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Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips
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作者 Jie Ren Yunfeng Li +3 位作者 Mingyu Li Xingyu Wu Jiabao Wang Qingxuan Zeng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期309-316,共8页
Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ... Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems. 展开更多
关键词 Copper-based azide chips SPECTROPHOTOMETRY Separation method quantitative analysis Ignition ability
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A quantitative analysis method for GPR signals based on optimal biorthogonal wavelet 被引量:7
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作者 LIU Hao-ran LING Tong-hua +2 位作者 LI Di-yuan HUANG Fu ZHANG Liang 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第4期879-891,共13页
Due to the disturbances arising from the coherence of reflected waves and from echo noise,problems such as limitations,instability and poor accuracy exist with the current quantitative analysis methods.According to th... Due to the disturbances arising from the coherence of reflected waves and from echo noise,problems such as limitations,instability and poor accuracy exist with the current quantitative analysis methods.According to the intrinsic features of GPR signals and wavelet time–frequency analysis,an optimal wavelet basis named GPR3.3 wavelet is constructed via an improved biorthogonal wavelet construction method to quantitatively analyse the GPR signal.A new quantitative analysis method based on the biorthogonal wavelet(the QAGBW method)is proposed and applied in the analysis of analogue and measured signals.The results show that compared with the Bayesian frequency-domain blind deconvolution and with existing wavelet bases,the QAGBW method based on optimal wavelet can limit the disturbance from factors such as the coherence of reflected waves and echo noise,improve the quantitative analytical precision of the GPR signal,and match the minimum thickness for quantitative analysis with the vertical resolution of GPR detection. 展开更多
关键词 GPR detection signal quantitative analysis wavelet time–frequency analysis biorthogonal wavelet basis
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Quantitative Ore Analysis Solution
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作者 Eddy Hill 《矿物学报》 CAS CSCD 北大核心 2013年第S1期19-19,共1页
Use of the scanning electron microscope (SEM) to characterize ores provides mineralogists and metallurgists with invaluable information for the optimisation of processes. Manually obtaining relevant information such a... Use of the scanning electron microscope (SEM) to characterize ores provides mineralogists and metallurgists with invaluable information for the optimisation of processes. Manually obtaining relevant information such as, for example, mineral coatings that may interfere with flotation, mineral separations, the location of values, mineralogical or process reasons for low recovery, etc, can be exhausting and time consuming. For this reason, automated SEM methods for mineralogical characterisation have been devised. These methods rely on qualitative analyses of the samples using EDX or BSD grey levels to classify the phases present. The non-quantitative nature of the analyses means that other techniques, such as electron microprobe analysis (EMPA), must be used in conjunction with the SEM to obtain quantitative information of the sample. To overcome this limitation, Carl Zeiss has devised a method for the quantitative analysis of the mineralogy of any ore or ore-derived processed material; allowing for the full quantitative evaluation of a resource to be performed automatically by the SEM. 展开更多
关键词 quantitative analysis BSE EDX AUTOMATED MINERAL analysis
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Automatic recognition and quantitative analysis of Ω phases in Al-Cu-Mg-Ag alloy
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作者 刘冰滨 谷艳霞 +1 位作者 刘志义 田小林 《Journal of Central South University》 SCIE EI CAS 2014年第5期1696-1704,共9页
The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as hi... The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as high labor intensity and low accuracy statistic results exist in these methods. In order to overcome the shortcomings of the current methods, the Ω phase in A1-Cu-Mg-Ag alloy is taken as the research object and an algorithm based on the digital image processing and pattern recognition is proposed and implemented to do the A1 alloy TEM (transmission electron microscope) digital images process and recognize and extract the information of the second phase in the result image automatically. The top-hat transformation of the mathematical morphology, as well as several imaging processing technologies has been used in the proposed algorithm. Thereinto, top-hat transformation is used for elimination of asymmetric illumination and doing Multi-layer filtering to segment Ω phase in the TEM image. The testing results are satisfied, which indicate that the Ω phase with unclear boundary or small size can be recognized by using this method. The omission of these two kinds of Ω phase can be avoided or significantly reduced. More Ω phases would be recognized (growing rate minimum to 2% and maximum to 400% in samples), accuracy of recognition and statistics results would be greatly improved by using this method. And the manual error can be eliminated. The procedure recognizing and making quantitative analysis of information in this method is automatically completed by the software. It can process one image, including recognition and quantitative analysis in 30 min, but the manual method such as using Image Tool or Nano Measurer need 2 h or more. The labor intensity is effectively reduced and the working efficiency is greatly improved. 展开更多
关键词 auto pattern recognition top-hat transformation second phases in A1 alloy quantitative analysis
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A Review of Quantitative Analysis Methods of Tea Saponin
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作者 Meng Shi Hui-Shi Wu Yue-Long Liang 《茶叶》 2013年第4期388-393,共6页
This paper summarized the quantitative analysis methods of tea saponin,including gravimetry,colorimetry,fluorescence spectrophotometry,thin layer scanning and HPLC method.Through the summary of quantitative analysis m... This paper summarized the quantitative analysis methods of tea saponin,including gravimetry,colorimetry,fluorescence spectrophotometry,thin layer scanning and HPLC method.Through the summary of quantitative analysis methods,this paper tried to compare different quantitative determination methods so as to provide a guidance to establish the standard quantitative analysis method of tea saponin from various sources. 展开更多
关键词 定量分析方法 茶皂素 综述 荧光分光光度法 高效液相色谱法 薄层扫描 定量测定 重量法
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Texture features analysis on micro-structure of paste backfill based on image analysis technology 被引量:8
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作者 YIN Sheng-hua SHAO Ya-jian +2 位作者 WU Ai-xiang WANG Yi-ming GAO Zhi-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第10期2360-2372,共13页
The strength of cement-based materials,such as mortar,concrete and cement paste backfill(CPB),depends on its microstructures(e.g.pore structure and arrangement of particles and skeleton).Numerous studies on the relati... The strength of cement-based materials,such as mortar,concrete and cement paste backfill(CPB),depends on its microstructures(e.g.pore structure and arrangement of particles and skeleton).Numerous studies on the relationship between strength and pore structure(e.g.,pore size and its distribution)were performed,but the micro-morphology characteristics have been rarely concerned.Texture describing the surface properties of the sample is a global feature,which is an effective way to quantify the micro-morphological properties.In statistical analysis,GLCM features and Tamura texture are the most representative methods for characterizing the texture features.The mechanical strength and section image of the backfill sample prepared from three different solid concentrations of paste were obtained by uniaxial compressive strength test and scanning electron microscope,respectively.The texture features of different SEM images were calculated based on image analysis technology,and then the correlation between these parameters and the strength was analyzed.It was proved that the method is effective in the quantitative analysis on the micro-morphology characteristics of CPB.There is a significant correlation between the texture features and the unconfined compressive strength,and the prediction of strength is feasible using texture parameters of the CPB microstructure. 展开更多
关键词 microstructure texture feature Tamura texture GLCM feature unconfined compressive strength quantitative analysis cement paste backfill
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Progress on Mapping of Quantitative Trait Loci in Crops 被引量:3
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作者 DU Minmin WANG Chao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2008年第3期63-67,共5页
Most important agricultural traits of crops are controlled by many genes. These traits have complicated genetic basis and are difficult for genetic analysis. Due to application of molecular marker techniques in the la... Most important agricultural traits of crops are controlled by many genes. These traits have complicated genetic basis and are difficult for genetic analysis. Due to application of molecular marker techniques in the last two decades, genetic and molecular dissection of quantitative traits has become possible. In this paper, recent progress on mapping of quantitative trait loci in crops was reviewed. 展开更多
关键词 quantitative traits mapping populations high-resolution mapping association analysis
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Reliability analysis for aeroengine turbine disc fatigue life with multiple random variables based on distributed collaborative response surface method 被引量:2
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作者 高海峰 白广忱 +1 位作者 高阳 鲍天未 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4693-4701,共9页
The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to am... The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to ameliorate reliability analysis efficiency without loss of reliability,the distributed collaborative response surface method(DCRSM) was proposed,and its basic theories were established in this work.Considering the failure dependency among the failure modes,the distributed response surface was constructed to establish the relationship between the failure mode and the relevant random variables.Then,the failure modes were considered as the random variables of system response to obtain the distributed collaborative response surface model based on structure failure criterion.Finally,the given turbine disc structure was employed to illustrate the feasibility and validity of the presented method.Through the comparison of DCRSM,Monte Carlo method(MCM) and the traditional response surface method(RSM),the results show that the computational precision for DCRSM is more consistent with MCM than RSM,while DCRSM needs far less computing time than MCM and RSM under the same simulation conditions.Thus,DCRSM is demonstrated to be a feasible and valid approach for improving the computational efficiency of reliability analysis for aeroengine turbine disc fatigue life with multiple random variables,and has great potential value for the complicated mechanical structure with multi-component and multi-failure mode. 展开更多
关键词 complicated mechanical structure reliability analysis multiple random variables multi-component and multi-failure mode distributed collaborative response surface method
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Proteomics analysis on hypolipidemic mechanisms of total phenylpropanoid glycosides from Ligustrum robustum(Roxb.) Blume in hamsters fed a high fat diet
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作者 Run-mei YANG Zi-wen ZHANG +5 位作者 Le SUN Ning ZHAO Yong XIE Wen JIN Rui-le PAN Nan-nan GAO 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2018年第4期325-325,共1页
OBJECTIVE To explore the hypolipidemic mechanisms of the total phenylpropanoid glycosides fromLigustrum robustum(Roxb.) Blume(LRTPG) in hamsters using proteomics technique.METHODS The hamsters were fed with a high fat... OBJECTIVE To explore the hypolipidemic mechanisms of the total phenylpropanoid glycosides fromLigustrum robustum(Roxb.) Blume(LRTPG) in hamsters using proteomics technique.METHODS The hamsters were fed with a high fat diet to induce hyperlipidemia.Then LRTPG of high(1.2 g·kg^(-1)),medium(0.6 g·kg^(-1)) and low(0.3 g·kg^(-1)) doses were administrated daily for 4 weeks.Then the concentrations of plasma and hepatic lipids were determined using enzymic methods.The total protein was extracted from livers of the model group and the group treated with the high dose of LRTPG for label-free quantitative proteomics.RESULTS LRTPG significantly reduced the concentrations of plasma and hepatic lipids in hamsters fed a high fat diet.The proteomics data showed that a total of 2231 proteins were identified,and 549 proteins were found to be differentially expressed between the model group and the group treated with LRTPG.Among the 549 proteins,93 proteins were up-regulated and 59 proteins were down-regulated,and 397 proteins were absent or not.And some of these proteins were much related to the lipid metabolism.Further,gene ontology(GO) analysis indicated metabolic process,transport,oxidation-reduction process,phosphorylation,signal transduction,lipid metabolic process were the main biological processes that those differentially expressed proteins participated.KEGG pathway analysis showed that those proteins were involved in several metabolic pathways including oxidative phosphorylation,non-alcoholic fatty liver disease(NAFLD),PI3K-Akt signaling pathway,cAMP signaling pathway,cGMP-PKG signaling pathway.CONCLUSION The proteomics study could provide valuable clues to help us to understand the hypolipidemic mechanisms of LRTPG much better. 展开更多
关键词 total phenylpropanoid glycosides Ligustrum robustum(Roxb) Blume label-free quantitative proteomics pathway analysis gene ontology analysis
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公立医院行风管理核心要求现状、问题及对策研究 被引量:1
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作者 蔡志玲 桂德权 +3 位作者 谭旭彤 王子元 马小军 陈政 《中国医院》 北大核心 2025年第4期69-72,共4页
目的:选取国家层面颁布的与公立医院行风管理相关政策文件,分析国家对公立医院廉洁风险防控要点的情况,为行风管理制度建设顶层设计提供参考。方法:访问国家卫生健康委官方网站,以“行风”“廉洁”“作风”“纠正不正之风”“腐败”等... 目的:选取国家层面颁布的与公立医院行风管理相关政策文件,分析国家对公立医院廉洁风险防控要点的情况,为行风管理制度建设顶层设计提供参考。方法:访问国家卫生健康委官方网站,以“行风”“廉洁”“作风”“纠正不正之风”“腐败”等为关键词检索其发布的相关政策文件,时间跨度为2013年1月1日~2024年5月31日;运用内容分析法对文件发布时间、发布单位、廉洁风险防控要点内容等进行量化分析。结果:共纳入29份政策文件进行研究,68.97%的文件由医政部门发布;廉洁风险防控要点主要包括医疗机构管理权力、医疗服务廉洁风险、医药购销领域行为和其他4个方面。结论:建议从顶层设计上完善制度建设和实施细则;在医疗服务廉洁风险防控方面发布实施细则和具体罚则;在医药购销领域加强部门联动,建立协同机制;在新兴领域如基因检测、外配处方等方面填补制度空缺。 展开更多
关键词 公立医院 行风管理 制度建设 量化分析
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基于最大信息系数法的卧沙溪滑坡变形相关性分析及预警模型研究 被引量:2
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作者 尚敏 王殿鹏 +2 位作者 易庆林 袁朔 宋云鹏 《工程地质学报》 北大核心 2025年第2期572-580,共9页
本篇以三峡库区卧沙溪滑坡为研究对象,运用最大信息量法对滑坡变形影响因素相关性进行了定量分析。结果表明降雨是坡体加速变形的主要诱因,库水位变化仅起到加速滑坡变形的作用,而非既有研究认为的动水压力型滑坡。为提升滑坡预警和预... 本篇以三峡库区卧沙溪滑坡为研究对象,运用最大信息量法对滑坡变形影响因素相关性进行了定量分析。结果表明降雨是坡体加速变形的主要诱因,库水位变化仅起到加速滑坡变形的作用,而非既有研究认为的动水压力型滑坡。为提升滑坡预警和预测的准确度,采用了最大信息系数法(MIC)与改进的切线角法,对近8年来滑坡次级滑体发生的4次阶跃变形进行了分析,确定了引发这些阶跃变形的降雨阈值和位移速率阈值。基于这些阈值,建立了一个更加完善的新型预警模型。研究结果不仅有助于提升对卧沙溪滑坡的监测水平,也为类似地质灾害的监测预警提供了有价值的参考。 展开更多
关键词 卧沙溪滑坡 定量分析 最大信息系数 预警模型
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基于心脏磁共振探究扩张型心肌病患者经标准化抗心力衰竭药物治疗后左心室逆重构的预测因素 被引量:1
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作者 刘涛 高晓坤 +6 位作者 范茜寒 郭沛宏 吴灵教 杞天付 赵卫 王钰 陈伟 《中国心血管杂志》 北大核心 2025年第1期35-44,共10页
目的基于心脏磁共振(CMR)定量评价心肌纤维化,探索扩张型心肌病(DCM)患者经标准化抗心力衰竭(心衰)药物治疗后左心室逆重构(LVRR)的CMR预测指标。方法临床回顾性研究。连续纳入2020年9月至2023年7月昆明医科大学第一附属医院DCM患者48例... 目的基于心脏磁共振(CMR)定量评价心肌纤维化,探索扩张型心肌病(DCM)患者经标准化抗心力衰竭(心衰)药物治疗后左心室逆重构(LVRR)的CMR预测指标。方法临床回顾性研究。连续纳入2020年9月至2023年7月昆明医科大学第一附属医院DCM患者48例,其中男性32例(66.7%);并选取同期年龄、性别相匹配的健康成人40名作为对照组,其中男性27名(67.5%)。所有DCM患者接受标准化抗心衰药物治疗,并于基线行CMR检查,于基线和随访时行超声心动图检查。CMR检查:(1)电影序列,评价心功能,包括左心室舒张末期容积指数(LVEDVi)、左心室收缩末期容积指数(LVESVi)、左心室心肌质量指数(LVMMi)、左心室射血分数(LVEF)、左心室整体纵向应变(GLS)、整体径向应变(GRS)和整体周向应变(GCS);(2)T1 mapping技术,评价心肌弥漫性纤维化,包括native T1值、细胞外容积分数(ECV);(3)钆延迟强化(LGE)技术,评价心肌替代性纤维化,以LGE占左心室心肌质量百分比(%LV)表示。超声心动图检查指标包括LVEF和左心室舒张末期内径指数(LVEDDi)。根据基线和随访时的LVEF和LVEDDi,将DCM患者分为LVRR(+)组和LVRR(-)组。采用单因素和多因素logistic回归分析筛选DCM患者发生LVRR的预测因素。绘制受试者工作特征(ROC)曲线分析CMR参数对LVRR的预测效能。结果中位随访时间为10.5(6,15.8)个月。DCM患者14例(29.2%)发生LVRR。与对照组相比,DCM组患者的体质指数和心率较高,吸烟、酗酒和高血脂病史比例较高,LVEDVi、LVESVi、LVMMi、native T1值和ECV明显升高,GLS、GRS、GCS和LVEF明显降低,差异均有统计学意义(均为P<0.05)。与LVRR(-)组比较,LVRR(+)组的基线LVEF无统计学差异(P=0.526),随访时LVEF明显升高、LVEDD明显降低(均为P<0.001)。DCM患者基线时CMR检查均存在左心室心肌LGE。与LVRR(-)组比较,LVRR(+)组的基线B型利钠肽[384.4(76.7,536.5)pg/ml比760.6(310.7,1067.6)pg/ml]、LVEDVi[145.8(110.9,157.3)ml/m^(2)比155.8(130.9,210.2)ml/m^(2)]、LVESVi[105.7(83.1,128.2)ml/m^(2)比134.8(116.3,173.5)ml/m^(2)]、native T1值[1048(1031,1069)ms比1071(1039,1098)ms]、ECV(27.2%±3.5%比30.1%±4.2%)和LGE[1.6%(1.0%,3.2%)比3.7%(2.1%,6.1%)]显著降低(均为P<0.05)。多因素logistic回归分析结果显示,基线LGE是DCM患者发生LVRR的独立预测因子(OR=2.612,95%CI:1.180~5.782,P=0.018)。ROC曲线分析结果显示,基线LGE预测DCM患者发生LVRR的敏感度为73.5%,特异度为71.4%,ROC曲线下面积为0.765,最佳截断值为2.35%(P=0.004)。结论基线LGE可作为DCM患者经标准化抗心衰药物治疗后发生LVRR的预测指标。 展开更多
关键词 扩张型心肌病 心力衰竭 心肌纤维化 左心室逆重构 磁共振成像 钆延迟强化 定量分析
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柑橘化渣性量化指标参数优化及模型建立 被引量:1
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作者 陈红 李孝贤 +5 位作者 周少秀 蔡欣睿 王秋丰 田皓予 汪鑫茂 陈寅 《农业工程学报》 北大核心 2025年第1期330-338,共9页
化渣性是反映柑橘质地特性的主要参数之一,为了客观、定量地评价柑橘的化渣性,该研究通过分析柑橘感官评分和化渣性定量评价指标之间的相关性,确定了化渣性定量评价指标及其基于质构特性的检测方法;进一步开展单因素和响应面试验,筛选... 化渣性是反映柑橘质地特性的主要参数之一,为了客观、定量地评价柑橘的化渣性,该研究通过分析柑橘感官评分和化渣性定量评价指标之间的相关性,确定了化渣性定量评价指标及其基于质构特性的检测方法;进一步开展单因素和响应面试验,筛选最优参数组合,建立化渣性等级评价模型。结果表明,感官评分与纤维素含量、囊衣厚度等5种指标呈显著负相关(P<0.05),其中囊衣厚度与感官评分相关系数最高(−0.92),可作为化渣性定量评价指标;囊衣厚度与最大剪切力、穿刺力等5种质构指标呈显著正相关,与最大剪切力相关系数最高(0.83),确定最大剪切力为囊衣厚度的检测指标;以平口双刀、刀片厚度2 mm、剪切速率180 mm/min、剪切瓣数2为测试参数时,所测最大剪切力与囊衣厚度相关系数最高,为0.942;所建模型的回归方程的R^(2)=0.951;“化渣性指数”在0~1范围内划分为6个等级,指数越高则化渣性越好,预测准确率为91.43%。研究可为准确客观地评价柑橘化渣性提供技术参考。 展开更多
关键词 柑橘 化渣性 定量评价 囊衣厚度 质构剪切 响应面分析 回归分析
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生成式人工智能驱动下电信网络诈骗受害风险影响因素量化分析 被引量:1
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作者 周胜利 徐睿 +1 位作者 陈庭贵 汪邵杰 《电信科学》 北大核心 2025年第7期71-84,共14页
开展生成式人工智能驱动下电信网络诈骗的受害风险影响因素研究,对于揭示犯罪规律和提升技术防治能力具有重要的理论价值与实践意义。为此,依托真实AI诈骗案件数据开展模拟实验,将犯罪过程解构为伪造信息的生成、传播与影响3个阶段,从... 开展生成式人工智能驱动下电信网络诈骗的受害风险影响因素研究,对于揭示犯罪规律和提升技术防治能力具有重要的理论价值与实践意义。为此,依托真实AI诈骗案件数据开展模拟实验,将犯罪过程解构为伪造信息的生成、传播与影响3个阶段,从中提取生成式人工智能、数据流、数据包、网络行为和受害风险等潜变量,再结合结构方程模型理论构建分析框架,系统量化了不同要素对受害风险的影响路径与作用贡献度。研究结果表明,生成式人工智能对受害风险具有显著的直接效应,且在整体影响效应中占据主导地位;数据流与数据包特征的中介效应较弱,在影响路径中作用不显著。 展开更多
关键词 生成式人工智能 电信网络诈骗 结构方程模型 量化分析
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富春江水库流域径流变化及其量化归因分析 被引量:1
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作者 司伟 黄思琦 +2 位作者 王培霞 张永康 张健 《河海大学学报(自然科学版)》 北大核心 2025年第3期1-7,共7页
为探明富春江水库流域径流演变的主要驱动因子,基于对富春江水库流域1970—2022年径流深、降水量、潜在蒸散发的趋势性和突变性分析,采用Budyko假设归因法量化降水量、潜在蒸散发、下垫面条件对径流变化的贡献。结果表明:降水量和径流... 为探明富春江水库流域径流演变的主要驱动因子,基于对富春江水库流域1970—2022年径流深、降水量、潜在蒸散发的趋势性和突变性分析,采用Budyko假设归因法量化降水量、潜在蒸散发、下垫面条件对径流变化的贡献。结果表明:降水量和径流深均呈不显著上升趋势,潜在蒸散发呈显著上升趋势;径流深突变年份为2012年;径流深增大的主要原因是降水量的增加、由不透水区域面积增加与森林面积减少导致的下垫面参数改变,其贡献率分别为51.61%和52.55%;径流深减小由潜在蒸散发的增加造成,贡献率为4.16%。 展开更多
关键词 径流变化 Budyko假设归因法 量化归因分析 富春江水库流域
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基于凝胶电泳芯片的DNA定量分析方法的研究
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作者 李振庆 陈沁 +3 位作者 朱建东 曾媛 张大伟 山口佳则 《分析测试学报》 北大核心 2025年第5期931-935,共5页
为确定凝胶电泳后条带中DNA的长度和浓度,该文提出了一种通过DNA荧光强度精确分析DNA长度及浓度的有效方法。对D2000 DNA ladder进行凝胶电泳,采集图像并进行处理。利用荧光强度与DNA浓度之间的线性关系以及迁移距离与DNA长度的线性关... 为确定凝胶电泳后条带中DNA的长度和浓度,该文提出了一种通过DNA荧光强度精确分析DNA长度及浓度的有效方法。对D2000 DNA ladder进行凝胶电泳,采集图像并进行处理。利用荧光强度与DNA浓度之间的线性关系以及迁移距离与DNA长度的线性关系进行数据分析。结果显示:采用SYBR Green I作为荧光染料电泳DNA时,图像中各像素点中的绿色与红色灰度值可以反映DNA的特征信息,且绿色灰度值明显高于红色灰度值;对于小于2000 bp的DNA片段,其分子量与迁移距离呈反比例函数关系,当二者分别取对数时,其相关系数达0.971,可用于建立DNA分子量与迁移距离的数学模型以计算DNA分子量;通过计算电泳峰峰值及电泳峰积分面积,发现对于浓度比为2∶1的两个DNA条带,二者的比值为2.16与1.96、2.11与1.94、2.16与1.93,表明电泳峰积分面积能更有效地反映DNA的真实浓度值。该研究对于核酸凝胶电泳仪的开发具有重要应用价值。 展开更多
关键词 核酸 凝胶电泳 定量分析 生物芯片
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冲击地压扰动响应失稳理论并行计算 被引量:1
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作者 潘一山 王学滨 +1 位作者 郑一方 陈双印 《煤炭学报》 北大核心 2025年第1期81-91,共11页
目前,冲击地压理论研究已经完成了从定性分析到定量分析的转变。巷道围岩临界应力计算是巷道安全性评价的重要依据。鉴于冲击地压问题的极度复杂性,在理论上继续取得突破极为困难。基于理论公式的巷道围岩临界应力计算,无法考虑更复杂... 目前,冲击地压理论研究已经完成了从定性分析到定量分析的转变。巷道围岩临界应力计算是巷道安全性评价的重要依据。鉴于冲击地压问题的极度复杂性,在理论上继续取得突破极为困难。基于理论公式的巷道围岩临界应力计算,无法考虑更复杂的实际情况,例如非圆形巷道、非静水压力和复杂岩层结构。冲击地压理论和数值计算相结合具有更加广阔的应用前景,能使冲击地压理论进一步走向实际应用,这是极有价值的发展方向。这方面研究成果的成功取得依赖于数值计算技术的快速发展。研究将当今较先进的岩层运动并行计算系统StrataKing(一种自主开发的以拉格朗日元与离散元耦合方法为基础的非线性断裂力学GPU并行计算方法)与冲击地压扰动响应失稳理论相结合,首次提出了圆形巷道扰动响应失稳理论的数值模拟方法。该方法的思想是将非线性断裂力学数值分析方法中的Ⅱ型断裂能设定为中间变量,从而建立了静水压力条件下圆形巷道围岩临界应力与冲击能指数之间的关系。为了获取冲击能指数的数值解,采用了仅出现一个剪切面的理想岩样进行单轴压缩数值试验,以排除其他因素对应力-应变曲线峰后倾向于直线部分斜率的影响。对于高角度剪切破裂,提出了将非标准岩样的计算结果转换成标准岩样的结果的折算方法。折算后冲击能指数的范围为0.17~13.52,位于全国131个冲击地压矿井的调研数据之内。巷道围岩临界应力的计算结果是理论结果的0.4~2.5倍,这与针对全国20个冲击地压矿井的调研数据(临界应力的修正系数普遍大于1,甚至接近8)定性相符,从局部化破坏围岩比均匀破坏围岩的承载力高的角度进行了解释。冲击地压与局部化的关系过去有讨论,扰动响应失稳理论与局部化过去并无关系。通过局部化,扰动响应失稳理论与冲击地压之间在破坏机理上产生了密切的关联。StrataKing可为冲击地压矿井巷道安全性评价提供强大的算力支撑。 展开更多
关键词 冲击地压 定量分析 扰动响应失稳理论 冲击能指数 局部化 并行计算 临界应力
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全岩矿物定量分析方法——以第9届雷诺杯样品为例
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作者 李艳丽 刘志飞 《海洋地质与第四纪地质》 北大核心 2025年第4期208-215,共8页
X射线衍射(XRD)法是矿物样品分析最常用的方法,被广泛用于矿物学定量分析研究。对于含有黏土矿物的样品进行准确的定量分析一直以来都充满挑战。本文以第9届雷诺杯(Reynolds)提供的3种未知混合样为例,使用Rietveld法对矿物进行定量分析... X射线衍射(XRD)法是矿物样品分析最常用的方法,被广泛用于矿物学定量分析研究。对于含有黏土矿物的样品进行准确的定量分析一直以来都充满挑战。本文以第9届雷诺杯(Reynolds)提供的3种未知混合样为例,使用Rietveld法对矿物进行定量分析。首先采用XRD法获得样品图谱,鉴定图谱中的矿物组成后,使用Rietveld法对全岩图谱进行拟合得出矿物的质量相对含量。最终分析结果与雷诺杯举办方赛后提供的准确值进行比较。研究结果表明,样品中的主要矿物比较容易鉴定,大部分鉴定出的矿物都可以通过Rietveld法准确计算。其中,非黏土类矿物(不含无定形相)的质量分数高于1.5%即可准确鉴定,而黏土类矿物由于较为复杂,鉴定和计算更为困难。且非黏土类矿物的定量偏差(平均质量偏差1.0%~1.3%)要低于黏土类矿物(平均质量偏差2.8%~5.8%)。经举办方比对定量分析结果,3个样品的质量偏差总和为156.7%(最终结果排名24位,本次获奖前三名的质量偏差总和分别为70.5%、89.8%、95.6%)。偏差主要来自矿物(特别是黏土类矿物)鉴定不准确。在矿物鉴定准确的条件下,如有合适的晶体结构卡片和拟合条件,其矿物的计算偏差可以大大降低(如RC9-3的偏差和可降至19.2%)。结果表明,Rietveld法能准确定量出样品中的大多数矿物含量,但也依赖研究人员对矿物组成做出准确的鉴定。总体而言,我分析室已初步建立了可靠的XRD法分析矿物组分,对于指示海洋沉积物的来源、成因及古环境等具有重要意义。 展开更多
关键词 矿物定量分析 粉末X射线衍射 Rietveld法
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约束隐结构建立含主-次症的糖尿病胃肠湿热辨证规则
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作者 许玉龙 陈锦华 +3 位作者 朱红磊 吕雅丽 胡镜清 张连文 《世界科学技术-中医药现代化》 北大核心 2025年第2期452-459,共8页
经典隐结构方法在对症状分析时,没有考虑主、次症以及证候兼加、症状兼加的影响,约束隐结构分析能够考虑兼加造成的影响,得到更适宜的辨证规则。本文针对1087例糖尿病患者胃肠湿热证涉及症状数据,首先使用经典隐结构分析,得到定量化辨... 经典隐结构方法在对症状分析时,没有考虑主、次症以及证候兼加、症状兼加的影响,约束隐结构分析能够考虑兼加造成的影响,得到更适宜的辨证规则。本文针对1087例糖尿病患者胃肠湿热证涉及症状数据,首先使用经典隐结构分析,得到定量化辨证规则。然后使用约束隐结构分析,得到含有主症、次症的定量化辨证规则如下,主症:口臭(2.3)、舌苔黄(2)、腹痞胀(2.3)、舌苔腻(2.1)、大便秘结或便溏不爽(1.5)、舌色红(1.3)、滑脉(1.4);次症:胃脘痞胀(1.1)。将两种方法得到规则进行对比分析,结果显示约束隐结构分析能通过主、次症阈值降低兼加因素的影响,得到的规则更符合主症、次症语义和中医常识。最后,再用逻辑回归分析得到辨证规则,并将3种规则做准确率对比测试,结果显示约束隐结构分析得到的规则识别准确率最高。从而得出约束隐结构分析得到的胃肠湿热辨证规则,符合主、次症的约束语义和中医理论,具有较高的客观性,有助于推广使用。 展开更多
关键词 辨证规则 主症 次症 约束隐结构分析 定量化
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基于CiteSpace食品抗菌膜领域研究态势分析
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作者 李娟 张源 +2 位作者 张子桐 王淼 张东杰 《包装工程》 北大核心 2025年第1期89-96,共8页
目的系统分析食品抗菌膜领域的发展历程以及研究动态、热点和趋势。方法基于中国知网(CNKI)和Web of Science(WOS)数据库,采用CiteSpace可视化分析软件,对2000—2024年食品抗菌膜领域的文献进行量化统计分析。结果国内外发文数量稳步增... 目的系统分析食品抗菌膜领域的发展历程以及研究动态、热点和趋势。方法基于中国知网(CNKI)和Web of Science(WOS)数据库,采用CiteSpace可视化分析软件,对2000—2024年食品抗菌膜领域的文献进行量化统计分析。结果国内外发文数量稳步增长,多见于食品领域高质量期刊;中国、伊朗和印度为主要发文国家,其中中国贡献最大,占比42.83%;研究主要集中在高校和科研院所,其中中国的江南大学(21篇)和伊朗的阿扎德大学(40篇)发文量居前,全球发文机构前10名中,中国占7席。该领域核心作者包括国内44位和国外37位;研究热点涵盖制备工艺、抗菌性能和应用效果,前沿领域聚焦于天然抗菌剂和抗菌性能研究。结论全球食品抗菌膜研究呈现稳步推进态势,研究深度和广度不断扩展,热度逐年攀升;中国在全球学术影响力显著,但仍有提升空间。该领域跨团队、跨国界的学术交流与合作仍显不足,未来需进一步加强;预计抗菌机理及性能研究仍是主要方向。 展开更多
关键词 食品抗菌膜 CITESPACE 文献计量学 量化分析 研究热点
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