Experimental and numerical analyses of the effect of fibre content on the close-in blast performance of a UHPFRC beam

Limited research has been conducted on the influences of fiber content on close-in blasting characteristics for ultrahigh-performance fiber-reinforced concrete(UHPFRC)beams.This paper aims to address this knowledge gap through experimental and mesoscale numerical methods.Experiments were conducted on ten UHPFRC beams built with varying steel fiber volumetric fractions subjected to close-in explosive conditions.Additionally,this study considered other parameters,such as the longitudinal reinforcement type and ratio.In the case of UHPFRC beams featuring normal-strength longitudinal reinforcement of diametersΦ12,Φ16,andΦ20,a reduction in maximum displacement by magnitudes of19.6%,19.5%,and 17.4%was observed,respectively,as the volumetric fractions of fiber increased from1.0%to 2.5%.In addition,increasing the longitudinal reinforcement ratio and using high-strength steel longitudinal reinforcement both significantly reduced the deformation characteristics and increase the blasting resistances of UHPFRC beams.However,the effects on the local crushing and spalling damage were not significant.A mesoscale finite element model,which considers the impacts of fiber parameters on UHPFRC beam behaviors,was also established and well correlated with the test findings.Nevertheless,parametric analyses were further conducted to examine the impacts of the steel fiber content and length and the hybrid effects of various types of microfibers and steel fibers on the blasting performance of UHPFRC beams.

Toward high-sulfur-content,high-performance lithium-sulfur batteries:Review of materials and technologies

Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.

Effect of cobalt content on electrochemical performance of La-Mg-Ni system (Ce_2Ni_7-type) electrode alloys

In order to improve the cyclic stability of La-Mg-Ni system （Ce2Ni7-type） alloy electrode, small amount of Co was added in La0.75Mg0.25Ni3.5 alloy. The effect of Co on electrochemical performance and microstructure of the alloys were investigated in detail. XRD results showed that the alloys had multiphase structure composed of （La, Mg）2Ni7, LaNi5 and small amount of LaNi2 phases. The discharge capacity of the alloys first increased and then decreased with increasing Co content. At a discharge current density of 900 mA/g, the HRD of the alloy electrodes increased from 81.3% （x=0） to 89.2 % （x=0.2）, and then reduced to 87.8 % （x=0.6）. After 60 charge/discharge cycles, the capacity retention rate of the alloys enhanced from 52.67% to 61.32%, and the capacity decay rate of the alloys decreased from 2.60 to 2.05 mAh/g per cycle with increasing Co content. The obtained results by XPS and XRD showed that the fundamental reasons for the capacity decay of the La-Mg-Ni system （Ce2Ni7-type） alloy electrodes were corrosion and oxidation as well as passivation of Mg and Lain alkaline solution.

Performance evaluation of CLM5.0 in simulating liquid soil water in high mountainous area,Northwest China

The model performance in simulating soil water content(SWC) is crucial for successfully modeling earth’s system,especially in high mountainous areas.In this study,the performance of Community Land Model 5.0(CLM5.0) in simulating liquid SWC was evaluated against observations from nine in-situ sites in the upper reach of the Heihe River Watershed(HRW),Northwest China.The CLM5.0 shows reliable performance in the study area with correlation coefficients(R) ranging between 0.79–0.93,root mean standard errors(RMSE)ranging between 0.044–0.097 m^(3)/m^(3),and the mean bias(BIAS) ranging between-0.084–0.061 m^(3)/m^(3).The slightly worse performance of CLM5.0 than CLM4.5 on alpine meadow and grassland is mainly caused by the revised canopy interception parameterization.The CLM5.0 overestimates interception and underestimates evapotranspiration(ET) on both alpine meadow and grassland during the growth period.The systematical overestimations at all the grassland sites indicate that the underestimation of ET is much larger than the overestimation of interception on grassland during growth period,while the errors of simulated interception and ET are partially canceled out on alpine meadow.Moreover,the underestimation of ET is more responsible for the overestimation of SWC than the overestimation of interception in the high mountainous area.It is necessary to estimate reasonable empirical parameter α(proportion of leaf water collection area) in interception parameterization scheme and further improve the dry surface layerbased soil evaporation resistance parameterization introduced in CLM5.0 in future researches.The performance of CLM5.0 is better under completely frozen stage than thawing stage and freezing stage,because of low variations of liquid SWC caused by extremely low hydraulic conductivity of soils.The underestimation of liquid SWC under frozen state is caused by underestimation of soil temperature,which leads to more ice mass and less liquid water in total water content.

Performance of Random Contention PRMA: A Protocol for Fixed Wireless Access

This paper introduces a packet reservation multiple access (PRMA) with random contention for fixed wireless access communications. The performance of PRMA scheme with random contention is compared with the performances of traditional PRMA under permission contention scheme. The proposed scheme is a simpler contention mechanism that does not depend on a pre-determined permission probability as PRMA under permission contention scheme. In this new method, terminals select the contention slot uniformly from the pool of remaining free slots in the current frame. We evaluate the performance of the new contention mechanism in terms of various metrics including maximum number of carried voice calls and packet delays for a given acceptable drop rate of voice packets. We show that the new mechanism is superior to that of PRMA under permission contention scheme for loaded systems and is expected to be insensitive for traffic source burstiness.

Growth Performance of Butcher’s Pigs Fed on Diets Made from the Ruminal Contents of Bovine Animals

Both quantitatively and qualitatively, underfeeding materialized by underconsumption of meat remains one of the things most felt in Africa. To make up for this deficit, emphasis is placed on the production of short-cycle animals such as poultry, rabbits and pork. Among these animals, pig plays a very important socio-economic role in the life of local populations. Its meat is required in various ceremonies such as the dowry and funerals. For this purpose, twenty four males cross piglets with Large White × Landrace × Duroc × Pietrain phenotypic traits, aged between 58 and 62 days and having an average weight of 9.978 ± 1.11 kg were used to evaluate the influence of graded levels of bovine rumen content on the growth performances of grower finisher pigs. The piglets were submitted to 4 treatments, housed in pairs and fed ad libitum with a diet containing 0, 5%, 10% and 20% bovine rumen content. The trial which lasted for 18 weeks was carried out at the Teaching and Research Farm of the University of Dschang. The results showed that drying process destroyed most microbes found in the rumen content. These results also showed that the incorporation of bovine rumen content in diets had no significant (p > 0.05) effect on feed conversion ratio efficiency. However, feed intake, body weight and body weight gain were significantly higher in pigs fed with a diet (R5) containing 5% of bovine rumen content. Feed cost per kg of live body weight was significantly (p 20 diet compared to the animals receiving the control diet which was lower than that of the other two diets (R0) and (R5) but comparable with animals fed diet R10. The analysis of the carcass showed that increasing incorporation level of bovine rumen content in the diet reduces abdominal fat and back fat thickness. For offal, the lowest weight was recorded in animals fed the control diet (R0) and the highest weight with animals fed a diet containing 5% bovine rumen content. Carcass length of animals fed the control diet (R0) was significantly greater compared with the carcass of animals fed diet R10 and comparable to that of the other two treatments. The pH of the pork was comparable (p > 0.05) in all the treatments. In conclusion, a diet containing 5% bovine rumen content induced the best growth performances compared to all the other groups, while diet R20 produced lean pork with the higher production cost.

Comprehensive Analysis of Caching Performance under Probabilistic Traffic Patterns for Content Centric Networking

The phenomenon of data explosion represents a severe challenge for the upcoming big data era.However,the current Internet architecture is insufficient for dealing with a huge amount of traffic owing to an increase in redundant content transmission and the end-point-based communication model.Information-centric networking(ICN)is a paradigm for the future Internet that can be utilized to resolve the data explosion problem.In this paper,we focus on content-centric networking(CCN),one of the key candidate ICN architectures.CCN has been studied in various network environments with the aim of relieving network and server burden,especially in name-based forwarding and in-network caching functionalities.This paper studies the effect of several caching strategies in the CCN domain from the perspective of network and server overhead.Thus,we comprehensively analyze the in-network caching performance of CCN under several popular cache replication methods(i.e.,cache placement).We evaluate the performance with respect to wellknown Internet traffic patterns that follow certain probabilistic distributions,such as the Zipf/Mandelbrot–Zipf distributions,and flashcrowds.For the experiments,we developed an OPNET-based CCN simulator with a realistic Internet-like topology.

Design Method and Performance for Large Stone Porous Asphalt Mixtures

Design method for large stone porous asphalt mixtures （LSPM） was analyzed to avoid the early distresses of semi-rigid asphalt pavements. Based on stone-to-stone skeleton structure concept, processes of LSPM gradation design was given. The gradation composite design for LSPM shows that the LSPM nominal maximum size （ N MS） should be larger than 26.5 mm, and the NMS sieve passing percentage should be greater than 50%. Through experiments and calculations on the volume properties of the aggregate, the range of aggregate gradation curve of LSPM was given. In terms of asphalt binder＇s normalized test results, MAC-70 and SBS modified asphalt were selected as the asphalt binders. The applicability of large scale Marshall Method and gyratory compaction method to shape specimens was investigated. Based on the asphalt mixture performance evaluation, the optimum asphalt content range （3.1%-3.6%）, the bitumen film＇s thickness range （13-16 μm） and the air void range （13%-18 %） were recommended. Finally, LSPM was tested by the laboratory performance tests including rutting resistance test, fatigue test and water stability test. The theoretic and practical analysis shows that LSPM has a good performance on water permeability, rutting resistance and reflection crack resistance.

Effect of preparation methods on the hydrocracking performance of NiMo/Al_(2)O_(3) catalysts

In this work,NiMo catalysts with various contents of MoO_(3)were prepared through incipient wetness impregnation by a twostep method(NMxA)and onepot method(NMxB).The catalysts were then characterized by XRD,XPS,NH3TPD,H_(2)TPR,HRTEM,and N_(2)adsorptiondesorption technologies.The performance of the NiMo/Al_(2)O_(3) catalysts was investigated by hydrocracking lowtemperature coal tar.When the MoO3 content was 15 wt%,the interaction between Ni species and Al_(2)O_(3) on the NM15B catalyst was stronger than that on the NM15A catalyst,resulting in the poor performance of the former.When the MoO^(3) content was 20 wt%,MoO_(3) agglomerated on the surface of the NM20A catalyst,leading to decreased number of active sites and specific surface area and reduced catalytic performance.The increase in the number of MoS_(2) stack layers strengthened the interaction between Ni and Mo species of the NM20B catalyst and consequently improved its catalytic performance.When the MoO_(3) content reached 25 wt%,the active metals agglomerated on the surface of the NiMo catalysts,thereby directly decreasing the number of active sites.In conclusion,the twostep method is suitable for preparing catalysts with large pore diameter and low MoO_(3) content loading,and the onepot method is more appropriate for preparing catalysts with large specific surface area and high MoO_(3) content.Moreover,the NMxA catalysts had larger average pore diameter than the NMxB catalysts and exhibited improved desulfurization performance.

Effect of Salinity on the Growth Performance, Body Composition, Antioxidant Indexes of Perinereis aibuhitensis and Total Nitrogen in the Substrate

In this study, the effects of different salinity levels (9, 12, 15, 18, 21, 24, 27, 30, and 33) on the growth performance, body composition, antioxidant indexes of Perinereis aibuhitensis (initial average mass, 20.4 ± 0.3 mg) and total nitrogen in the substrate were investigated. The survival rate, specific growth rate, feed coefficient, and protein efficiency ratio under different salinity levels were measured. The results showed that the survival rate of P. aibuhitensis at the salinity level of 9 was significantly lower than that of P. aibuhitensis at other salinity levels (P P. aibuhitensis at other salinity levels was not significant (P > 0.05). On the basis of quadratic polynomial fitting of the relationship between salinity levels and the specific growth rate, feed coefficient, and protein efficiency ratio, it was concluded that 25.36 - 25.9 is the most suitable salinity range for the growth performance of P. aibuhitensis. The main body composition (moisture, crude fat, crude protein, and ash content) was measured at different salinity levels. The results indicated that, with the increase in salinity, the moisture content of P. aibuhitensis decreased gradually;in contrast, the ash content increased gradually, as the salinity level increased. However, in the salinity range of 18 to 33, the difference in ash content was not significant (P > 0.05). Salinity had a significant influence on the crude protein content (P P. aibuhitensis specimens were cultured for 60 days was higher than the total nitrogen in the soil. With an increase in salinity, the total nitrogen content first decreased and then increased, and the lowest value was observed at the salinity level of about 24.

Experimental Study on Fatigue Performance of Gussasphalt Mixture

Four-point flexural fatigue test for Gussasphalt mixture specimen was carried out at a straincontrolled mode system. The results showed that the development of the tested stiffness modulus and phase angle of the mixtures with increasing load cycles exhibited three periods, initial generation, slow development and failure period. The fatigue crack generation zone formed in the third period, in which the macro mechanical properties were signifi cantly decreased. Moreover, we also analyzed the effects of asphalt content and mixing temperature on the fatigue life of the mixture. The results showed that the fi rst period when the specimen＇s initial stiffness modulus was reduced to 80% accounted for 5%-10% of the total fatigue life; the second period in which the reduction became slow and demonstrated a liner relationship with load cycles occupied 70%-85% of the fatigue life; and the third period was about 5%-10%. The results indicated that the lower the mixing temperature, the longer the fatigue life of Gussasphalt mixture. Besides, the increasing of asphalt content has a minor effect on the fatigue life of Gussasphalt mixture

Determination of the Content of Five Active Components in Toad Skin

[Objectives] To establish a method for the determination of active components in toad skin. [Methods] HPLC method was used to determine the content of five active components (bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin) in toad skin. [Results] Chromatographic conditions are as follows: Agilent ZORBAX SB-C 18 chromatographic column was used;acetonitrile (A)-0.3% glacial acetic acid (B) gradient elution (0-15 min, 28%A-54%A;15-35 min, 54%A-54%A) was conducted;the flow rate was 0.6 mL/min;the detection wavelength was 296 nm;the column temperature was 30 ℃;the sample size was 10 μL. Under the above conditions, the determination method of the five components can be established at one time. [Conclusions] The method was stable and reliable, and can provide experimental basis for the development and utilization of active ingredients in toad skin.

基于内容分析法的临床药师岗位胜任力指标构建

目的 对国内外临床药师胜任力评价指标进行内容分析,为临床药师岗位胜任力构建提供参考。方法 检索国内外临床药师岗位胜任力相关文献,采用内容分析法对符合标准的文献进行分析。结果 最终纳入22篇文献及14篇胜任力评估框架及模型,提取个人素质、知识、个人能力、药学服务、教研5个一级类目、15个二级类目及61个三级类目。结论 初步构建了临床药师岗位胜任力指标体系,为临床药师开展实践工作提供参考。

高效液相色谱法同时测定果蔬中有机酸和维生素C含量

采用1%草酸(含10%甲醇)溶液提取果蔬的有机酸(酒石酸、柠檬酸、苹果酸、丁二酸、反丁烯二酸)和维生素C,色谱柱为InertSustain C18(250 mm×4.6 mm,5μm),流动相A为0.1%磷酸水溶液,流动相B为甲醇,梯度洗脱,进样体积为20μL,柱温为30℃,流速为0.8 mL/min,在210 nm和254 nm波长处分别检测5种有机酸和维生素C的含量。结果表明,该方法在标准曲线范围内线性关系良好,相关系数(R^(2))均大于0.9990,检出限为0.01~0.90μg/mL,定量限为0.15~5.00μg/mL,方法的相对标准偏差为2.40%~3.75%,回收率在86.4%~115.2%;该方法具有分析速度快、灵敏度高、重复性好、效率高等优点,可用于果蔬中有机酸和维生素C的含量测定。

Construction Method for Performance Management Curriculum Content System Based on Knowledge Graph

Performance Management is the core course of human resource management major,but its knowledge points lack multi-dimensional correlations.There are problems such as scattered content and unclear system,and it is urgent to reconstruct the content system of the course.Knowledge graph technology can integrate massive and scattered information into an organic structure through semantic correlation and reasoning.The application of knowledge graph to education and teaching can promote scientific and personalized teaching evaluation and better realize individualized teaching.This paper systematically combs the knowledge points of Performance Management course and forms a comprehensive knowledge graph.The knowledge point is associated with specific questions to form the problem map of the course,and then the knowledge point is further associated with the ability target to form the ability map of the course.Then,the knowledge point is associated with teaching materials,question bank and expansion resources to form a systematic teaching database,thereby giving the method of building the content system of Performance Management course based on the knowledge map.This research can be further extended to other core management courses to realize the deep integration of knowledge graph and teaching.

HPLC法测定十三味逐瘀合剂中游离大黄酚含量

目的建立十三味逐瘀合剂中大黄酚高效液相含量测定的方法。方法采用高效液相色谱法(HPLC法)对十三味逐瘀合剂中游离大黄酚含量进行测定,从提取溶剂、取样量、提取时间等影响因素中选出最优条件,建立完整的含量测定方法。结果用thermos C18色谱柱(250 mm×4.6 mm,5μm);以甲醇-0.1%磷酸(75∶25,V/V)为流动相,采用等度洗脱法,254 nm波长的色谱条件;以甲醇为浸膏提取溶剂,超声30 min的提取方法;大黄酚质量浓度在1.63~16.32μg/mL(R^(2)=0.9995)范围内具有良好的线性关系;平均回收率为104.17%;测得十三味逐瘀合剂中游离大黄酚平均含量为15.32μg/mL。结论本实验所建立的方法操作简单,专属性强,重现性好,可用于十三味逐瘀合剂中游离大黄酚的含量测定。

基于在线柱切换液相色谱技术的红霉素软膏含量测定研究

目的建立在线柱切换高效液相色谱法测定红霉素软膏中主药含量的方法,为相关制剂的质量控制提供有效手段。方法样品经80℃提取后直接进样,柱切换系统下,采用C_(18)(50 mm×2.1 mm,5μm)色谱柱初步分离,2.5 min后转入C_(18)(150 mm×2.1 mm,5μm)柱进行分析,流速0.2 mL·min^(-1),柱温35℃。结果红霉素在1~100μg·mL^(-1)范围内线性关系良好(r=0.9994);平均加样回收率大于96.9%;日内和日间精密度小于1.29%(n=6)。结论本研究改进样品提取方法,并通过在线柱切换完成目标组分的净化和富集,该方法操作简单、准确灵敏、稳定性好,可用于红霉素软膏的含量测定。

电位滴定法与高效液相色谱法测定兽用复方制剂中巴比妥含量

分析比较电位滴定法与高效液相色谱法在巴比妥含量测定上的差异,以期为实际检测工作提供参考。采用916 Ti-Touch自动电位滴定仪,用硝酸银滴定液进行电位滴定。高效液相色谱法采用Xbridge C18色谱柱(150.0 mm×4.6 mm,5µm);流动相为乙腈-0.05 mol/L磷酸二氢钾溶液(体积比25∶75,用三乙胺调节pH值至8.2);检测波长240 nm;柱温30℃,流速1.0 mL/min,进样体积10µL。结果显示,电位滴定法加标回收率为100.2%~101.2%,RSD为0.1%;高效液相色谱法加标回收率为99.0%~101.6%,RSD为0.1%~0.2%。分别采用电位滴定法和高效液相色谱法测定12批不同厂家兽用复方氨基比林注射液和安痛定注射液中巴比妥含量,两种方法测定结果差异不显著(P>0.05)。高效液相色谱法耗时长,成本高,更适用于复方制剂中多种成分的同时测定;电位滴定法操作简便快速,准确度高,精密度好,更适用于巴比妥单一成分含量的测定。

饲料中添加β-胡萝卜素对肝胰腺白化症扣蟹生长性能的影响

开展了饲料中添加藻源天然β-胡萝卜素对肝胰腺白化症扣蟹的生长性能的影响试验。在基础饲料中添加不同水平的杜氏盐藻,配制成2组饲料,分别为Diet 2和Diet 3,对应β-胡萝卜素含量分别为100和200 mg/kg,不添加杜氏盐藻的饲料组为对照组Diet 1。结果表明,Diet 2和Diet 3组显著提高了肝胰腺白化扣蟹的质量增加率及成活率(P<0.05),显著增加了扣蟹肝胰腺指数、肝胰腺总脂含量(P<0.05),以及肝胰腺中总类胡萝卜素、虾青素和β-胡萝卜素含量。Diet 1、Diet 2和Diet3组扣蟹肝胰腺中粗蛋白及灰分含量差异较小;蟹肝胰腺红度值a*及黄度值b*均随着饲料中杜氏盐藻的增加而显著增加。指出,饲料中添加藻源β-胡萝卜素,在一定程度上改善了扣蟹的肝胰腺白化症状。

2种豆科牧草生产性能与营养价值比较研究

为丰富云南草田轮作中优质豆科牧草种质资源,试验对黄花鸡足豆(Ornithopus compressus L.)开展了生产性能和营养价值评价研究。结果得出,黄花鸡足豆在云南温带地区具有良好的适应性,鲜草产量为15 525kg/hm^(2),干草产量为7 091.53kg/hm^(2),两者均高于光叶紫花苕,尤其是干鲜比较后者提高了27.8%。营养成分方面,光叶紫花苕的粗蛋白含量为17.43%,比黄花鸡足豆高出了3.09%(P<0.05),而黄花鸡足豆的P含量为0.25%,显著高于光叶紫花苕(P<0.05)。黄花鸡足豆的粗纤维含量为38.39%,高于光叶紫花苕,但是差异性不显著。综合营养成分分析,黄花鸡足豆与目前大面积利用的光叶紫花苕相比,营养价值较为一致。