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Metagenomic Insight Reveals the Microbial Structure and Function of the Full-Scale Coking Wastewater Treatment System:Gene-Based Nitrogen Removal
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作者 Jiaying Ma Fan Wang +4 位作者 Haifeng Fan Enchao Li Huaqiang Chu Xuefei Zhou Yalei Zhang 《Engineering》 SCIE EI CAS CSCD 2024年第5期76-89,共14页
Microbial communities play crucial roles in pollutant removal and system stability in biological systems for coking wastewater(CWW)treatment,but a comprehensive understanding of their structure and functions is still ... Microbial communities play crucial roles in pollutant removal and system stability in biological systems for coking wastewater(CWW)treatment,but a comprehensive understanding of their structure and functions is still lacking.A five month survey of four sequential bioreactors,anoxic 1/oxic 1/anoxic 2/oxic 2(A1/O1/A2/O2),was carried out in a full-scale CWW treatment system in China to elucidate operational performance and microbial ecology.The results showed that A1/O1/A2/O2 had excellent and stable performance for nitrogen removal.Both total nitrogen(TN;(17.38±6.89)mgL1)and ammonium-nitrogen(NH4 t-N;(2.10±1.34)mg·L^(-1))in the final biological effluent satisfied the Chinese national standards for CWW.Integrated analysis of 16S ribosome RNA(rRNA)sequencing and metagenomic sequencing showed that the bacterial communities and metagenomic function profiles of A1 and O1 shared similar functional structures,while those of A2 significantly varied from those of other bioreactors(p<0.05).The results indicated that microbial activity was strongly connected with activated sludge function.Nitrosospira,Nitrosomonas,and SM1A02 were responsible for nitrification during the primary anoxic-oxic(AO)stage and Azoarcus and Thauera acted as important denitrifiers in A2.Nitrogen cycling-related enzymes and genes work in the A1/O1/A2/O2 system.Moreover,the hao genes catalyzing hydroxylamine dehydrogenase(EC 1.7.2.6)and the napA and napB genes catalyzing nitrate reductase(EC 1.9.6.1)played important roles in the nitrification and denitrification processes in the primary and secondary AO stages,respectively.The mixed liquor suspended solids(MLSS)/total solids(TS),TN removal rate(RR),total organic carbon(TOC)(RR),and NH_(4)^(+)t-N(RR)were the most important environmental factors for regulating the structure of core bacterial genera and nitrogen-cycling genes.Proteobacteria were the potential main participants in nitrogen metabolism in the A1/O1/A2/O2 system for CWW treatment.This study provides an original and comprehensive understanding of the microbial community and functions at the gene level,which is crucial for the efficient and stable operation of the full-scale biological process for CWW treatment. 展开更多
关键词 Coking wastewater full-scale Microbial community Metagenomic sequencing Nitrogen-cycling genes Environmental factor
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Resistance of full-scale beams against close-in explosions.Numerical modeling and field tests
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作者 A.Prado A.Alañón +5 位作者 R.Castedo A.P.Santos L.M.López M.Chiquito M.Bermejo C.Oggeri 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期35-47,共13页
This paper explores the performances of a finite element simulation including four concrete models applied to a full-scale reinforced concrete beam subjected to blast loading. Field test data has been used to compare ... This paper explores the performances of a finite element simulation including four concrete models applied to a full-scale reinforced concrete beam subjected to blast loading. Field test data has been used to compare model results for each case. The numerical modelling has been, carried out using the suitable code LS-DYNA. This code integrates blast load routine(CONWEP) for the explosive description and four different material models for the concrete including: Karagozian & Case Concrete, Winfrith, Continuous Surface Cap Model and Riedel-Hiermaier-Thoma models, with concrete meshing based on 10, 15, and 20 mm. Six full-scale beams were tested: four of them used for the initial calibration of the numerical model and two more tests at lower scaled distances. For calibration, field data obtained employing pressure and accelerometers transducers were compared with the results derived from the numerical simulation. Damage surfaces and the shape of rupture in the beams have been used as references for comparison. Influence of the meshing on accelerations has been put in evidence and for some models the shape and size of the damage in the beams produced maximum differences around 15%. In all cases, the variations between material and mesh models are shown and discussed. 展开更多
关键词 Blast test Numerical simulation LS-DYNA Concrete model Mesh effect full-scale beams
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Full-Scale Isogeometric Topology Optimization of Cellular Structures Based on Kirchhoff-Love Shells
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作者 Mingzhe Huang Mi Xiao +3 位作者 Liang Gao Mian Zhou Wei Sha Jinhao Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2479-2505,共27页
Cellular thin-shell structures are widely applied in ultralightweight designs due to their high bearing capacity and strength-to-weight ratio.In this paper,a full-scale isogeometric topology optimization(ITO)method ba... Cellular thin-shell structures are widely applied in ultralightweight designs due to their high bearing capacity and strength-to-weight ratio.In this paper,a full-scale isogeometric topology optimization(ITO)method based on Kirchhoff-Love shells for designing cellular tshin-shell structures with excellent damage tolerance ability is proposed.This method utilizes high-order continuous nonuniform rational B-splines(NURBS)as basis functions for Kirchhoff-Love shell elements.The geometric and analysis models of thin shells are unified by isogeometric analysis(IGA)to avoid geometric approximation error and improve computational accuracy.The topological configurations of thin-shell structures are described by constructing the effective density field on the controlmesh.Local volume constraints are imposed in the proximity of each control point to obtain bone-like cellular structures.To facilitate numerical implementation,the p-norm function is used to aggregate local volume constraints into an equivalent global constraint.Several numerical examples are provided to demonstrate the effectiveness of the proposed method.After simulation and comparative analysis,the results indicate that the cellular thin-shell structures optimized by the proposed method exhibit great load-carrying behavior and high damage robustness. 展开更多
关键词 Cellular thin-shell structures isogeometric analysis full-scale topology optimization Kirchhoff–Love shells
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Behavior of transporting pipeline sections without and with hydrogen exposure based on full-scale tests
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作者 Nóra Nagy János Lukács 《China Welding》 CAS 2024年第3期14-24,共11页
Pipeline transport of hydrogen is one of today’s economic and environmental challenges.In order to find safe and reliable application of both existing gas and build new pipelines,it is essential to carry out tests on... Pipeline transport of hydrogen is one of today’s economic and environmental challenges.In order to find safe and reliable application of both existing gas and build new pipelines,it is essential to carry out tests on full-scale pipeline section,including the potentially more dangerous places than the main pipe,the girth welds.For the investigations,pipeline sections of P355NH steel with girth welds were prepared and exposed to pure hydrogen at twice the maximum allowable operating pressure for 41 days.Subsequently,full-scale burst tests were carried out and specimens were cut and prepared from the typical locations of the failed pipeline sections for mechanical,and macro-and microstructural investigations.The results obtained were evaluated and compared with data from previous full-scale tests on pipeline sections without hydrogen exposure.The results showed differences in the behavior of pipeline sections loaded in different ways,with different characteristics of the materials and the welded joints,both in the cases without hydrogen exposure and in the cases exposed to hydrogen. 展开更多
关键词 gas transporting pipeline full-scale pipeline test complex loading condition hydrogen exposure safety factor
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Full-Scale Numerical Simulation of the Local Scour Under Combined Current and Wave Conditions Based on Field Data 被引量:1
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作者 SUI Shu-huan ZHAO Xue-liang +2 位作者 CHEN Xin-rui DENG Wen-ni SHEN Kan-min 《China Ocean Engineering》 SCIE EI CSCD 2023年第6期1032-1043,共12页
The monopile is the most common foundation to support offshore wind turbines.In the marine environment,local scour due to combined currents and waves is a significant issue that must be considered in the design of win... The monopile is the most common foundation to support offshore wind turbines.In the marine environment,local scour due to combined currents and waves is a significant issue that must be considered in the design of wind turbine foundations.In this paper,a full-scale numerical model was developed and validated based on field data from Rudong,China.The scour development around monopiles was investigated,and the effects of waves and the Reynolds number Re were analyzed.Several formulas for predicting the scour depth in the literature have been evaluated.It is found that waves can accelerate scour development even if the KC number is small(0.78<KC<1.57).The formula obtained from small-scale model tests may be unsafe or wasteful when it is applied in practical design due to the scale effect.A new equation for predicting the scour depth based on the average pile Reynolds number(Rea)is proposed and validated with field data.The equilibrium scour depth predicted using the proposed equation is evaluated and compared with those from nine equations in the literature.It is demonstrated that the values predicted from the proposed equation and from the S/M(Sheppard/Melville)equation are closer to the field data. 展开更多
关键词 full-scale numerical simulation field data scale effect Reynolds number effects local scour
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A Full-Scale Optimization of a Crop Spatial Planting Structure and its Associated Effects 被引量:1
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作者 Qi Liu Jun Niu +1 位作者 Taisheng Du Shaozhong Kang 《Engineering》 SCIE EI CAS CSCD 2023年第9期139-152,共14页
Driven by the concept of agricultural sustainable development,crop planting structure optimization(CPSO)has become an effective measure to reduce regional crop water demand,ensure food security,and protect the environ... Driven by the concept of agricultural sustainable development,crop planting structure optimization(CPSO)has become an effective measure to reduce regional crop water demand,ensure food security,and protect the environment.However,traditional optimization of crop planting structures often ignores the impact on regional food supply–demand relations and interprovincial food trading.Therefore,using a system analysis concept and taking virtual water output as the connecting point,this study proposes a theoretical CPSO framework based on a multi-aspect and full-scale evaluation index system.To this end,a water footprint(WF)simulation module denoted as soil and water assessment tool–water footprint(SWAT-WF)is constructed to simulate the amount and components of regional crop WFs.A multi-objective spatial CPSO model with the objectives of maximizing the regional economic water productivity(EWP),minimizing the blue water dependency(BWFrate),and minimizing the grey water footprint(GWFgrey)is established to achieve an optimal planting layout.Considering various benefits,a fullscale evaluation index system based on region,province,and country scales is constructed.Through an entropy weight technique for order preference by similarity to an ideal solution(TOPSIS)comprehensive evaluation model,the optimal plan is selected from a variety of CPSO plans.The proposed framework is then verified through a case study of the upper–middle reaches of the Heihe River Basin in Gansu province,China.By combining the theory of virtual water trading with system analysis,the optimal planting structure is found.While sacrificing reasonable regional economic benefits,the optimization of the planting structure significantly improves the regional water resource benefits and ecological benefits at different scales. 展开更多
关键词 Planting structure optimization full-scale evaluation index system Water footprint SWAT-WF module Interprovincial food trade Entropy weight TOPSIS
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Stiffness Degradation Modeling for Composite Wind Turbine Blades Based on Full-Scale Fatigue Testing
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作者 Haixia Kou Kongyuan Wei +1 位作者 Yanhu Liu Xuyao Zhang 《Journal of Beijing Institute of Technology》 EI CAS 2023年第4期517-528,共12页
In order to provide more insights into the damage propagation composite wind turbine blades(blade)under cyclic fatigue loading,a stiffness degradation model for blade is proposed based on the full-scale fatigue testin... In order to provide more insights into the damage propagation composite wind turbine blades(blade)under cyclic fatigue loading,a stiffness degradation model for blade is proposed based on the full-scale fatigue testing of a blade.A novel non-linear fatigue damage accumulation model is proposed using the damage assessment theories of composite laminates for the first time.Then,a stiffness degradation model is established based on the correlation of fatigue damage and residual stiffness of the composite laminates.Finally,a stiffness degradation model for the blade is presented based on the full-scale fatigue testing.The scientific rationale of the proposed stiffness model of blade is verified by using full-scale fatigue test data of blade with a total length of 52.5 m.The results indicate that the proposed stiffness degradation model of the blade agrees well with the fatigue testing results of this blade.This work provides a basis for evaluating the fatigue damage and lifetime of blade under cyclic fatigue loading. 展开更多
关键词 composite wind turbine blades fatigue damage stiffness degradation model full-scale fatigue testing
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Bird specimen number linked with species trait and climate niche breadth
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作者 Xiaoyu Duan Xiongwei Huang +4 位作者 Jingya Zhang Shuo Lv Gang Song Yanping Wang Gang Feng 《Avian Research》 SCIE CSCD 2024年第1期108-115,共8页
Biological specimens are fundamental for taxonomy and flora/fauna research.More importantly,they also play crucial roles in recording environmental impacts on morphology and behavior,which is vital for biodiversity re... Biological specimens are fundamental for taxonomy and flora/fauna research.More importantly,they also play crucial roles in recording environmental impacts on morphology and behavior,which is vital for biodiversity research and conservation.However,there are few systematic studies on the patterns and drivers of bird specimen number at regional scales.This study is the first attempt to examine the relationships between bird specimen number and species traits as well as climate niche breadth in China,aiming to answer two questions:1)how do species’temperature niche breadth and precipitation niche breadth influence specimen number?2)which trait is most associated with bird specimen number?The associations between bird specimen number and explanatory variables were examined using ordinary least squares,generalized linear models,phylogenetic generalized linear mixed models,and multiple comparisons.The results showed that Muscicapidae was the family with the highest specimen number,and Passeriformes was the order with the highest specimen number.Bird specimen number significantly increased with larger temperature niche breadth and precipitation niche breadth.Specimen number was also positively associated with geographic range size,habitat specificity,hunting vulnerability and clutch size,but negatively associated with body size.These findings suggest that future bird specimen collection should pay more attention to birds with limited ecological niches,large body sizes,and small clutch sizes.This research enhances the use of bird specimen data to study and preserve biodiversity. 展开更多
关键词 Biodiversity conservation Biological specimens Bird traits Scientific collection specimen number Temperature and precipitation
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Dynamic characteristics of coal specimens with varying static preloading levels under low-frequency disturbance load
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作者 WEN Xiao-ze FENG Guo-rui +5 位作者 GUO Jun YU Lu-yang QIAN Rui-peng ZHANG Jie ZHANG Peng-fei FENG Wen-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2644-2657,共14页
The mechanical properties of residual coal pillars under the influence of upward mining disturbances significantly affect the safety of residual mining activities on working faces.This study conducted low-frequency di... The mechanical properties of residual coal pillars under the influence of upward mining disturbances significantly affect the safety of residual mining activities on working faces.This study conducted low-frequency disturbance dynamic uniaxial compression tests on coal specimens using a self-developed dynamic-static load coupling electro-hydraulic servo system,and studied the strength evolutions,surface deformations,acoustic emission(AE)characteristic parameters,and the failure modes of coal specimens with different static preloading levels were studied.The disturbance damage is positively correlated with the coal specimen static preload level.Specifically,the cumulative AE count rates of the initial accelerated damage stage for the coal specimens with static preloading level of 60%and 70%of the uniaxial compressive strength(UCS)were 2.66 and 3.19 times that of the 50%UCS specimens,respectively.Macroscopically,this behaviour manifested as a decrease in the compressive strength,and the mean strengths of the disturbance-damaged coal specimens with 60%and 70%of UCS static preloading decreased by 8.53%and 9.32%,respectively,compared to those of the specimens under pure static loading.The crack sources,such as the primary fissures,strongly control the dynamic response of the coal specimen.The difference between the dynamic responses of the coal specimens and that of dense rocks is significant. 展开更多
关键词 low-frequency disturbance dynamic response coal specimens static preloading level
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Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China
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作者 Jingya Zhang Cui Xiao +5 位作者 Xiaoyu Duan Xin Gao Hao Zeng Rong'an Dong Gang Feng Keping Ma 《Plant Diversity》 SCIE CAS CSCD 2024年第3期353-361,共9页
Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection... Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate. 展开更多
关键词 Biological specimen Collection preference Dominant plant species Environmental range Geographical range Species traits
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Direct Pointwise Comparison of FE Predictions to StereoDIC Measurements:Developments and Validation Using Double Edge-Notched Tensile Specimen
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作者 Troy Myers Michael A.Sutton +2 位作者 Hubert Schreier Alistair Tofts Sreehari Rajan Kattil 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1263-1298,共36页
To compare finite element analysis(FEA)predictions and stereovision digital image correlation(StereoDIC)strain measurements at the same spatial positions throughout a region of interest,a field comparison procedure is... To compare finite element analysis(FEA)predictions and stereovision digital image correlation(StereoDIC)strain measurements at the same spatial positions throughout a region of interest,a field comparison procedure is developed.The procedure includes(a)conversion of the finite element data into a triangular mesh,(b)selection of a common coordinate system,(c)determination of the rigid body transformation to place both measurements and FEA data in the same system and(d)interpolation of the FEA nodal information to the same spatial locations as the StereoDIC measurements using barycentric coordinates.For an aluminum Al-6061 double edge notched tensile specimen,FEA results are obtained using both the von Mises isotropic yield criterion and Hill’s quadratic anisotropic yield criterion,with the unknown Hill model parameters determined using full-field specimen strain measurements for the nominally plane stress specimen.Using Hill’s quadratic anisotropic yield criterion,the point-by-point comparison of experimentally based full-field strains and stresses to finite element predictions are shown to be in excellent agreement,confirming the effectiveness of the field comparison process. 展开更多
关键词 StereoDIC spatial co-registration data transformation finite element simulations point-wise comparison of measurements and FEA predictions double edge notch specimen model validation
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Perioperative outcomes of transvaginal specimen extraction laparoscopic total gastrectomy and conventional laparoscopicassisted total gastrectomy
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作者 Zhi-Cao Zhang Wen-Sheng Wang +5 位作者 Jiang-Hong Chen Yuan-Hang Ma Qi-Fa Luo Yun-Bo Li Yang Yang Dan Ma 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第6期1527-1536,共10页
BACKGROUND Natural orifice specimen extraction surgery(NOSES)has emerged as a promising alternative compared to conventional laparoscopic-assisted total gastrectomy(LATG)for treating gastric cancer(GC).However,evidenc... BACKGROUND Natural orifice specimen extraction surgery(NOSES)has emerged as a promising alternative compared to conventional laparoscopic-assisted total gastrectomy(LATG)for treating gastric cancer(GC).However,evidence regarding the efficacy and safety of NOSES for GC surgery is limited.This study aimed to compare the safety and feasibility,in addition to postoperative complications of NOSES and LATG.METHODS Dual circular staplers were used in Roux-en-Y digestive tract reconstruction for transvaginal specimen extraction LATG,and its outcomes were compared with LATG in a cohort of 51 GC patients with tumor size≤5 cm.The study was conducted from May 2018 to September 2020,and patients were categorized into the NOSES group(n=22)and LATG group(n=29).Perioperative parameters were compared and analyzed,including patient and tumor characteristics,postoperative outcomes,and anastomosis-related complications,postoperative hospital stay,the length of abdominal incision,difference in tumor type,postoperative complications,and postoperative survival.RESULTS Postoperative exhaust time,operation duration,mean postoperative hospital stay,length of abdominal incision,number of specific staplers used,and Brief Illness Perception Questionnaire score were significant in both groups(P<0.01).In the NOSES group,the postoperative time to first flatus,mean postoperative hospital stay,and length of abdominal incision were significantly shorter than those in the LATG group.Patients in the NOSES group had faster postoperative recovery,and achieved abdominal minimally invasive incision that met aesthetic requirements.There were no significant differences in gender,age,tumor type,postoperative complications,and postoperative survival between the two groups.CONCLUSION The application of dual circular staplers in Roux-en-Y digestive tract reconstruction combined with NOSES gastrectomy is safe and convenient.This approach offers better short-term outcomes compared to LATG,while long-term survival rates are comparable to those of conventional laparoscopic surgery. 展开更多
关键词 Gastric cancer Circular stapler Natural orifice specimen extraction surgery Laparoscopic-assisted total gastrectomy
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Wireless Preamplifier for the Specimen Current Mode Detector in a SEM
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作者 Valentin G. Dyukov 《Optics and Photonics Journal》 2024年第2期23-28,共6页
Using a scanning electron microscope (SEM) in the back-scattered electron (BSE) mode the composition of multi-element specimens may be determined based on the strong dependence of emission coefficient η on the averag... Using a scanning electron microscope (SEM) in the back-scattered electron (BSE) mode the composition of multi-element specimens may be determined based on the strong dependence of emission coefficient η on the average atomic number of elements Z. The output video signal of the usual BSE detectors is produced from their sensors, and the larger proportion of high-energy electrons with modified spectrum is added. Since η = is/ip (is and ip currents of specimen and probe), better accuracy must be achieved by direct measurements those currents on the specimen surface. Here, an experimental model of a current detector for a presented specimen is described. The cage is mounted on the carousel of the moving specimen stage. The input of the preamplifier is connected to the specimen holder in the form of a disk, the diameter of which is 12 mm. When the probe along its surface scanned, the input potential begins to pulsate with a negative polarity. The output of this preamplifier is connected to a small light-emitting diode, which creates intensity-modulated radiation in the chamber. Thus created the light video signal will be picked up by the photomultiplier of the E-T detector. The modes of true SE and BSE are set by applying tens bias volts of various polarities to the specimens or the cage itself. 展开更多
关键词 Scanning Electron Microscopy Backscattered Electron Imaging Wireless specimen Current Preamplifier Universal (SE/BSE) Dyukov Detector
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Application Effect of Feedforward Control in Outpatient Blood Specimen Management
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作者 Meiying Lu 《Journal of Clinical and Nursing Research》 2024年第6期177-183,共7页
Objective:To analyze the application effect of feedforward control in outpatient blood specimen management.Methods:1,200 patients who had their venous blood collected in outpatient phlebotomy room of our hospital'... Objective:To analyze the application effect of feedforward control in outpatient blood specimen management.Methods:1,200 patients who had their venous blood collected in outpatient phlebotomy room of our hospital's outpatient clinic from January 2021 to April 2021 were selected as study subjects and divided into 600 cases in the control group and 600 cases in the observation group.The two groups of patients were compared in terms of their satisfaction with the staff,the efficiency of the nurses and the quality of nursing care,turnaround time before specimen analysis,the rejection rate of the blood specimens,and the time of result reporting.Results:After the implementation of feedforward control,patients'satisfaction with staff,nurses work efficiency and quality of care,turnaround time before specimen analysis,specimen rejection rate,and result reporting time in the observation group were significantly higher than those in the control group(P<0.05).Conclusion:The application of feedforward control in the management of outpatient blood specimens has significant effect,which effectively improves patients'satisfaction,enhances the efficiency of nurses and the quality of nursing care,shortens the turnaround time of specimens before analysis and the reporting time of results,and reduces the rejection rate of specimens. 展开更多
关键词 Feedforward control Venous blood specimen Nursing management Application effect
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Parallel Computing of the Underwater Explosion Cavitation Effects on Full-scale Ship Structures 被引量:7
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作者 Zhi Zong Yanjie Zhao +2 位作者 Fan Ye Haitao Li Gang Chen 《Journal of Marine Science and Application》 2012年第4期469-477,共9页
As well as shock wave and bubble pulse loading, cavitation also has very significant influences on the dynamic response of surface ships and other near-surface marine structures to underwater explosive loadings. In th... As well as shock wave and bubble pulse loading, cavitation also has very significant influences on the dynamic response of surface ships and other near-surface marine structures to underwater explosive loadings. In this paper, the acoustic-structure coupling method embedded in ABAQUS is adopted to do numerical analysis of underwater explosion considering cavitation. Both the shape of bulk cavitation region and local cavitation region are obtained, and they are in good agreement with analytical results. The duration of reloading is several times longer than that of a shock wave. In the end, both the single computation and parallel computation of the cavitation effect on the dynamic responses of a full-scale ship are presented, which proved that reloading caused by cavitation is non-ignorable. All these results are helpful in understanding underwater explosion cavitation effects. 展开更多
关键词 underwater explosion CAVITATION parallel computation full-scale ship
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Experimental investigations on small-and full-scale ship models with polyurea coatings subjected to underwater explosion 被引量:6
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作者 Jian Liu Feng-jiang An +4 位作者 Cheng Wu Sha-sha Liao Ming-xue Zhou Dong-yu Xue Huan Guo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第7期1257-1268,共12页
Nowadays, the mitigation of damage to a ship caused by the underwater explosion attracts more and more attention from the modern ship designers. In this study, two kinds of scale tests were conducted to investigate th... Nowadays, the mitigation of damage to a ship caused by the underwater explosion attracts more and more attention from the modern ship designers. In this study, two kinds of scale tests were conducted to investigate the effects of polyurea coatings on the blast resistance of hulls subjected to underwater explosion. Firstly, small-scale model tests with different polyurea coatings were carried out. Results indicate that polyurea has a better blast resistance performance when coated on the front face, which can effectively reduce the maximum deflection of the steel plate by more than 20% and reduce the deformation energy by 35.7%-45.4%. Next, a full-scale ship(approximately 50 m × 9 m) under loadings produced by the detonation of 33 kg of spherical TNT charges was tested, where a part of the ship was coated with polyurea on the front face(8 mm + 24 mm) and not on the contrast area. Damage characteristics on the bottom were statistically analyzed based on a 3D scanning technology, indicating that polyurea contributes to enhancing the blast protection of the ship. However, damage results of this test were different from those of the small-scale tests. Moreover, the deformation area of the bottom with polyurea was greatly increased by 40.1% to disperse explosion energy, a conclusion that cannot be drown from the small-scale tests. 展开更多
关键词 Polyurea coatings Small-scale model full-scale ship Underwater explosion Blast resistance
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Experimental and analytical study on design performance of full-scale viscoelastic dampers 被引量:2
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作者 Shiang-Jung Wang I-Chen Chiu +1 位作者 Chung-Han Yu Kuo-Chun Chang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第4期693-706,共14页
Viscoelastic(VE) dampers, with their stiffness and energy dissipation capabilities, have been widely used in civil engineering for mitigating wind-induced vibration and seismic responses of structures, thus enhancin... Viscoelastic(VE) dampers, with their stiffness and energy dissipation capabilities, have been widely used in civil engineering for mitigating wind-induced vibration and seismic responses of structures, thus enhancing the comfort of residents and serviceability of equipment inside. In past relevant research, most analytical models for characterizing the mechanical behavior of VE dampers were verified by comparing their predictions with performance test results from small-scale specimens, which might not adequately or conservatively represent the actual behavior of full-scale dampers, especially with regard to the ambient temperature, temperature rise, and heat convection effects. Thus, in this study, by using a high-performance testing facility with a temperature control system, full-scale VE dampers were dynamically tested with different displacement amplitudes, excitation frequencies, and ambient temperatures. By comparing the analytical predictions with the experimental results, it is demonstrated that adopting the fractional derivative method together with considering the effects of excitation frequencies, ambient temperatures, temperature rises, softening, and hardening, can reproduce the design performance of full-scale VE dampers very well. 展开更多
关键词 viscoelastic damper full-scale designperformance dynamic test fractional derivative model
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A Non-geometrically Similar Model for Predicting the Wake Field of Full-scale Ships 被引量:1
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作者 Chunyu Guo Qi Zhang Yu Shen 《Journal of Marine Science and Application》 CSCD 2015年第3期225-233,共9页
The scale effect leads to large discrepancies between the wake fields of model-scale and actual ships, and causes differences in cavitation performance and exciting forces tests in predicting the performance of actual... The scale effect leads to large discrepancies between the wake fields of model-scale and actual ships, and causes differences in cavitation performance and exciting forces tests in predicting the performance of actual ships. Therefore, when test data from ship models are directly applied to predict the performance of actual ships, test results must be subjected to empirical corrections. This study proposes a method for the reverse design of the hull model. Compared to a geometrically similar hull model, the wake field generated by the modified model is closer to that of an actual ship. A non-geometrically similar model of a Korean Research Institute of Ship and Ocean Engineering (KRISO)’s container ship (KCS) was designed. Numerical simulations were performed using this model, and its results were compared with full-scale calculation results. The deformation method of getting the wake field of full-scale ships by the non-geometrically similar model is applied to the KCS successfully. 展开更多
关键词 wake field full-scale ships non-geometrically similar model scale effect KRISO’s container ship (KCS)
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Full-scale multi-functional test platform for investigating mechanical performance of track–subgrade systems of high-speed railways 被引量:2
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作者 Wanming Zhai Kaiyun Wang +3 位作者 Zhaowei Chen Shengyang Zhu Chengbiao Cai Gang Liu 《Railway Engineering Science》 2020年第3期213-231,共19页
Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure,a fullscale multi-functional test platform for high-speed railway... Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure,a fullscale multi-functional test platform for high-speed railway track–subgrade system is developed in this paper,and its main functions for investigating the mechanical performance of track–subgrade systems are elaborated with three typical experimental examples.Comprising the full-scale subgrade structure and all the five types of track structures adopted in Chinese high-speed railways,namely the CRTS I,the CRTS II and the CRTS III ballastless tracks,the double-block ballastless track and the ballasted track,the test platform is established strictly according to the construction standard of Chinese high-speed railways.Three kinds of effective loading methods are employed,including the real bogie loading,multi-point loading and the impact loading.Various types of sensors are adopted in different components of the five types of track–subgrade systems to measure the displacement,acceleration,pressure,structural strain and deformation,etc.Utilizing this test platform,both dynamic characteristics and long-term performance evolution of high-speed railway track–subgrade systems can be investigated,being able to satisfy the actual demand for large-scale operation of Chinese high-speed railways.As examples,three typical experimental studies are presented to elucidate the comprehensive functionalities of the full-scale multi-functional test platform for exploring the dynamic performance and its long-term evolution of ballastless track systems and for studying the long-term accumulative settlement of the ballasted track–subgrade system in high-speed railways.Some interesting phenomena and meaningful results are captured by the developed test platform,which provide a useful guidance for the scientific operation and maintenance of high-speed railway infrastructure. 展开更多
关键词 full-scale test High-speed railway Track–subgrade system Ballastless track Ballasted track Mechanical performance Long-term performance evolution Damage and degradation
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Robotic natural orifice specimen extraction surgery I-type F method vs conventional robotic resection for lower rectal cancer 被引量:2
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作者 Fang Tao Dong-Ning Liu +4 位作者 Peng-Hui He Xin Luo Chi-Ying Xu Tai-Yuan Li Jin-Yuan Duan 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第10期2142-2153,共12页
BACKGROUND Robotic resection using the natural orifice specimen extraction surgery I-type F method(R-NOSES I-F)is a novel minimally invasive surgical strategy for the treatment of lower rectal cancer.However,the curre... BACKGROUND Robotic resection using the natural orifice specimen extraction surgery I-type F method(R-NOSES I-F)is a novel minimally invasive surgical strategy for the treatment of lower rectal cancer.However,the current literature on this method is limited to case reports,and further investigation into its safety and feasibility is warranted.AIM To evaluate the safety and feasibility of R-NOSES I-F for the treatment of low rectal cancer.METHODS From September 2018 to February 2022,206 patients diagnosed with low rectal cancer at First Affiliated Hospital of Nanchang University were included in this retrospective analysis.Of these patients,22 underwent R-NOSES I-F surgery(RNOSES I-F group)and 76 underwent conventional robotic-assisted low rectal cancer resection(RLRC group).Clinicopathological data of all patients were collected and analyzed.Postoperative outcomes and prognoses were compared between the two groups.Statistical analysis was performed using SPSS software.RESULTS Patients in the R-NOSES I-F group had a significantly lower visual analog score for pain on postoperative day 1(1.7±0.7 vs 2.2±0.6,P=0.003)and shorter postoperative anal venting time(2.7±0.6 vs 3.5±0.7,P<0.001)than those in the RLRC group.There were no significant differences between the two groups in terms of sex,age,body mass index,tumor size,TNM stage,operative time,intrao-perative bleeding,postoperative complications,or inflammatory response(P>0.05).Postoperative anal and urinary functions,as assessed by Wexner,low anterior resection syndrome,and International Prostate Symptom Scale scores,were similar in both groups(P>0.05).Long-term follow-up revealed no significant differences in the rates of local recurrence and distant metastasis between the two groups(P>0.05).CONCLUSION R-NOSES I-F is a safe and effective minimally invasive procedure for the treatment of lower rectal cancer.It improves pain relief,promotes gastrointestinal function recovery,and helps avoid incision-related complications. 展开更多
关键词 Robotic surgery Natural orifice specimen extraction surgery Lower rectal cancer Robotic resection using the natural orifice specimen extraction surgery I-type F method
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