bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnosing elementary teacher’s misconceptions of gravity
Authors: Desstya A , Prasetyo Z K , Suyanta
Published: January 2021

Gravity is one of the important concepts in elementary school. The teachers must understand it well without misconceptions. Furthermore, it is obvious that research on elementary teacher misconceptions of this concept is rarely done. The goal of this study was to describe the elementary school teacher’s misconceptions of gravity. This was a qualitative research. The study was conducted on 30 public and private elementary school teachers in Surakarta. The test was used as data collection instrument consist of 3 true false questions with reasons. The teacher was to be a misconception if the justification of a statement was true, the discussion was wrong. The result indicated that 30% of teachers experienced misconceptions. They stated that objects on earth were not thrown into space due to the earth’s magnetic force. Tides were caused by the rotation of the moon around the earth and the evaporation of water. Parachutists with closed parachutes fall faster because the earth’s gravity was not obstructed. These indicated the need for efforts to improve teacher professionalism so that the quality of learning was better.
Rigorous Thinking in Mathematics Modelling for Slow Learners
Authors: Setyawan F , Andriyani  , Handayani Tri Kinasih , Ratih Koesoemo , Sutopo Anam , Rusli Tri Indah , Alfiany Nur Rizky
Published: January 2021

Rigorous questions in discussion learning method plays a dominant role in the successful delivery of lessons for slow learners at higher education. This study aims to propose a framework to achieve good critical thinking for slow learners through Rigorous Mathematics computational Thinking (RMcT) model. This study used qualitative approach to describe slow learner’s critical thinking by using RMcT model. The instruments used in this study were test instrument, critical thinking questionnaire, and interview guideline as supporting instrument to describe slow learner’s critical thinking through RMcT model. The subjects were college students in mathematics modelling course in mathematics education department. Based on critical thinking test results, slow learners could divide variable used in mathematics modelling. Based on questionnaire results, slow learner students build their own understanding and solve the problem based on their experience while answering the given question during learning process. In addition, the interview they feel that the instructor can mediated the problem by giving analogy to the other material. In summary, RMcT could mediate slow learner’s critical thinking as its characteristics (by using Rigorous questions). Findings are useful for designers, service providers and policy makers of special needs higher school when implementing teaching strategy to mediated real-life problems into mathematics modelling for slow learners.
PISA Problems Solving of Students with a Visual Learning Styles
Authors: Machromah Isnaeni Umi , Ishartono Naufal , Mirandhani Angie , Muhroji  , Samsudin Muh. , Basry Wahiduddin , Ernitasari
Published: January 2021

Mathematics’ problem on PISA measures students’ ability of reasoning, problem solving and argument. So far, students are not well trained in solving PISA problems. Therefore it is necessary to know the ability to solve mathematical problems to be taken into consideration in providing questions that are similar to PISA questions. This study aims to describe students’ ability to solve mathematical problems oriented to PISA on space and shape content. This type of research is a qualitative descriptive study. The subjects of this study were students who have visual learning styles. The instruments in this study involves PISA mathematics question about space and shape content and student learning style questionnaires. The data analysis techniques used were data reduction, data presentation, and conclusion. In obtaining data validity, researchers used sources triangulation. The results of this study show that students with a visual learning style understand the problem systematically and clearly by determining the known and unknown of the data. At devising a plan phase, students could find the connection of the given diagram and they have constant character. At the carrying out the plan, students solve the problem coherently. At the looking back phase, students did not recheck every steps on problem solving as they confident with their answer.
Ethnomathematics: Mathematics in Batik Solo
Authors: Faiziyah Nuqthy , Khoirunnisa’ Mufti , Azizah Navia Nur , Nurrois Muhammad , Prayitno Harun Joko , Desvian  , Rustamaji  , Warsito
Published: January 2021

All people in the world have their culture in living the life. These culture is built of activities they do every day in a long time. Batik is one of traditional art of Indonesia’s cultural heritage. It has many varieties, one of them is Batik Solo. It also has many motifs. Ethnomathematics is a study about culture and mathematics concepts. This research is to explore Batik Solo and to find the mathematics concept in it. Using ethnography method, the data collection uses principles in ethnography namely observation, interview, and documentation. The results of the research in this article are twofold. Some Batik Solo motifs contain mathematical elements, especially geometric material, namely the principles of translation and reflection. Besides, that there are vertical and horizontal lines as well as perpendicular and parallel lines included. The mathematical concept, especially the geometry used in the making of Batik, is the use of the tessellation or tiling principle. The tessellation principle is the basis for the development of the Solo batik motifs.
Developing Mathematics Learning Kits Using the RME Approach for Students of Marine Vocational High School
Authors: Ralmugiz Uke , Merliza Pika , Sari Desy Kumala , Yusuf St Muthmainnah , Zulfikar Ryan Nizar
Published: January 2021

This study aims to produce a mathematics instructional kits for students of Marine Vocational High School using Realistic Mathematics Education (RME) approach and oriented to mathematics reasoning, connection, and curiosity which is valid, practical, and effective. This study was a research and development study. It developed instructional kits using Plomp development model which consisted of three main steps, that is: (1) preliminary research, (2) development or prototyping phase, and (3) assessment phase. The subjects of the study were 28 students of grade X in Marine Major class of SMK Negeri 7 Kupang. The validity of the instruments used was a validation sheet. The practicality of the instruments used was a teacher assessment sheet, students assessment sheets, and observation sheets of learning implementation. Then, the effectiveness of the instruments consisted of a test for measuring students’ reasoning and connection, meanwhile a questionnaire was to measure students’ curiosity. Data analysis was conducted by converting quantitative data of assessment scores, students’ scores of test, and questionnaire to qualitative data. This research resulted mathematics learning kits for students of Marine Vocational High School using Realistic Mathematics Education approach and oriented to mathematics reasoning, connection, and curiosity in the form of lesson plan and student worksheet which have met the criteria of validity, practicality, and effectiveness.
Probalistic Thinking Based on Probabilistic Thinking Responses to Math Problem Solving
Authors: Hidayati Yulia Maftuhah , Afifah Nurul , Nurhidayat  , Fuadi Djalal , Apuanor  , Wiguna Alivermana , Waluyo Muhammad
Published: January 2021

The objective of the study is to describe the fourth-grade students’ probabilistic thinking response of SD State Elementary 4 Kaliwuluh, Karanganyar regency, Central Java, Indonesia to math solving the problem of geometry. It used a qualitative approach. The results of the study show that the students’ responses were in four categories. Their non-response responses were difficult to understand questions and so that they guested their answers. In the non-statistic responses, they could solve their answers self-confidently. In the partial statistic response, they related the materials obtained, but they did not use a proper concept. In the statistic responses, they could relate the answers by using a mathematical concept and count systematically.
Gifted Children’s Mathematical Reasoning Abilities on Problem-Based Learning and Project-Based Learning Literacy
Authors: Abidin Z , Sutama  , Herman T , Jupri A , Farokhah L , Apuanor  , Sonedi
Published: January 2021

This article describes gifted children’s mathematical reasoning abilities. They have a natural talent that must be facilitated, namely reasoning. In mathematics, problem-based learning, project-based learning literacy and Inquiry are learning models commonly used. Mathematics learning can improve the ability of mathematical reasoning because children are required to think logically. The research method was quantitative with the randomized pretest-posttest control group design. This research was conducted in three special classes of gifted children. The results showed that the reasoning of gifted children who obtained problem-based learning was better than gifted children who received other learning. It was caused by activities that always present problems contextually with everyday life. Then, gifted children were still required to be problem solvers by conducting in-depth investigations and collaborating with friends. Gifted children who get project-based learning literacy have good mathematical reasoning skills. It was because gifted children were required to make literacy work oriented to the mathematical problems presented. Furthermore, gifted children who obtain inquiry learning have a middle ability. Gifted children were asked to find mathematical concepts so that learning is meaningful.
Comparative Study of Switched Capacitor Converter Topologies for Wearable Devices
Authors: Do Wanglok , Eguchi Kei
Published: January 2021

As wearable devices with low input voltages have drawn much attention from academic and industrial fields, the use of switched capacitor converters (SCC) also increases. This is because the wearable devices are required to utilize small size power converters and SCCs have no bulky circuit components such as magnetic components. Many kinds of SCCs have been suggested but they are based on three fundamental SCC topologies that are Dickson, series-parallel and Fibonacci topologies. In this study, three topologies are theoretically analyzed and simulated. With the results from them, a comparison is conducted to provide future circuit designers with a standard to choose a proper SCC topology for wearable devices.
Optimization of Filter and Operational Amplifier Based on Evolutionary Strategy
Authors: Lu Tengteng , Luo Chao , Xu Jun , Guo Guoping
Published: January 2021

Optimization of analog circuits relies on engineers’ experience and intuition to find suitable parameters to satisfy circuit specifications. This job is highly labor-intensive, highly repetitive, and time-consuming, but the optimized circuit is sub-optimal. In this paper, the evolutionary strategy is proposed to optimize analog circuit design strategy. The filter designed by engineers and operational amplifier with random generated instances’ parameters are included, and the S parameters of the filter and the gain and dynamic power consumption of the operational amplifier are optimized respectively. The simulation results show that the filter and operational amplifier can be further optimized by using the evolutionary strategy. This method can greatly reduce the workload of analog circuit designers, improve the performance of analog circuits and shorten the design cycle.
FPGA Implementation of 3-bit Quantized CNN for Semantic Segmentation
Authors: Miyama Masayuki
Published: January 2021

Semantic segmentation is a task of inputting an image and performing category classification for each pixel. Semantic segmentation by CNN has high accuracy but its calculation using floating-point numbers consumes a large amount of power. We adopted UNET as the semantic segmentation CNN and improved it for FPGA implementation. We quantized both weights and activations of the network up to 3-bit. Then, we devised a dedicated hardware architecture for the quantized CNN and implemented it on an FPGA. This circuit uses only internal memory to perform forward propagation calculations, that eliminates high-power external memory accesses. This circuit is a stall-free pixel-by-pixel pipeline, and performs 8 rows, 16 input channels, 16 output channels, 3 by 3 pixels convolution calculations in parallel. The convolution calculation performance at an operating frequency of 300 MHz is 11 TOPs/s.
Experimental Examination of Component-Differentially-Challenged XOR PUF Circuits
Authors: Mursi Khalid T. , Zhuang Yu
Published: January 2021

Physical unclonable functions (PUFs), leveraging tiny physical variations of the circuits to produce unique responses for individual PUF instances, are emerging as a promising class of hardware security primitives for resource-constrained IoT devices. Component-differentially-challenged XOR PUFs (CDC XPUFs) are among the PUFs which were shown to be highly secure to machine learning modeling attacks. However, no study of implementation and experimentation has been carried out. In this paper, we report our implementations of CDC XPUFs on FPGAs and experimental studies of the essential properties of CDC XPUFs.
A Hybrid-Optimizer-Enhanced Neural Network Method for the Security Vulnerability Study of Multiplexer Arbiter PUFs
Authors: Mursi Khalid T. , Thapaliya Bipana , Zhuang Yu
Published: January 2021

With the advent of the Internet of Things, security has become indispensable. Physical unclonable functions (PUFs) are emerging as a promising alternative to classical cryptographic algorithms as it provides a lightweight and cost-effective solution for implementing a keyless security mechanism. Before adopting a PUF for real-world applications, a thorough examination of all important properties of PUF is necessary, and security and reliability are two of the important properties. The multiplexer based PUF (MPUF) was recently designed to improve upon the reliability while maintaining a similar resistance to machine learning (ML) attacks as compared with XOR PUFs of certain sizes. Recently, feed-forward neural network (NN) methods were found to be an effective tool for studying PUFs’ security against ML attacks, and a study in 2019 found that some MPUFs are insecure against NN attack methods. In this paper, we try to gain further insight into various factors of NNs that affect the predictive power of NN as PUF attack methods. We investigate a NN that employs different optimizers at different stages of the machine learning process, leading to what is called a hybrid-optimizer-enhanced NN. We implemented the new NN for ML attack of MPUFs, and experimental results have shown it converges faster than a traditional NN with a single optimizer on attacking MPUFs, and the new method also requires less training data as compared with a recent NN-based attack study of MPUFs.
HISTORY AND GEOGRAPHY OF THE RUSSIAN ARCTIC IN THE DOMESTIC TRAVELOGUE
Authors: Sukhorukov V D , Gladkiy Yu N , Grigor’ev A A , Paranina A N
Published: January 2021

Historical and geographical information about the Arctic were being accumulated gradually. The starting point here can be considered the ancient myths of Hyperborea as the northern ancestral home of mankind. However, only in the X century the Europeans (Normans) were in the circumpolar part of the world. The Russians came to the Arctic in the XII century and established themselves in the territories called “Pomor’e” (the lands from Karelia to the Northern Urals). Active promotion of our ancestors on the Asian coast of the Arctic took place in the XVII-XVIII centuries. Further study and development of this region unfolded in the XIX-XX centuries. The modern historical stage – the time of intensive development of the Arctic. Many successes have been achieved by scientists, engineers, prospectors, and numerous enthusiasts. The names of the most outstanding Arctic conquerors have not only received scientific and public recognition but are also immortalized on geographical maps in the names of seas, straits, islands, bays, coasts, capes, cities, towns and other objects.

Despite the harsh nature, the Arctic was and remains an integral part of the world’s Ecumene. This testifies to the indissoluble unity of man with the surrounding reality, connections with which have no restrictions. In fact, there is a constantly expanding and deepening dialogue of people with the external environment and among themselves. The result of this existence is the comprehension of man himself and his being. The most important condition for this communication is the ability of the individual to master and learn the world, appreciate the surrounding space and exchange exchange the received information. At the same time, the feeling of life’s reality occurs not so much in the given mode, as in the field of active communications.

Mass and individual tourism, which has covered the whole world, is now a widespread communicative practice instead of former trips and expeditions. Travelogue as a genre of stereoscopic narration of experiences and a special type of reporting has become a cognitive response of modern “wanderers” to the impressions received from their trips. The authors of the article analyze the content of this concept in the research meaning and experimental application to the Arctic.
Distribution of Polychaete Communities along the Novaya Zemlya Archipelago
Authors: Dikaeva D R
Published: January 2021

The species composition and quantitative characteristics of polychaete communities have been analyzed along the western coast of the Novaya Zemlya archipelago based on the materials collected in the expeditions of Murmansk Marine Biological Institute (MMBI) in 2006, 2007, and 2019. Three faunistic complexes have been identified in the study area in accordance to the changing environmental conditions northwards along the western coast of the Novaya Zemlya. The species composition and structure of polychaete communities depended on the structure of bottom sediments, depth, and the hydrodynamics of the near-bottom water layer. The polychaete fauna of the studied area has been compared with the literature data; particularly, we have observed as well the dominance of the detritus feeder Spiochaetopterus typicus, which role increased in the deep water areas on silty sands and silty clays rich in detritus. In the area of the Novaya Zemlya shallow waters, unfavorable habitat conditions for the detritus-feeders existed on rough sands with active hydrodynamics, which led to a decrease in the biomass of polychaetes and to a change in the dominant species
Ecological and geographical features of the true bugs (Heteroptera) fauna of the Japanese elm communities in the lower reaches of the Selenga River
Authors: Sofronova E V
Published: January 2021

Japanese elm (Ulmus japonica Rehder) grows in the Baikal Region in the lower reaches of the Selenga River and forms refugia of nemoral biota where many rare and relict species of plants, fungi, bryophytes, lichens and invertebrate animals are found. Refugia of nemoral biota represent an important object to study environmental conditions of the Baikal Region in the past geologic epochs, as they are slightly changing ecosystems. Comprehensive research of elm communities, including qualitative and quantitative studies of insects, is required to fully understand functioning of these refugia and develop measures for their protection. The study summarizes data on 29 true bug species of 24 genera and 10 families, which inhabit closely in the Japanese elm communities. Polyphytophagous species prevalent in the investigated fauna, mixotrophic species also make significant contribution. Carnivores and species with more specific nutritional adaptation are significantly less numerous. As for distribution pattern, species with Trans-Eurasian and Trans-Palaearctic ranges prevail, individual species have Siberian-Far-Eastern and European-Siberian ranges. Species diversity of true bugs is significantly lower in the depths of dense elm forests than at the edges of the communities, especially in place of contact with open habitats. Some Heteroptera species which are typical of the genus Ulmus and live on a different species (U. pumila) in the Baikal Siberia, are not found on the Japanese elm, which confirms distinctness of these communities.
Landscape-hydrochemical aspects of geoecological monitoring
Authors: Semenov Yu M , Semenov M Yu , Silaev A V , Snytko V A
Published: January 2021

A comprehensive geoecological monitoring program is implemented in the Lake Baikal basin. The methodology is guided by the principle of mixing. Identification of anthropogenic sources of substance and observation of connections between them and environmental objects occurs by considering objects as a mixture, and sources as their components, using landscape monitoring approach. The main research methods are landscape science and hydrochemistry. The pollution structure of geosystems is revealed by analyzing the spatial-temporal distribution of pollutants and subsequent reconstruction of their composition from sources. A cartographic basis has been developed to substantiate the observation and control network, extrapolate the monitoring results and represent operational information about the geosystem state. The mapping procedure is based on the main provisions of the teaching about geosystems by V.B. Sochava. We mapped differentiation, migration and accumulation of pollutants using modern methods of geoinformation analysis and modeling, adapted to the research region and analyzed the main parameters of landscape-geochemical differentiation of the Lake Baikal basin. A zoning scheme for the territory according to the ability to provide a specific composition of waters has been compiled. The ability of surface waters of the basin to self-purification is estimated. An approach for the conjugate assessment of the permissible pollution load on aquatic and terrestrial ecosystems is developed.
The current state of the water and bottom sediments in the Irkutsk Reservoir
Authors: Karnaukhova G A , Shtel’makh S I
Published: January 2021

We present the results of the study on the state of the water and bottom sediments in the Irkutsk Reservoir for the period from 1976 to 2018. This reservoir is the main in the cascade of the Angara River reservoirs. It belongs to shallow artificial reservoirs with high flow. The Irkutsk Reservoir receives the basic water supply from Lake Baikal, which serves as its summit pound. We have determined that the composition of the water and bottom sediments in the reservoir depends on the elemental composition of the rock composing its eroded banks as well as on the water flowing from Lake Baikal. Based on the concentrations of the main elements, the water in the reservoir after 60 years of its operation corresponds to potable water standards. The water pollution coefficient for all elements, especially for Pb and Mn, slightly exceeded the MPC values at the sites of Nikola (Baikal water) and Solnechny (near the dam of the Irkutsk Hydroelectric Power Station). Based on the pollution coefficients, the bottom sediments are at the level of the geochemical background of the rocks composing the south of the Siberian platform. The geochemical parameters of the water and bottom sediments indicate that the Irkutsk Reservoir belongs to water bodies with the low anthropogenic pressure.
An assessment of the regional development well-being taking into account the environmental component
Authors: Glazyrina I P , Zabelina I A
Published: January 2021

The paper presents the results of socio-ecological and economic well-being estimation of the Russian regions using a multiplicative model, based on the A. Sen extended function. This model includes GRP per capita, share of the personal incomes in GRP, the regional cost of living index, the intra-regional income inequality and the integrated environmental index. It is defined as average of the specific environmental indices calculated on the basis of the following indicators: the share of the negative air, water and soil tests. Calculations have revealed that there is a significant interregional differentiation in the level of social well-being. The inclusion of the environmental component into the multiplicative model had a significant impact on the results of a comprehensive assessment of regional development. In some Russian regions, the environmentally adjusted level of well-being was significantly lower than the indicator that does not take this aspect into account. It is shown that the role of the environmental factors in the quality of life in the East of Russia is quite significant. The research novelty is to take into account the environmental component in assessing the well-being of the regions using a multiplicative model, based on the A. Sen extended function. The analysis results can be used in the process of making management decisions in the field of environmental and economic interactions, as well as in the preparation of strategic documents for sustainable regional development.
The experience in the implementation of adaptive-landscape systems of agriculture in Rostov Oblast
Authors: Gaevaya E A , Bezuglova O S , Ilinskaya I N , Taradin S A , Nezhinskaya E N , Mishchenko A V
Published: January 2021

The goal of the adaptive-landscape organization of the territory is to ensure effective protection of soils from degradation under the anthropogenic impact. The experiment was performed in the permanent study area located on the slope of the Bolshoi Log clough, Aksay District of Rostov Oblast from 2016 to 2019. The use of adaptive-landscape territory organization of the slope prone to erosion allowed reducing soil erosion by 35-43%. The use of soil protection treatments as the main tillage reduced soil erosion by more than 13-24%. For this, it is provided on arable lands prone to erosion and poorly eroded areas with a degree of the slope from 2 to 3°, an extended complex of agrotechnical measures is applied. Crop rotation with 40% of perennial grasses, 20% of row crops, and 40% of winter and spring grain crops is recommended. Productivity is up to 3.9 t/ha of grain units when applying manure in a dose of 5 tons and mineral fertilizers, N46P24K30, ensuring the preservation of soil fertility at the initial level. With a 1.5-fold increase in organic fertilizers (manure at a dose of 8 tons and mineral fertilizers, N84P30K48), productivity increases to 4.3 t/ha of grain units, and humus content increases to 4.1% (or 7.8%).
Climate, natural environment and the life support system of the Tungus: cultural and ecological aspects
Authors: Ragulina M V
Published: January 2021

The article considers the features of the influence of natural and climatic conditions on life support of the Tungus (Evenks) in the 18th-19th centuries. During the period under review they lived in forest-steppe, taiga and mountain-taiga natural landscapes, surrounded by a sedentary Russian and semi-nomadic Buryat population. The Tungus were distinguished by ensoulment of nature, close vital connection of landscape, worldview and economy. We have drawn on the regularities of climate variability and its influence on the society of Siberia reported in the literature. Then we selected data and analyzed them from the standpoint of historical geography, cultural anthropology and intrasecular climate change. Chronicles on the ice regime of the Angara river in Irkutsk from 1721 to 1921 were used for the reconstruction of climatic fluctuations. During the study period the life support systems of the Tungus was to adapt to the natural and social changing in the context of multiethnic environment of the region. Although the available data have been preserved fragmentarily and do not represent continuous series of information, the content from folklore, chronicles, statistics, archive documents and observations of contemporaries confirm the influence of intrasecular climatic variability on Evenks. The related hunger years, crop failures, epidemics, fluctuations in the volume of biological resources affected all groups of the population. The diversity of neighboring cultures and geographic conditions, as well as their dynamics, contributed to the formation of specifics in the Tungus economy and different rates of their acculturation.
Big business in the Baikal Region
Authors: Ippolitova N A , Grigoryeva M A
Published: January 2021

The nature of interaction between big business and territory is one of the most important indicators of the development of economy and society. The interest of big business in the regions of Siberia, including the Baikal region, is caused by the availability of a sufficient amount of natural and economic resources. Resource-extracting assets and enterprises of the first redistribution, which operate in Irkutsk oblast, the Republic of Buryatia and the Zabaikalskii Krai, which make up the Baikal region, are of particularly interest to big business. The work considers the territorial and organizational structure of big business in the Baikal region. The sectoral heterogeneity and uneven localization of big business objects in the territory of the Baikal region are shown. We analyzed the level of investment for urban districts and municipal districts geographically and identified five groups of territories where large business is present. The resources-based development combined with system-forming industries prevails in the intraregional structure of big business. The paper presents significant investment projects carried out by big business structures in the Baikal region. It is noted that, despite the current existing challenges caused by unfavorable socio-economic and natural conditions, the territories, especially those specializing in the extraction of minerals, are dependent on the investment policy of large companies.
Mapping of the current state of forest vegetation in the north Baikal Region based on the merging of remote sensing data and ground observations
Authors: Vladimirov I N , Kobylkin D V , Sorokovoy A A
Published: January 2021

Geoinformation analysis and modeling study of the current state of vegetation (as exemplified by the southeastern macroslope of the Baikal Range, Eastern Siberia) were performed. The phytocenoses of the territory differ from each other in many features, namely in projective cover, ratio of ecological groups, confinement to landforms, epiterranean phytomass, etc. These details help to interpret the types of plant communities based on the values of the calculated vegetation index. We proposed a technique that assumes the joint use of the NDVI and NDWI indices, a digital elevation model (DEM) based on SRTM radar topographic survey data, forest inventory data and materials from field expeditions. The use of the DEM and the indices reflecting the physiological state of vegetation considering their availability of chlorophyll and water helps to arrange the communities under study into groups determined by moisture conditions and biomass supply. To determine the species composition of forest stand, we proposed a method based on the Boolean logic-a decision tree-a schematic representation in the form of a tree structure of a complex decision-making process used in a multi-step analysis. The results obtained show that the use of the relationship between the ratio of plant communities to the moisture factor and their spectral characteristics, taking into account the use of DEMs, enables us to create very informative maps, to improve the reliability of interpretation of satellite information, and to map territories not covered by ground-based surveys with the use of interpolation.
Synoptic processes over the Kodar glacier zone during the ablation period
Authors: Osipova O P , Osipov E Y
Published: January 2021

The small glaciers of the Kodar ridge (south of Eastern Siberia), located inland Asia under the influence of both Atlantic and Pacific air transport, are the valuable objects for studying their response to changes in mid-latitude atmospheric circulation. However, detailed meteorological studies on the glaciers have been limited so far. For the first time, in July–August 2019, the meteorological characteristics were measured on the Sygyktinsky glacier using automatic weather station. We have analyzed the relationship between variations of large-scale atmospheric circulation and meteorological regime of the glacier using the NCEP–NCAR reanalysis data. During the observation period, Kodar was under the influence of a positive geopotential anomaly in the lower troposphere, which determined increased temperatures and decreased relative humidity and precipitation. Quasi-cyclic fluctuations in meteorological time series (e.g. air temperature) reflect the influence of large scale synoptic changes caused by the front passages, warm and cold air advections. High ablation rates on the glacier were associated with anticyclones, subtropical ridges, and warm air advections (from southeast and southwest), while decreased ablation was observed during the cyclone passage and cold air advection (from north, northeast, and west).
Pine radial growth in the Trans-Baikalian steppe and taiga zones as a reflection of the climatic parameters and lake hydrological regime dynamics
Authors: Vakhnina I L , Zamana L V
Published: January 2021

The paper presents the results of the annual rings width research of the trunk test core sampled from standing common pines. The purpose of the research is the analysis of the ability to use the radial recruitment changes of the trees growing in different natural zones for further reconstruction and prognosis of the climatic variables and lake hydrological regime. It was revealed that the dynamics of annual rings width in the steppe zone is characterized by the maximum values of the standard deviation and sensitivity to environmental factors in comparison with taiga zone trees. The radial growth of trees in the steppe zone shows a significant positive reaction to atmospheric precipitation and a negative reaction to air temperature from May to October. The influence of meteorological parameters on the annual growth of pine in the taiga zone is less considerable. The analysis of the synchronicity of changes in pine increments in the steppe zone with interannual fluctuations in the water level of Lake Barun-Torey due to the climatic conditions dynamics showed the significant correlation; therefore, the maximum correlation is observed with lake reaction lag for 4-5 years. Dendrochronological analysis of trees in the taiga zone (Baikal-Stanovoye Upland) revealed only a weak correlation with the average annual level of Lake Bount in the current year. Thus, the tree-ring chronology based on pines of steppe zone can be used for retrodiction of the hydrometeorologic elements.
Study on the stability and rheological properties of nitrogen foam under high-pressure condition
Authors: Chen Danqi , Cui Shiti , Liu Zhiliang , Xu Zhengxiao , Li Binfei
Published: January 2021

After a period of exploitation of carbonate fractured-vuggy reservoir, the water content of oil well keeps increasing, and some wells appear violent water flooding in a short period of time, which leads to the rapid decrease of production. The injection of particle plugging agent is one of the main measures to improve the oil recovery. Foam fluid has the characteristics of low density, high viscosity and low moisture filtration, which can effectively carry plugging particles to the target plugging layers. A stable foam system with high temperature and salinity is optimized and the rheological properties of the foam are studied in this research. The results show that the foam can maintain high viscosity and carry particles effectively even at a higher shear rate.
Method for Determining Lowest Oil Price Limit by Developing Tight Peripheral Oil in Daqing
Authors: Zhu Haihui
Published: January 2021

The outer oil field of Daqing is a low-permeability oil field, which has a large proportion of the tight oil reserves. Due to the high development costs of the tight oils, many fields are difficult to reach the standard of economic evaluation. It increases the difficulty in optimizing reserves and use of reserves. In the process of the development of the tight oil field, it is important to determine the limit of starting oil price. It is also an important basis for determining the launch of the oil field development project. The evaluation of present value method does not consider the change process of external conditions and has certain limitations. However, the introduction of investment option value method for evaluation can fully consider changes in oil prices and other external factors, and provide a more realistic assessment of the oilfield development process. In the case of low oil prices, some tight oil fields can also be used effectively, which improves the efficiency of resource utilization, increases the scale of reserves utilization, and solves the problem of optimization and evaluation of reserves.
Application of “direct method” in the evaluation of CBM resources in old goaf of Nanzhuang Coal Mine
Authors: Wang Ran
Published: January 2021

With the cessation of mining in Nanzhuang Coal mine, the amount of gas extraction decreases, and the utilization rate of coalbed methane decreased significantly. Many coalbed methane resources exist in the old goaf after years of mining, which has a very high utilization value, Therefore, it is necessary to estimate the reserves of coal-bed methane in goaf before mining. Based on the geology and production data of No.12 coal seam of Nanzhuang Coal Mine, the application of direct method in Nanzhuang coal mine is explored. The total amount of geological gas in No.12 coal seam was about 159,496,100 m3, among which, the total amount of free gas was about 20,637,100 m3.
Walking-Type Bidirectional Incremental Launching and Mid-Span Closure Technology for Steel Box Girders with Long Cantilevers
Authors: Wang Kai , Lu Wei , Zhang Zhongbiao
Published: January 2021

Unidirectional incremental launching is not applicable for the incremental launching construction of large-span bridges owing to the span capacity of steel box girders is restricted by the cantilever length and the setting of temporary piers. Aiming at the limitation, by taking Qingdao (Shandong Province)–Lanzhou (Gansu Province) expressway bridge crossing over the main canal in the South-to-North Water Diversion Project as the engineering background, a key construction technique, that is, bidirectional incremental launching and mid-span closure of steel box girders with long cantilevers was proposed. On this basis, the walking-type incremental launching device system and the technique of bidirectional incremental launching and mid-span closure were explored and also a finite element analysis model was established to compute the pre-camber. Moreover, the results of the alignment control of structures during the construction were compared and analyzed. The research result showed that during the construction using bidirectional incremental launching and mid-span closure, it was unnecessary to set the steel launching nose and it was able to greatly improve the span capacity of steel box girders and the construction efficiency during incremental launching. The research provides reliable experience in engineering practice for the future similar engineering.
Research of the Anti-Scale Technology for High Density Brine Killing Fluid
Authors: Wang Xiaofang , Fan Songlin , Han Enjun , Zhang Zufeng , You Qiuyan , Zhao Junfeng , Qin Feixiang
Published: January 2021

There are various formation damage in the exploitation of shale oil, for example water blocking, water sensitive and incompatibility, and so on, which will influence the recovery period and recovery rate of oil well. In this paper, an Anti-Scale technology for high density brine killing fluid was researched. The result show that the brine killing fluid can withstand high salinity (Ca2+<180000mg/l, NaHCO3<10000mg/l), and has well compatibility with common formation water. The puzzle for the scaling of high density brine kill fluid has been resolved.
Modal Analysis of Components and Whole of Gear Pump
Authors: Guo Fengquan , Du Haiming
Published: January 2021

The vibration characteristics of Gear pump are studied to avoid the Damage of parts caused by resonance. The modal of Pump body, driving gear shaft, Driven gear shaft and Gear pump are analyzed by using the Workbench module of ansys14.0 analysis software, Statistics of the first ten natural frequencies and the maximum total deformation data, Analyze the modal shape diagram. Comprehensive analysis results, There is a big gap between the natural frequency and the working frequency, the gear pump will not resonate, The local position of the parts and the whole of the gear pump will be deformed, but will not cause damage to the gear pump, and will not affect the performance of the gear pump. Computer aided research of vibration characteristics can shorten the research period and avoid safety problems.
Experimental Study on The Performance of FCV in Standard Test Cycle
Authors: Wang Tong , Jia Guorui , He Shaoqing , Lei Nanlin , Kang Zejun , Zou Daijiang , Zhang Qiang , Kou Wenlong , Xia Lina
Published: January 2021

The experiments of one FCV (Fuel Cell Vehicle) are conducted in three standard cycle conditions of NEDC (New European Driving Cycle), WLTC (Worldwide Light-duty Test Cycle) and CLTC (China Light-duty vehicle Test Cycle), and the performance of stack power, temperature and system efficiency are compared and analysed. Results show that the variation range of fuel cell system efficiency is ordered as: WLTC > NEDC > CLTC. The efficiency of fuel cell system is highest in CLTC; the fuel cell stack power and temperature are relatively low; the hydrogen consumption is lowest(0.93kg/100km). According to the analysis on experimental data of FCV in NEDC, the output power of stack is proportional to accelerator pedal when the accelerator pedal opening is greater than 25%.
Bioinformatics Analysis of the Lycopene β-Cyclase Gene in Jujube (Ziziphus jujube Mill)
Authors: Hou Yanxia , Guo Yan , Yang Jing , Bo Xuan
Published: January 2021

Lycopene β-cyclase enzyme is a key cyclase in carotenoid synthesis pathway, which catalyzes the formation of catalytic ring to synthesize α-carotene and β-carotene. In this study, the physicochemical properties, secondary structure, subcellular localization and homology of ZjLCYb were analyzed. Here, the genomic mRNA sequences of LCYb gene of jujube were downloaded from NCBI and then used to bioinformatic analysis. The ZjLCYb gene sequence was 1518 bp in length and encoded 505 amino acids. The molecular mass of ZiLCYb protein is 56.81 kD, and the isoelectric point (pI) is 7.65. Subcellular localization of ZjLCYb protein was most likely located in the chloroplast.The ZjLCYb protein has a Rossmann-fold NAD(P)H/NAD(P)(+) binding (NADB) domain and a PLN02463 specific hit. Homologous analysis showed that ZjLCYb and LCYb proteins from 17 other species contained more than 84.42% similarity, with the highest similarity being Vitis vinifera and Prunus persica. This study laid a foundation for bioinformatics analysis of carotenoid biosynthesis genes of jujube.
Screening of Cellulose Degrading Bacteria and Construction of Complex Microflora
Authors: Sui Ming , Rong Jiachao , Zhang Yang , Xie Huirong , Zhang Cai
Published: January 2021

The collected samples were pre-screened with Congo red cellulose medium according to the ratio of transparent circle diameter/colony diameter, and 10 strains with strong ability to decompose cellulose were obtained. Then, these strains were inoculated into the liquid production enzyme medium to measure the CMC enzyme activity for rescreening, and finally the N05, N13, N213 strain high-efficiency cellulose degradation strains were screened. These three strains were combined and cultured, and the best combination of effects was obtained by comparing the enzyme activities.
The International Energy Trade Pattern Reshaping, Competition and Energy Revolution
Authors: Hua Xu
Published: January 2021

Under the global economic slowdown and shale oil and gas technology revolution, the current international energy trade is reshaping, forming a new one whose characteristics are totally different from the old. The energy price fluctuations, the international energy supply and demand structure have been shuffled, and the geopolitical landscape has changed. The energy trade bloc led by the United states realizes self-circulation and high stability. The differentiation of the supply and demand in East Asia-Southeast Asia trade bloc has expanded, the risks increasing. The U.S. geopolitical leadership becomes more and more strong. The energy giants such as Saudi Arabia and Russia competed in production and price are further strengthening this trend. At present, an energy revolution is imperative. It is necessary to focus on improving energy efficiency and energy use structure. There is also have an effect on the global production. The distributions of world's manufacturing industry will readjust due to the costs.
Establishment of A New HBV Cell Culture Model by Covalently Closed Circular DNA Direct Transfect
Authors: Zhao Zhonghua , Tang Yuwei , Wei Qinglv , Zhang Huatang
Published: January 2021

Hepatitis B virus (HBV) infection is a public health problem in China and worldwide. Covalently closed circular DNA (cccDNA) is the template for HBV replication and exists stably in hepatocytes, which is the main factor for persistent HBV infection and the key target for the cure of HBV infection. The establishment of a suitable cell model is helpful to research the HBV pathogenesis and antiviral drug screening. We have established a new cell culture model of HBV infection by direct transfect of cccDNA, which provides a practical model for further research of HBV virology and antiviral drug development.
Study on Equilibrium Relationship Between Government Regulation and Social Environmental Responsibility of Energy Enterprises
Authors: Lin Liu , Yu Shen , Huang Xianan , Tu Xiazhe , Hong Juhua
Published: January 2021

This paper uses the evolutionary game model to analyze the relationship between government regulation and social environmental responsibility of energy enterprises. Then, we use the Matlab to simulate the dynamic change between government regulation and social environmental responsibility of energy enterprises. The conclusion of the study shows that: (1) The strategic choice based on corporate social environmental responsibility is must be the green technology innovation, and if we want to the maximum profit, we need to find a balance between government regulation and corporate social environmental responsibility. (2) Whether the government supervises enterprise, whether an enterprise fulfills its social environmental responsibility, depends on the specific circumstances. We must take an overall consideration of the cost of government, the bonuses, and penalties, the corporate different earnings because of different choices between fulfills and defaults its social responsibility, the bonuses the company achieved, the penalties the company must pay, and many other factors. The main contribution of this thesis is: break through the static research about the relationship between government and energy enterprise. We acquire the dynamic relation between government and energy enterprise based on green technology innovation. And it provides great help for our energy companies future direction of development.