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Effectiveness of inhibitors in increasing chloride threshold value for steel corrosion 被引量:12
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作者 Jin-xia XU Lin-hua JIANG +2 位作者 Wei-lun WANG Li TANG Li CUI 《Water Science and Engineering》 EI CAS CSCD 2013年第3期354-363,共10页
This investigation was aimed at evaluating the effectiveness of corrosion inhibitors in increasing the chloride threshold value for steel corrosion. Three types of corrosion inhibitors, calcium nitrite (Ca(NO2)2),... This investigation was aimed at evaluating the effectiveness of corrosion inhibitors in increasing the chloride threshold value for steel corrosion. Three types of corrosion inhibitors, calcium nitrite (Ca(NO2)2), zinc oxide (ZnO), and N,N'-dimethylaminoethanol (DMEA), which respectively represented the anodic inhibitor, cathodic inhibitor, and mixed inhibitor, were chosen. The experiment was carried out in a saturated calcium hydroxide (Ca(OH)2) solution to simulate the electrolytic environment of concrete. The inhibitors were initially mixed at different levels, and then chloride ions were gradually added into the solution in several steps. The open-circuit potential (Ecorr) and corrosion current density (lcorr) determined by electrochemical impedance spectra (EIS) were used to identify the initiation of active corrosion, thereby determining the chloride threshold value. It was found that although all the inhibitors were effective in decreasing the corrosion rate of steel reinforcement, they had a marginal effect on increasing the chloride threshold value. 展开更多
关键词 steel corrosion chloride threshold value electrochemical impedance spectra (EIS) corrosion inhibitor
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On Accelerated Singular Value Thresholding Algorithm for Matrix Completion 被引量:3
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作者 Li Wang Jianfeng Hu Chuanzhong Chen 《Applied Mathematics》 2014年第21期3445-3451,共7页
An accelerated singular value thresholding (SVT) algorithm was introduced for matrix completion in a recent paper [1], which applies an adaptive line search scheme and improves the convergence rate from O(1/N) for SVT... An accelerated singular value thresholding (SVT) algorithm was introduced for matrix completion in a recent paper [1], which applies an adaptive line search scheme and improves the convergence rate from O(1/N) for SVT to O(1/N2), where N is the number of iterations. In this paper, we show that it is the same as the Nemirovski’s approach, and then modify it to obtain an accelerate Nemirovski’s technique and prove the convergence. Our preliminary computational results are very favorable. 展开更多
关键词 Matrix COMPLETION SINGULAR value thresholdING Nemirovski’s LINE SEARCH Scheme Adaptive LINE SEARCH
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Predicting the Threshold Values based on Diffusion Model of Nitrite Ions in Reinforced Concrete 被引量:1
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作者 柳俊哲 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第2期308-311,共4页
The prediction model for inhibition effect of reinforced concrete was presented based on the Magge's model when the concrete surface was brushed with nitrite solution. The influence of the amount of nitrite solution ... The prediction model for inhibition effect of reinforced concrete was presented based on the Magge's model when the concrete surface was brushed with nitrite solution. The influence of the amount of nitrite solution on inhibiting duration was also discussed through a simulation analysis when the amount of solution were 250 g/m^2, 500 g/m^2, 1000 g/m^2 and 1500 g/m^2, respectively. The experimental results confirm that nitrite ion can diffuse well in concrete to reach an effective mol ratio from the surface of the concrete to the surface of the reinforcement, and has an effective protection for the bars against corrosion. The higher the amount of solution, the better it will accelerate getting the threshold value of mol ratio on the surface of rebar, and retarding the time for loosing the effective threshold value of mol ratio. It helps to increase the tendency of inhibiting duration and prolong the life of reinforced concrete. The nitrite solution amount is used to predict the corrosion inhibiting duration of concrete that contains chloride salt. 展开更多
关键词 reinforced concrete nitrite ion DIFFUSION threshold value
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THRESHOLD VALUE FOR DIAGNOSIS OF CHAOTIC NATURE OF THE DATA OBTAINED IN NONLINEAR DYNAMIC ANALYSIS 被引量:1
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作者 马军海 陈予恕 刘曾荣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第6期513-520,共8页
In this paper surrogate data method of phase-randomized is proposed to identify the random or chaotic nature of the data obtained in dynamic analysis: The calculating results validate the phase-randomized method to be... In this paper surrogate data method of phase-randomized is proposed to identify the random or chaotic nature of the data obtained in dynamic analysis: The calculating results validate the phase-randomized method to be useful as it can increase the extent of accuracy of the results. And the calculating results show that threshold values of the random timeseries and nonlinear chaotic timeseries have marked difference. 展开更多
关键词 chaotic timeseries surrogate-data threshold value random timeseries
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The Effect of a High-Frequency-Hearing-Threshold Weighted Value on the Diagnosis of Occupational-Noise-Induced Deafness 被引量:1
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作者 Laijun Xue Yanhong Zhang Aichu Yang 《Journal of Biosciences and Medicines》 2018年第12期88-99,共12页
Objective: In order to provide a theoretical basis for the revision of the current diagnostic criteria for occupational noise-induced deafness (ONID), we evaluated the degree of ONID by analyzing different high-freque... Objective: In order to provide a theoretical basis for the revision of the current diagnostic criteria for occupational noise-induced deafness (ONID), we evaluated the degree of ONID by analyzing different high-frequency-hearing- threshold-weighted values (HFTWVs). Methods: A retrospective study was conducted to evaluate the diagnosis of patients with ONID from January 2016 to January 2017 in Guangdong province, China. Based on 3 hearing tests (each interval between the tests was greater than 3 days), the minimum threshold value of each frequency was obtained using the 2007 edition’s diagnostic criteria for ONID. The speech frequency and the HFTWVs were analyzed based on age, noise exposure, and diagnostic classi-fication using SPSS21.0. Results: 168 patients in total were involved in this study, 154 males and 14 females, and the average age was 41.18 ± 6.07. The diagnosis rate was increased by the weighted value of the high frequencies and was more than the mean value of the pure speech frequency (MVPSF). The diagnosis rate for the weighted 4 kHz frequency level increased by 13.69% (χ2 = 9.880, P = 0.002), the weighted 6 kHz level increased by 15.47% (χ2 = 9.985, P = 0.002), and the weighted 4 kHz + 6 kHz level increased by 15.47% (χ2 = 9.985, P = 0.002). The differences were all statistically significant. The diagnostic rate of the different thresholds showed no obvious difference between the genders. The age groups were divided into less than or equal to 40 years old (group A) and 40 - 50 years old (group B). There were several groups with a high frequency: high frequency weighted 4 kHz ( group A χ2 = 3.380, P = 0.050;group B χ2 = 4.054, P = 0.032), high frequency weighted 6 kHz (group A χ2 = 6.362, P = 0.012;group B χ2 = 4.054, P = 0.032), weighted 4 kHz + 6 kHz (group A χ2 = 6.362 P = 0.012;B χ2 = 4.054, P = 0.032) than those of MVPSF in the same group on ONID diagnosis rate. The differences between the groups were statistically significant. There was no significant difference between the age groups (χ2 = 2.265, P = 0.944). The better ear’s (the smaller hearing threshold weighted value) MVPSF and the weighted values for the different high frequencies were examined in light of the number of working years;the group that was exposed to noise for more than 10 years had significantly higher values than those of the average thresholds of each frequency band in the groups with 3 - 5 years of exposure (F = 2.271, P = 0.001) and 6 - 10 years of exposure (F = 1.563, P = 0.046). The differences were statistically significant. The different HFTWVs were higher than those of the MVPSF values, and the high frequency weighted 4 kHz + 6 kHz level showed the greatest difference, with an average increase of 2.83 dB. The diagnostic rate that included the weighted high frequency values was higher for the mild, moderate, and severe cases than those patients who were only screened with the pure frequency tests. The results of the comparisons of the diagnosis rates for mild ONID were as follows: the weighted 3 kHz high frequency level (χ2 = 3.117, P = 0.077) had no significant difference, but the weighted 4 kHz level (χ2 = 10.835, P = 0.001), 6 kHz level (χ2 = 9.985, P = 0.002), 3 kHz + 4 kHz level (χ2 = 6.315, P = 0.012), 3 kHz + 6 kHz level (χ2 = 6.315, P = 0.012), 4 kHz + 6 kHz level (χ2 = 9.985, P = 0.002), and 3 kHz + 4 kHz + 6 kHz level (χ2 = 7.667, P = 0.002) were significantly higher than the diagnosis rate of the mean value of the PSF. There was no significant difference between the 2 groups for the moderate and severe grades (P > 0.05). Conclusion: Different HFTWVs increase the diagnostic rate of ONID. The weighted 4 kHz, 6 kHz, and 4 kHz + 6 kHz high frequency values greatly affected the diagnostic results, and the weighted 4 kHz + 6 kHz high frequency hearing threshold value has the maximum the effect on the ONID diagnosis results. 展开更多
关键词 Noise OCCUPATIONAL Noise DEAFNESS NOISE-INDUCED HEARING Loss High Fre-quency HEARING threshold WEIGHTED value Diagnostic Rate
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Optimized quantum singular value thresholding algorithm based on a hybrid quantum computer 被引量:1
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作者 Yangyang Ge Zhimin Wang +9 位作者 Wen Zheng Yu Zhang Xiangmin Yu Renjie Kang Wei Xin Dong Lan Jie Zhao Xinsheng Tan Shaoxiong Li Yang Yu 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第4期752-756,共5页
Quantum singular value thresholding(QSVT) algorithm,as a core module of many mathematical models,seeks the singular values of a sparse and low rank matrix exceeding a threshold and their associated singular vectors.Th... Quantum singular value thresholding(QSVT) algorithm,as a core module of many mathematical models,seeks the singular values of a sparse and low rank matrix exceeding a threshold and their associated singular vectors.The existing all-qubit QSVT algorithm demands lots of ancillary qubits,remaining a huge challenge for realization on nearterm intermediate-scale quantum computers.In this paper,we propose a hybrid QSVT(HQSVT) algorithm utilizing both discrete variables(DVs) and continuous variables(CVs).In our algorithm,raw data vectors are encoded into a qubit system and the following data processing is fulfilled by hybrid quantum operations.Our algorithm requires O [log(MN)] qubits with0(1) qumodes and totally performs 0(1) operations,which significantly reduces the space and runtime consumption. 展开更多
关键词 singular value thresholding algorithm hybrid quantum computation
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Efficient Global Threshold Vector Outlyingness Ratio Filter for the Removal of Random Valued Impulse Noise
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作者 J. Amudha R. Sudhakar 《Circuits and Systems》 2016年第6期692-700,共9页
This research paper proposes a filter to remove Random Valued Impulse Noise (RVIN) based on Global Threshold Vector Outlyingness Ratio (GTVOR) that is applicable for real time image processing. This filter works with ... This research paper proposes a filter to remove Random Valued Impulse Noise (RVIN) based on Global Threshold Vector Outlyingness Ratio (GTVOR) that is applicable for real time image processing. This filter works with the algorithm that breaks the images into various decomposition levels using Discrete Wavelet Transform (DWT) and searches for the noisy pixels using the outlyingness of the pixel. This algorithm has the capability of differentiating high frequency pixels and the “noisy pixel” using the threshold as well as window adjustments. The damage and the loss of information are prevented by means of interior mining. This global threshold based algorithm uses different thresholds for different quadrants of DWT and thus helps in recovery of noisy image even if it is 90% affected. Experimental results exhibit that this method outperforms other existing methods for accurate noise detection and removal, at the same time chain of connectivity is not lost. 展开更多
关键词 Image Restoration Noise Detection Noise Removal Random valued Impulse Noise Global threshold Vector Outlyingness Ratio
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The Innovation Research of Financial Early-Warning Index Measurement 被引量:3
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作者 Zhang You-tang Cheng Jun-ning Liang Wei-jun 《Wuhan University Journal of Natural Sciences》 CAS 2002年第3期281-284,共4页
The period economic fluctuation is vital for an enterprise to exist and further develop, it directly affect the enterprise financial health. So, it is significant to build up financial early-warning index and measure ... The period economic fluctuation is vital for an enterprise to exist and further develop, it directly affect the enterprise financial health. So, it is significant to build up financial early-warning index and measure the warning condition that the enterprise faces and take the effective measures to eliminate. We criticize Altman’sZ calculating model and build up some new indexes for enterprise financial early-warning condition measuring and making sound decision. 展开更多
关键词 financial early-warning index critical value cash earning value cash added value
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Main Principles and Methods of Identification of High Conservation Value Forests in the Conditions of Mountainous Relief: Case of Armenia 被引量:2
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作者 Zhirayr Vardanyan Tatyana Danielyan +1 位作者 George Fayvush Siranush Galstyan 《Journal of Life Sciences》 2017年第6期269-278,共10页
Armenia is a small mountainous country with remarkable biodiversity. The forest cover of Armenia makes up 11.17% of the total territory of Armenia. The forests of Armenia make important habitat for numerous biological... Armenia is a small mountainous country with remarkable biodiversity. The forest cover of Armenia makes up 11.17% of the total territory of Armenia. The forests of Armenia make important habitat for numerous biological objects. They also provide important ecosystem services, including key services to forest adjacent population. Deforestation and forest degradation are serious threats in Armenia. In the result of special studies the principles and criteria for identification of HCVFs (high conservation value forests) in the conditions of Armenia were developed. They are based on the guidelines for identification and management of HCVFs, but adapted to the conditions of mountainous forests of Armenia as a small country. Out of six generic types of HCVFs, it is suggested to define five types of HCVFs with respective sub-types. Proper protection of such forests shall ensure conservation of biological diversity and maintenance of ecosystem services provided by forests. 展开更多
关键词 HCVFs (High conservation value forests) IDENTIFICATION CRITERIA thresholds Armenia.
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A More Effective Method of Extracting the Characteristic Value of Pulse Wave Signal Based on Wavelet Transform 被引量:1
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作者 Xuanwei Zhang Yazhou Shang +3 位作者 Daoxin Guo Tianxia Zhao Qiuping Li Xin’an Wang 《Journal of Biomedical Science and Engineering》 2016年第10期9-19,共11页
Pulse wave contains human physiological and pathological information. Different people will exhibit different characteristics, and hence determining the characteristic points of the pulse wave of human physiological h... Pulse wave contains human physiological and pathological information. Different people will exhibit different characteristics, and hence determining the characteristic points of the pulse wave of human physiological health makes sense. It is common that we extract the characteristic value of pulse wave signal with the method based on wavelet transform on a small scale, and then determine the locations of the characteristic points by modulus maxima and modulus minima. Before determining characteristic value by detecting modulus maxima and modulus minima, we need to determine every period of the pulse wave. This paper presents a new kind of adaptive threshold determination method which is more effective. It can accurately determine every period of the pulse wave, and then extract characteristic values by modulus maxima and modulus minima in every period of the pulse wave. The method presented in this paper promotes the research utilizing pulse wave on health life. 展开更多
关键词 Pulse Wave Wavelet Transform Adaptive threshold Characteristic values
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Analysis of Network Traffic with Extreme Value Theory
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作者 舒炎泰 汪广洪 +2 位作者 高德云 刘嘉焜 王旭 《Transactions of Tianjin University》 EI CAS 2003年第2期131-135,共5页
It is very im portant to analyze network traffic in the network control and management. In thi s paper, extreme value theory is first introduced and a model with threshold met hods is proposed to analyze the character... It is very im portant to analyze network traffic in the network control and management. In thi s paper, extreme value theory is first introduced and a model with threshold met hods is proposed to analyze the characteristics of network traffic. In this mode l, only some traffic data that is greater than threshold value is considered. Th en the proposed model with the trace is simulated by using S Plus software. The modeling results show the network traffic model constructed from the extreme va lue theory fits well with that of empirical distribution. Finally, the extreme v alue model with the FARIMA(p,d,q) modeling is compared. The anal ytical results illustrate that extreme value theory has a good application foreg round in the statistic analysis of network traffic. In addition, since only some traffic data which is greater than the threshold is processed, the computation overhead is reduced greatly. 展开更多
关键词 extreme value theory generalized Pare to distribution threshold value FARIMA(p d q) model
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Application of Extreme Value Theory to Generation and Analysis of Pseudorandom Samples
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作者 Svitlana Trukhan Petro Bidyuk 《Journal of Mathematics and System Science》 2016年第4期129-138,共10页
The article deals with the methodology of pseudorandom data analysis. As a mathematical tool for carrying out the research the extreme value theory was used that creates one of the directions in mathematical statistic... The article deals with the methodology of pseudorandom data analysis. As a mathematical tool for carrying out the research the extreme value theory was used that creates one of the directions in mathematical statistics, and is related to investigating the extreme deviations from the median values in probability distributions. Also, the methods for estimating unknown parameters and algorithm of random-number generation are discussed. The models of treatment the extreme values are constructed which are based on machine generated sample and approach is proposed for their future application for constructing forecasting models. 展开更多
关键词 Extreme value theory extreme value threshold simulation and modeling maximum likelihood estimator pseudorandomsample generation.
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Alarm Correlation Rules Generation Algorithm Based on Confidence Covered Value
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作者 李彤岩 《Journal of Donghua University(English Edition)》 EI CAS 2015年第2期268-271,共4页
In communication alarm correlation analysis,traditional association rules generation(ARG) algorithm usually has low efficiency and high error rate.This paper proposes an alarm correlation rules generation algorithm ba... In communication alarm correlation analysis,traditional association rules generation(ARG) algorithm usually has low efficiency and high error rate.This paper proposes an alarm correlation rules generation algorithm based on the confidence covered value.Confidence covered value method can judge whether a rule is redundant or not scientific After the rules that based on weighted frequent patterns(WFPs) generated,the association rules were deleted by the confidence covered value,in order to delete the redundant rules and keep the rules with more information.Experiments show that the alarm correlation rules generation algorithm based on the confidence covered value has higher efficiency than the traditional method,and can effectively remove redundant rules.Thus it is very suitable for telecommunication alarm association rules processing. 展开更多
关键词 alarm Correlation redundant confidence remove delete frequent covered judge resolve
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DWT-SVD Based Image Steganography Using Threshold Value Encryption Method
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作者 Jyoti Khandelwal Vijay Kumar Sharma +1 位作者 Dilbag Singh Atef Zaguia 《Computers, Materials & Continua》 SCIE EI 2022年第8期3299-3312,共14页
Digital image steganography technique based on hiding the secret data behind of cover image in such a way that it is not detected by the human visual system.This paper presents an image scrambling method that is very ... Digital image steganography technique based on hiding the secret data behind of cover image in such a way that it is not detected by the human visual system.This paper presents an image scrambling method that is very useful for grayscale secret images.In this method,the secret image decomposes in three parts based on the pixel’s threshold value.The division of the color image into three parts is very easy based on the color channel but in the grayscale image,it is difficult to implement.The proposed image scrambling method is implemented in image steganography using discrete wavelet transform(DWT),singular value decomposition(SVD),and sorting function.There is no visual difference between the stego image and the cover image.The extracted secret image is also similar to the original secret image.The proposed algorithm outcome is compared with the existed image steganography techniques.The comparative results show the strength of the proposed technique. 展开更多
关键词 Image steganography threshold value sorting discrete wave transformation singular value decomposition color band division permutation
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惩罚矩阵T混合模型及其在省域经济分类中的应用
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作者 李泽安 汪钱荣 赵为华 《统计与决策》 北大核心 2025年第1期41-46,共6页
为充分考虑矩阵数据的特性和数据内部的关联性,文章基于矩阵T分布建立矩阵T混合模型及其惩罚模型来研究聚类问题。在矩阵T混合模型的似然函数上对均值矩阵分量施加自适应核范数低秩惩罚,应用ECM算法提出惩罚似然估计算法,同时提出了一... 为充分考虑矩阵数据的特性和数据内部的关联性,文章基于矩阵T分布建立矩阵T混合模型及其惩罚模型来研究聚类问题。在矩阵T混合模型的似然函数上对均值矩阵分量施加自适应核范数低秩惩罚,应用ECM算法提出惩罚似然估计算法,同时提出了一种改进的BIC模型选择准则来选择最优的混合模型数量和调节参数,进而通过自适应核范数阈值自动实现低秩估计,实现准确聚类。最后,通过数值模拟研究及与已有方法的对比验证了该方法的有用性,且将所建立的惩罚混合模型应用于中国省域经济发展水平划分研究,得到了比较准确的聚类结果。 展开更多
关键词 矩阵T分布 混合模型 自适应核范数 ECM算法 奇异值阈值
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低带宽场景下防合谋多方隐私集合并集协议
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作者 张恩 王梦涛 +2 位作者 郑东 禹勇 黄昱晨 《通信学报》 北大核心 2025年第1期210-221,共12页
针对现存的多方隐私集合并集(MPSU)协议存在交互轮数多以及通信开销大等问题,使其无法在低带宽场景中得以有效应用,设计了一种基于不经意键值存储和门限同态加密技术的不经意匹配置换方法,并运用该方法提出了一种半诚实模型下的多方隐... 针对现存的多方隐私集合并集(MPSU)协议存在交互轮数多以及通信开销大等问题,使其无法在低带宽场景中得以有效应用,设计了一种基于不经意键值存储和门限同态加密技术的不经意匹配置换方法,并运用该方法提出了一种半诚实模型下的多方隐私集合并集协议。该协议允许N个参与方共同计算所有集合的并集,且不会泄露任何其他的信息,具有通信轮数少、能抵御N-1个参与方的合谋、通信开销低等优势,比现有最先进的多方隐私集合并集的通信开销降低了65%左右。 展开更多
关键词 多方隐私集合并集 低带宽场景 不经意键值存储 半诚实模型 门限同态加密
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Scales,methods and technical analysis of China's residential environment evaluation 被引量:2
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作者 李绥 石铁矛 周乐 《Journal of Southeast University(English Edition)》 EI CAS 2009年第2期274-277,共4页
To improve China's residential environment evaluation system and enhance its guiding role, current research results are analyzed and summarized from three aspects including research scales, evaluation methods and app... To improve China's residential environment evaluation system and enhance its guiding role, current research results are analyzed and summarized from three aspects including research scales, evaluation methods and applied technology by means of comparison, induction and empirical application. The guiding role of the current macro-scale evaluation system of urban planning and construction is generally not obvious, whereas the guiding role of medium and micro-scale systems to the improvement of residential environments is improving. There are diversified methods for determining the threshold values and the weights of indices in China's evaluation system. For instance, the analytic hierarchy process(AHP) method is adopted to determine the weights of indices. The advantages and disadvantages of the method are analyzed on the basis of empirical calculation. In the course of comprehensive analyses, a nonlinear model can reflect interactions among indices more than a linear model; the evaluation model under the ARCGIS platform prevails since it combines space and attribute, and it has intuitive results. So far, the methodological system of China's residential environment evaluation has not been established; its subject coverage and research category should be expanded, and its guiding role should be enhanced. 展开更多
关键词 residential environment evaluation system SCALE threshold value WEIGHT evaluation model geographic information system (GIS)
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东北典型盐碱湿地碳排放的水深临界阈值及其温度依赖性
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作者 李姝臻 刘强 +2 位作者 甘罗扬 武海涛 王波 《湖泊科学》 EI CAS 北大核心 2025年第1期159-170,I0015-I0017,共15页
作为全球重要的碳库,湿地在缓解气候变化方面发挥了重要作用。然而在全球变暖背景下,湿地的碳排放(尤其是甲烷(CH_(4))排放)存在高度变异性和不确定性,极大地削弱了湿地碳库功能的发挥。为了探究不同水深梯度下东北盐碱湿地碳排放通量... 作为全球重要的碳库,湿地在缓解气候变化方面发挥了重要作用。然而在全球变暖背景下,湿地的碳排放(尤其是甲烷(CH_(4))排放)存在高度变异性和不确定性,极大地削弱了湿地碳库功能的发挥。为了探究不同水深梯度下东北盐碱湿地碳排放通量的特征,本研究以莫莫格湿地为主要研究区,选取5种代表性植被(芦苇(Phragmites australis)、扁秆藨草(Bolboschoenus planiculmis)、三江藨草(Schoenoplectus nipponicus)、香蒲(Typha orientalis C.Presl)和碱蓬(Suaeda glauca)),布设Marsh Organ中型实验生态系统模拟不同水深生境,揭示CH_(4)和二氧化碳(CO_(2))排放通量变化及其环境影响因子。结果表明,莫莫格湿地-10~50 cm水深范围内5种代表性植被生长季CH_(4)排放通量范围为0.07~86.74 mg/(m^(2)·h),平均值为8.89 mg/(m^(2)·h),其主要环境影响因素为水深、气温和表层10 cm土壤含水量;在研究水深范围内,代表性植被生长季CO_(2)排放通量范围为10.59~1891.08 mg/(m^(2)·h),平均值为450.12 mg/(m^(2)·h),其主要环境影响因素为水深、气温和表层10 cm土壤含水量。不同植被对碳排放的贡献量有所差异,具体来说,芦苇和香蒲的CH_(4)排放通量最高,而藨草的CO_(2)排放通量最高。碳排放随水深变化呈现分段规律,CH_(4)排放随水深变化呈现先增加后减少的趋势,而CO_(2)则呈现相反规律,随水深变化先减小后增加,其水深临界阈值均出现在22 cm处。在不同水深范围内,CO_(2)排放对于水深的敏感性均大于CH_(4),且当水深大于22 cm时,CH_(4)和CO_(2)均呈现出更高的水深敏感性。碳排放在不同水深范围对温度的敏感程度不同,当水深小于22 cm时,CH_(4)和CO_(2)均呈现出更高的温度敏感性,然而当水深大于22 cm时,二者对温度均不敏感。结果表明升温背景下,东北典型盐碱湿地水陆过渡区关键生态系统在不同水深范围内呈现出不对称的响应模式,频繁的水位波动会极大地改变湿地碳排放格局,从而影响到湿地碳功能的稳定发挥。 展开更多
关键词 碳排放 水深 温度依赖性 莫莫格湿地 阈值
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轴向及环向变形加载控制方式对花岗岩力学及声发射特性影响的试验研究
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作者 徐荣超 王怡博 +4 位作者 张圣哲 孟凡震 李震 高梁 阎震 《工程地质学报》 北大核心 2025年第1期123-134,共12页
加载控制方式是影响岩石力学性质重要因素之一。采用轴向变形控制和环向变形控制两种加载方式,对花岗岩试样开展变形速率为0.005 mm·s^(-1)条件下的单轴压缩试验,分析两种加载控制方式对花岗岩强度、应力及应变门槛值、能量演化及... 加载控制方式是影响岩石力学性质重要因素之一。采用轴向变形控制和环向变形控制两种加载方式,对花岗岩试样开展变形速率为0.005 mm·s^(-1)条件下的单轴压缩试验,分析两种加载控制方式对花岗岩强度、应力及应变门槛值、能量演化及声发射特性等的影响规律。结果表明,与环向变形控制方式相比,轴向变形控制加载条件下:试样的峰值强度、损伤应力、起裂应力分别高12.8%、15.1%、13.1%;峰值轴向应变、损伤轴向应变及起裂轴向应变分别大12.5%、14.3%、15.2%,而峰值环向应变、起裂环向应变分别小24.2%、16.7%;峰值总能量大23.9%,储能能力R e大2.6%;声发射累计计数及累计能量分别高48.8%、106.1%,声发射b值大14.1%;通过声发射AF-RA值分析发现,两种加载控制方式对裂纹类型的影响不显著。研究结果对于深入揭示脆性岩石破裂机制具有重要意义。 展开更多
关键词 花岗岩 轴向变形控制 环向变形控制 应力门槛值 能量演化 声发射
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高声压下二值逻辑电路系统设计
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作者 史亮 赵英亮 +2 位作者 庞存锁 王黎明 苏灿生 《工业仪表与自动化装置》 2025年第1期3-7,47,共6页
高声压二值逻辑电路是一种特殊类型的电路。为了处理来自高声压环境下的声信号,并能够对这些信号进行快速准确的逻辑处理,该文设计了一种成本较低、结构简单的处理声信号的二值逻辑电路系统,其输出为二值逻辑信号,处理时具有数据量小以... 高声压二值逻辑电路是一种特殊类型的电路。为了处理来自高声压环境下的声信号,并能够对这些信号进行快速准确的逻辑处理,该文设计了一种成本较低、结构简单的处理声信号的二值逻辑电路系统,其输出为二值逻辑信号,处理时具有数据量小以及便于快速传输的特点,可以很好地满足对声信号实时处理的要求。系统设计时,根据传感器选择类型设计电路的各个模块,对信号进行放大和滤波处理,通过传感器对不同声压下的声信号的接收能力设置不同的电压阈值,根据不同阈值的触发状态可以快速地对声信号进行处理。此外,还通过模拟测试验证了设计的可行性。 展开更多
关键词 高声压 二值逻辑 声信号处理 阈值比较
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