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Incorporating shape constraints in generalized additive modelling of the height-diameter relationship for Norway spruce

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Forest Ecosystems 2016年第2期3卷 112-125页

作者： natalya Pya Matthias Schmidt Department of Mathematics School of Science and TechnologyNazarbayev University The Northwest German Forest Research Station Department of Forest Growth

Background： Measurements of tree heights and diameters are essential in forest assessment and modelling. Tree heights are used for estimating timber volume, site index and other important variables related to forest growth and yield, succession and carbon budget models. However, the diameter at breast height （dbh） can be more accurately obtained and at lower cost, than total tree height. Hence, generalized height-diameter （h-d） models that predict tree height from dbh, age and other covariates are needed. For a more flexible but biologically plausible estimation of covariate effects we use shape constrained generalized additive models as an extension of existing h-d model approaches. We use causal site parameters such as index of aridity to enhance the generality and causality of the models and to enable predictions under projected changeable climatic conditions. Methods： We develop unconstrained generalized additive models （GAM） and shape constrained generalized additive models （SCAM） for investigating the possible effects of tree-specific parameters such as tree age, relative diameter at breast height, and site-specific parameters such as index of aridity and sum of daily mean temperature during vegetation period, on the h-d relationship of forests in Lower Saxony, Germany. Results： Some of the derived effects, e.g. effects of age, index of aridity and sum of daily mean temperature have significantly non-linear pattern. The need for using SCAM results from the fact that some of the model effects show partially implausible patterns especially at the boundaries of data ranges. The derived model predicts monotonically increasing levels of tree height with increasing age and temperature sum and decreasing aridity and social rank of a tree within a stand, The definition of constraints leads only to marginal or minor decline in the model statistics like AIC An observed structured spatial trend in tree height is modelled via 2-dimensional surface fitting. Conclusions： We

关键词： Height-diameter curve Norway spruce Shape constrained additive models Impact of climate change,Varying coefficient models

Influence of friction on buckling of a drill string in the circular channel of a bore hole

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Petroleum Science 2016年第4期13卷 698-711页

作者： Valery Gulyayev natalya Shlyun Department of Mathematics National Transport UniversityKiev Ukraine

Enhancement of technology and techniques for drilling deep directed oil and gas bore hole is one of the most important problems of the current petroleum *** infrequently, the drilling of these bore holes is attended by occurrence of extraordinary situations associated with technical accidents. Among these is the Eulerian loss of stability of a drill string in the channel of a curvilinear bore hole. Methods of computer simulation should play a dominant role in prediction of these states. In this paper, a new statement of the problem of critical buckling of the drill strings in 3D curvilinear bore holes is proposed. It is based on combined use of the theory of curvilinear elastic rods, Eulerian theory of stability, theory of channel surfaces, and methods of classical mechanics of systems with nonlinear constraints. It is noted that the stated problem is singularly perturbed and its solutions have the shapes of localized harmonic wavelets. The calculation results showed that the friction effects lead to essential redistribution of internal axial forces, as well as changing the eigenmode shapes and sites of their localization. These features make the buckling phenomena less predictable and raise the role of computer simulation of these effects.

关键词： Directed bore hole Drill string Critical states Singular perturbation Friction forces Harmonic wavelet

Positron Spectroscopy of Free Volume in Poly(vinylidene fluoride) after Helium Ions Irradiation

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Chinese Journal of Polymer Science 2019年第5期37卷 527-534页

作者： Jin-Zhe Lyu Roman Laptev natalya Dubrova Division for Experimental Physics School of Nuclear Science & EngineeringNational Research Tomsk Polytechnic University

Free volume is an extremely important intrinsic defect in polymers. Structurally, free volume is the randomly distributed holes in the polymer molecular chain segments. In proton exchange membrane fuel cells, free volume is also the space needed for the directional conduction of protons. Irradiation by α particles to grafting sulfonated poly(vinylidene fluoride)(PVDF) is one of the methods to produce proton exchange membrane with good proton channel rate. Positron annihilation lifetime spectroscopy was used to study the free volume size at different absorbed dose levels from 0.13 MGy to 0.65 MGy. Measurement method of positron annihilation lifetime spectroscopy for PVDF based on ^(44) Ti positron source was developed. For low dose irradiation at 0.26 MGy, a decrease in free volume and practically unchanged crystallinity were observed. Further increase of absorbed dose range from 0.26 MGy to 0.39 MGy led to an increasing crystallinity with the same free volume level. For the absorbed dose from 0.39 MGy to 0.65 MGy, crystallinity was decreased but free volume remained almost constant.

关键词： Positron annihilation Free volume XRD Poly(vinylidene fluoride) Helium ions Connection Degradation

Surgical techniques for the management of male infertility

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Asian Journal of Andrology 2012年第1期14卷 94-102,177页

作者： natalya A Lopushnyan Thomas J Walsh Department of Urology University of Washington Seattle WA 98195 USA

Evaluation and surgical treatment of male infertility has evolved and expanded, now leading to more precise diagnoses and tailored treatments with diminished morbidity and greater success. Surgeries for male infertility are divided into four major categories：（i） diagnostic surgery; （ii） surgery to improve sperm production; （iii） surgery to improve sperm delivery; and （iv） surgery to retrieve sperm for use with in vitrofertilization and intracytoplasmic sperm injection （IVF-ICSI）. While today we are more successful than ever in treating male infertility, pregnancy is still not always achieved likely due to factors that remain poorly understood. Clinicians treating infertility should advocate for couple-based therapy, and require that both partners have a thorough evaluation and an informed discussion before undergoing specific surgical therapies.

关键词： male infertility testis varicocele

Russian school of the theory and geometry of gearing： Its origin and golden period （1935-1975）

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Frontiers of Mechanical Engineering 2016年第1期11卷 44-59页

作者： Dmitry BABICHEV Sergey LAGUTIN natalya BARMINA Department of Applied Mechanics Tyumen State Oil and Gas University Tyumen 625000 Russia Electrostal Plant of Heavy Machine Engineering Electrostal City144012 Russia Institute of Mechanics Kalashnikov Izhevsk State Technical Universitylzhevsk 426069 Russia

During the second half of the twentieth century, Soviet scientists were among the world leaders in the theory and geometry of gearing or the theoretical fundamentals of designing gears and gear-cutting tools. The authors of the current paper review works related to the development of the theory of gearing （TG） written in Russian from the mid-1930s to the present. Overall, the review covers more than 400 publications of nearly 200 authors （among more than 1000 studied works）. This review involves some works on gear strength and accuracy to attract more experts. This paper presents a short list of works from the seventeenth century to the nineteenth century and discusses the basic concepts of the TG. This paper also includes a review of more than 160 papers in Russian for the period of 1935-1975, which is the ＂golden age＂ of the TG. The main features and achievements during this period are also considered. The distinctive feature of this review is the use of diagrams that visually present TG experts and the dates and themes of their published works. The diagrams also show the following aspects： 1） The most popular and important themes in a specific period, 2） the most important publications on the themes of interest to readers, and 3） the direction of the works and scope of interests of every researcher.

关键词： theory of gearing (TG) gear geometry,generating surface gear synthesis gear analysis

Fine structure and phase composition of Fe–14Mn–1.2C steel:influence of a modified mixture based on refractory metals

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International Journal of Minerals,Metallurgy and Materials 2017年第5期24卷 523-529页

作者： Anna Zykova natalya Popova Mark Kalashnikov Irina Kurzina Tomsk Polytechnic University Tomsk State University of Architecture and Building Chemical Department Tomsk State University

The effect of TiO;,ZrO;and Na;AlF;ultrafine powders on the fine structure and the phase composition of Fe–14Mn–1.2C steel was *** introduction of the ultrafine powders into the melt influenced the grain size,the quantity,and the character of distribution of nonmetallic inclusions in the railroad *** microstructure of castings was improved significantly because of the refinement of the grain structure and an increase of the grain-boundary *** the modifying mixture was introduced into the melt,either the microtwins of one or two intersecting systems or the precipitations of ε-martensite of different types,or simultaneously the microtwins and wafers of ε-martensite,were present in each grain.

关键词： manganese steel fine structure phase composition refractory metals

Contribution of pancreatic enzyme replacement therapy to survival and quality of life in patients with pancreatic exocrine insufficiency

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World Journal of Gastroenterology 2019年第20期25卷 2430-2441页

作者： Peter Layer Nataliya Kashirskaya natalya Gubergrits Department of Internal Medicine Israelitic HospitalHamburg 22297Germany Department of Genetic Epidemiology (Cystic Fibrosis group) Federal State Budgetary Institution “Research Centre for Medical Genetics”Moscow 115522Russia Department of Internal Medicine Donetsk National Medical UniversityLyman 83001Ukraine

The objective of this study was to analyze the current evidence for the use of pancreatic enzyme replacement therapy (PERT) in affecting survival and quality of life in patients with pancreatic exocrine insufficiency (PEI). Systematic searches of the literature were performed using the PubMed database. Articles were selected for inclusion if they reported findings from trials assessing the effects of PERT on quality of life, survival, malabsorption, growth parameters (such as height, body weight and body mass index), or gastrointestinal symptoms (such as abdominal pain, stool consistency and flatulence). PERT improved PEI-related malabsorption and weight maintenance in patients with cystic fibrosis, chronic pancreatitis, pancreatic cancer, and post-surgical states. In patients with chronic pancreatitis, PERT improved PEI-related symptoms and quality of life measures. Several small retrospective studies have also suggested that PERT may have a positive impact on survival, but long-term studies assessing this effect were not identified. PERT is effective for treating malnutrition and supporting weight maintenance, and it is associated with improved quality of life and possibly with enhanced survival in patients with PEI. However, there is evidence that not all patients with PEI receive adequate PERT. Future work should aim to assess the long-term effects of PERT on the survival of patients with PEI.

关键词： Pancreatic exocrine insufficiency Pancreatic enzyme replacement therapy Survival Quality of life Malabsorption Cystic fibrosis Chronic pancreatitis Pancreatic cancer Post-surgical states

Impact of aridization on soil cover transformation of the Aral Sea and the modern Syr-Darya Delta

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Journal of Arid Land 2011年第2期3卷 150-154页

作者： Tomina Tatyana KONSTANTINOVNA Azhikina natalya ZHEKSEMBAEVNA Kazakh Research Institute of Soil Science and Agrochemistry named after Uspanov

The effects of human activities on the soil cover transformation in the eastern part of Kazakhstan were investigated during the period of *** results of the research for different soil types in Priaralye indicated that there was 643.3×103 hm2 solonchaks,accounting for 38.5 % of the total area（1670.5×10^3 hm^2） in *** areas are occupied with dried lakeshore soil（311.1× 10^3 hm^2）,sandy soils（147.6×10^3 hm^2） and grey-brown desert soils and solonetzes（146.7×10^3 hm^2）.In 2001 the area of solonchak was 755×103 hm2 and decreased to 643.3×10^3 hm^2 in 2008,which due to the shrinkage of the Aral Sea,the areas of marsh and lakeshore solonchaks decreased with the increase of dried bottom of the Aral *** level of soil cover transformation in the modern delta of the Syr-Darya River can be seen from the comparison of the results obtained from the different years in the study *** area of solonchaks increased by 10×10^3 hm^2 and the area of alluvial-meadow salinizied soils increased by 17.9×10^3 hm^2 during the period of *** means that many non-salinizied soils were transformed into salinizied *** changes occurred in the structure of soil cover as a result of ***,the researches in1969 significantly determined the areas of hydromorphic soils subjected to desertification（it was not fixed on the map before 1956）.Later,these soils were transformed into takyr-like *** area of takyr-like soils increased almost by 3 times for 34 years（from 1956 to 1990）.The long-term soil researches on soil cover transformation in Priaralye have shown that the tendencies of negative processes（salinization and deflation） are being kept and lead to further soil and eco-environment degradation in the region.

关键词： soil transformation aridization Aral Sea Syr-Darya Delta

Morphology and biology of Cyclops scutifer Sars, 1863 in high mountain lakes of East Siberia (including Lake Amut)

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Chinese Journal of Oceanology and Limnology 2017年第2期35卷 258-264页

作者： natalya G. SHEVELEVA Mydygma Ts. ITIGILOVA Ayushcuren CHANANBAATOR Institute of Limnology Siberian Branch of Russian Academy Science Ulan-Batorskaya 3 lrkutsk 664033 Russian Federation Institute of Natural Resources Ecology and Cryology Siberian Branch of Russian Academy Science Nedorezova 16a Chita 672014 Russian Federation Institute of Biology Mongolian Academy of Science Pr. Zhukova Ulan-Bator 210351 Mongolia

Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among *** July,its abundance comprised 64%-98%of the total plankton fauna in the pelagial of these lakes,approximately 30%in the littoral zone and10%in small northern thermokarst *** measurements and morphological descriptions based on scanning microscope images are supplemented by the data on its geographic distribution and phenology.

关键词： high mountain lakes Cyclops scutifer morphology biology distribution