检索结果-南通市图书馆

Learning from regularized regression algorithms with p-order Markov chain sampling

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2011年第3期26卷 295-306页

作者： ZHANG Jing wang jian-li SHENG Bao-huai Department of Mathematics Shaoxing College of Arts and Sciences Shaoxing 312000 China.

Evaluation for the performance of learning algorithm has been the main thread of theoretical research of machine learning. The performance of the regularized regression algorithm based on independent and identically distributed（i.i.d.） samples has been researched by a large number of references. In the present paper we provide the convergence rates for the performance of regularized regression based on the inputs of p-order Markov chains.

关键词： p-order Markov chain uniformly ergodic learning rate.

Direct hydrothermal synthesis and magnetic property of titanate nanotubes doped magnetic metal ions

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第5期15卷 644-648页

作者： Meili wang Gongbao Song jian li Landong Miao Baoshu Zhang School of Materials Science and Engineering Southwest University of Science and Technology Mianyang 621002 China

Pure titanate nanotubes and titanate nanotubes doped with Fe^3＋/Ni^2＋/Mn^2＋ ions were synthesized by the hydrothermal method. In this process,titanate nanotubes were first prepared synchronously with doping Fe^3＋/Ni^2＋/Mn^2＋ ions. The morphology,structure,thermal stability and magnetic property of titanate nanotubes were characterized by X-ray diffraction （XRD）,transmission electron microscope （TEM）,and magnetic measurement. The titanate nanotubes transformed into the anatase titania nanocrystals,and further the mixture of anatase and rutile titania along with increasing temperature. The results indicate that the titanate nanotubes doped with Fe^3＋/Ni^2＋/Mn^2＋ ions are paramagnetic behaviors.

关键词： titanate nanotubes direct hydrothermal synthesis doping magnetic property

在线全文

学校读者我要写书评

暂无评论

干旱胁迫对苜蓿种子萌发的影响

饲料研究 2024年第9期47卷 89-92页

作者：王晓龙杨曌来永才柴华李莎莎徐艳霞吴玥王建丽黑龙江省农业科学院畜牧兽医分院黑龙江齐齐哈尔161005 黑龙江省农业科学院博士后科研工作站黑龙江哈尔滨150086 黑龙江省农业科学院草业研究所黑龙江哈尔滨150086

研究旨在筛选出适宜干旱、半干旱地区种植的苜蓿品种。选取5个苜蓿品种为试验材料,采用聚乙二醇(PEG)模拟干旱胁迫(10%、15%和20%)处理,测定苜蓿种子发芽率、发芽指数、简化活力指数和抗旱指数,并利用隶属函数对供试苜蓿材料的抗旱性进... 详细信息

研究旨在筛选出适宜干旱、半干旱地区种植的苜蓿品种。选取5个苜蓿品种为试验材料,采用聚乙二醇(PEG)模拟干旱胁迫(10%、15%和20%)处理,测定苜蓿种子发芽率、发芽指数、简化活力指数和抗旱指数,并利用隶属函数对供试苜蓿材料的抗旱性进行评价。结果显示,随着PEG胁迫加剧,供试苜蓿种子的发芽率、发芽指数、简化活力指数及抗旱指数均呈现降低的变化趋势。重度(20%PEG)胁迫下,龙牧801的发芽率、发芽指数及抗旱指数最高,且显著高于其他品种(P草原3号>WL168HQ>赛特>赛迪。研究表明,龙牧801和草原3号的抗旱性较强,适宜干旱、半干旱地区种植。

关键词：苜蓿萌发期抗旱性隶属函数法

维普期刊数据库博看期刊

Incomplete fingerprint recognition based on feature fusion and pattern entropy

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第3期20卷 121-128页

作者： ZHANG Jie JING Xiao-jun CHEN Na wang jian-li School of Information and Communication Engineering Beijing University of Posts and Telecommunications Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education Beijing University of Posts and Telecommunications

Considering the inherent characteristics of incomplete fingerprint： local feature loss and global information distortion, the recognition progress has been mainly restricted by two critical problems： how to precisely extract informative features and still with compact representation of the incomplete fingerprint; and how to effectively measure the similarity between fingerprint images. In this paper, to handle the first problem, both the minutiae and orientation field feature are extracted and then fused to get a more comprehensive feature with scale and rotation invariability. Dealing with the second one, the pattern entropy is introduced to robustly measure the similarity of two incomplete fingerprints. Extensive experiments have been conducted on both those popular fingerprint databases and our extended databases containing more incomplete fingerprints. Meanwhile, thorough performance comparisons have been made with existing approaches. Experimental results show that our approach has more efficient ability especially in incomplete fingerprint recognition, and also performs well in both accuracy and efficiency.

关键词： incomplete fingerprint recognition feature fusion pattern entropy similarity measurement

在线全文

学校读者我要写书评

暂无评论

龙菁1号紫花苜蓿新品种的选育

饲料研究 2024年第12期47卷 134-138页

作者：王建丽牟林林庄煦张冬梅尤佳邸桂俐王晓龙韩微波黑龙江省农业科学院草业研究所黑龙江哈尔滨150086 黑龙江省农业科学院经济作物研究所黑龙江哈尔滨150086 黑龙江省农业科学院畜牧兽医分院黑龙江齐齐哈尔161005

试验为解决寒区优质紫花苜蓿种质资源匮乏的难题,以抗寒、高产为育种目标,2002年起对9个国内外紫花苜蓿品种经过混合单株选择法及四代田间表型混合选择,选育龙菁1号紫花苜蓿品种。结果显示:在品种比较试验中,龙菁1号紫花苜蓿的干草产量... 详细信息

试验为解决寒区优质紫花苜蓿种质资源匮乏的难题,以抗寒、高产为育种目标,2002年起对9个国内外紫花苜蓿品种经过混合单株选择法及四代田间表型混合选择,选育龙菁1号紫花苜蓿品种。结果显示:在品种比较试验中,龙菁1号紫花苜蓿的干草产量、越冬率和粗蛋白含量最高,分别为10920.2 kg/hm^(2)、95.2%、19.22%;在区域试验中,龙菁1号紫花苜蓿在吉林白城地区的干草产量(11866.18 kg/hm^(2))最高;在生产试验中,与龙牧803、WL323HQ相比,龙菁1号紫花苜蓿在杜蒙地区的干草产量(10088 kg/hm^(2))最高。研究表明,龙菁1号紫花苜蓿品种的耐寒性、干草产量、粗蛋白含量均优于龙牧803和WL323HQ,是适合东北寒区人工草地建植、退化草原改良、粮改饲和草田轮作的优质牧草。

关键词：龙菁1号紫花苜蓿新品种选育抗寒干草产量

Synthesis, Crystal Structure and Biological Activity of 2-Chloro-N-{2-fluoro-5-[N-(phenylsulfonyl) phenyl-sulfonamido]phenyl}benzamide

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2008年第3期24卷 295-298页

作者： li Wen-ming wang jian-guo li Zheng-ming SONG Hai-bin Elemento-Organic Chemistry Institute State Key Laboratory of Elemento-Organic Chemistry National Pesticide Engineering Research Center Nankai University Tianjin 300071 P R. China

2-Chloro-N-{2-fluoro-5-[N-（phenylsulfonyl）phenylsulfonamido]phenyl}benzamide was synthesized and its crystal structure was also determined by X-ray single-crystal diffraction. The title compound（C25H18ClFN2O5S2） belongs to monoclinic, space group P21/n with a=0.7377（3） nm, b=1.2036（5） nm, c=2.6846（11） nm, β=90.895（9）°, V=2.3833（16） nm3, Mr=544.98, Z=4, Dc=1.519 g/cm3, μ=0.385 mm–1, F（000）=1120, R1=0.0632, and wR2=0.1438. Its crystal structure belongs to a novel class that has not been reported yet, and its preliminary herbicidal activity was also tested. Its inhibition rate to seedling growth of barnyard grass reaches 15.1% at 100 μg/mL.

关键词： X-ray diffraction Crystal structure Synthesis Biological activity

Glucocorticoid receptor expression in neonatal rat cortex following recurrent seizures The role in developing brain injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2010年第2期5卷 146-149页

作者： Tao Bo Lu Yi Tuanmei wang jian li Xingfang li Dingan Mao Department of Pediatrics Second Xiangya Hospital Central South University Changsha 410011 Hunan Province China

BACKGROUND： Studies have explored changes in neonatal rat glucocorticoid receptor （GR） expression changes following mature brain injury. OBJECTIVE： To investigate the temporal and special changes of GR during brain development in rats with recurrent seizures. DESIGN, TIME AND SE＇n＇ING： A randomized, controlled animal experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central South University, from February 2008 to March 2009. MATERIALS： Rabbit anti-rat GR monoclonal antibody was purchased from Santa Cruz Biotechnology, USA; goat anti-rabbit IgG was purchased from Zhongshan Goldenbridge Biotechnology, China. METHODS： A total of 48 Sprague-Dawley rats, 7 days old, were randomly assigned to control and seizure groups, with 24 animals in each group. Seizures were induced by inhalant flurothyl. MAIN OUTCOME MEASURES： Changes in GR protein expression in the rat cerebral cortex were detected by Western blotting analysis and immunohistochemistry. RESULTS： GR expression in the cerebral cortex of control rats significantly increased with aging （P 〈 0.05）, and varied in the frontal lobe, temporal lobe, and parietal lobe. GR was predominantly expressed in the cytoplasm early and rapidly increased in the nuclei. GR protein expression in the cerebral cortex after seizure was lower in the cytoplasm at 15 days and in nuclear protein at 19 days. CONCLUSION： GR expression displayed temporal and spatial changes in brain development. Recurrent seizures in neonatal rats cause abnormal GR expression and might play an important role in developing brain injury.

关键词： seizure neonatal glucocorticoid receptor brain development rats

Novel Fréchet-type dendritic BINOL ligands and their applications in Ti(IV) complex catalyzed asymmetric addition of diethylzinc to aldehydes

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第12期18卷 1487-1489页

作者： liang Yin Chao Feng wang Huan ling wang Rong li jian Tai Ma College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 China

New Frechet-type dendritic BINOL ligands bearing several BINOL units at the periphery have been successfully synthesized. The （dendritic BINOL） Ti（IV） complexes were proved to be efficient catalysts for the enantioselective addition of diethylzinc to aromatic aldehydes. Moreover, these ligands could be quantitatively recovered and reused at least five times without a loss of the yield and enantioselectivity.

关键词： Asymmetric catalysis BINOL Aldehydes

Hydrometallurgical purification of metallurgical grade silicon

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2009年第3期28卷 221-225页

作者： MA Xiaodong ZHANG jian wang Tongmin li Tingju State Key Laboratory of Materials Modification School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

The effects of the particle size of ground metallurgical grade silicon （MG-Si）, the sort of acids, and the type of stirring on the purified efficiency of MG-Si were investigated. It was found that a particle size less than 0.1 mm was most effective for acid leaching; the extraction yield of impurities was increased by 9% with HF leaching compared with HCl leaching and HNO3 leaching, and increased by 7% with ultrasonic stirring compared with mechanical stirring. The principle of hydrometallurgical purification of metallurgical grade silicon under ultrasonic fields was also discussed.

关键词： metallurgical grade silicon ultrasonic field acid leaching metallic impurities