068/j.issn.1005-3026.2015.04.011
Abstract: 摘要 结合微观偏析模型及Thermo-calc软件,考虑了MnS的析出,用微观偏析理论研究了含锡铁素体不锈钢中溶质的偏析行为.主要讨论了铁素体不锈钢中C,Mn,S,P,Cr在凝固过程中的偏析程度,研究了溶质偏析对零强度温度(ZST)、零塑形温度(ZDT)的影响规律.分析了锡在铁素体钢和低碳钢中偏析行为的差异,解释了低碳钢的热加工塑形凹槽现象,理论分析了微量元素对热塑性的影响.结果表明,Sn的凝固偏析比远大于除P,S外的其他元素,Mn对S元素凝固偏析有抑制作用.锡为易偏析元素,其在奥氏体相中的凝固偏析比大于在铁素体相中的偏析比.
Abstract:Combined a micro-segregation model with Thermao-calc software, the segregation condition of tin-containing ferritic stainless steel was studied in which the precipitation of MnS was considered. The effects of C, Mn, S, P, and Cr on the interdendritic segregation, zero strength temperature (ZST), and zero ductility temperature (ZDT) of steel were discussed. The segregation of tin in ferritic steel and low-carbon steel was analyzed, the plastic trough phenomenon in the hot-working process of low-carbon steel was explained and the improvement of plasticity by adding tin was studied. The results showed that the segregation ratio of Sn is much higher than that of other elements except for P and S, and Mn restrains the solidification segregation of S. Tin trends to segregate to grain boundary and the segregation ratio of tin in austenite is much higher than that in ferrite.
甘蓝型油菜与黑芥双倍体减数分裂的原位杂交分析
In situ hybridization analysis on meiosis of Brassica napus and Brassica nigra amphiploids

,生强,刘显军,
- , 2016,
Abstract: 【目的】探明植物杂种后代减数分裂异常与花粉败育之间的关系。【方法】通过甘蓝型油菜与黑芥种间杂交和基因组加倍,获得芸薹属三基因组双倍体,采用基因组原位杂交方法,观察三基因组双倍体花粉母细胞的减数分裂规律。【结果】与单倍体相比,双倍体花粉育性得到一定恢复,但可育花粉的比例较低,只有10%~20%。基因组原位杂交结果显示,双倍体花粉母细胞减数分裂终变期染色体以形成同源二价体为主,但也有部分染色体形成四价体或六价体。四价体有3种形式:B基因组染色体形成的四价体、AC基因组染色体形成的四价体及B与AC基因组之间形成的异配四价体。减数分裂后期Ⅰ染色体均等分离的细胞占总数的70%左右,在第2次减数分裂期也观察到非正常分裂如非四分孢子、微核等现象。【结论】减数分裂过程中的染色体异常行为可能是导致花粉育性不高的重要原因;虽然不正常的减数分裂导致花粉育性下降,但双亲染色体的异源联会可为双亲遗传物质的交换提供条件。
【Objective】This study investigated the relationship between abnormal meiosis and pollen fertility of plant hybrid offspring. 【Method】Trigenomic amphiploids between Brassica napus and Brassica nigra were obtained by interspecific hybridization and genome doubling.Genomic in situ hybridization (GISH) was carried out to observe chromosome behavior in meiosis of pollen mother cells (PMC) of the amphiploids.【Result】Pollen fertility of the amphiploids was determined and majority of pollen grains was sterile with fertile ratio of 10%-20%.Multivalents were formed as quadrivalents and hexavalents at diakinesis.The quadrivalents included autosyndetic quadrivalents of B genome,AC genomes and allosyndetic quadrivalents betwee B and AC genomes.The hexavalents also appeared in amphiploids at very low frequencies.Total chromosomes were segregated equally at about 70% PMCs at anaphase Ⅰ.At the end of second stage of meiosis,non-tetrads and micro-nucleus were also observed.Some abnormalities including chromosome bridges and laggards were observed at low frequency in some PMCs at anaphase Ⅱ/Ⅱ.【Conclusion】The non-diploidized cytological behavior of these amphiploids contributed to their low fertility.Although abnormal meiosis decreased pollen fertility,heterologous recombination improved exchange of genetic materials between parents
多帧速度场估计方法及在交通视频监测中的应用
房桂英,,,邹大
公路交通科技 , 2006,
Abstract: 基于速度场的运动估计方法是进行运动物体分割的有效途径,提出了一种视频图像处理中基于多帧速度场的运动物体分割方法,针对简单速度场运动物体分割方法的不足,提出对多帧速度场图像提取的运动物体信息相融合的方法。试验结果证明用此方法提取的运动物体核心点更完备,提高了运动物体分割的准确性。该方法在智能交通、视频监控系统中都有广泛应用。
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