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Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences最新文献

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Translation-invariant Gibbs measures of a model on Cayley tree Cayley树模型的平移不变Gibbs测度
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-25 DOI: 10.56017/2181-1318.1011
G. Botirov
{"title":"Translation-invariant Gibbs measures of a model on Cayley tree","authors":"G. Botirov","doi":"10.56017/2181-1318.1011","DOIUrl":"https://doi.org/10.56017/2181-1318.1011","url":null,"abstract":"","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116675193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Electron exchange between impurity centers of tin in PbS and PbSe 锡在PbS和PbSe中杂质中心之间的电子交换
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-25 DOI: 10.56017/2181-1318.1015
S. Zaynabiddinov, K. Bobokhujaev
{"title":"Electron exchange between impurity centers of tin in PbS and PbSe","authors":"S. Zaynabiddinov, K. Bobokhujaev","doi":"10.56017/2181-1318.1015","DOIUrl":"https://doi.org/10.56017/2181-1318.1015","url":null,"abstract":"Electron exchange between neutral and doubly ionized U -minus centers of tin in par-tially compensated solid solutions Pb1−xSnxS and Pb1−xSnxSe has been investigated using 119mmSn(119mSn) emission Mössbauer spectroscopy. The activation energy of the process for Pb1−xSnxS solid solutions is 0.11±0.02 eV and is comparable to the depth of energy levels of tin in the PbS band gap, while the activation energy of this process for Pb1−xSnxSe solid solutions is comparable to the activation energy of donor U -minus centers of tin in PbSe being 0.05 ± 0.01 eV. The exchange has been performed by the simultaneous transfer of two electrons with the use of the valence band states.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131480249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Thermal evolution modification due to radio-wave production inside rotating magnetized NS 旋转磁化NS内无线电波产生的热演化变化
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-09 DOI: 10.56017/2181-1318.1039
P. Tadjimuratov
{"title":"Thermal evolution modification due to radio-wave production inside rotating magnetized NS","authors":"P. Tadjimuratov","doi":"10.56017/2181-1318.1039","DOIUrl":"https://doi.org/10.56017/2181-1318.1039","url":null,"abstract":"We study effect of additional cooling mechanism on the thermal evolution of rotating magnetized neutron star (NS). The influence of general relativistic effects on charge distribution inside a NS leads to the qualitative distinction of space charge distribution inside the conducting crust from that inside the super-conducting core which may play a source of a possible mechanism of radio-wave radiation production in the intermediate medium inside a rotating neutron star. This radiation may interact the matter of the neutron star and energy of the electromagnetic radiation can be transformed into the heating energy. The intensity of radio-wave radiation produced inside NS and its relation for the relaxation time of cooling of the rotating magnetized neutron star in the curved space-time are estimated. The relaxation time of cooling of the rotating mag-netized neutron star is essentially increased by heating arisen by the interaction of the generated electromagnetic radiation with the conducting matter of the neutron star crust. New suggested physical mechanism for the heating energy of the radio-wave radiation is proposed and some estimates on.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127563453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The extent of destruction of landscapes in the Tashkent region 塔什干地区景观的破坏程度
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-09 DOI: 10.56017/2181-1318.1045
S. Sharipov, Kamoliddin Khakimov, Davronbek Boymurodov
{"title":"The extent of destruction of landscapes in the Tashkent region","authors":"S. Sharipov, Kamoliddin Khakimov, Davronbek Boymurodov","doi":"10.56017/2181-1318.1045","DOIUrl":"https://doi.org/10.56017/2181-1318.1045","url":null,"abstract":"The article points to those parts of landscape of the Tashkent region that have become unfit for use in the economy destroyed lands and their extension as a result of natural and anthropogenic factors.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125371155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The optimal risk of estimator of conditional distribution function in a model of heteroscedastic regression with weakly dependent observations 弱相关异方差回归模型中条件分布函数估计量的最优风险
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-09 DOI: 10.56017/2181-1318.1041
F. Abdikalikov, Laura Reymova
{"title":"The optimal risk of estimator of conditional distribution function in a model of heteroscedastic regression with weakly dependent observations","authors":"F. Abdikalikov, Laura Reymova","doi":"10.56017/2181-1318.1041","DOIUrl":"https://doi.org/10.56017/2181-1318.1041","url":null,"abstract":"","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129187732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Creation of a numerical mathematical model of geofiltration processes and its adaptation for solving epignosic and forecast problems (in terms of Gurlen District of Khorezm Region) 创建地质过滤过程的数值数学模型，并将其用于解决地震和预报问题(以Khorezm地区的Gurlen地区为例)
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-09 DOI: 10.56017/2181-1318.1042
Tolkun Mirakhmedov
{"title":"Creation of a numerical mathematical model of geofiltration processes and its adaptation for solving epignosic and forecast problems (in terms of Gurlen District of Khorezm Region)","authors":"Tolkun Mirakhmedov","doi":"10.56017/2181-1318.1042","DOIUrl":"https://doi.org/10.56017/2181-1318.1042","url":null,"abstract":"The article considers the creation of a mathematical model of geofiltra-tion processes in Gurlen District. Methods for calculating and developing a mathematical model and algorithms were carried out, and applied software was developed, and the developed geofiltration mathematical model was adapted to solve the epignosic and forecast problems of the area under consideration","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129777494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Amidoalkylation of aromatic compounds 芳香族化合物的氨基烷基化
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-09-09 DOI: 10.56017/2181-1318.1040
M. Yuldasheva, K. Turaeva, Tursunali Kholiqov
{"title":"Amidoalkylation of aromatic compounds","authors":"M. Yuldasheva, K. Turaeva, Tursunali Kholiqov","doi":"10.56017/2181-1318.1040","DOIUrl":"https://doi.org/10.56017/2181-1318.1040","url":null,"abstract":"As the result of systematical investigation of amidomethylation reaction benzene, toluene, isomeric xylenes, benzodioxane-1,4, monoand dimethyl ethers of resorcinole, dimethyl ethers of hydroquinone with methylol and ethylol derivatives amides and imides, acetonitrile, benzonitrile and paraform the amidomethyl derivatives have been obtained and also influence of different factors on their yields and direction of investigated reactions was determined. Synthesis of amidomethyl derivatives of aromatic hydrocarbons, ethers dihydricpenols and most probable reaction mechanism was proposed.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130930495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Neuro-fuzzy identification of nonlinear dependencies 非线性相关性的神经模糊辨识
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-06-25 DOI: 10.56017/2181-1318.1020
A. Marakhimov, K. Khudaybergenov
{"title":"Neuro-fuzzy identification of nonlinear dependencies","authors":"A. Marakhimov, K. Khudaybergenov","doi":"10.56017/2181-1318.1020","DOIUrl":"https://doi.org/10.56017/2181-1318.1020","url":null,"abstract":"The paper proposes a fuzzy multilayer perceptron (MLP) and a modified algorithm for its training for solving problems of identification of nonlinear dependencies. The obtained results show a sharp reduction in the search for the optimal parameters of the neuro-fuzzy model compared to classical MLP and increase its accuracy. In the work, questions of optimization of the rule base of the neuro-fuzzy model are also investigated and the temporal and spatial complexity of the proposed algorithm is analyzed. The results of computational experiments show that the number of training epochs has sharply decreased, and productivity has increased compared to the well-known MLP models.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134128894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Formation of the database in the history of development of geodesy and cartography science (an example of Medieval East) 大地测量学与地图学发展史上数据库的形成(以中世纪东方为例)
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-06-25 DOI: 10.56017/2181-1318.1038
E. Safarov, Sunnatilla Uvrayimov, K. Bekanov
{"title":"Formation of the database in the history of development of geodesy and cartography science (an example of Medieval East)","authors":"E. Safarov, Sunnatilla Uvrayimov, K. Bekanov","doi":"10.56017/2181-1318.1038","DOIUrl":"https://doi.org/10.56017/2181-1318.1038","url":null,"abstract":"In the study of the history of science, scientific activity in the Eastern countries of the Middle Ages emphasized the contribution of foreign thinkers to the development of Geodetic and cartographic Sciences, and the study is one of the topical issues of Science today. The article highlights the role of the Geoinformation database in the history of the development of Geodesy and cartography, the database available in the Middle Ages, their importance on the path of science fiction. In addition, there was an opinion on the use of data and the methods of their processing. In the work, the cartographic scientific work of the Greek scientist Ptolemy and the eastern thinker Al-Khwarizmi was studied separately and the views on science were emphasized on the basis of that. As a result, the differences between the two maps, which are shown below, and in similar aspects, are discussed. In general, there are still many subjects that need to be studied and opened on this topic, as well as research work. And their study from the point of view of Geodesy and cartography remains one of the urgent tasks of specialists in the field today.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114732648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Extraction conductometric determination of scandium and thorium in kaolins 萃取电导法测定高岭土中钪和钍
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences Pub Date : 2018-06-25 DOI: 10.56017/2181-1318.1035
Nigora Kutlimurotova, Z. Smanova, Habibulla Tojimuhamedov, Z. Yaxshiyeva, Jasur Tursunqulov
{"title":"Extraction conductometric determination of scandium and thorium in kaolins","authors":"Nigora Kutlimurotova, Z. Smanova, Habibulla Tojimuhamedov, Z. Yaxshiyeva, Jasur Tursunqulov","doi":"10.56017/2181-1318.1035","DOIUrl":"https://doi.org/10.56017/2181-1318.1035","url":null,"abstract":"A method for extraction conductometric determination of scandium and thorium with tributyl phosphate and trioctyl phosphine oxide in kaolin was developed. The equivalent electrical conductivity of the complex of scandium and thorium with 2,7-dinitrozo-1,8-dihydroxynaphthalene-3,6-disulfonic acid was found. A scheme for the separation and determination of kaolin content is proposed. The isotherms of scandium and thorium extraction are constructed. It was shown that at a concentration of nitric acid of 15.6 M they do not interfere with the determination of thorium and scandium.","PeriodicalId":127023,"journal":{"name":"Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115479054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
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