bluuebunny/crossref_metadata_2025 huggingface dataset:
Noether symmetry approach in energy-momentum squared gravity
Authors: Sharif M , Gul M Zeeshan
Published: November 2020

In this paper, we investigate the newly developed f(R, T
2) theory (R is the Ricci scalar and T
2 = T

α
β

T

α
β
, T

α
β
demonstrates the energy-momentum tensor) to explore some viable cosmological models. For this purpose, we use the Noether symmetry approach in the context of flat Friedmann-Robertson-Walker (FRW) universe. We solve the Noether equations of this modified theory for two types of models and obtain the symmetry generators as well as corresponding conserved quantities. We also evaluate exact solutions and investigate their physical behavior via different cosmological parameters. For the prospective models, the graphical behavior of these parameters indicate consistency with recent observations representing accelerated expansion of the Universe. In the first case, we take a special model of this theory and obtain new class of exact solutions with the help of conserved quantities. Secondly, we consider minimal and non-minimal coupling models of f(R, T
2) gravity. We conclude that conserved quantities are very useful to derive the exact solutions that are used to study the cosmic accelerated expansion.
Peristaltically driven flow of hybrid nanofluid in a sinusoidal wavy channel with heat generation
Authors: Salahuddin T , Khan Muhammad Habib Ullah , Khan Mair , Alharbi Sayer Obaid , Chu Yu-Ming
Published: November 2020

The present analysis is reported to analyze the hybrid nanofluid (SiO
2 − CNT/H
2
O) flow as peristaltic transport under the influence of heat generation/absorption in a sinusoidal wavy channel. We have expressed the non-dimensional equations into two dimensional coordinate system by using vary long wavelength (δ < 1) and low Reynolds number

(
Re
)

assumptions. The non-dimensional hybrid nanofluid (SiO
2 − CNT/H
2
O) equations are solved approximately by using well known perturbation approach. The numerical solutions for temperature and two dimensional peristaltic flow are obtained by using Mathematica software. The obtaining solutions for temperature and peristaltic transport are expressed graphically with help of Matlab software. The graphical results show that pressure rise, temperature profile and pressure gradient of hybrid nanofluid (SiO
2 − CNT/H
2
O) flow increases due to increase of heat generation. The pressure rise and pressure gradient of hybrid nanofluid decreases due to increase of phase difference ϑ. Furthermore, pressure gradient and pressure rise of SiO
2 − CNT/H
2
O hybrid nanofluid also decreases by increase in channel width. The streamlines for peristaltic transport are also elucidated in present analysis. The streamlines show that bolus size increases due to increase of amplitude but decreases by increase of heat generation.
Nonlinear nonlocal-surface energy-based vibrations of a bidirectionally excited nanobeam at its supports
Authors: Xu Bo , Kiani Keivan
Published: November 2020

This study concerns with nonlinear axial and lateral vibrations of nanoscaled beams under action of bidirectional support excitations. Using the Euler-Bernoulli beam model through considering the von-Karman terms, small-scale effect, and surface energy, the nonlinear equations of motion of an excited nanobeam are derived in terms of purely dynamical deformations. By utilizing the Galerkin approach on the basis of the appropriate modes, the resulting nonlinear equations are reduced to the nonlinear ordinary differential equations, and these are solved for the unknown elastic deformations due to the most general form of support excitations. The roles of the excitation amplitude, excitation frequency, geometry of the nanostructure, surface energy, and nonlocality on the nonlinear dynamic response are investigated constructively. The importance of nonlinear analysis in capturing the more realistic dynamic response of the bi-directionally excited nanobeam at its ends is also revealed and explained methodically.
Gravitational instability with dust charge gradient and ion drag forces in unmagnetized dusty plasma
Authors: Dolai Bivash , Prajapati R P
Published: November 2020

The influence of dust charge gradient force and ion drag force on the fragmentation of unmagnetized, self-gravitating dust cloud has been studied. The thermal electrons satisfy the Boltzmann relation, while inertialess ions are affected by the ion-neutral collisions. The dynamics of dusty fluid are modified by ion drag, charge gradient, and gravitational forces. The onset criterion of pinching instability and gravitational instability is derived. The pinching instability depends upon the critical ion drag coefficient and dust charge variation parameter. In the laboratory complex plasma, with finite dust charge variations, the ion drag coefficient larger than the critical value causes pinching instability. This results in the fragmentation of the dusty cloud, which is affected due to the dust charge variations. The ion drag coefficient has destabilizing, while the dust charge variation parameter has stabilizing influence on the growth rate of the linear gravitational instability. The results have been discussed to understand the dust cloud collapse in the astrophysical system.
Modeling and analysis of a coupled novel nonlinear magneto-electro-aeroelastic lumped model for a flutter based energy harvesting system
Authors: Zaheri Abdehvand Mehran , Seyed Roknizadeh Seyed Alireza , Sedighi Hamid Mohammad
Published: November 2020

The present paper investigates the modeling and analysis of a novel aeroelastic energy harvesting system using magneto-electro-elastic (MEE) material considering the nonlinear elastic effects of the structure. The main aim of using this group of composite materials, as compared to common piezoelectric materials used in aeroelastic harvesters, is to increase the harvested electrical power. The proposed model to improve energy harvesting is composed of a rigid airfoil connected to an elastic beam, with the elastic beam covered by one or two layers of MEE material and two electrodes connected to the top and bottom of the MEE layers to harvest the electric potential from the generated electric field. An external coil was also provided around the oscillating beam to induce the electrical energy generated by the magnetic field established within the MEE layer. Firstly, simulating the harvesting system as a discrete model considering bending and torsional cubic nonlinear springs, the governing equations are extracted using the constitutive equations of MEE materials, Gauss’s law, and Faraday’s law of induction through Hamilton’s principle. Next, the effects of different design parameters are evaluated to find their optimal values to maximize the generated power as well as the harvester stability. Finally, a comparison is made between the considered MEE harvester and a piezo-aeroelastic (PA) energy harvester, indicating the superiority of the proposed MEE energy harvester.
Statistical properties of radio flux densities of solar flares
Authors: Wang Lu , Liu Si-Ming , Ning Zong-Jun
Published: November 2020

Short timescale flux variations are closely related to the energy release process of magnetic reconnection during solar flares. Radio light curves at 1, 2, 3.75, 9.4, and 17 GHz of 209 flares observed by the Nobeyama Radio Polarimeter from 2000 to 2010 are analyzed with a running smooth technique. We find that the impulsive component (with a variation timescale shorter than 1 s) of 1 GHz emission of most flares peaks at a few tens of solar flux unit and lasts for about 1 minute and the impulsive component of 2 GHz emission lasts a shorter period and peaks at a lower flux level, while at the three high frequency channels the occurrence frequency of flares increases with the decrease of the flux density up to the noise level of the corresponding background. However, the gradual components of these emissions have similar duration and peak flux density distributions. We also derive the power spectrum on different timescales and a normalized wavelet analysis is used to confirm features on short timescales. At a time resolution of 0.1 s, more than ∼60% of these radio light curves show significant flux variation on 1 s or shorter time scales. This fraction increases with the decrease of frequency and reaches ∼100% at 1 GHz, implying that short timescale processes are universal in solar flares. We also study the correlation between the impulsive radio flux densities and soft X-ray fluxes obtained with the GOES satellites and find that more than 65% of the flares with an impulsive component have their impulsive radio emission reach a peak value ahead of the soft X-ray fluxes and this fraction increases with the radio frequency.
Estimating up-limits of eccentricities for the binary black holes in the LIGO-Virgo catalog GWTC-1
Authors: Yun Qian-Yun , Han Wen-Biao , Wang Gang , Yang Shu-Cheng
Published: November 2020

In the first Gravitational-Wave Transient Catalogue of LIGO and Virgo, all events are announced having zero eccentricity. In the present paper, we investigate the performance of SEOBNRE, which is a spin-aligned eccentric waveform model in time-domain. By comparing with all the eccentric waveforms in SXS library, we find that the SEOBNRE coincides perfectly with numerical relativity data. Employing the SEOBNRE, we re-estimate the eccentricities of all black hole merger events. We find that most of these events allow a possibility for existence of initial eccentricities at 10 Hz band, but are totally circularized at the observed frequency (≳ 20 Hz). The upcoming update of LIGO and the next generation detector like Einstein Telescope will observe the gravitational waves starting at 10 Hz or even lower. If the eccentricity exists at the lower frequency, then it may significantly support the dynamical formation mechanism taking place in globular clusters.
Gravitational wave sensitivity curve of pulsar timing arrays affected by correlated noises
Authors: Liu Shu , Tong Ming-Lei
Published: November 2020

The detection of gravitational waves (GWs) by pulsar timing arrays (PTAs) is not only a very important supplementation of the verification of general relativity but also a new window to study the evolution of supermassive binary black holes and the early universe. However, so far the detection sensitivity of PTAs is not good enough to catch signals of GWs due to the disturbance of various noises. In this paper we explore the influences of the correlated noises caused by the reference clock errors and solar system ephemeris errors in pulsar timing on the detection of stochastic gravitational waves background (GWB). We demonstrate the power-law integrated sensitivity curves of GWB detection under the impacts from these correlated noises. From the simulated data, we find that the influence of different reference time-scale is non-negligible, and the influence is even quite huge if one uses a very old version of solar system ephemeris. However, the impact from these correlated noises on the sensitivity curve is very limited for the real observational data released by international pulsar timing arrays (IPTA). We also calculate the signal-to-noise ratios based on the theoretical GW amplitude permitted by observations. Moreover, we study how the detection sensitivity increases with more pulsar number and longer observation.
Chinese sunspot drawings and their digitization – (III) quasi-biennial oscillation of the hand-drawn sunspot records
Authors: Wan Miao , Zeng Shu-Guang , Zheng Sheng , Lin Gang-Hua
Published: November 2020

Quasi-biennial Oscillations (QBOs) of the Sun have a significant meaning as a benchmark of solar cycle, not only for understanding the dynamo action but also in terms of space weather prediction. In this paper, the hand-drawn sunspot images recorded from the Purple Mountain Observatory are used to investigate the solar QBOs and the Gnevyshev gap of the sunspot relative numbers (Rs) and group sunspot numbers (Rg) during the period 1954–2011. The main results are as follows: (1) both the Rs and Rg exhibit similar periods including the 22-year magnetic cycle, the 11-year Schwabe cycle, and the QBOs modes; (2) the reconstructed QBOs of both data sets exhibit coherent behavior and tend to have a high amplitude during the maximum phase of each solar cycle; (3) the Gnevyshev gap is produced by the superposition of the QBOs and the 11-year Schwabe cycle, and the Rs is better to study the variation of the Gnevyshev gap rather than the Rg.
Optimized finite-build stellarator coils using automatic differentiation
Authors: McGreivy N. , Hudson S.R. , Zhu C.
Published: November 2020

A new stellarator coil design code is introduced that optimizes the position and winding pack orientation of finite-build coils. The new code, called flexible optimized curves in space using automatic differentiation (AD) and finite build (FOCUSADD), performs gradient-based optimization in a high-dimensional, non-convex space. The derivatives with respect to parameters of finite-build coils are easily and efficiently computed using AD. FOCUSADD parametrizes coil positions in free space using a Fourier series and uses a multi-filament approximation to the coil winding pack. The orientation of the winding pack is parametrized with a Fourier series and can be optimized as well. Optimized finite-build coils for a Wendelstein 7-X (W7-X)-like stellarator are found, and compared with filamentary coil results. The final positions of optimized finite-build W7-X-like coils are shifted, on average, by approximately 2.5 mm relative to optimized filamentary coils. These results suggest that finite-build effects should be accounted for in the optimization of stellarators with low coil tolerances.
Assessment of the durability of corrosion-damaged prefabricated reinforced concrete structures
Authors: Tamrazyan A G , Koroteev D D
Published: November 2020

During exploitation, reinforced concrete structures are under the influence of an aggressive environment, as a result of which they are damaged and destroyed. The durability of structures depends on the nature of its interaction with aggressive environmental factors, which is described using general models of external influences, such as the action of loads, climatic, aggressive and other influences and their combinations. An example of calculating durability based on corrosion of concrete and reinforcement is given. The selected protective layer and the diameter of the reinforcement were checked in case of general corrosion. The average value of the service life in years was determined on the basis of carbonization of the protective layer of concrete and the formation of cracks in it. The methods for predicting the service life of reinforced concrete structures are analysed. The service life of the structure is determined taking into account the assessment of the technical condition of the structure according to external signs. In theoretical terms, the influence of various factors by the introduction of a multifactorial measure of damage is shown. The calculations for predicting the service life of structures and for determining the durability are analysed. The example of calculating the probabilistic service life is considered.
Effect of silica fume on the ultrasonic pulse velocity of cemented sand
Authors: Shooshpasha I , Hasanzadeh A , Kharun M
Published: November 2020

One of the geotechnical engineering strategies for dealing with weak soils in a construction site is to modify their mechanical properties with the aid of soil improvement techniques. Chemical stabilization of soil using cement is one of these effective approaches that can considerably enhance workability and shear strength parameters of soil. However, very limited investigations have been carried out to reveal the effect of silica fume on the ultrasonic pulse velocity (UPV) and the ultrasonic stiffness (Eu) of cement-treated sandy soil. For this purpose, in the present research, a series of UPV tests were performed on sand-cement-silica fume specimens. The cement percentages were 3, 5 and 7% and silica fume contents were 0, 0.25, 0.5 and 1% by weight of dry sand. The cylindrical samples were prepared and cured for 3, 7, 14, 28, 42 and 56 days and tested. The results show that inclusion of silica fume to the cemented sand increases UPV and Eu which this enhancement is more pronounced at longer ages.
Factors influencing the critical piles length in reinforced slope
Authors: Shooshpasha I , Amirdehi H A , Kharun M
Published: November 2020

In this research, the performance of a homogeneous slope reinforced with one row of piles is studied using coupled numerical analysis and the method of shear strength reduction as implemented in the finite element analysis software, ABAQUS. Parametric studies are performed by changing geometric and strength parameters such as piles head conditions, piles location and the soil cohesion to assess their influence on the slope stability. For each of these parameters, the safety factor of the slope and the piles critical length was assessed. The results indicates the performance level of piles with different head conditions will not be similar; so that hinged and fixed heads are the most effective and cause the piles critical length to reduce, whilst free heads are less effective. The optimum location of the piles depends on their length, but regardless of the piles head type, the maximum increase of the safety factor is achieved when the piles are located in the mid-section of the slope. In addition to this, various levels of soil cohesion do not affect the piles optimum location, whilst cause significant changes in their critical length and increase rate of safety factor.
The impact of section properties on thin walled beam sections with restrained torsion
Authors: Gebre T H , Galishnikova V V
Published: November 2020

In this paper the influence of section properties on thin walled beam sections with restrained torsion is studied by considering the angle of twisting for non-uniform torsion. The study is based on the governing equation for non-uniform torsion of thin-walled beam of open and closed cross-sections, including the restrained behavior. The hyperbolic shape functions is used to generate the general solution for homogenous equation as it gives the exact results in accordance with the analytical solution. This study is focused on a bar subjected to torsion with warping of wide-ranging open and closed cross-sections with different value of characteristics number for torsion. The impact of the characteristics number for torsion on different section type is studied and evaluated. The obtained results are compared based on the influence of section properties on the components of the total applied torsion and presented graphical for different value of characteristics number for torsion.
Numerical study of free vibration behaviour of filled tool holder using epoxy-granite
Authors: Kashyzadeh K R , Ghorbani S
Published: November 2020

This paper presents a computer simulation focused on identifying the effect of cutting tool construction and damping material on its natural frequency. To this end, nine cutting tools with different cross-section of tool holder filled up with high damping material were presented. The free vibration analysis performed by ANSYS Workbench indicated that vibration amplitude decreases in cutting tools with epoxy-granite compared to that of conventional cutting tool. The relationship between the first and second natural frequencies with the length and diameter of the absorber chamber reveals that increase in diameter and length will reduce the natural frequency. Moreover, Multiple Regression Technique (MRT) was used to present a new equation for calculating the first natural frequency of filled tool holder via the dimensions of epoxy-granite cell. Next, various cases of filled tool holder were analysed based on Taguchi method. The results of the Taguchi sensitivity analysis showed the effect of length parameter (58%) on the natural frequency is more than the effect of diameter parameter (42%) on it. Moreover, it is also concluded that the natural frequency is more effectively reduced if the part between tool head and first tightening screw is filled with an increased volume of the absorbent.
Influence of environmental factors on the processes of biodegradation of vinylester composites
Authors: Kablov E N , Erofeev V T , Dergunova A V , Deraeva E V , Svetlov D A
Published: November 2020

Polymer composite materials based on various binders are widely used in the construction industry. Polymer composites are characterized by high performance. Of great interest is the study of more economical compared to other polymers vinylester composites. They are successfully used in the US and European countries. In Russia, the use of polyester resin as a binder is not as common as abroad. At the same time, the influence of environmental factors on the biodegradation of vinyl ester polymer composites has not been sufficiently studied to date. This study is devoted to the study of the biostability of vinyl-ether composites under the influence of environmental factors. The most significant are the processes of atmospheric aging of materials, which include a complex effect of climatic and environmental factors. The study of changes in the species composition of microflora and indicators of resistance of composites, depending on their composition and operating conditions in the conditions of the seacoast.
Behavior of conventional and fibered concrete shear walls during earthquake, an analytical simulation in SAP2000
Authors: Kharun M , Koroteev D D , Hemati Bahar M , Huang J , Kamrunnaher Mimi
Published: November 2020

The investigation of this paper was about non-liner behavior of shear walls against seismic wave by using conventional and fibered concrete. Case of earthquake study was Iripina 1980, Italy with Ms = 6.9 and fourth kind of shear walls with glass fiber, basalt fiber, steel fiber concrete and conventional concrete shear walls simulated in SAP2000 with dynamic analysis method. Analysis shows that glass fiber concrete and conventional concrete shear walls had similar behavior, also these shear walls had more suitable response. All shear walls behavior were same at the beginning of earthquake but at the end of earthquake basalt and steel fiber concretes had a lot of displacement. Furthermore, behavior of steel fiber concrete shear wall could not return at the last moments of earthquake. Beside modulus of elasticity and compressive strength had most effect on reaction of shear walls such that modulus of elasticity was the cause of doing linear behavior of shear walls during all times of earthquake, on the other hand compressive strength had most efficiently in dissipation energy. Best result in earthquake was with conventional concrete due to modulus of elasticity and compressive strength.
Strength of frozen soils during thawing
Authors: Ya Maslikova O , Debolsky V K , Ionov D N , Gritsuk I I , Sinichenko E K
Published: November 2020

More than a third of the Earth’s surface is subject to seasonal or prolonged soil frosts, and the recent warming of the climate requires revision of the construction standards in the conditions of permafrost because under heavy load in low-strength soils, there is a high risk of mobility of thawing rock and collapse of the construction structures, which is fraught with disastrous consequences. For design tasks it is necessary to know the behavior of frozen soils under certain changing conditions. This creates new requirements related to the degradation of permafrost and, as a result, the criteria for strength and stability of soils suitable for construction are changing. Calculation of loads during construction in the permafrost zone requires a special approach in each specific case, since it is impossible to make a single model in connection with the variety of soils and the history of their freezing. Soil typization does not give a clear picture at negative temperatures, since the transition “water-ice-water” in the soil changes the behavior of the grounds, and the unpredictability of climatic changes affecting this process greatly complicates the task. In the hydraulic laboratory of the RUDN University, a series of experiments was conducted for various types of soil subject to load, in order to determine the main parameters affecting the stability of soils during thawing, and to give approximate recommendations regarding the use of these soils as bases.
Application Analysis of WF / HDPE Composite in Landscape Design
Authors: Sun Qinghui , Lai Yibing , Shi Huiquan
Published: November 2020

Based on the brief introduction of the basic concept of landscape design, the anti-aging properties of WF / HDPE composite with UV-326 absorbent and WF / HDPE composite with UV-P absorbent were compared, It is concluded that the UV-P modified WF / HDPE composite can replace the UV-326 modified WF / HDPE composite in landscape design, The effects of UV-P and UV-326 contents on the aging resistance of WF / HDPE composites were analyzed. The application of UV-P modified WF / HDPE composite in modern landscape design is presented, and the structure and application place of paving board are introduced.
Applicability of Epoxy Materials for Repairing Wet and Underwater Concrete
Authors: Lu Zhihua
Published: November 2020

Concrete structures in wet or underwater environment are damaged by erosion of water medium and other external factors for a long time. The working environment is bad, and they need to be repaired in time after diseases occur. Otherwise, it will have a serious impact on the safe use and durability of the whole structure. Because there is a large amount of water in the construction environment, the repair and reinforcement of such structures often need wet or underwater construction. Based on the above background, the purpose of this study is to study the applicability of epoxy materials for wet and underwater concrete repair. In this study, the influence of steel sheet, substrate and surface treatment on the underwater bonding ability was discussed. The EM underwater performance of different curing agent and curing agent compounding was studied. The basic principle of curing agent compounding was put forward, and the comprehensive performance of EM optimized formula was tested. The results show that the underwater properties of different curing agents are very different, but it is difficult for a single curing agent to meet the comprehensive performance requirements; the use of different kinds of curing agent compounding technology is an effective means to improve its underwater properties, but the effect of different compounding methods is significantly different, when using the modified alicyclic amine and phenolic amine compounding system, After optimization, the water pull-down shear strength of epoxy solution is 20.1mpa, air pull-shear strength is 22.7mpa, air tensile strength is 41.6mpa, air compressive strength is 100.9mpa, elastic modulus is 2.53gpa, the underwater positive pull bonding strength of epoxy mortar is 4.31mpa and the failure mode is cohesive failure of base mortar block. The underwater long-term bonding performance of epoxy mortar is excellent, After immersion for one year, the strength of the specimens has not decreased significantly, which can fully meet the actual engineering needs.
Ecosystem Health and Forest Ecosystem Management
Authors: Wang Ding , Yang Xue , Xing Wenhui , Liu Chunlei , Chang Huiping
Published: November 2020

Forest ecosystem management and ecosystem health are two related but different concepts. This paper expounds the origin, development, evaluation and research progress of ecosystem health, the difference between forest ecosystem management and traditional forest management science, and discusses the relationship between forest ecosystem management and ecosystem health, and holds that: 1) the health of forest ecosystem should be the goal pursued by forest ecosystem management; 2) Ecosystem health theory provides theoretical basis for specific measures of forest ecosystem management; 3) Forest ecosystem management measures also provide necessary means to maintain the health of forest ecosystem. In order to realize sustainable forest management, the goal of forest management should be changed from the traditional priority of utilization to the direction of emphasizing the health of forest ecosystem, which is the necessary prerequisite for sustainable development of ecological, economic and social benefits of forests.
Progress of Marine Ranching Technologies in China
Authors: Yu Jing , Wang Dongliang , Chen Pimao
Published: November 2020

China’s offshore habitats are seriously degraded, leading to continuous decrease in fishery resources. Marine ranching, which can not only conserve diverse fishery resources, but also restore the ecological environment, play an important role in the harmonious development of China’s marine fishery resources and offshore ecosystems. In this study, the definition and methods of the major technologies for the construction of marine ranching were introduced, their application in various sea areas were reviewed, and combined with the development stage of marine pasture in China, the problems faced by marine pasture in research foundation, scientific and technological level and supporting development in China were expounded. The development trend and research direction of marine pasture technology in China are prospected. Suggestions for the improvement of marine-ranching technologies in the future were proposed also.
Relationship between Geological Hazards Distribution and Slope Factors in Qin-Ba Mountain Area
Authors: Zhao Lixing
Published: November 2020

The distribution of geological hazards is closely related to the slope factors. This paper adopts the methods of field geological survey and GIS software to investigate the geological hazards in the study area, and uses statistical methods to analyze the relationship between landslides development and slope factors, including elevation, slope shape and topographic relief amplitude. The results are as follows. (1) Landslides are mainly distributed in low altitude areas, and the disaster density is highest in the range of 500 to 700 meters elevations. (2) Compared with other slope shape types, the number and density of landslides on linear slope are the highest. (3) Within the topographic relief amplitude range of 0 to 10 meters, the landslide density is the highest.
Evaluation of a Pilot Scale Combined Constructed Wetlands and Stabilization Ponds for Initial Rainwater Treatment
Authors: Li Jingshi , Lei Lei , Lei Yutao , Luo Qijin , Lai Houwei , Liu Li , Li Xinhua , Liang Wenzhong
Published: November 2020

For the storage rainwater quality maintenance and purification and the ecological water replenishment in the rain source river of industrial park, a combined process of “plant stabilization ponds and vertical flow constructed wetlands” was developed. The scale of pilot plant was 20 m3/h. The research showed that the combined process of constructed wetlands and stabilization ponds had a significant removal rate of COD, NH4+-N, TN, TP, SS of 14.13% ∼ 31.99%,33.64% ∼ 77.42%,24.72% ∼ 48.04%,61.29% ∼ 67.20%,45.44% ∼ 76.90%, with better treatment effect on N, P and SS in medium and low concentration. The circulation time has a relatively large impact on the removal rate of COD and SS, and a relatively small impact on NH4+-N, TN, TP, TN and TP.
Application Review of Container Building and Wood Building in Post-disaster Reconstruction
Authors: Zhou Kang , Krisztián Kovács-Andor dr.  , Qi WenYu
Published: November 2020

In recent years, China has encountered Wenchuan, Yushu, Taiwan earthquake and other major disaster events pushed the research of emergency building to the forefront. Judging from the present situation of post-earthquake reconstruction in China, it is not perfect in terms of emergency reconstruction and the design of buildings is also deficient to some extent. At present, the forefront of international research on post-disaster emergency measures is mainly focused on earthquake-prone countries, such as Japan and the United States. After the Wenchuan earthquake, the Chinese government quickly deployed post-disaster reconstruction and issued a series of regulations. The application of some light structures such as container and wood building in post-disaster reconstruction has gradually become the focus of scholars. R factor analysis method is adopted in this article, try to research on the design of the container and wood buildings combined with the practice of reconstruction, and has set up a variety of structure in the field of light structure architectural practice support as a case, a container and wooden buildings in the post-disaster reconstruction design strategies and explore possibilities for the future development, the application of the post-disaster reconstruction work after have a certain guiding significance.
The Government Purchases Municipal Waste Classification Services to Promote Diversified Governance Based On Environmental Pollution
Authors: Chen Guoping , Shi Xiuhua , Yue Shuya
Published: November 2020

The deterioration of the ecological environment has attracted society to focus on how to control environmental pollution and other serious issues, so the whole society has vigorously promoted the trend of garbage classification. Garbage classification is a hot topic in society at present, how to do a good job in garbage classification. Among them, the government purchase of municipal waste classification service is one of the means to change the function of the government, build a service-oriented government, promote the cooperation of various subjects, enhance the effectiveness of comprehensive garbage management, and speed up the improvement of the level of “reduction, resource utilization and innocuity” of garbage. This article explores the historical experience and development trend of the government’s purchase of municipal waste classification services through literature survey methods and examples and empirical research methods. It focuses on analyzing of problems in the government’s purchase of waste classification services and proposes corresponding solutions to drive all parties, subjects actively participate in garbage classification services and innovative service spaces.
Research Status of Influencing Factors on Superplastic Properties of Titanium Alloy
Authors: Yin Dongdong , Qin Guangyao , Cao Kai
Published: November 2020

Titanium alloy is an important structural material with high specific strength, excellent corrosion resistance and high heat resistance. It has been widely used in aviation, automotive industry and other industries. But its cutting performance is poor, especially the manufacture of some complex parts, the rate of finished products is very low. Superplastic processing is very effective to improve the rate of finished product. In view of this, the effects of grain size and deformation temperature on the superplastic properties of titanium alloy were investigated. The superplastic deformation behavior of the titanium alloy under different influencing factors was also reviewed.
The Effects of Undenatured Type II Collagen on Inflammatory Mediators and Oxidative Stress in an Osteoarthritis Rat Model
Authors: Yan Zheng , Zhao Hongyu , Liu Aiqing , Liu Shuang , Zou Guoqing , Wang Haiyan
Published: November 2020

The present study aimed to investigate the effects of undenatured type II collagen on monosodium iodoacetate-induced osteoarthritis (OA) rats, and elucidate its underlying anti-inflammatory and antioxidant mechanisms. Several parameters such as body mass, pain threshold of knee joint, supporting force of the left and right feet, serum levels of inflammation mediators and cartilage metabolic marker, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity and knee joint histopathology were measured. The results demonstrated that undenatured type II collagen enhanced the pain threshold of knee joint and reduced the difference in supporting force between the left and right feet. Moreover, undenatured type II collagen increased serum TGF-β concentration and decreased the serum levels of TNF-α, MMP-13 and CTX-II in OA rats. In addition, decreased serum MDA content and increased serum SOD activity were found in undenatured type II collagen treatment group when compared to those in model group. Histopathological data indicated that undenatured type II collagen exhibited protective effects on both synovial and cartilaginous tissues in OA rats. Taken altogether, the findings of this study reveal that undenatured type II collagen can relieve and prevent OA symptoms by regulating inflammatory mediators and oxidative stress. Additionally, this collagen helps to reduce knee OA pain and maintain normal joint function.
Institutional Analysis of Multifunctional Fruit Picker
Authors: Zhao Jinling
Published: November 2020

Fruit is a major pillar industry for economic development in many regions of China, and it is the third largest crop after crops and vegetables. However, the level of mechanization of fruit harvesting is still in its infancy, and most of them are mainly manual harvesting. The workload is heavy, the picking intensity is not easy to grasp, and it is easy to damage the fruit. Based on the research of fruit picking devices at home and abroad and field visits to orchards, this paper draws up design schemes and conducts main structural design and parameter calculations. The product can achieve 10 kinds of picking work, such as fruit apple, peach, orange, litchi. This greatly reduces the labor intensity of the picking work, improves the efficiency of the picking operation, and provides reference design experience for the fruit picking industry.
Monitoring the Utilization of Glyphosate Resistance Genes Based on Patent Analysis
Authors: Jia Xudong , Zhao Fei , Zheng Yuyuan , Cao Gaoyi
Published: November 2020

As a widely used herbicide in the world, glyphosate occupies an important position in the global agrochemical market. the first genetically modified glyphosate-resistant crop was successfully studied in the United States. Monsanto, as a giant in the agrochemical field, has extensive influence in the field of genetically modified glyphosate resistance. Phosphoenolpyruvate shikimate synthase ((EPSPS)) is a key enzyme that catalyzes the synthesis of EPSP from PEP and S3P in shikimic acid pathway. As an important prerequisite for branched acid synthesis in photosynthesis, shikimate synthase plays an important regulatory role. Glyphosate is the structural analogue of S3P, which competitively inhibits the enzyme activity of EPSPS, resulting in the interruption of shikimic acid pathway, which leads to the death of plants. According to their conserved domains, EPSPS can be divided into type I EPSPS and type II EPSPS, type I EPSPS sensitive to glyphosate, while type II EPSPS is inherently tolerant to glyphosate, and the two types of EPSPS have specific mutants, showing different degrees of sensitivity to glyphosate inhibition in the catalytic shikimic acid pathway. Based on China knowledge Network and other databases, mining the current types, sequence characteristics and transformation events of glyphosate-resistant genes will help our country to occupy a favorable position in the field of glyphosate-resistant transgenic and maintain the agricultural security of our country.
Evaluation on Synergetic Innovation Ability of Environmental Protection Industrial Park
Authors: Lu Jing , Wang Xinfen , Xin Lu , Xu Zhijie , Wang Zhikai , Zhao Yunhao
Published: November 2020

Evaluating the innovation ability of environmental protection industrial park is an important method to promote the construction of the park and master the development status and problems of the park. Based on the theory of synergetic innovation, this research analyzes the technological innovation system of the park, and selects 9 evaluation indexes to build an evaluation model of the park’s synergetic innovation capability from three aspects: innovation input, innovation output and innovation support. Using factor analysis method, through horizontal and vertical comparison, this paper evaluates the technological innovation level of Case Parks and Comparison Parks as well as the collaborative development degree of various subsystems, analyzes the main problems in the innovative development of environmental protection industrial parks, and puts forward relevant suggestions for optimization and adjustment.
Influence of Environmental Regulation and Energy Price on Energy Efficiency
Authors: Zhang Zihui , Zhu Yingming
Published: November 2020

In recent years, the Chinese government has attached great importance to the improvement of energy efficiency, and has formulated many corresponding policies for this purpose Based on the theoretical analysis, this paper selects the relevant provincial data from 2009 to 2015, establishes a panel model and adds a dynamic panel model of lagging energy efficiency, and studies the effect of the combination of environmental policy and energy price on energy efficiency. The results show that environmental regulation has a negative effect on energy efficiency after eliminating endogenous models, and energy prices have a significant positive effect on energy efficiency. According to the above empirical results, the following policy recommendations are proposed: (1) to improve environmental legislation and supervision, continue to accelerate the study of economic regulation and environmental regulation policies; (2) continue to give full play to the significant role of energy prices in energy efficiency, continue to accelerate the market-oriented reform of factors, and gradually establish market-based policy tools.
Training Appraisal Value Evaluation Model of Power Grid Enterprises Based on Value Creation
Authors: Xu Youfeng , Gao Jingxian
Published: November 2020

In order to improve the value of training evaluation of power grid enterprises, we combed the value creation process of training management and designed the integrator model of training value chain through theoretical research on mature training evaluation with the help of enterprise operation analysis process. Taking the training evaluation project of Yunnan Power Grid Company as an example and based on the value-creation process of training management, we sorted out the evaluation index systems respectively for individual training project, training project, assessment project and resource development project, and verified their feasibility according to the previous data of the company.
Study on the Simulation of Electromagnetic Squint
Authors: Huang Jian
Published: November 2020

This paper introduces the simulation electromagnetic gun device based on STM32, which mainly uses openmv and laser ranging module as recognition sensor. The system obtains the target position through openmv, uses PID algorithm to control the steering gear with two degrees of freedom to make the gun barrel aim at the target, then obtains the target distance through the laser ranging module, obtains the target and controls the energy storage capacitor voltage of the electromagnetic gun, increases the voltage through the DC power supply, charges and discharges the capacitor through the thyristor controlled by the relay, the capacitor discharge generates the magnetic field through the coil, and generates the magnetic field inside the steel ball Instead, a magnetic field ejects the ball. This design realizes the closed-loop control of the capacitor voltage to ensure the stability of the projectile exit velocity. The system is stable in operation and has high precision.
Quantity and Utilization of Crop Straw Resources in China
Authors: Gao Zhongpo
Published: November 2020

China is one of the major agricultural countries in the world, which is rich of crop straw resources. However, the types, quantities and changes of straw resources of major crops have not been known for a long time. This paper tries to estimating the quantities of straw resources of major food crops, which uses the output data of five major food crops such as rice, corn, wheat, beans, and potatoes in China in 2019. On the basis of scientifically determining the Residue to Product Ratio(RPR), this paper uses the grass-to-valley ratio method to measure the quantities of straw resources of major food crops, in order to provides reference and decision support for the development of comprehensive straw utilization policies and plans in China. At last, this paper points out the problems existing in the comprehensive utilization of straw resources in China and proposes countermeasures based on the actual situation.
Adsorption of Petroleum Hydrocarbon by Modified Biomass Carbon
Authors: Wang Tianshu , Song Dongxue , Zhang Shaojun , Zhang Zhen , Wang Mingyu
Published: November 2020

In order to improve the oil adsorption performance of biomass carbon, a new oil removal adsorbent was prepared by modifying natural material. Hydrophobic agent is used as modifier to graft biomass carbon. The structural characteristics and microstructure of biomass carbon treated by modifiers are characterized by FTIR spectroscopy and SEM observation. The results showed that self-made biomass charcoal has good floatability, and biomass carbon treated by the hydrophobic agent has a higher oil adsorption capacity than those of untreated ones. Peanut shell carbon and corn cob carbon modified by nano-SiO2 dispersant obtained the best results with an oil absorption rate of about 1.5 g/g and an oil retention rate of about 95%. As determinate by GC/MS, the modified biomass carbon before and after the adsorption of marine oil, the alkane changed significantly, indicating that the adsorption capacity of oil is very obvious.
A Decision-Making Model of Port Carbon Emission Reduction Investment under Uncertainty
Authors: Guo Jin , Kuang Haibo , Luo Jiaqi
Published: November 2020

Ports are big emitters of carbon emissions and often spend a lot of money and time on carbon emission reduction. Therefore, this paper constructs a port carbon emission reduction investment decision-making model under the uncertainty of carbon emission amount and carbon trading price, which taking the minimization of carbon emission reduction comprehensive cost as the optimization objective including some key factors such as the budget constraint of port carbon emission investment, carbon emission quota, and so on. At last, the case study of Shanghai port is carried out, and the optimization results show that Shanghai port should invest 3.10 Yi yuan in 2019 for carbon emission reduction. It is useful for the port carbon emission reduction managers and policy makers.
Preliminary plant design of thermochemical conversion for rice straw-based second-generation bioethanol production in West Java
Authors: Harahap A F P , Arya Ramadhan M Y , Lee W C , Gozan M
Published: November 2020

Thermochemical conversion is selected in the design of a rice straw-based bioethanol production plant. This study examines the gasification and catalytic synthetic process technologies of rice straw into ethanol. The size of rice straw was reduced and dried before entering the gasification reactor to convert into syngas. The clean gas goes to the mixed alcohol synthesis process in a plug flow reactor with CuO/ZnO as a catalyst. The product is then purified through several separation methods, i.e., column distillation, stripping, and absorption. The controlled parameters for this plant are temperature, flow rate, pressure, level, and concentration. The paper describes the piping instrumentation diagram with a graphical representation of the equipment, piping, and instrumentation. A Heat Exchanger Network analysis achieves an efficiency of 34.4%. The electricity required is fulfilled by turbine expander for about 1,493 kW, and the rest of it is provided by PLN, besides an emergency generator sets. The capacity of this plant is 100,000 kL/year.