bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculation method of stiffness of partially fabricated steel reinforced concrete beams
Authors: Yong Yang , Yanni Cao , Yicong Xue , Yunlong Yu 
Published: March 2021

Abstract
In this paper, two new types of partially precast steel reinforced concrete beams are proposed by combining the advantages of steel reinforced concrete beams, high strength concrete beams and precast assembly structures. Partially fabricated steel reinforced concrete beams are composed of precast high-strength concrete shell and cast-in-place concrete core area. In order to further reduce the dead weight of the members, partially fabricated steel concrete beam sections are hollow or can be filled with thermal insulation materials. In this paper, by using the superposition method and based on the existing test results, two new stiffness calculation methods for partially prefabricated SRC beams are proposed.
Research on earth pressure monitoring data of soil-stone assorted foundation pit
Authors: Quanming Zheng , Junyan Liu , Yan Liu , Donglin He , Yang Wang , Xiaodong Feng , Xiwen Zhang 
Published: March 2021

Abstract
Earth pressure is the most important type of load acting on the supporting structure of a foundation pit, and it is also a key factor in the design of foundation pit supporting. However, in engineering practice, the calculated value differs greatly from the actual value, which puzzles many engineers. This paper analyzes the field measured data of the earth pressure of the foundation pit in Minghucheng (Jinan city), and compares the calculated values of the Rankine active earth pressure and the passive earth pressure theory. The analysis finds that: (1) The measured value is between the active earth pressure and the passive earth pressure, and as the excavation of the foundation pit and the inward displacement of the supporting structure, the measured earth pressure value becomes smaller and approaches the active earth pressure. (2) When the pre-stressed anchors is applied, due to the fastening effect of the anchors, the earth pressure behind the supporting pile has a tendency to increase. (3) The theoretical value of Rankine’s active earth pressure in the soil-rock combination is obviously lower than the measured values.
Monitoring System Design for Intelligent Hydraulic Safety Based on the IoT
Authors: Wenfeng Ma , Haiyin Jin , Zhangyu Pan , Qi LinG , Jianhua Deng 
Published: March 2021

Abstract
In order to improve the safety operation management of hydraulic structures in hydropower stations, this paper analyzes the status and shortcomings of hydraulic safety monitoring automation system, and puts forward the design idea and scheme based on IoT. The intelligent connection of hydraulic monitoring equipment is realized by optimizing the design of sensing collection, communication network, monitoring application and information security of the system. By coordinating the monitoring, configuration and management of each monitoring terminal equipment, and using cloud computing technology to calculate, analyze and evaluate the monitoring data in real time, the intelligent online monitoring of hydraulic structures is realized, so as to ensure the safe and efficient operation of hydropower station infrastructure.
Finite Element Analysis of Deformation Effect of Concrete Filled Steel Tubular Composite Frame under High Temperature
Authors: Li Yucheng , Wang Wei , Wang Xing 
Published: March 2021

Abstract
The research on the mechanical characteristics of concrete-filled steel tubular composite frame under high temperature is one of the hot topics. In this paper, through the finite element simulation software, the failure characteristics of the deformation of concrete-filled steel tubular composite frame and the simulation results of the deformation effect of concrete-filled steel tubular composite frame structure are analyzed, including the effect of each component in different temperature fields, different structural fields and various coupling fields, the redistribution and change of the local plastic region of the component under high temperature, and the change of the local plastic region of the component under high temperature. The comparative analysis of the flexural effect of two-story two span concrete-filled steel tubular composite frame under different fire positions shows that: with the rising of fire time, the vertical displacement is also increasing, the scope of local plastic area is expanding, the deflection redistribution is obvious, and finally the mechanism is formed, and the failure occurs. The deformation effect of condition 1 changes more than that of condition 2, which indicates that the two-story two span steel tubular composite frame has a large deformation effect. The fire resistance of concrete-filled tubular composite frame is better under the condition of full section fire. The research results can provide reference value for strengthening and repairing of concrete-filled steel tubular composite frame under high temperature.
Study on tensile mechanical properties of polymer cement composite joint sealant under negative temperature
Authors: Wang Zhihang , Xu Jinyu , Meng Xin , Huang Zhe , Xia Wei 
Published: March 2021

Abstract
Tensile tests were carried out on polymer cement composite joint sealant(PCJS) after different negative temperature action time. By testing the tensile strength index, tensile deformation index and tensile energy consumption index of PCJS, the effect of negative temperature action time on the tensile mechanical properties of PCJS was studied. The results show that with the extension of the negative temperature, the tensile strength of PCJS continues to increase, the tensile elongation at break and the tensile toughness first increase and then decrease, the tensile peak strain and the tensile pre-peak toughness keep decreasing. After 1 d of negative temperature, the tensile elongation at break and the tensile toughness of PCJS were the largest.
Feasibility study of the binary geopolymer as the dredged silt stabilizer
Authors: Shi Yupeng , Zhang Mo , Pan Zhu , Sanjayan Jay 
Published: March 2021

Abstract
With the increasing dredging activities, a large quantity of silt is removed from the bottom of waterbody and dumped on the landfill site, having the potential to cause a number of environmental issues. Given that dredged silt is the soft and weak soil, it is usually stabilized with ordinary Portland cement (OPC) and/or lime for application in construction. However, the production processes of traditional stabilizers are energy intensive and high CO2 emission. In this study, attempts are being made to find an alternative environmentally friendly stabilizer with a low carbon footprint using industrial by-products. Six mixtures were prepared and these mixes can be grouped into two series. Series I includes untreated soil (S), cement stabilized soil (CS), the binary geopolymer (alkali-activated slag-fly ash) stabilized soil (SFS) and the alkali-activated soil (AS). In series II, 18% sand (by the weight of total soil) was added to SFS and AS. The properties of stabilized soils were evaluated via unconfined compressive strength (UCS) test, scanning electron microscopy (SEM) imaging and X-ray diffractometer (XRD) test. The results showed the formation of geopolymer gel for both AS and SFS. The formation of sodium alumino silicate hydrate was also detected, which may result in higher strength of SFS, as compared to AS. The strength of SFS is similar to that of CS while the emission CO2-e values of SFS are 76% lower than that of CS, indicates the effectiveness of the binary geopolymer as an effective and green soil stabilizer alternative to OPC.
The Movement Track of the Ocean Current in Jiaozhou Bay
Authors: Yang Dongfang , Li Haixia , Wang Qi , Zhang Longlei , Lin Dong 
Published: March 2021

Abstract
According to the data on the investigation of Jiaozhou Bay in May, August and October, 1992, the Pb content and the horizontal distribution in the surface of Jiaozhou Bay were studied. The results show that in May, the open ocean current with a high content of Pb entered Jiaozhou Bay surrounding the nearshore waters of the bay. In August, in the waters of Jiaozhou Bay, there was only one high Pb content source - open ocean current transportation. The open ocean current entered Jiaozhou Bay with a high content of Pb. The ocean current passed from the outside of the bay to the inside through the bay mouth with 37.53 μg/L Pb content. Then the ocean current made a circle around the inshore waters of Jiaozhou Bay, bringing a high Pb content zone of 11.30 - 27.44 μg/L. At this point, a low Pb content area of 5.53 μg/L appeared in the central waters of Jiaozhou Bay. So, in August, the open ocean current with a high content of Pb moved into Jiaozhou Bay. Then it surrounded the nearshore waters of the bay. By the authors’ Dongfang Yang’s migration law of material content, it is obtained that the open ocean current with high Pb content moves into Jiaozhou Bay. And with the continuous decrease of Pb content, the flow path of the open ocean current in the bay, illustrated by a model block diagram, is left. Furthermore, the migration law reveals that the unit water body with the ocean current returns to the inlet water in a counterclockwise direction along the inshore water in the bay. Thus, under the combined action of ocean current and tide, this unit of water body shows zigzag movement from east to north and to west along the eastern, northern and western coastal waters of Jiaozhou Bay, leaving the center of the bay barely affected by the unit water. The unit body of water has a circular center in the center of the bay and a zigzag motion along the edges. Moreover, the topography and geomorphology of the bottom of Jiaozhou Bay also confirm the movement track of the ocean current in the waters of Jiaozhou Bay proposed by the authors.
Research on end location of 32m box girder in high-speed railway
Authors: Du Xiaorui 
Published: March 2021

Abstract
The creep camber of 32m high-speed railway box girder causes periodic track longitudinal level irregularity, so it is necessary to strictly and accurately control the line change caused by creep to ensure the operation safety. The traditional analysis is mainly done by manual work. Based on the longitudinal level data of dynamic track inspection, this paper uses wavelet decomposition and moving-average filter to study the end location of box girder. the longitudinal level at the girder’s end can be extracted and the line state can be analyzed automatically. The results show that: compared with other time-frequency analysis methods, the proposed method can accurately locate the end of the box girder, and has good applicability.
Research on Frost Heave of High Speed Railway in Seasonal Frozen Region Based on Track Geometry Measurements
Authors: Wang Xiang 
Published: March 2021

Abstract
The frost heave and thawing settlement in the seasonal frozen areas can cause the track geometry change, even seriously affect the driving safety. Taking the HSR-A railway as the research object, this paper divides the change process of track surface during the period of frost heave and thawing settlement into four stages, and equates the four stages into a trapezoidal change process. Then the characteristics of these stages are summarized. Finally, based on the track geometry measurements (TGM), two different linear functions are used to represent the track surface changes before and after frost heave start respectively, and this essay proposes the start time estimations model(STEM) to estimate the start time of frost heave. STEM is applied to 10 typical frost heave positions in the HSR-A. The results show: the estimated effect is good.
Field measurement, analysis and protection for the vibration response of granary ruins caused by train load
Authors: Ma Qingwen , Li Xingang , Cheng Chaoqun , Yan Haitao 
Published: March 2021

Abstract
In this paper, the vibration effect of Longhai Railway on a granary ruins is taken as the research object. Firstly, the vibration response of the granary ruins is obtained by field test. Then, using FLAC3D finite element analysis software to establish an overall calculation model, and the shock absorption effect of vibration isolation barrier is analyzed and predicted. The conclusions are as follows: the horizontal vibration of granary ruins is stronger than the vertical vibration; because of the special structure of the granary ruins, when the vibration propagates to the interface of the cellar wall, it will produce horizontal vibration amplification phenomenon, and the vibration intensity of the granary ruins away from the vibration source will decrease faster; discontinuous concrete isolation piles are used to protect granary ruins. Under the premise of considering more economical, double-row piles with staggered layout have the best vibration isolation effect.
Study on a 2D flow and sediment mathematical model for the reach where a bridge is located
Authors: Ge Hua , Deng Chunyan , Gong Ping 
Published: March 2021

Abstract
In order to evaluate the feasibility of constructing a bridge in the end of Ganjiang River, a two-dimensional mathematical model was established in this paper. In order to verify the reliability of the mathematical model, based on the water and sediment processes from 2013 to 2018, the riverbed erosion and deposition were calculated. According to the measured terrain in 2013 and 2018, the calculated amount and distribution of erosion and deposition were verified. The verification results show that the mathematical model established in this paper can better simulate the erosion and deposition amount and distribution of the river reach, which can provide a reliable technical support for the construction of bridges.
Experimental Research on Pressure Pulsation and Stability of Giant Francis Turbine
Authors: Geng Qinghua 
Published: March 2021

Abstract
Pressure pulsation is an important factor affecting the stability of the turbine. The test studied the characteristics and laws of pressure fluctuations of giant hydraulic turbines to provide guidance for the design and stable operation of giant hydraulic turbines. The test used time-domain analysis and frequency-domain analysis methods to test and analyze the pressure pulsating real machine of giant hydraulic turbine. The test results show that the amplitude of pressure pulsation has a negative correlation with active power. The active power ranges from no-load to 40%P, and the pressure pulsation is mainly expressed as a high-frequency waveform with a frequency conversion of 8.8 to 24.4 times. The active power ranges from 40%P to 75%P, and the pressure pulsation mainly manifests as a low-frequency waveform with a frequency conversion of 0.19 to 0.28 times. Active power range from 75%P to 100%P, the amplitude of pressure pulsation decreases significantly. The above three load areas coincide with the vibration area of the unit, indicating that the hydraulic factor is the main factor affecting the stability of the unit.
Surrounding the solution of a linear system of equations from all sides
Authors: Steinerberger Stefan 
Published: March 2021

Suppose

A
∈

R

n
×
n

A \in \mathbb {R}^{n \times n}

is invertible and we are looking for the solution of

A
x
=
b

Ax = b

. Given an initial guess

x
1

∈

R

x_1 \in \mathbb {R}

, we show that by reflecting through hyperplanes generated by the rows of

A
A

, we can generate an infinite sequence

(

x
k

)

k
=
1

∞

(x_k)_{k=1}^{\infty }

such that all elements have the same distance to the solution

x
x

, i.e.

‖

x
k

−
x
‖
=
‖

x
1

−
x
‖

\|x_k - x\| = \|x_1 - x\|

. If the hyperplanes are chosen at random, averages over the sequence converge and

E

‖
x
−

1
m

∑

k
=
1

m

x
k

‖

≤

1
+
‖
A

‖
F

‖

A

−
1

‖

m

⋅
‖
x
−

x
1

‖
.

\begin{equation*} \mathbb {E} \left \| x - \frac {1}{m} \sum _{k=1}^{m}{ x_k} \right \| \leq \frac {1 + \|A\|_F \|A^{-1}\|}{\sqrt {m}} \cdot \|x-x_1\|. \end{equation*}

The bound does not depend on the dimension of the matrix. This introduces a purely geometric way of attacking the problem: are there fast ways of estimating the location of the center of a sphere from knowing many points on the sphere? Our convergence rate (coinciding with that of the Random Kaczmarz method) comes from simple averaging, can one do better?
Correlated sexual selection on male genitalia, copulatory performance and nuptial gifts in a bushcricket (Orthoptera: Tettigoniidae) indicated by allometric scaling
Authors: Lehmann Gerlind U C , Kuchenreuther Sina , Lehmann Arne W , Dickhaus Thorsten 
Published: March 2021

AbstractWe adopt an allometric framework of scaling relationships for comparison between mating-related traits in the middle European bushcricket Roeseliana roeselii (Hagenbach, 1822). Eight characters, covering ontogenetic fitness (size traits; fixed at final moult), male condition (mass traits) and mating motivation (reproductive behaviours), were analysed in unrestricted matings and in matings involving genital manipulation. Shortening the male titillators had no effect on mating-related traits in males. However, titillators, known to be under sexual selection, scale hyperallometrically, with larger males possessing proportionally longer titillators, performing more titillator movements and exhibiting a reduced duration of copulation. Scaling was also hyperallometric for spermatophore mass, with larger males being heavier and transferring heavier nuptial gifts. Both titillator length and spermatophore mass might be condition-dependent indicators, because their variances were nearly twice as large those of body size or body mass. Mass traits were also dynamic, increasing by 11% for male body mass and 17% for spermatophore mass between the first and second matings. Sexual selection by female choice seems to favour larger trait size in the bushcricket R. roeselii, acting in concert on titillator length, intensity of titillator movements and spermatophore mass.
Overview of extracellular vesicles in the pathogenesis of preeclampsia
Authors: Wang Zheng , Zhao Gongxiao , Zeng Ming , Feng Weiyi , Liu Jinjun 
Published: March 2021

Abstract
Preeclampsia (PE) is a leading cause of maternal and fetal-neonatal deaths, and its pathogenesis has been linked to the involvement of extracellular vesicles (EVs). EVs are a heterogeneous group of cell-originated membranous vesicles including exosomes, microvesicles, and apoptotic bodies. EVs transport various bioactive cargos such as lipids, proteins, or nucleic acids, and thus mediate cellular communication and contribute to the proper functioning of cells, organs and processes, including normal pregnancy. Numerous studies have reported that EVs are associated with abnormal levels of soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), and placental growth factor (PlGF) in PE. EVs isolated from preeclamptic women have been implicated in trophoblast dysfunction and have been reported to activate endothelium, monocytes, and platelets, and to be involved in defective placentation, imbalanced angiogenesis, and intravascular inflammation. When injected into pregnant rodents, these EVs induced hypertension, proteinuria, and adverse fetal outcomes. Deciphering the contribution of EVs to PE will advance our current understanding of this disorder and may lead to more clinical strategies for the management of PE. Of note, the composition of EV cargos may be characteristic of the status and stages of gestation, providing researchers the possibility of one day using EVs as novel, noninvasive, biomarkers for early screening of PE. Herein, we reviewed the latest research into EVs with emphasis on their role in the pathogenesis of PE and their applications as biomarkers in the early screening of this pregnancy-specific disorder.
Diffusion Imaging Reveals Sex Differences in the White Matter Following Sports-Related Concussion
Authors: Wright David K , Symons Georgia F , O’Brien William T , McDonald Stuart J , Zamani Akram , Major Brendan , Chen Zhibin , Costello Daniel , Brady Rhys D , Sun Mujun , Law Meng , O’Brien Terence J , Mychasiuk Richelle , Shultz Sandy R 
Published: March 2021

Abstract
Sports-related concussion (SRC) is a serious health concern. However, the temporal profile of neuropathophysiological changes after SRC and how these relate to biological sex are still poorly understood. This preliminary study investigated whether diffusion-weighted magnetic resonance imaging (dMRI) was sensitive to neuropathophysiological changes following SRC; whether these changes were sex-specific; and whether they persisted beyond the resolution of self-reported symptoms. Recently concussed athletes (n = 14), and age- and education-matched nonconcussed control athletes (n = 16), underwent MRI 24–48-h postinjury and again at 2-week postinjury (i.e., when cleared to return-to-play). Male athletes reported more symptoms and greater symptom severity compared with females. dMRI revealed white matter differences between athletes with SRC and their nonconcussed counterparts at 48-h postinjury. These differences were still present at 2-week postinjury, despite SRC athletes being cleared to return to play and may indicate increased cerebral vulnerability beyond the resolution of subjective symptoms. Furthermore, we identified sex-specific differences, with male SRC athletes having significantly greater white matter disruption compared with female SRC athletes. These results have important implications for the management of concussion, including guiding return-to-play decisions, and further improve our understanding regarding the role of sex in SRC outcomes.
Quantitative Determination of Methohexital in Human Whole Blood by Liquid Chromatography Tandem Mass Spectrometry
Authors: Zhang Yi , Zhang Yunfeng , Zhai Chunfeng 
Published: March 2021

Abstract
A rapid, simple and sensitive liquid chromatography tandem mass spectrometry method for the determination of methohexital in human whole blood was developed and validated. Ethyl acetate/n-hexane (9:1) was used as extraction solvent while aprobarbital was used as internal standard. Methohexital was recovered by liquid–liquid extraction from 100 μL of human whole blood. The mobile phase was water-acetonitrile, and an ACQUITY BEH C18 (2.1 × 100 mm, 1.7 μm) column was adopted. Negative electrospray ionization source and multiply reaction monitoring mode were applied. The transitions of m/z were 261.2/42.2 and 261.2/119.0 for methohexital. The limit of detection was 0.5 ng/mL, which was lower than the previous methods. Wide linear range (2–2,000 ng/mL) with a good correlation coefficient (r &gt; 0.99) was also obtained. The intra- and inter- day precisions represented by relative standard deviation were &lt;11.5%, and the recoveries were &gt;79.67%. This analytical method involved small sample volume and had been proven to be rapid, easy, sensitive and specific. Therefore, it could be used for the clinical analysis of methohexital.