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Application of the Sub-Model Method in the Engine Strength Analysis 被引量:9
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作者 邹文胜 左正兴 +1 位作者 冯慧华 廖日东 《Journal of Beijing Institute of Technology》 EI CAS 2001年第3期260-265,共6页
On the basis of introducing the fundamental theory and the basic analysis steps of the sub model method, the strength of the new engine complex assembly structure was analyzed according to the properties of the engin... On the basis of introducing the fundamental theory and the basic analysis steps of the sub model method, the strength of the new engine complex assembly structure was analyzed according to the properties of the engine structures, some of the key parts of the engine were analyzed with refined mesh by sub model method and the error of the FEM solution was estimated by the extrapolation method. The example showed that the sub model can not only analyze the comlex structures without the restriction of the software and hardware of the computers, but get the more precise analysis result also. This method is more suitable for the strength analysis of the complex assembly structure. 展开更多
关键词 sub model method ENGINE strength analysis FEM
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Thermo-hydraulic analysis for sub-module of Chinese HCSB TBM design 被引量:1
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作者 ZHAO Zhou FENG Kai-ming WANG Xiao-yu YUAN Tao 《核聚变与等离子体物理》 CAS CSCD 北大核心 2006年第3期186-189,共4页
Thermo-hydraulic calculation and analysis for sub-module of Chinese HCSB TBM were carried out using FE code ANSYS. Results indicate that temperature distribution in materials used in sub-module is reasonable and accep... Thermo-hydraulic calculation and analysis for sub-module of Chinese HCSB TBM were carried out using FE code ANSYS. Results indicate that temperature distribution in materials used in sub-module is reasonable and acceptable. 展开更多
关键词 次模块 热水压分析 温度分布 再生区
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Regional Frequency Analysis of Observed Sub-Daily Rainfall Maxima over Eastern China 被引量:2
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作者 Hemin SUN Guojie WANG +3 位作者 Xiucang LI Jing CHEN Buda SU Tong JIANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第2期209-225,共17页
Based on hourly rainfall observational data from 442 stations during 1960-2014, a regional frequency analysis of the annual maxima (AM) sub-daily rainfall series (1-, 2-, 3-, 6-, 12-, and 24-h rainfall, using a mov... Based on hourly rainfall observational data from 442 stations during 1960-2014, a regional frequency analysis of the annual maxima (AM) sub-daily rainfall series (1-, 2-, 3-, 6-, 12-, and 24-h rainfall, using a moving window approach) for eastern China was conducted. Eastern China was divided into 13 homogeneous regions: Northeast (NE1, NE2), Central (C), Central North (CN1, CN2), Central East (CE1, CE2, CE3), Southeast (SE1, SE2, SE3, SE4), and Southwest (SW). The generalized extreme value performed best for the AM series in regions NE, C, CN2, CE1, CE2, SE2, and SW, and the generalized logistic distribution was appropriate in the other regions. Maximum return levels were in the SE4 region, with value ranges of 80-270 mm (1-h to 24-h rainfall) and 108-390 mm (1-h to 24-h rainfall) for 20- and 100 yr, respectively. Minimum return levels were in the CN1 and NE1 regions, with values of 37-104 mm and 53-140 mm for 20 and 100 yr, respectively. Comparing return levels using the optimal and commonly used Pearson-III distribution, the mean return-level differences in eastern China for 1-24-h rainfall varied from -3-4 mm to -23-11 mm (- 10%-10%) for 20-yr events, reaching -6-26 mm (-10%-30%) and -10-133 mm (-10%-90%) for 100-yr events. In view of the large differences in estimated return levels, more attention should be given to frequency analysis of sub-daily rainfall over China, for improved water management and disaster reduction. 展开更多
关键词 sub-daily rainfall annual maxima regional frequency analysis return level eastern China
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Analysis of Observed and Modelled Near-Surface Wind Extremes over the Sub-Arctic Northeast Pacific 被引量:1
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作者 Alexander Kislov Vladimir Platonov 《Atmospheric and Climate Sciences》 2019年第1期146-158,共13页
Wind speed extremes in the sub-Arctic realm of the North-East Pacific region were investigated through extreme value analysis of wind speed obtained from wind simulations of the COSMO-CLM (Consortium for Small-scale M... Wind speed extremes in the sub-Arctic realm of the North-East Pacific region were investigated through extreme value analysis of wind speed obtained from wind simulations of the COSMO-CLM (Consortium for Small-scale Modelling, climate version) mesoscale model, as well as using observed data. The analysis showed that the set of wind speed extremes obtained from observations is a mixture of two different subsets each neatly described by the Weibull distribution. Using special metaphoric terminology, they are labelled as “Black Swans” and “Dragons”. The “Dragons” are responsible for strongest extremes. It has been shown that both reanalysis and GCM (general circulation model) data have no “Dragons”. This means that such models underestimate wind speed maxima, and the important circulation process generating the anomalies is not simulated. The COSMO-CLM data have both “Black Swans” and “Dragons”. This evidence provides a clue that an atmospheric model with a detailed spatial resolution (we used in this work the data from domain with 13.2 km spatial resolution) does reproduce the special mechanism responsible for the generation of the largest wind speed extremes. However, a more thorough analysis shows that the differences in the parameters of the cumulative distribution functions are still significant. The ratio between the modelled Dragons and Black Swans can reach up to only 10%. It is much less than 30%, which was the level established for observations. 展开更多
关键词 EXTREME WIND SPEED analysis Modelled EXTREME WIND SPEED Arctic and sub-ARCTIC Circulation
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STATISTICAL ANALYSIS OF TEMPERATURES ON BOTH THE UPPER AND LOWER BOUNDARIES OF SUB-ALPINE DARK CONIFER FORESTS IN CHINA
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作者 王建 徐孝彬 《Chinese Geographical Science》 SCIE CSCD 1995年第4期300-315,共16页
Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these esti... Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these estimated data, the heat factors to influence and control the distribution and growth of subalpine dark conifer forests in China are discussed. It is found that the most important heat index to influence and control the distribution and growth of subalpine dark conifer forests is neither the mean temperature in the warmest month, nor the maximum or minimum temperatures, but monthly accumulated temperature of>0℃ or monthly effective accumulated temperature of>5℃.When monthly accumulated temperature of>0℃ is more than 40℃, or monthly effective accumulated temperature of>5℃ is over 50℃, sub-alpine dark conifer forests cannot grow well. When monthly accumulated temperature of>5℃ is less than 60℃, sub-alpine dark conifer forests can not grow at all. When monthly effective accumulated temperature of>5℃ is in the range 15℃-45℃, subalpine dark conifer forests in China can grow well. The ecological significance of temperature in May and September, and in summer half year are discussed. 展开更多
关键词 sub-alpine DARK CONIFER FORESTS temperature STATISTICAL analysis
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Analysis method of chaos and sub-harmonic resonance of nonlinear system without small parameters
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作者 刘延彬 陈予恕 曹庆杰 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第1期1-10,共10页
The Melnikov method is important for detecting the presence of transverse homoclinic orbits and the occurrence of homoclinic bifurcations. Unfortunately, the traditional Melnikov methods strongly depend on small param... The Melnikov method is important for detecting the presence of transverse homoclinic orbits and the occurrence of homoclinic bifurcations. Unfortunately, the traditional Melnikov methods strongly depend on small parameters, which do not exist in most practical systems. Those methods are limited in dealing with the systems with strong nonlinearities. This paper presents a procedure to study the chaos and sub-harmonic resonance of strongly nonlinear practical systems by employing a homotopy method that is used to extend the Melnikov functions to the strongly nonlinear systems. Applied to a given example, the procedure shows the effectiveness via the comparison of the theoretical results and the numerical simulation. 展开更多
关键词 homotopy analysis Melnikov function CHAOS sub-harmonic resonance
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Tobacco use among population sub-groups: A gender analysis
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作者 Ahmed Mandil Sahar Abdel Maqsoud +1 位作者 Kholoud Tayel Mona Shama 《Open Journal of Preventive Medicine》 2012年第4期468-477,共10页
Women comprise 20% of world’s billion smokers. Especially troubling is raising prevalence of tobacco use among girls. In fact, it is expected that 20% of women in developing/developed countries will be smokers by 202... Women comprise 20% of world’s billion smokers. Especially troubling is raising prevalence of tobacco use among girls. In fact, it is expected that 20% of women in developing/developed countries will be smokers by 2025. This study analytically compares knowledge, attitudes, and practices of tobacco use, by gender, among 4 sub-populations in Alexandria, Egypt. Methods: A cross sectional approach was used for 4 subgroups (high school students, university students, shopping malls/clubs’ attendees, employees of health-related facilities), 1000 each (total sample size = 4000). A modified version of WHO questionnaire was used for data collection. Results: Smoking prevalence was generally higher among males (29%-44%) compared to females (2% - 9%) in the studied groups. Cafeterias were preferable smoking places for both genders, especially among high school/university students. Most smokers in the 4 subgroups reported that most or all their friends were smokers. Mean knowledge scores were found to be higher among male employees/high school students, compared to females in the same sub-groups. Mean attitude scores towards smoking were higher among females (i.e. against smoking) in the 4 sub-samples. Conclusion & Recommendations: Tobacco use among males is generally higher among males, but females seem to be catching up. Social gatherings seem to attract many youngsters, of both genders, to smoke in public, especially waterpipe (which is a growing epidemic of tobacco use in our communities). Mass community- and gender-based health awareness campaigns are needed, using different channels, including school-based health education interventions, at the earliest age possible. 展开更多
关键词 TOBACCO USE GENDER analysis POPULATION sub-Groups
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Thermo-Dynamical Analysis on Electricity-Generation Subsystem of CAES Power Plant
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作者 Wenyi Liu Gang Xu Yongping Yang 《Journal of Power and Energy Engineering》 2014年第4期729-734,共6页
Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart... Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart power grids. Linked with the flow structure and dynamic characteristic of electricity generation subsystem and its components, a simulation model is proposed. Thermo-dynamical performance on off-design conditions have been analyzed with constant air mass flux and constant gas combustion temperature. Some simulation diagrams of curve are plotted too. The contrast of varied operation mode thermal performance is made between CAES power plant and simple gas turbine power plant. 展开更多
关键词 ELECTRICITY Generation sub-System CAES Power PLANT Thermal Performance Simulation analysis OFF-DESIGN Conditions
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Analysis of the Effect of Subgroup Size on the X-Bar Control Chart Using Forensic Science Laboratory Sample Influx Data
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作者 Samwel Victor Manyele 《Engineering(科研)》 2017年第5期434-456,共23页
This paper analyzes the effect of subgroup size on the x-bar chart characteristics using sample influx (SIF) into forensic science laboratory (FSL). The characteristics studied include changes in out-or-control points... This paper analyzes the effect of subgroup size on the x-bar chart characteristics using sample influx (SIF) into forensic science laboratory (FSL). The characteristics studied include changes in out-or-control points (OCP), upper control limit UCLx, and zonal demarcations. Multi-rules were used to identify the number of out-of-control-points, Nocp as violations using five control chart rules applied separately. A sensitivity analysis on the Nocp was applied for subgroup size, k, and number of sigma above the mean value to determine the upper control limit, UCLx. A computer code was implemented using a FORTRAN code to create x-bar control-charts and capture OCP and other control-chart characteristics with increasing k from 2 to 25. For each value of k, a complete series of average values, Q(p), of specific length, Nsg, was created from which statistical analysis was conducted and compared to the original SIF data, S(t). The variation of number of out-of-control points or violations, Nocp, for different control-charts rules with increasing k was determined to follow a decaying exponential function, Nocp = Ae–α, for which, the goodness of fit was established, and the R2 value approached unity for Rule #4 and #5 only. The goodness of fit was established to be the new criteria for rational subgroup-size range, for Rules #5 and #4 only, which involve a count of 6 consecutive points decreasing and 8 consecutive points above the selected control limit (σ/3 above the grand mean), respectively. Using this criterion, the rational subgroup range was established to be 4 ≤ k ≤ 20 for the two x-bar control chart rules. 展开更多
关键词 Forensic Science LABORATORY SAMPLE Influx Statistical analysis X-bar Control CHART sub-Group Size Control CHART Rules Multi-Rules for X-Bar CHART Out-of-Control Points
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Improved Qualitative Trajectory Calculus for Pair-Activity Analysis
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作者 Shengsheng Wang Guangyao Wang +1 位作者 Yungang Zhu Jingwen Shao 《Journal of Beijing Institute of Technology》 EI CAS 2019年第2期318-326,共9页
Trajectory provides the most robust feature for activity recognition in far-field surveillance videos,in which increasing attentions have been given to the use of qualitative methods with symbolic rather than real-val... Trajectory provides the most robust feature for activity recognition in far-field surveillance videos,in which increasing attentions have been given to the use of qualitative methods with symbolic rather than real-value features.Qualitative trajectory calculus(QTC)showed a good performance in pair-activity from video.However,QTC and similar works are not good at dealing with noise,since they are all considering short-term features.To deal with the problems mentioned above,two types of long-term features,including sub-trajectory feature and point-trajectory feature,are designed.The sub-trajectory feature is a long-term feature in a coarse granularity,while the point-trajectory feature is a long-term feature in a relatively fine granularity.Using the sub-trajectory feature,a couple of trajectories are segmented into sub-trajectories and enveloping boxes are used to substitute the original sub-trajectory for capturing the major attributes.The point-trajectory feature describes the relationship between a single point in one trajectory and all parts of the other trajectory.The experiments on the human activity classification data demonstrated that our proposed methods are better than the original QTC and previous short-term features. 展开更多
关键词 pair-activity analysis qualitative TRAJECTORY CALCULUS sub-trajectory FEATURE point-trajectory FEATURE
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Numerical analysis of electromagnetic force field through the use of two examples
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作者 BAI Yunfeng 《Baosteel Technical Research》 CAS 2013年第3期50-56,共7页
In modern processing of conducting materials, such as steel,the time-varying electromagnetic field plays a key role in obtaining the desired microstructure or eliminating solidification defects such as porosity and se... In modern processing of conducting materials, such as steel,the time-varying electromagnetic field plays a key role in obtaining the desired microstructure or eliminating solidification defects such as porosity and segregation in cast billets. Up to now,few studies on the induced electromagnetic force (also called the Lorentz force) field in liquid metal have been reported. Compared with the magnetic field, the induced force field is the real and only direct cause for flow control. The electromagnetic force is comprised of two components. One is time-independent and the other is time- dependent. The time-dependent component varies with time in both amplitude and direction. When it reaches the extreme value,it can be one dozen times larger than the time-independent component. In this paper, a new method to quantitatively describe the induced electromagnetic force in liquid metal under a harmonic electromagnetic field,including both its time- independent and dependent components, was proposed based on the formula derivation from the data of amplitude and phase angle. Through this method ,the features of the time-dependent component were discussed, including the directions of rotation and the long axis. As a result, the force pattern was described. With two example calculations, the method was explained in detail. The results of both examples show that the force field in liquid metal can be divided into several regions with different force features. Example 1 shows the effect of coil position on the evolution of the force field pattern in liquid metal. Example 2 is a kind of stirring by the travelling magnetic field ,whose results present the sub-structures in metal and show that most of them have almost the same rotating direction. 展开更多
关键词 electromagnetic force field numerical analysis time-dependent component quantitative description sub-structure in force field
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The Superconductivity in Fe-Based Family of Superconductors and Its Electronic Structure Analysis in Presence of Dopants Rh and Pd
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作者 Ronald Columbié-Leyva Alberto López-Vivas +2 位作者 ] Ulises Miranda Ilya G. Kaplan 《Journal of Quantum Information Science》 CAS 2022年第4期111-124,共14页
The discovered in 2008 Fe-based superconductors (SC) are a paramagnetic semimetal at ambient temperature and in some cases they become superconductor upon doping. In spite of so many years since its discovery it is st... The discovered in 2008 Fe-based superconductors (SC) are a paramagnetic semimetal at ambient temperature and in some cases they become superconductor upon doping. In spite of so many years since its discovery it is still not known the mechanism that leads to superconductivity. The electronic structure study is used for determining key features of the SC mechanism in these materials. The calculations were performed using the modern suite of programs MOLPRO 2021. We performed quantum calculations of a cluster embedded in a background charge distribution that represents the infinite crystal. The Natural Population Analysis was used for determining the charge and spin distribution in the studied materials. As follows from our results, the possible mechanism for superconductivity corresponds to the RVB theory proposed by Anderson for high T<sub>c</sub> superconductivity in cuprates. 展开更多
关键词 Iron-Based High-T<sub>csub> Superconductors SUPERCONDUCTIVITY Embeded Cluster Method Natural Bonding Orbitals analysis
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Sparse Representation by Frames with Signal Analysis
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作者 Christopher Baker 《Journal of Signal and Information Processing》 2016年第1期39-48,共10页
The use of frames is analyzed in Compressed Sensing (CS) through proofs and experiments. First, a new generalized Dictionary-Restricted Isometry Property (D-RIP) sparsity bound constant for CS is established. Second, ... The use of frames is analyzed in Compressed Sensing (CS) through proofs and experiments. First, a new generalized Dictionary-Restricted Isometry Property (D-RIP) sparsity bound constant for CS is established. Second, experiments with a tight frame to analyze sparsity and reconstruction quality using several signal and image types are shown. The constant  is used in fulfilling the definition of D-RIP. It is proved that k-sparse signals can be reconstructed if  by using a concise and transparent argument1. The approach could be extended to obtain other D-RIP bounds (i.e. ). Experiments contrast results of a Gabor tight frame with Total Variation minimization. In cases of practical interest, the use of a Gabor dictionary performs well when achieving a highly sparse representation and poorly when this sparsity is not achieved. 展开更多
关键词 Compressed Sensing Total Variation Minimization l<sub>1sub>-analysis D-Restricted Isometry Property Tight Frames
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3D Modelling from New and Existing Gravity Data of an Intrusive Body in the Northern Part of Kribi-Campo Sub-Basin in Cameroon 被引量:4
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作者 Kue Petou Rokis Malquaire Owona Angue Marie Louise +1 位作者 Njingti Nfor Manguelle-Dicoum Eliezer 《International Journal of Geosciences》 2017年第8期984-1003,共20页
A new gravity survey was carried out in the northern part of the onshore Kribi- Campo sub-basin in Cameroon. The data were incorporated to the existing ones and then analyzed and modeled in order to elucidate the subs... A new gravity survey was carried out in the northern part of the onshore Kribi- Campo sub-basin in Cameroon. The data were incorporated to the existing ones and then analyzed and modeled in order to elucidate the subsurface structure of the area. The area is characterized in its north-western part by considerably high positive anomalies indicative of the presence of a dense intrusive body. We find, 1) from the analysis of the gravity residual anomaly map, the high positive anomalies observed are the signature of a shallow dense structure;2) from the multi-scale analysis of the maxima of the horizontal gradient, the structure is confined between depths of 0.5 km and 5 km;3) from the quantitative interpretation of residual anomalies by spectral analysis, the depth to the upper surface of the intrusive body is not uniform, the average depth of the bottom is h1 = 3.6 km and the depths to particular sections of the roof of the intrusion are h2 = 1.6 km and h3 = 0.5 km;4) and the 3D modeling gives results that are suggestive of the presence of contacts between rocks of different densities at different depths and a dense intrusive igneous body in the upper crust of the Kribi zone. From the 3D model the dense intrusive igneous block is surrounded by sedimentary formations to the south-west and metamorphic formations to the north-east. Both formations have a density of about 2.74 g/cm3. The near surface portions of this igneous block lie at a depth range of 0.5 km to 1.5 km while its lower surface has a depth range of 3.6 km to 5.2 km. The shape of the edges and the bottom of the intrusive body are suggestive of the fact that it forms part of a broader structure underlying the Kribi-Campo sub-basin with a great influence on the sedimentary cover. 展开更多
关键词 Kribi-Campo sub-Basin GRAVITY Data 3D MODELLING SPECTRAL analysis RESIDUAL ANOMALY
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Design and Analysing the Various Parameters of CMOS Circuit’s under Bi-Triggering Method Using Cadence Tools
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作者 A. Sridevi V. Lakshmiprabha N. Prabhu 《Circuits and Systems》 2016年第9期2622-2632,共12页
Reducing the power and energy required by the device/circuit to operate is the main aim of this paper. Here the new design is implemented to reduce the power consumption of the device using the triggering pulses. The ... Reducing the power and energy required by the device/circuit to operate is the main aim of this paper. Here the new design is implemented to reduce the power consumption of the device using the triggering pulses. The proposed triggering method uses a complementary MOS transistor (pMOS and nMOS) as a voltage divider and ground leakage suppressor (i.e.);these designs are named as Trig01 and Trig10 designs. In Trig01 design the pair of CMOS is placed in the voltage divider part;similarly in Trig10 design the pair of CMOS is placed at the ground leakage suppressor part. Standard CMOS gates like NOT, NAND, NOR, EX-OR etc. are designed with these technologies and these gates are designed with 180 nm technology file in the cadence tool suite;compared to the normal CMOS gates, the Bi-Trig gate contains 4 inputs and 2 outputs. The two extra inputs are used as Bi-Trig control signaling inputs. There are 2 control inputs and thus 2<sup>2</sup> = 4 combination of controlling is done (i.e.);both pMOS and nMOS are ON, both pMOS and nMOS are OFF, pMOS ON and nMOS OFF and pMOS ON and nMOS ON. Depending on the usage of the circuit, the mode of operation is switched to any one of the combination. If the output of the circuit is not used anywhere in the total block, that specified circuit can be switched into idle mode by means of switched OFF both the pMOS and nMOS transistor in the control unit. This reduces the leakage current and also the power wastage of the circuits in the total block. Bi-Trig controlled circuit reduces the power consumption and leakage power of the circuit without affecting a performance of the circuits. 展开更多
关键词 Bi-Triggering Power analysis Energy analysis Circuit Simulation Delay analysis sub Clock Method
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Construction of Fluorescence Sensing Platform on the Basis of Molybdenum Disulfide Nanosheet for the Detection of AFB1
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作者 Xiaoqing Wen Zichun Song +3 位作者 Jiuying Cui Yan Li Qianli Tang Xianjiu Liao 《Journal of Biosciences and Medicines》 CAS 2023年第2期1-14,共14页
Purpose: Aflatoxin B<sub>1</sub> is the most common mycotoxin in cereal crops;it is of stronger toxicity and has a carcinogenic effect. In recent years, a series of fluorescence sensors constructed on the ... Purpose: Aflatoxin B<sub>1</sub> is the most common mycotoxin in cereal crops;it is of stronger toxicity and has a carcinogenic effect. In recent years, a series of fluorescence sensors constructed on the basis of MoS<sub>2</sub>NS fluorescence quenching property have become a research hotspot. Therefore, we can construct a fast and simple analysis method with high specificity to detect AFB<sub>1</sub> by utilizing MoS<sub>2</sub>NS, which can be effectively applied to food safety monitoring and clinical diagnosis. Method: In the current research, a fluorescence biosensor is developed on the basis of a new type of two-dimensional nano-material namely MoS<sub>2</sub>NS applied for the detection of AFB<sub>1</sub>. The fluorescence of Apt@AFB<sub>1</sub> can be quickly quenched by MoS<sub>2</sub>NS through the fluorescence resonance energy transfer (FRET). When the target molecule AFB<sub>1</sub> exists, after the specificity binding between AFB<sub>1</sub> and aptamer, the Apt@AFB<sub>1</sub> loses its single stranded structure and is away from MoS<sub>2</sub>NS, and the fluorescence of Apt®AFB<sub>1</sub> cannot be quenched effectively. Such sensing signals can be used to achieve the sensitive detection of AFB<sub>1</sub>. Result: With this new method, under the optimized conditions, the AFB<sub>1</sub> is analyzed in the MoS<sub>2</sub>NS/Apt®AFB<sub>1</sub> sensing platform. Within the dynamic range of 0.2 - 25 ng/mL, the sensing platform expresses a good linear response to the level of AFB<sub>1</sub> with the R<sup>2</sup> = 0.9964 and LOD as 90 pg/mL. This method is applied to detect the actual serum samples and soybean milk with the recovery rate of 93.10% - 107.23% and 95.15% - 102.60% separately, and it can be used in the quantitative detection under the interference of other mycotoxins in a relatively accurate way. Conclusion: It is proved that this new detection method can be used as a potential biosensor platform for the detection of AFB<sub>1</sub>. This detection method features several advantages such as specificity, rapidness and low costs, which can meet the requirement of trace detection in clinical detection and food safety. 展开更多
关键词 MoS<sub>2sub>NS APTAMER Aflatoxin B<sub>1sub> Fluorescence Sensing analysis Food Monitoring
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乌苏市PM2.5浓度分布特征及与气象要素相关分析
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作者 张玉 吴娟 +2 位作者 许铭 杨丹 靳晶 《气候变化研究快报》 2020年第6期635-641,共7页
利用乌苏市2016~2018年PM2.5质量浓度和气象资料,运用常规统计、Pearson相关分析、T检验分析方法对乌苏市PM2.5浓度分布特征及与气象要素相关性进行分析:结果表明乌苏市PM2.5质量浓度日变化曲线呈单峰型特征,PM2.5质量浓度的高值区出现... 利用乌苏市2016~2018年PM2.5质量浓度和气象资料,运用常规统计、Pearson相关分析、T检验分析方法对乌苏市PM2.5浓度分布特征及与气象要素相关性进行分析:结果表明乌苏市PM2.5质量浓度日变化曲线呈单峰型特征,PM2.5质量浓度的高值区出现在13:00~23:00,峰值出现在15:00;1月空气污染最严重;PM2.5质量浓度表现出一定的季节性特征,冬季 】秋季 】春季 】夏季,冬季污染日数占全年的75%,冬季空气污染达到中度污染水平;乌苏市PM2.5质量浓度与温度、降水、平均风速、最大风速、日照呈负相关关系;与相对湿度、气压呈正相关关系。 展开更多
关键词 乌苏 PM<sub>2.5sub> 气象要素 相关分析
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广州市黄埔大沙地NO2污染特征分析及来源解析
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作者 张雪梅 侯红霞 +2 位作者 张金文 毕燕茹 黄渤 《环境保护前沿》 2020年第5期702-713,共12页
于2020年1月1日~4月23日对广州市及黄埔区各站点NO2进行分析,结果表明黄埔大沙地点位NO2污染较为严重。NO2与PM2.5源解析结果相关分析表明,大沙地站点位NO2同时受到移动源和周边工业源的影响,其中受到移动源的影响程度高于工业源。污染... 于2020年1月1日~4月23日对广州市及黄埔区各站点NO2进行分析,结果表明黄埔大沙地点位NO2污染较为严重。NO2与PM2.5源解析结果相关分析表明,大沙地站点位NO2同时受到移动源和周边工业源的影响,其中受到移动源的影响程度高于工业源。污染源分布表明,站点NO2一定程度受到周边大型钢铁及发电企业的影响。车流量和车型分析表明,NO2污染高峰日受重型货车的影响较大。拥堵数据分析表明,站点周边3公里左右分别在早7时、10时、18~19时出现拥堵高峰,特别是18~19时拥堵次数和拥堵长度都较大,拥堵后NO2的质量浓度显著升高。此外,以含钒颗粒物作为船舶排放示踪物,发现黄埔大沙地NO2的污染在特定时段会受到东南区域港口船舶尾气排放影响。因此,黄埔大沙地站点NO2受到了道路移动源、工业源、船舶排放的综合影响,需进行综合性的污染防控。 展开更多
关键词 NO<sub>2sub>来源 移动源 工业源 拥堵分析 船舶排放
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Variation in Expression of <i>Sub</i>1 Gene and Association with Submergence Stress Related Traits in Advance Rice (<i>Oryza sativa</i>L.) Genotypes as a Tool of Climate Change Adaptation
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作者 Zulqarnain Haider Muhammad Akhter +1 位作者 Abid Mahmood Usman Saleem 《American Journal of Climate Change》 2018年第2期171-186,共16页
Floods have now become most detrimental natural catastrophe worldwide due to radical climatic fluxes. Therefore, there is a dire necessity to develop a high yielding rice lines to deal with this scenario. For this pur... Floods have now become most detrimental natural catastrophe worldwide due to radical climatic fluxes. Therefore, there is a dire necessity to develop a high yielding rice lines to deal with this scenario. For this purpose, a large scale experiment was conducted including one hundred and fifteen (115) rice genotypes having SUB1 gene imported from International Rice Research Institute (IRRI) Philippines, six local cultivars/approved varieties and three high yielding rice varieties i.e. Sabitri, IR6 and NSICRC222 being used as potential varieties in different countries of Asia as susceptible check and IR64-SUB1 as tolerant check. The genotypic screening was performed using two PCR-based DNA markers i.e. ART5 and SC3. Phenotypic screening was conducted in a natural pond to assess the interaction of SUB1 gene in natural stagnant flood water as well as the suitability of introgression of SUB1 gene into approved varieties and elite rice lines. The genotypes were assessed in terms of plant survival percentage, submergence tolerance index, physical condition, stem elongation, number of grains per panicle, thousand grain weight, grain yields and deviations in these traits after submergence stress. The PCR results suggested that both the primers ART5 and SC3 may be used as potential PCR-based markers for molecular screening of rice genotypes for SUB1 QTL. Furthermore, it confirmed the presence of SUB1 gene in all the lines imported from IRRI, while it was absent in all the local cultivars studied. All the genotypes with submergence tolerant gene (SUB1) showed significantly greater tolerance level in submergence stress of 14 days, as compared to other local cultivars/varieties, authenticating the effectiveness of SUB1QTL in conferring submergence tolerance. Significantly different performances of all the SUB1 genotypes in terms of all the studied traits indicate high Genotypic and Genotypic Environment Interaction (GEI) of SUB1QTL. Employment of SUB1 lines such as R105479:149-18, IR64-SUB1 and Rl05469:81-22-3 in breeding programs for developing flood tolerant rice varieties might further upsurge rice yields in flash flood areas. Correlation analysis revealed that plant survival percentage after submergence, reduced stem elongation during submergence and submergence tolerance index are very important traits for developing submergence tolerant lines. 展开更多
关键词 Oryza SATIVA L. sub1 QTL Floods Climate Change PHENOTYPIC EXPRESSION ASSOCIATION analysis Stress Related Traits
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A Comparative Study on Dry Sliding Wear Characteristics of Al2O3 and Bone Powder Filled Hybrid Composites
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作者 Sudeep Deshpande T. Rangaswamy 《Journal of Minerals and Materials Characterization and Engineering》 2016年第2期164-180,共17页
The aim of the research was to develop E-glass/jute fiber reinforced epoxy composites with an addition of Al<sub>2</sub>O<sub>3</sub> and bone powder by using hand layup technique and to compar... The aim of the research was to develop E-glass/jute fiber reinforced epoxy composites with an addition of Al<sub>2</sub>O<sub>3</sub> and bone powder by using hand layup technique and to compare tribological properties of these composites under similar test conditions. The wear experiments were designed according to Taguchi’s (L<sub>27</sub>) orthogonal array with three control variables such as sliding velocity, filler content and normal load. The results indicated that the normal load for Al<sub>2</sub>O<sub>3</sub> and filler content for bone powder emerged as the significant factors affecting specific wear rate of hybrid composites. An addition of 10 wt% of bone powder or Al<sub>2</sub>O<sub>3</sub> into E-glass/jute fiber reinforced epoxy composites increased the wear resistance considerably, and natural waste bone powder can be used instead of ceramic filler Al<sub>2</sub>O<sub>3</sub> in hybrid composites. After the analysis of control factors, an optimal factor setting has been suggested for specific wear rate and coefficient of friction. Further, the scanning electron microscopy (SEM) images for worn surfaces of hybrid composites were studied. Finally, a confirmation test was carried out to validate the results. 展开更多
关键词 Al<sub>2sub>O<sub>3sub> Bone Powder Wear Test Taguchi analysis SEM
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