bluuebunny/crossref_metadata_2025 huggingface dataset:
On-surface synthesis of singly and doubly porphyrin-capped graphene nanoribbon segments
Authors: Mateo Luis M. , Sun Qiang , Eimre Kristjan , Pignedoli Carlo A. , Torres Tomas , Fasel Roman , Bottari Giovanni
Published: October 2020

Singly and doubly porphyrin-capped graphene nanoribbon segments are reported and their electronic properties are studied by high-resolution scanning tunneling microscopy and spectroscopy, and DFT calculations.
Hierarchical 2D yarn-ball like metal–organic framework NiFe(dobpdc) as bifunctional electrocatalyst for efficient overall electrocatalytic water splitting
Authors: Qi Lixia , Su Ya-Qiong , Xu Zichen , Zhang Guanghui , Liu Kang , Liu Min , Hensen Emiel J. M. , Lin Ryan Yeh-Yung
Published: October 2020

MOF electrocatalyst, NiFe(dobpdc) (dobpdc = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate), has a 2D nanosheets structure with large pore size, high surface area and exhibits electrocatalytic activity for OER and HER with extremely low overpotentials.
One-pot synthesis of acid-degradable polyphosphazene prodrugs for efficient tumor chemotherapy
Authors: Zhou Na , Zhang Ning , Zhi Zhe , Jing Xunan , Liu Daomeng , Shao Yongping , Wang Daquan , Meng Lingjie
Published: October 2020

In order to improve the therapeutic efficacy and reduce the side effects of anticancer drugs, pH sensitive and biodegradable polyphosphazene prodrugs were prepared.
A 3D-printed adaptive cloaking–illusion-integrated metasurface
Authors: Liang Qingxuan , Li Zhaohui , Jiang Zijie , Duan Yubing , Chen Tianning , Li Dichen
Published: October 2020

An adaptive cloaking–illusion-integrated metasurface is realized for the first time by combining stereolithography of 3D printing technology and injection molding of liquid metals.
Enhancing the red upconversion luminescence of hybrid porous microtubes via an in situ O-substituted reaction through heat treatment
Authors: Gao Dangli , Gao Jie , Zhao Dan , Pang Qing , Xiao Guoqing , Wang Liangliang , Ma Kaiwei
Published: October 2020

Uniform NaYF4:Yb/Er@YOF:Yb/Er porous microtubes with single-band red emission have been synthesized via a hydrothermal approach followed by an annealing treatment, which provides potential opportunities for anti-counterfeiting applications.
LncRNA HOTAIR modulates hepatitis B virus transcription and replication by enhancing SP1 transcription factor
Authors: Ren Fang , Ren Ji-Hua , Song Chun-Li , Tan Ming , Yu Hai-Bo , Zhou Yu-Jiao , Qin Yi-Ping , Cheng Sheng-Tao , Zhang Yuan , Huang Ai-Long , Chen Juan , Yang Xiao
Published: October 2020

Hepatitis B virus (HBV) infection remains a global public health problem. Nearly 257 million people worldwide have been infected with HBV, resulting in 887,000 people dying of cirrhosis or liver cancer caused by chronic hepatitis B (CHB) annually. Therefore, identification of new targets against HBV is urgently needed. Long noncoding RNAs (LncRNAs) have gained widespread attention in recent years due to their function in cancer, inflammation and other diseases. Notably, a growing number of lncRNAs have been found to play a role in HBV development. In the present study, we first identified a famous lncRNA, HOTAIR, which was significantly up-regulated in HBV-infected cells and PBMCs from CHB patients. Furthermore, we evaluated the clinical relevance of HOTAIR in 20 CHB patients and found that higher levels of HOTAIR expression were associated with higher ALT/AST levels and were positively correlated with HBsAg and HBV DNA levels. In addition, functional analysis showed that HOTAIR promoted HBV transcription and replication by elevating the activities of HBV promoters via modulation of the levels of cccDNA-bound SP1. In conclusion, our study reveals that HOTAIR expression is correlated with the clinicopathological and physiological characteristics of HBV. Thus, HOTAIR may serve as a novel HBV diagnostic and therapeutic biomarker based on its ability to facilitate HBV transcription and replication.
Quantitative Videofluoroscopic Analysis of Swallowing Physiology and Function in Individuals With Chronic Obstructive Pulmonary Disease
Authors: Mancopes Renata , Peladeau-Pigeon Melanie , Barrett Emily , Guran Andrea , Smaoui Sana , Pasqualoto Adriane Schmidt , Steele Catriona M.
Published: October 2020

Purpose

Dysphagia is a serious extra pulmonary manifestation of chronic obstructive pulmonary disease (COPD). However, the nature of abnormalities in swallowing physiology in COPD has yet to be clearly established. We explored the frequency of swallowing measures outside the healthy reference range in adults with COPD.

Method

Participants were 28 adults aged 41–79 years (18 men, 20 women) with stable COPD. Disease severity was classified as GOLD (Global Initiative For Chronic Obstructive Lung Disease) Stages 1 (4%), 2 (25%), 3 (53%), and 4 (18%). Participants underwent a videofluoroscopy and swallowed 20% w/v thin barium in, followed by 20% w/v mildly, moderately, and extremely thick barium prepared with a xanthan gum thickener. Blinded duplicate ratings of swallowing safety, efficiency, kinematics, and timing were performed according to the ASPEKT method (Analysis of Swallowing Physiology: Events, Kinematics and Timing). Comparison data for healthy adults aged < 60 years were extracted from an existing data set. Chi-square and Fisher's exact tests compared the frequencies of measures falling < 1
SD
/ > 1
SD
from mean reference values (or < the first or > the third quartile for skewed parameters).

Results

Participants with COPD did not display greater frequencies of penetration–aspiration, but they were significantly more likely (
p
< .05) to display incomplete laryngeal vestibule closure (LVC), longer time-to-LVC, and shorter LVC duration. They also displayed significantly higher frequencies of short upper esophageal sphincter opening, reduced pharyngeal constriction, and pharyngeal residue.

Conclusion

This analysis reveals differences in swallowing physiology in patients with stable COPD characterized by impaired safety related to the mechanism, timing, and duration of LVC and by impaired swallowing efficiency with increased pharyngeal residue related to poor pharyngeal constriction.
Evolution of spheroidal dust in electrically active sub-stellar atmospheres
Authors: Stark C. R. , Diver D. A.
Published: October 2020

Context. Understanding the source of sub-stellar polarimetric observations in the optical and near-infrared is key to characterizing sub-stellar objects and developing potential diagnostics for determining properties of their atmospheres. Differential scattering from a population of aligned, non-spherical dust grains is a potential source of polarization that could be used to determine geometric properties of the dust clouds.

Aims. This paper addresses the problem of the spheroidal growth of dust grains in electrically activated sub-stellar atmospheres. It presents the novel application of a mechanism whereby non-spherical, elongated dust grains can be grown via plasma deposition as a consequence of the surface electric field effects of charged dust grains.

Methods. We numerically solve the differential equations governing the spheroidal growth of charged dust grains via plasma deposition as a result of surface electric field effects in order to determine how the dust eccentricity and the dust particle eccentricity distribution function evolve with time. From these results, we determine the effect of spheroidal dust on the observed linear polarization.

Results. Numerical solutions show that e ≈ 0.94 defines a watershed eccentricity, where the eccentricity of grains with an initial eccentricity less than (greater than) this value decreases (increases) and spherical (spheroidal) growth occurs. This produces a characteristic bimodal eccentricity distribution function yielding a fractional change in the observed linear polarization of up to ≈0.1 corresponding to dust grains of maximal eccentricity at wavelengths of ≈1 μm, consistent with the near infrared observational window. Order of magnitude calculations indicate that a population of aligned, spheroidal dust grains can produce degrees of polarization P ≈ 𝒪(10−2 − 1%) consistent with observed polarization signatures.

Conclusions. The results presented here are relevant to the growth of non-spherical, irregularly shaped dust grains of general geometry where non-uniform surface electric field effects of charged dust grains are significant. The model described in this paper may also be applicable to polarization from galactic dust and dust growth in magnetically confined plasmas.
The molecular mass function of the local Universe
Authors: Andreani P. , Miyamoto Y. , Kaneko H. , Boselli A. , Tatematsu K. , Sorai K. , Vio R.
Published: October 2020

Aims.We construct the molecular mass function using the bivariateK-band-mass function (BMF) of theHerschelReference Survey (HRS), which is a volume-limited sample that has already been widely studied at the entire electromagnetic spectrum.

Methods.The molecular mass function was derived from theK-band and the gas mass cumulative distribution using a copula method, which is described in detail in our previous papers.

Results.The H2mass is relatively strongly correlated with theK-band luminosity because of the tight relation between the stellar mass and the molecular gas mass within the sample with a scatter, which is likely due to those galaxies which have lost their molecular content because of environmental effects or because of a larger gas consumption due to past star formation processes. The derived H2MF samples the molecular mass range from ∼4 × 106M⊙to ∼1010 M⊙, and when compared with theoretical models, it agrees well with the theoretical predictions at the lower end of the mass values; whereas at masses larger than 1010 M⊙, the HRS sample may miss galaxies with a large content of molecular hydrogen and the outcomes are not conclusive. The value of the local density of the molecular gas mass inferred from our analysis is ∼1.5 × 107 M⊙Mpc−3, and it is compared with the results at larger redshifts, confirming the lack of strong evolution for the molecular mass density betweenz= 0 andz= 4.

Conclusions.This is the first molecular mass function that has been derived on a complete sample in the local Universe, which can be used as a reliable calibration at redshiftz= 0 for models aiming to predict the evolution of the molecular mass density.
SP_Ace v1.4 and the new GCOG library for deriving stellar parameters and elemental abundances
Authors: Boeche C. , Vallenari A. , Lucatello S.
Published: October 2020

Context. Ongoing and future massive spectroscopic surveys will collect very large numbers (106–107) of stellar spectra that need to be analyzed. Highly automated software is needed to derive stellar parameters and chemical abundances from these spectra.

Aims. We present the new version of SP_Ace (Stellar Parameters And Chemical abundances Estimator) a code that derives stellar parameters and elemental abundance from stellar spectra. The new version covers a larger spectral resolution interval (R = 2000−40 000) and its new library covers bluer wavelengths (4800–6860 Å).

Methods. SP_Ace relies on the General-Curve-Of-Growth (GCOG) library based on 6700 absorption lines whose oscillator strengths were calibrated astrophysically. We developed the calibration method and applied it to all the lines. From the new line list obtained we build the GCOG library, adopting an improved method to correct for the opacity of the neighboring lines. We implemented a new line profile for the code SP_Ace that better reproduces that of synthetic spectra. This new version of SP_Ace and the GCOG library has been tested on synthetic and real spectra to establish the accuracy and precision of the derived stellar parameters.

Results. SP_Ace can derive the stellar parameters Teff, log g, [M/H], and chemical abundances with satisfactory results; the accuracy depends on the spectral features that determine the quality, such as spectral resolution, signal-to-noise ratio, and wavelength coverage. Systematic errors were identified and quantified where possible. The source code is publicly available.
Satellite observation of the dust trail of a major bolide event over the Bering Sea on December 18, 2018
Authors: Borovička J. , Setvák M. , Roesli H. , Kerkmann J. K.
Published: October 2020

Context.One of the most energetic bolide events in recent decades was detected by the US Government sensors (USGS) over remote areas of the Bering Sea on December 18, 2018, 23:48 UT. No ground-based optical observations exist.

Aims.Using the satellite imagery of the dust trail left behind by the bolide, we tried to reconstruct the bolide trajectory. In combination with the bolide speed reported by the USGS, we computed the pre-atmospheric orbit. Observations in various spectral bands from 0.4 to 13.3μm enabled us to study the dust properties.

Methods.Images of the dust trail and its shadow obtained from various angles by the Multi-angle Imaging SpectroRadiometer (MISR) on board the Terra polar satellite and geostationary satellites Himawari-8 and Geostationary Operational Environmental Satellite 17 (GOES-17) were used. The initial position and orientation of the trail was varied, and its projections into the geoid coordinate grid were computed and compared with real data. Trail motion due to atmospheric wind was taken into account. Radiances and reflectances of selected parts of the dust trail were taken from the Moderate-resolution Imaging Spectroradiometer (MODIS) on board Terra. Reflectance spectra were compared with asteroid spectra.

Results.The bolide radiant was found to be 13° ± 9° from that reported by the USGS, at azimuth 130° (from south to west) and zenith distance 14°. The bolide position was confirmed, including the height of maximum dust deposition around 25 km. The incoming asteroid had to be quite strong to maintain a high speed down to this height. The speed of 32 km s−1, reported by the USGS, was found to be plausible. The orbit had a high inclination of about 50° and a perihelion distance between 0.95–1 AU. The semimajor axis could not be restricted well but was most probably between 1–3 AU. The dust reflectance was much lower in the blue than in the red, consistent with the material of A- or L-type asteroid. The absorption at 11μm confirms the presence of crystalline silicates in the dust.
Safety state identification of concrete pumping pipeline based on multi-channel audio signals
Authors: He Guanghui
Published: October 2020

Based on the principle of superposition and attenuation of sound propagation, a Multi-point Multi-channel noise Reduction Method (MMRM) for audio monitoring is proposed. With the help of the proposed noise reduction method, the sounds made by the concrete pumping-pipelines themselves on the construction site and the environmental noises are separated in real time. Then, the Mel-Frequency Cepstral Coefficients (MFCCs) and spectral centroids of the filtered pumping-pipeline signals are extracted in real time as the features. Finally, the distance between the currently obtained feature vector of the pipeline signals and the previous accumulated MFCC clustering are determined as the parameter for safety identification. In order to verify the actual effects of the MMRM and the analysis accuracy of MFCCs in the clustering, several numerical tests and field measurements are carried out. The numerical results show that the MMRM has an excellent performance on noise reduction; the feature vectors composed of the MFCCs with length no greater than 4 are sufficient for the recognition and clustering of pumping-pipeline operation state.
Experimental Research on C60 Concrete Strength Evolution under Different Curing Conditions
Authors: Ran Zhu , Jun Xu , Yijian Zhan , Zibo Zuo , Xiangyang Zhou , Zhiyong Shen
Published: October 2020

An experimental study on the C60 concrete was carried out under five different curing conditions based on the maturity theory. The influence patterns of the curing conditions on the increase of the C60 concrete strength were discussed. The experimental data were fitted using different strength-maturity models, the accuracies of which were then analyzed. The results show that the mapping relation between the compressive strength and maturity of the C60 concrete could be well characterized by the logarithmic functional relation.
Research on mix proportion and solid rebound detection of high strength concrete in super high rise building
Authors: Hao Zhonghai
Published: October 2020

At present, the application of high performance concrete in super high-rise building engineering structure is more and more extensive. The mix proportion of high-strength concrete is the basic variable of concrete, and the rebound detection of building structure is carried out. On this basis, the design method of building pressure matching is proposed. Due to the large error of the estimated value of the strength test curve unified by the whole country, in a new project in Xi’an, the rebound method and core drilling method are carried out on several concrete members, and it is concluded that the test results of rebound method and core drilling method with different strength levels are quite different. In view of the difference of test results of mix proportion rebound method of high-strength concrete of super high-rise buildings in Xi’an area, the correction method of rebound difference of different strength levels is put forward.
Research and analysis of new paste filling material based on red mud iron tailings
Authors: Wang Lihua , Zhang Jie , Sun Gaochao
Published: October 2020

In order to reduce the amount of high energy consumption materials such as cement in filling, save resources, and fully recycle industrial waste. In this paper, Changxing coal mine as the research background, through data analysis, and through the test configuration based on red mud iron tailings, mixed with desulfurization gypsum, lime, cement, activator of new cementitious materials. And through the test analysis, the best proportion of coagulant admixture is determined as follows: red mud iron tailings dosage 6, cement sand ratio 1:3, mass concentration 68%.
Calculation of Cd Content Settlement in a Circle of Coastal Waters
Authors: Yang Dongfang , Li Haixia , Zhang Longlei , Wang Qi , Zhu Hong
Published: October 2020

With the help of the data about Cd in the southeast and southwest waters of Jiaozhou bay and models of horizontal and vertical matter content variation proposed by the authors, horizontal loss amount and vertical diluted amount of Cd content in the surface layer and bottom layer are calculated, and the model block diagrams of horizontal and vertical variation of Cd content are determined. The calculation shows that in August, the absolutely horizontal loss amount of Cd content in the surface layer and bottom layer was 0.06-0.43μg/L, and the relatively horizontal loss amount of Cd content in the surface layer and bottom layer was 42.85-57.33%. In the southeast and southwest waters of the bay, the absolutely verticaldiluted amount of Cd content in the surface layer and bottom layer was 0.24-0.61μg/L, and the relatively vertical diluted amount was 75.00-81.33%. In the process of horizontal migration in August, in the surface waters, the main sea current carried Cd content through a circle of the nearshore waters in the bay, and there was almost no source of Cd content. Therefore, in the horizontal migration process of Cd content, after a long journey, the Cd content in the surface layer and bottom layer got a lot of losses. Specifically, the absolutely horizontal loss amount was 0.06- 0.43μg/L, and the relatively horizontal loss amount was 42.85-57.33%, which proved Dongfang Yang’s migration law of matter content put forward by the authors. In the process of vertical migration in August, the Cd content transported by the main sea current was higher in the southeast waters of the bay, and the vertical diluted amount of Cd content in the surface layer and bottom layer was 81.33%. The main sea current reached the waters of the southwest bay from the waters of the southeast bay through a circle of the nearshore waters in the bay. At this time, the Cd content transported by the main sea current was relatively low in the waters of the southwest bay, but the vertical diluted amount of Cd content in the surface layer and bottom layer was still very high, which was 75.00%. It reveals that the vertical diluted amount of Cd content in the surface layer and bottom layer was very high in any water area, whether the Cd content is high or low.
Research on Safety Spacing of Chemical Storage Tanks Based on Accident Consequence and Risk Analysis
Authors: Li Zhenping , Wang Sanming , Sun Dongliang
Published: October 2020

The placement of chemical storage tanks is an important topic in industrial safety, and its placement method is based on the study of the safety spacing of storage tanks. This paper takes LPG and LNG storage tanks as examples. It uses vapor cloud explosions, pool fires, pressure vessel explosions, boiling liquid expansion vapor explosions and other fire and explosion accident consequences models and risk probability analysis methods to analyze. It is proved that the transfer of storage tanks from ground to underground can significantly reduce the scope of impact of explosion accidents, thereby increasing the utilization rate of industrial land.
Research on the preparation of a new type steel slag ceramics with steel slag and coal ash
Authors: Xueting Liu
Published: October 2020

Along with our rapid development of steel industry, the output of steel slag was increasing these yesrs. But all kinds of industrial waste emissions increased rapidly too. Application of good solid wastes such as coal ash and mineral powder is under low utilization rate, a large number of accumulation is serious threat to the environment and other issues. Therefore, research on the preparation of a new type steel slag ceramics with steel slag and coal ash is important to improve the industrial solid waste resource utilization. In this paper, the new type of steel slag ceramics was prepared by industrial waste steel slag and industrial waste coal ash, and the new type of steel slag ceramics was prepared by appropriate sintering process system. Meanwhile, the performance indexes of ceramic bricks were tested to determine the influence of different factors on the performance of the new type of steel slag ceramics.
Mechanism analysis and model calculation of chloride ion diffusion in reinforced concrete structure
Authors: Yu Faqiang , Gao Weiwei , Liu Wenchao
Published: October 2020

Chloride-induced corrosion of steel in reinforced concrete structures is one of the major causes of their deterioration over time. The analysis and research on the diffusion mechanism of chloride ions in reinforced concrete structures is still insufficient, and it is necessary to calculate the path of chloride ions based on theoretical models. In this paper, the fick’s second law was used to describe the free chloride concentration evolution in concrete. The Monte Carlo simulation was used to predict the cumulative distribution of corrosion initiation of reinforcing steel.The results show that the calculated results of the established model are in good agreement with the measured results.
Coupling numerical model of hydraulic fracturing seepage in soft coal based on elastoplastic damage
Authors: Liangwei LI
Published: October 2020

In order to guide the field application of hydraulic fracturing of soft coal in coal mine, based on the elastic-plastic damage theory, the coupling numerical model of soft coal hydraulic fracturing seepage was studied. The porosity strain relationship equation, permeability strain relationship equation, the relationship between permeability and volume plastic tensile strain and volume plastic shear strain of coal and rock mass are derived, and the plastic correction equation and softening parameters are defined. The stress coupling equation and yield criterion are programmed and embedded into the finite difference software FLAC3D for numerical solution. The numerical simulation shows that the numerical calculation model of soft coal hydraulic fracturing conforms to the actual law, and the field fracturing radius investigation experiment is consistent with the numerical simulation results.
Experimental Study on Dynamic Splitting Tensile Failure Mode of Carbon Nanofibers Reinforced Concrete
Authors: Xia Wei , Xu Jinyu , Wang Zhihang , Huang Zhe , Liu Gaojie
Published: October 2020

Carbon nanofibers (CNFs) were used as admixtures to modify traditional concrete, and carbon nanofibers reinforced concrete (CNFC) with fiber volume fraction of 0%, 0.1%, 0.2%, 0.3% and 0.5% were prepared. The dynamic splitting tensile tests of concrete with different fiber volume contents under five loading rates were carried out by using the Φ100 mm split Hopkinson pressure bar (SHPB) test device. Based on the observation and analysis of the failure modes of the specimens, combined with the energy change rate of incident wave, the failure characteristics of CNFC under dynamic splitting tensile load are expounded. The results show that: the addition of CNFs has a certain inhibition effect on the dynamic splitting tensile failure of concrete; the failure modes of the specimens are the central failure along the loading direction; with the increase of the energy change rate of incident wave, the damage degree of the specimen is gradually aggravated.
Experimental study on demulsification speed of emulsified asphalt based on equivalent surface area principle
Authors: Li Yan , Liang Hao , Lin Jiangtao , Fan Liang , Li Yongzhen , Wei Hui
Published: October 2020

In order to simplify the demulsification speed test of emulsified asphalt, rapid-breaking, medium-breaking and slow-breaking emulsified asphalt as well as different aggregates were selected for the demulsification speed test. The specific surface area of each single grade was determined by the actual measurement, and the equivalent aggregate was collected according to the principle of equivalent surface area. The results show that the equivalent aggregate can be composed by the assembling of gradations smaller than 0.075mm and one or two bigger gradations. Therefore, the types of gradation in the equivalent aggregate will be reduced by one-half compared with that in the standard aggregate. The surface area of the equivalent aggregate is the same as that of the standard aggregate, and under a certain volume ratio, the demulsification rate determined by equivalent aggregate or standard aggregate is the same.There is also a critical volume ratio existing for the equivalent aggregate, If the critical volume ratio is exceeded, the demulsification rate determined by the equivalent aggregate will be greatly different from that determined by the standard aggregate. It is also found that the volume ratio turns to 1 without any changes when the proportion of gradation smaller than 0.075mm reaches 25%-30%.
Research on Interfacial Bonding Properties and Engineering Applications of Polymer Modified Mortar
Authors: Wang Zhihang , Xu Jinyu , Xia Wei , Huang Zhe , Meng Xin , Xiaoguang Xing
Published: October 2020

Using the slotting method to process the interface of ordinary mortar, based on ordinary mortar specimens, new and old mortar bonding specimens were prepared, and the bond strength test was carried out. The effect of interface roughness on the bonding strength of VAE rubber powder modified mortar and styrene-acrylic emulsion modified mortar was tested, and then the interfacial bonding properties of polymer modified mortar were studied. The test results show that the bonding strength of polymer-modified mortar increases with the increase of interface roughness; in engineering applications, the interface can be properly chiseled to increase the interface roughness, which is beneficial to the bonding of polymer-modified mortar firm. At the same time, the application prospects of VAE rubber powder modified mortar in the field of concrete anti-corrosion, and the application prospect of styrene-acrylic emulsion modified mortar in the repair and freeze-thaw damage of concrete structure and anti-seepage treatment are prospected.
Effects of calcium carbonate on hydro-mechanical properties of bentonite
Authors: Fu Xian-Lei , Qin Ai-Fang , Xu Wei-Fang , Jiang Liang-Hua
Published: October 2020

To simulate characteristic changes of the bentonite mixing with CaCO3crystals that precipitate from groundwater around the high-level radioactive waste repositories, different amounts of CaCO3powders were mixed in the bentonite. In this study, four series of bentonite/CaCO3mixtures were prepared with different contents of CaCO3powders. A series of swelling, compression and direct shear tests were conducted on the bentonite/CaCO3samples using deionized water. Terzaghi consolidation theory was adopted to compute the hydraulic conductivity of bentonite/CaCO3mixtures. The results demonstrated that the final swelling strain decreased with increasing vertical stress and the content of CaCO3powders. The compression index decreased slightly with increasing CaCO3content. It was found that as the CaCO3content increased, the hydraulic conductivity of bentonite/CaCO3mixtures decreased. There was a peak point in the shear strength of unsaturated samples with the differences of the CaCO3content. The cohesion of unsaturated samples increased first and then decreased, but saturated samples presented the opposite character. It could be seen from the scanning electron micrograph that the existence of CaCO3powders filled pores of bentonite/CaCO3mixtures and made the structure denser.
Research on Influencing Factors of Composite Foundation Settlement with Capped Pipe Piles Based on Centrifugal Model Test
Authors: Bei-bei Yao , Li-ping Zhao , Chun-feng Pan
Published: October 2020

In order to study the influence of design factors of capped pipe pile composite foundation on differential settlement of expressways, using a geotechnical centrifugal model test platform, a centrifugal model of widen roadbed has been constructed. The effects of pile length, pile spacing, pile cap and cushion thickness on differential settlement were analyzed through comparative experiments. The test results show that increasing the pile length, pile cap size and cushion thickness can effectively control the differential settlement between old and new embankments. The research results can provide a theoretical basis for the design of composite foundations with capped pipe piles.
Research progress of analysis method of slope stability combined with hot spots
Authors: Qiao XIE , Jia-sheng ZHANG , Xuan Wang
Published: October 2020

The analysis methods and theories of slope stability are constantly improving and developing, and more methods in line with the development characteristics of the times have been put forward by scholars at home and abroad. Combined with the latest research hot spots in the direction of analysis methods of slope stability in the world, the analysis methods of slope stability are systematically classified and summarized; The principles, characteristics, scope of application of various methods are summarized; The development trend of slope stability analysis is comprehensively analyzed from various aspects. It provides the follow-up scholars with the research of new methods. It can provide reference for the selection of evaluation methods of practical slope engineering stability.
Research on Influence of Road Tunnels with Different Lanes on Surrounding Rock Characteristic Curve
Authors: Yang Sun , Chengke Zhang , Junping Yu , Jiangpeng Wu , Liqing Zhu
Published: October 2020

Convergence confinement method is an important guidance method for tunnel construction and support design. Numerical simulation method was used to comparatively analyze the ground reaction curve and the plastic zone under different rock grade and roadway tunnel size. The results show that the change of tunnel size has different effects on the maximum deformation of the tunnel arch crown, the ground reaction curve and the plastic zone range. Finally, some suggestions were put forward for the construction and optimization of the large span arch tunnel support structure. The research results may provide some guidance for related engineering
The influence of the parameters of the diaphragm wall on the deformation of the excavation
Authors: CHEN Peng-fei , GONG Xiao-nan
Published: October 2020

A model of a certain excavation was established using PLAXIS 3D, and the measured value was compared with the calculated value. The thickness, elastic modulus, and embedded depth of the diaphragm wall are analysed by the controlled variable method. The graphs of the influence of the above three factors on the deformation of the retaining wall of the excavation, the settlement of the soil outside the pit, and the bending moment of the retaining wall are obtained. The data is relativized to make the comparison result more intuitive and vivid. With the increase of wall thickness or elastic modulus or embedded depth, the deformation of the retaining wall and the settlement of the soil outside the pit will decrease. As the wall thickness or elastic modulus increases, the bending moment of the retaining wall will increase. The embedded depth has almost no effect on the bending moment. The magnitude of the influence on the deformation and force of the excavation is sorted from the largest to the smallest as the wall thickness, the elastic modulus, and the embedded depth.
Research and Analysis on the Supporting Structure of the Second Lining of the Tunnel in the Phyllite Stratum
Authors: Zhiquan Wei , Baisheng Huang , Lu Yang , Yonghao Wei , Jianqiao Qiu
Published: October 2020

The reasonable construction of the secondary lining structure of the tunnel is an important link to ensure the stability of the surrounding rock of the tunnel. Taking a phyllite stratum tunnel project in Jiangxi as the background, the Flac3D finite difference software was used to numerically simulate and analyze the supporting structure of the secondary lining. The impact of support timing on surrounding rock stress. The calculation results show that with the progress of the construction step, the main period of the displacement of the vault is after the excavation of the upper section of the tunnel before the upper section support; The plastic zone of the surrounding rock changes obviously, especially above the tunnel, and finally the plastic zone develops to the ground; the stress of the surrounding rock shows a decreasing trend with the increase of the time of the secondary lining. The research results can provide certain guiding significance for the construction of the second lining of the tunnel under similar geological conditions.
Stability analysis of composite I-shaped masonry reinforced retaining wall
Authors: Yuedong Wu , Lei Zhang , Nan Xu , Jian Lui
Published: October 2020

Based on the actual project, the influence of geogrid on the stability of the retaining wall of the single-layer masonry reinforced retaining wall is studied through field test and finite element software ABAQUS numerical simulation. The influence of geogrid on the stability of the retaining wall was determined by analyzing the changes in the pressure of the backfill, the displacement of the retaining wall and the strain of the geogrid, and changing the length and spacing of the geogrid through the controlled variable method. The results show that the geogrid can limit the horizontal displacement of the soil, balance the earth pressure, and improve the overall stability of the retaining wall. By increasing the length of the geogrid and reducing the distance of the geogrid, the design of the retaining wall is optimized, which has good economic and time benefits.
Application of Wavelet Neural Network in Building Settlement Prediction
Authors: Zhang Ruijie
Published: October 2020

Deformation monitoring, as a key link of information construction, runs through the entire process of the building design period, construction period and operation period[1]. At present, more mature static prediction methods include hyperbolic method, power polynomial method and Asaoka method. But these methods have many problems and shortcomings. In this paper, based on the characteristics of building foundation settlement and the methods widely discussed in this field, a wavelet neural network model with self-learning, self-organization and good nonlinear approximation ability is applied to the prediction problem of building settlement[2]. Using comparative analysis and induction method. The 20-phase monitoring data representing the deformation monitoring points of different settlement states of the line tunnel, using the observation data sequence of the first 15 phases respectively to take the cumulative settlement and interval settlement as training samples, through the BP artificial neural network and the improved wavelet neural network, for the last five periods Predict the observed settlement.Through the comparison, it is found that whether the interval settlement or the cumulative settlement is used, the prediction results of the wavelet neural network are basically better than the prediction results of the BP artificial neural network, and the number of trainings is greatly reduced. The adaptive prediction of the wavelet neural network. The ability is particularly obvious, and the prediction accuracy is significantly improved. Therefore, it can be shown that the wavelet neural network is indeed used in the settlement monitoring and forecast of buildings, which can obtain higher prediction accuracy and better prediction effect, and is a prediction method with great development potential.
Research on Participatory Design Method of Mixed Bean Planting Machinery
Authors: aili ZHAO , zhanbin GUO , liming WANG , qingfeng QU , haibin QIN
Published: October 2020

To promote the realization of collaborative design path of mixed bean planting machinery by studying the application of participatory design method in mixed bean planting machinery. To clarify the importance of industrial design for the innovation and development of mixed bean planting machinery, use participatory design methods to coordinate the development trend of industrial design and mixed bean planting machinery, and guide design practice to achieve joint research and joint design, thus realizing the innovative development of mixed bean planting machinery.
Research on Behavior Cause of Limited Space Accident Based on “2-4” Model
Authors: Yu Fengjie , Zhang Lijing , Tao Gang
Published: October 2020

In order to prevent accidental casualties in the course of limited space operation, the behavioral safety “2-4” model is used to study the behavioral causes of typical limited space operation accidents. First, the causes of one-time and habitual behavior are studied from the individual level, that is, unsafe action, physical state and safety knowledge, consciousness; then, the research of operational behavior and guiding behavior is studied from the organizational level. Finally, the prevention and control suggestions are put forward to reduce the occurrence of such accidents.
Thoughts on Urban Planning of Big Cities in China Caused by the COVID-19 Epidemic
Authors: Zhao Huiyan
Published: October 2020

Public health emergencies such as the COVID-19 outbreak has made all industries to reexamine the way the cities have always grown. Urban planning is no exception. Based on the analysis of the development track and phenomenon of Wuhan City, this paper puts forward the planning thinking of the development of China’s big cities. According to the study, it is urgent to study the suitable size, structure and form of big cities. The consistent practice of high-intensity development needs to stop. Urban development should pay more attention to the space that can not directly generate economic benefits.
Research and Planning Design of Traditional Village Tourism Pension Model—Taking Madiping Village in Longnan as an example
Authors: Yang Zhiwei , Wang Yuan , Xiang Yingchang
Published: October 2020

The tourism pension in traditional villages is based on the rural agricultural production value and tourism cultural value as the attraction, relying on the natural landscape, human customs, historical buildings and other resources of traditional villages. With Madiping village as an example, through the surrounding economic factors, climate environment, comfort, leisure, entertainment, medical rehabilitation, spirit culture and service facilities of these seven factors questionnaire survey analysis, hierarchical structure model is established by using Analytic Hierarchy Process (AHP), it is concluded that the present stage tourism endowment patterns relations, weights of factors affecting peasant casual is the trend of the development of local tourism endowment. On the basis of qualitative research, based on the protection of the historical features of traditional villages, the principle of rural tourism, leisure and old-age care was created, and the planning and design of remote tourism and old-age care was carried out in combination with rural resources and environment, so as to achieve the purpose and significance of promoting rural economic revitalization and regional development.
The dust storm events recorded in DaQaidam region of Qaidam Basin since Late Glacial period: evidence from the grain size of lake sediment
Authors: Gao Chunliang , Yu Junqing , Min Xiuyun , Cheng Aiying
Published: October 2020

The paper focused on the study of detrital yellow layer from sediment profile D3 of DaQaidam Salt Lake, based on AMS 14C chronologic and mineralogical methods, aimed to discuss the dust storm events recorded by detrital yellow layer of DaQaidam region since Late Glacial period. The results showed that the grain-size distribution curve displayed double kurtosis, the main peak (10 µm in average) reflected the fine-grained fractions into lake by fluviation, and the secondary peak (> 32 µm) reflected the coarse silt fractions into lake by wind effect and fluviation. Finally, the coarse-grained fractions (> 64 µm) from sediment profile D3 probably recorded the dust storm events since Late Glacial period.
Lithostratigraphy, mineralogy and the boron-bearing brine evolution of DaQaidam Salt Lake in Qaidam Basin since Holocene period, northern Qinghai-Tibet Plateau
Authors: Gao Chunliang , Yu Junqing , Min Xiuyun , Cheng Aiying
Published: October 2020

Little attention has been paid to the study of sedimentary records from DaQaidam Salt Lake regarding brine evolution and hydro-climate change. Here we report the results of AMS 14C dating and mineralogical investigation on a sediment profile D4 from the south central of perennial saline water-body. The result revealed that pinnoite deposit in the lakebed was formed in early Holocene, the lake underwent three stages of lake-level and brine evolution in Holocene period, which were determined mainly by precipitation-controlled catchment inflow. The mineralogical records also depicted fluctuations in lake level and hydrochemistry on decadal and centennial scales.
Drop Foot Secondary to a Peroneal Intraneural Ganglion Connected to the Superior Tibiofibular Joint: A Case Report
Authors: Kıbıcı Kenan , Erok Berrin , Onat Akın
Published: October 2020

Peroneal neuropathy is the most frequent mononeuropathy of the lower extremity. Intraneural ganglion cysts (INGCs) are among rare causes of peroneal nerve palsy. According to the articular (synovial) theory, the articular branch plays the key role in the pathogenesis. Patients present with pain around the fibular head and neck, motor weakness resulting in foot drop and paresthesia in the anterolateral calf and foot. Ultrasonography (US) and MRI are both useful in the diagnosis, but MRI is the best imaging modality in the demonstration of the articular connection and the relation of the cyst with adjacent structures, even without special neurography sequences. We present a 32-year-old male patient referred to our neurosurgery clinic with suspicion of lumbar radiculopathy. He presented with right foot drop which began 3 weeks prior. On examination, there was 90% loss in the ankle dorsiflexion and finger extension. Ankle eversion was also weakened. There was no low back or posterolateral thigh pain to suggest L5 radiculopathy and sciatic neuropathy. Following negative lumbar spine MRI, peripheral neuropathy was concerned. Electrodiagnostic evaluations findings were consistent with acute/subacute common peroneal nerve (CPN) axonal neuropathy. Subsequent MRI of knee showed a homogeneous, thin-walled tubular cystic lesion, extending along the course of the CPN and its articular branch. Full recovery of the neuropathy was achieved with early diagnosis and decompression via microsurgical epineurotomy. The diagnosis of INGC was confirmed by histopathologic examination. INGCs, although rare, should also be considered in the differential diagnosis of peripheral mononeuropathies.
Pseudoobstrucción colónica aguda (Sindrome de Ogilvie) posterior a una nefrectomía radical: Reporte de caso
Authors: Gentili Georgina , Colella María Florencia , Deluca Agustín , Pérez Pablo Leonardo , Rossi Pablo Cesar , Damia Omar Pablo Alejandro , Laplumé Ezequiel Elizalde , Sarno Patricio Lucio
Published: October 2020

El Sindrome de Ogilvie se caracteriza por una dilatación masiva del colon y una clínica sugestiva de obstrucción intestinal mecánica, sin causa orgánica. Presentamos un caso de dilatación aguda idiopática del colon secundaria a una cirugía abdominal.

El objetivo de este reporte fue la descripción de una patología urológica inusual que puede pasarse por alto o tratarse como un íleo adinámico y, la revisión de la literatura relacionada con la definición, factores de riesgos, etiología, fisiopatología y el tratamiento de la misma.

Paciente masculino de 61 años con antecedente de nefrectomía radical izquierda por tumor renal que, a las 48hs del alta hospitalaria, consultó por presentar distensión abdominal aguda. Se solicitó una radiografía abdominal y una tomografía computada que evidenciaba importante dilatación intestinal y un diámetro cecal mayor a 12cm.

Se practicó una laparotomía exploradora de urgencia constatándose dilatación colónica del colon transverso y ascendente con un cambio de diámetro a nivel del ángulo esplénico, sin causa osbtructiva. Finalmente, se realizó colostomía en asa.

A los 6 meses de seguimiento, la videocolonoscopía no mostró lesiones endoluminales concluyendo en un Sindrome de Ogilvie secundario a la nefrectomía. Finalmente, se efectuó reconstrucción del tránsito con buena evolución posterior.

En nuestro caso, el Sindrome de Ogilvie fue una complicación postoperatoria y como fallaron las terapias conservadoras iniciales instauradas, este reporte provee una modalidad de tratamiento alternativo. Si se reconoce temprano y se trata adecuadamente, la pseudoobstrucción se resolverá en la mayoría de los pacientes y la tasa de mortalidad posterior será menor.
Epileptic Adolescents and Ramadan Fasting: A Prospective Cohort Study
Authors: Darwish Amira Hamed
Published: October 2020

This study aimed to evaluate the effect of Ramadan fasting on seizure control in epileptic adolescents. A prospective cohort study that included 56 epileptic patients aged 11 to 18 years. Patients were followed-up in the pediatric neurology clinic at Tanta University Children's Hospital during Ramadan 2019. Seizures frequency and severity, measured by Chalfont seizure severity scale, during Ramadan fasting were compared with those in the month before Ramadan. Before Ramadan, 43/56 patients were controlled and seizure free. Meanwhile, 13/56 patients were uncontrolled and had seizure frequency of one to six seizures in the month before Ramadan. There was no significant difference in seizure frequency during Ramadan compared with before Ramadan (p = 0.132), whereas seizure severity was significantly reduced during Ramadan (p = 0.028). Both seizure frequency and severity were significantly lower during Ramadan in uncontrolled epileptic patients compared with before Ramadan (p = 0.02 and 0.005). Ramadan fasting is safe in adolescents with epilepsy. Fasting is not a precipitating factor for seizures in epileptic adolescents, provided compliance to antiepileptic drugs, and could be beneficial for seizure control in uncontrolled epilepsy.