期刊文献+
共找到15,634篇文章
< 1 2 250 >
每页显示 20 50 100
冻融-弯曲荷载耦合作用下PP-ECC梁的抗弯性能
1
作者 李福海 杨宗驰 +4 位作者 刘耕园 刘梦辉 吴昊南 陈昭 李固华 《西南交通大学学报》 北大核心 2025年第1期53-62,共10页
为探究冻融以及冻融-弯曲荷载耦合作用对聚丙烯纤维水泥基复合材料(PP-ECC)梁抗弯性能的影响,设置7种试验工况,采用三分点加载方式对PP-ECC梁抗弯性能进行研究,分析冻融及冻融-弯曲荷载耦合作用下PP-ECC梁的荷载-跨中挠度曲线、抗弯承... 为探究冻融以及冻融-弯曲荷载耦合作用对聚丙烯纤维水泥基复合材料(PP-ECC)梁抗弯性能的影响,设置7种试验工况,采用三分点加载方式对PP-ECC梁抗弯性能进行研究,分析冻融及冻融-弯曲荷载耦合作用下PP-ECC梁的荷载-跨中挠度曲线、抗弯承载力及裂缝发展形态差异;基于计算假定和正常环境下PP-ECC梁抗弯承载力的计算模型,结合PP-ECC材料冻融劣化机理,推导出PP-ECC梁在冻融环境下抗弯承载力计算模型;在此基础上引入持荷损伤系数γ,建立冻融-弯曲荷载耦合作用下PP-ECC梁抗弯承载力计算模型.研究结果表明:不同持荷比的PP-ECC梁极限抗弯承载力在冻融循环作用下出现不同程度降低,500次冻融循环后,持荷比为0、0.25、0.50的PP-ECC梁极限抗弯承载力分别降低了28.70%、27.09%、35.69%;受拉区PP-ECC材料开裂后不退出工作仍能协同受拉钢筋参与全截面受力;PP-ECC梁在达到极限状态时,受拉区呈多条裂缝稳态发展模式,且随冻融损伤加剧,梁体最大裂缝宽度增大,裂缝数量减少;单一冻融以及冻融-弯曲荷载耦合作用下的PP-ECC梁仍满足平截面假定;基于平截面假定建立的冻融和冻融-弯曲荷载耦合作用下PP-ECC梁的抗弯承载力计算模型吻合度分别在0.88~1.06和0.96~1.10. 展开更多
关键词 冻融-弯曲荷载耦合作用 抗弯性能 聚丙烯纤维水泥基复合材料 抗弯承载力 多裂缝发展
下载PDF
The Pursuit of Happiness
2
作者 CHEN SIJIA 《China Today》 2024年第5期63-65,共3页
Xinjiang has effectively safeguarded the basic rights of people of all ethnic groups to work and employment,and made great strides in economic and social development,thus significantly improving people’s livelihoods.
关键词 XINJIANG pursuit EMPLOYMENT
下载PDF
新工科项目式教学PPS考核评价方法研究——以《3D基础造型》课程为例
3
作者 梁晓琳 《办公自动化》 2025年第1期28-30,共3页
项目式教学是软件类课程教学的有效途径,《3D基础造型》课程以产业需求为切入点,改革教学设计并优化评价考核方式。为综合考察学生在知识、能力、素质等方面的表现,提出以学生学习效果为中心的PPS评价方法,这是贯通课程始终的一种全链... 项目式教学是软件类课程教学的有效途径,《3D基础造型》课程以产业需求为切入点,改革教学设计并优化评价考核方式。为综合考察学生在知识、能力、素质等方面的表现,提出以学生学习效果为中心的PPS评价方法,这是贯通课程始终的一种全链条式的考核评价体系,使各评价环节全面覆盖课程目标并充分考虑学生需求,评价过程和结果公开、透明。实践证明,项目式教学与新的评价方式使学生综合能力得到显著的提升。 展开更多
关键词 新工科 PBL教学 ppS考核评价
下载PDF
抗γ射线辐照PP改性料
4
作者 雷周桥 刘鹏 +2 位作者 黎泽顺 孙阳昆 曹运良 《广州化工》 2025年第1期58-60,共3页
研究γ射线辐照对添加不同类型的受阻胺光稳定剂和抗氧剂的聚丙烯(PP)的色差值和PP辐照之后高温高湿颜色稳定性的影响。结果表明受阻胺光稳定剂LA-52SC和994比770更能有效阻止PP的辐射致色和提高辐照之后PP材料的耐高温高湿性能。PP中... 研究γ射线辐照对添加不同类型的受阻胺光稳定剂和抗氧剂的聚丙烯(PP)的色差值和PP辐照之后高温高湿颜色稳定性的影响。结果表明受阻胺光稳定剂LA-52SC和994比770更能有效阻止PP的辐射致色和提高辐照之后PP材料的耐高温高湿性能。PP中添加主抗氧剂FS-042和辅助抗氧剂608比添加主抗氧剂1010和辅助抗氧剂168更能有效提高PP料的抗γ射线辐照能力和耐高温高湿性能。 展开更多
关键词 聚丙烯(pp) 受阻胺类光稳定剂(HALS) 抗氧剂 辐照致色 高温高湿
下载PDF
度伐利尤单抗联合PP化疗方案治疗Ⅲ期非小细胞肺癌患者的效果
5
作者 王艳杰 潘春香 +2 位作者 胡祥坤 孙如坤 鹿敏 《中国民康医学》 2024年第12期39-41,共3页
目的:观察度伐利尤单抗联合PP化疗方案治疗Ⅲ期非小细胞肺癌(NSCLC)患者的效果。方法:回顾性分析2021年5月至2023年5月该院收治的66例Ⅲ期NSCLC患者临床资料,按治疗方案不同将其分为观察组和对照组各33例。对照组采用PP化疗方案治疗,观... 目的:观察度伐利尤单抗联合PP化疗方案治疗Ⅲ期非小细胞肺癌(NSCLC)患者的效果。方法:回顾性分析2021年5月至2023年5月该院收治的66例Ⅲ期NSCLC患者临床资料,按治疗方案不同将其分为观察组和对照组各33例。对照组采用PP化疗方案治疗,观察组在对照组基础上联合度伐利尤单抗注射液治疗,比较两组疾病缓解率、KPS评分、癌症治疗功能评价系统-肺癌模块(FACT-L)评分、血清生化因子[Ⅳ型胶原蛋白α3(COL4A3)、G蛋白偶联受体相关分选蛋白1(GASP-1)]水平和不良反应发生率。结果:观察组疾病缓解率为60.61%,明显高于对照组的36.36%,差异有统计学意义(P<0.05);治疗后,两组KPS评分高于治疗前,且观察组高于对照组,两组FACT-L评分和血清COL4A3、GASP-1水平低于治疗前,且观察组低于对照组,差异均有统计学意义(P<0.05);治疗期间,两组腹泻、脱发、骨髓抑制、恶心等不良反应发生率比较,差异均无统计学意义(P>0.05)。结论:度伐利尤单抗联合PP化疗方案治疗Ⅲ期NSCLC患者可提高疾病缓解率和KPS评分,降低FACT-L评分及血清COL4A3、GASP-1水平,效果优于单纯PP化疗方案治疗。 展开更多
关键词 非小细胞肺癌 度伐利尤单抗 pp化疗方案 疾病缓解率 KPS评分 COL4A3 GASP-1
下载PDF
利用远震深度震相pP测定玛多M_(s)7.4地震震源深度
6
作者 郑雪刚 马学军 +1 位作者 沙木哈尔·叶尔肯 赵鹏毕 《内陆地震》 2024年第4期307-314,共8页
对于中强地震震源深度的测定,远震转换波深度震相pP、sP测深是有效方法,在深度震相清晰时深度精度可以达到2 km。使用Teleseis程序拟合玛多M_(s)7.4地震的理论地震图,并与实际观测进行对比,对此次地震震源深度进行测定,分析探讨地壳速... 对于中强地震震源深度的测定,远震转换波深度震相pP、sP测深是有效方法,在深度震相清晰时深度精度可以达到2 km。使用Teleseis程序拟合玛多M_(s)7.4地震的理论地震图,并与实际观测进行对比,对此次地震震源深度进行测定,分析探讨地壳速度模型对远震体波深度震相pP测深的影响。结果表明,玛多地震的震源初始破深度为12 km,速度模型中Vp的不确定性对理论地震图中震相到时影响更大。 展开更多
关键词 震源深度 玛多地震 pp震相
下载PDF
枳PtrPP2C51基因克隆与非生物胁迫表达分析
7
作者 佟晓楠 胡文娟 +5 位作者 杨杰 陈凯 董小筠 钟奕恬 张晓媛 李兴涛 《江苏农业科学》 北大核心 2024年第10期49-54,共6页
克隆枳PP2C基因家族的PtrPP2C51基因,分析其在低温、高温和干旱等胁迫下的表达规律,探究其在非生物胁迫中的功能。以1年生枳苗为试材,从嫩叶克隆到PtrPP2C51基因cDNA序列,采用生物信息学方法对其进行分析,利用实时荧光定量PCR仪(qRT-PCR... 克隆枳PP2C基因家族的PtrPP2C51基因,分析其在低温、高温和干旱等胁迫下的表达规律,探究其在非生物胁迫中的功能。以1年生枳苗为试材,从嫩叶克隆到PtrPP2C51基因cDNA序列,采用生物信息学方法对其进行分析,利用实时荧光定量PCR仪(qRT-PCR)检测枳苗在低温、高温和干旱(15%PEG-6000)处理下的PtrPP2C51基因表达模式。克隆获得PtrPP2C51基因编码区CDS序列长度为879 bp,编码292个氨基酸,其蛋白分子量为31.36 ku,理论等电点4.9,脂肪系数79.52,不稳定系数39.57,亲水性平均值-0.279。PtrPP2C51蛋白的二级结构中α-螺旋、β-转角、延伸链和无规则卷曲占比分别为40.07%、7.88%、18.15%和33.90%。PtrPP2C51蛋白与克里曼丁橘的PP2C蛋白在同一小分支上,亲缘关系最近。经低温(0℃)、高温(38℃)和干旱(15%PEG-6000)3种不同胁迫处理,PtrPP2C51基因的相对表达量均表现持续上调趋势,并且均在处理12 h时表达量达到最高值。PtrPP2C51基因可能参与枳的抗逆胁迫调控机制。 展开更多
关键词 pp2C基因 基因克隆 非生物胁迫
下载PDF
RCEP与CPTPP的比较和融合之道 被引量:1
8
作者 朱思翘 《中国对外贸易》 2024年第9期68-70,共3页
当前,竞争政策在自由贸易协定中的地位愈发重要,约有五分之四的自由贸易协定涉及竞争条款。发达国家对于竞争法和区域自由贸易协定中的竞争条款都具有先进性,中国作为发展中国家对于竞争条款仍处于起步阶段,因此要在研究CPTPP等发达国... 当前,竞争政策在自由贸易协定中的地位愈发重要,约有五分之四的自由贸易协定涉及竞争条款。发达国家对于竞争法和区域自由贸易协定中的竞争条款都具有先进性,中国作为发展中国家对于竞争条款仍处于起步阶段,因此要在研究CPTPP等发达国家竞争条款的基础上,制定和完善符合发展中国家利益的竞争政策。 展开更多
关键词 自由贸易协定 竞争法 CPT 发展中国家 融合之道 发达国家 pp 先进性
下载PDF
基于灰色关联理论的PP-SACC修复材料弯曲性能
9
作者 崔圣爱 夏葳 +2 位作者 徐李麟 张书豪 李固华 《西南交通大学学报》 EI CSCD 北大核心 2024年第6期1497-1504,共8页
为提高水泥基增强复合材料(ECC)经济效益并控制修复周期,以较低成本的聚丙烯纤维和快硬早强硫铝酸盐水泥为关键组材,设计聚丙烯纤维硫铝酸盐水泥基(PP-SACC)修复材料,并探究水胶比、纤维掺量及骨料粒径对修复材料弯曲性能的影响规律,联... 为提高水泥基增强复合材料(ECC)经济效益并控制修复周期,以较低成本的聚丙烯纤维和快硬早强硫铝酸盐水泥为关键组材,设计聚丙烯纤维硫铝酸盐水泥基(PP-SACC)修复材料,并探究水胶比、纤维掺量及骨料粒径对修复材料弯曲性能的影响规律,联用灰色关联模型对PP-SACC各工况进行综合评价.研究结果表明:纤维掺量是影响强度、韧性及裂缝特性最重要的因素,纤维掺量对初裂强度、韧性指标及平均裂缝宽度的影响因子分别为−0.68、0.79和−0.98;骨料粒径对裂缝特性同样有明显的影响,石英砂尺寸对平均裂缝宽度的影响因子为−0.86;水胶比对强度和韧性也有着显著的影响,合理的水胶比更有利于充分发挥纤维的桥连效应;PP-SACC修复材料在具备优异韧性的同时具有挠曲硬化特性. 展开更多
关键词 pp纤维-硫铝酸盐水泥基修复材料 弯曲延性 挠曲硬化 改进灰色关联分析
下载PDF
Projection pursuit cluster model and its application in water quality assessment 被引量:20
10
作者 WANGShun-jiu YANGZhi-feng DINGJing 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第6期994-995,共2页
One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must ... One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must be used. In order to overcome this issues the projection pursuit principle is introduced into water quality assessment, and projection pursuit cluster(PPC) model is developed in this study. The PPC model makes the transition from high dimension to one-dimension. In other words, based on the PPC model, multifactor problem can be converted to one factor problem. The application of PPC model can be divided into four parts: (1) to estimate projection index function Q(); (2) to find the right projection direction ; (3) to calculate projection characteristic value of the i th sample z-i, and (4) to draw comprehensive analysis on the basis of z-i. On the other hand, the empirical formula of cutoff radius R is developed, which is benefit for the model to be used in practice. Finally, a case study of water quality assessment is proposed in this paper. The results showed that the PPC model is reasonable, and it is more objective and less subjective in water quality assessment. It is a new method for multivariate problem comprehensive analysis. 展开更多
关键词 projection pursuit CLUSTER MODEL water quality assessment
下载PDF
Projection Pursuit Dynamic Cluster Model and its Application to Water Resources Carrying Capacity Evaluation 被引量:4
11
作者 Shunjiu Wang Xinli Zhang 《Journal of Water Resource and Protection》 2010年第5期449-454,共6页
The research shows that projection pursuit cluster (PPC) model is able to form a suitable index for overcom-ing the difficulties in comprehensive evaluation, which can be used to analyze complex multivariate prob-lems... The research shows that projection pursuit cluster (PPC) model is able to form a suitable index for overcom-ing the difficulties in comprehensive evaluation, which can be used to analyze complex multivariate prob-lems. The PPC model is widely used in multifactor cluster and evaluation analysis, but there are a few prob-lems needed to be solved in practice, such as cutoff radius parameter calibration. In this study, a new model-projection pursuit dynamic cluster (PPDC) model-based on projection pursuit principle is developed and used in water resources carrying capacity evaluation in China for the first time. In the PPDC model, there are two improvements compared with the PPC model, 1) a new projection index is constructed based on dynamic cluster principle, which avoids the problem of parameter calibration in the PPC model success-fully;2) the cluster results can be outputted directly according to the PPDC model, but the cluster results can be got based on the scatter points of projected characteristic values or the re-analysis for projected character-istic values in the PPC model. The results show that the PPDC model is a very effective and powerful tool in multifactor data exploratory analysis. It is a new method for water resources carrying capacity evaluation. The PPDC model and its application to water resources carrying capacity evaluation are introduced in detail in this paper. 展开更多
关键词 PROJECTION pursuit DYNAMIC CLUSTER GENETIC Algorithm Water RESOURCES
下载PDF
Application of Projection Pursuit Evaluation Model Based on Real-Coded Accelerating Genetic Algorithm in Evaluating Wetland Soil Quality Variations in the Sanjiang Plain, China 被引量:34
12
作者 FUQIANG XIEYONGGANG WEIZIMIN 《Pedosphere》 SCIE CAS CSCD 2003年第3期249-256,共8页
A new technique of dimension reduction named projection pursuit is applied to model and evaluatewetland soil quality variations in the Sanjiang Plain, Helongjiang Province, China. By adopting the im-proved real-coded ... A new technique of dimension reduction named projection pursuit is applied to model and evaluatewetland soil quality variations in the Sanjiang Plain, Helongjiang Province, China. By adopting the im-proved real-coded accelerating genetic algorithm (RAGA), the projection direction is optimized and multi-dimensional indexes are converted into low-dimensional space. Classification of wetland soils and evaluationof wetland soil quality variations are realized by pursuing optimum projection direction and projection func-tion value. Therefore, by adopting this new method, any possible human interference can be avoided andsound results can be achieved in researching quality changes and classification of wetland soils. 展开更多
关键词 EVALUATION projection pursuit evaluation model real-coded acceleratinggenetic algorithm soil quality variations
下载PDF
Noise amplitude modulation jamming signal suppression based on weighted-matching pursuit 被引量:2
13
作者 Sun Minhongi Tang Bin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第5期962-967,共6页
To suppress noise amplitude modulation jamming in a single-antenna radar system, a new method based on weighted-matching pursuit (WMP) algorithm is proposed, which can achieve underdetermined blind sources separatio... To suppress noise amplitude modulation jamming in a single-antenna radar system, a new method based on weighted-matching pursuit (WMP) algorithm is proposed, which can achieve underdetermined blind sources separation of the jamming and the target echo from the jammed mixture in the single channel of the receiver. Firstly, the presented method utilizes a prior information about the differences between the jamming component and the radar transmitted signal to construct two signal-adapted sub-dictionaries and to determine the weights. Then the WMP algorithm is applied to remove the jamming component from the mixture. Experimental results verify the validity of the presented method. By comparison of the pulse compression performance, the simulation results shows that the presented method is superior to the method of frequency domain cancellation (FDC) when the jamming-to-signal ratio (JSR) is lower than 15 dB. 展开更多
关键词 electronic counter-countermeasures noise amplitude modulation jamming atomic decomposition matching pursuit.
下载PDF
An application of matching pursuit time-frequency decomposition method using multi-wavelet dictionaries 被引量:2
14
作者 Zhao Tianzi Song Wei 《Petroleum Science》 SCIE CAS CSCD 2012年第3期310-316,共7页
In the time-frequency analysis of seismic signals, the matching pursuit algorithm is an effective tool for non-stationary signals, and has high time-frequency resolution and a transient structure with local self-adapt... In the time-frequency analysis of seismic signals, the matching pursuit algorithm is an effective tool for non-stationary signals, and has high time-frequency resolution and a transient structure with local self-adaption. We expand the time-frequency dictionary library with Ricker, Morlet, and mixed phase seismic wavelets, to make the method more suitable for seismic signal time-frequency decomposition. In this paper, we demonstrated the algorithm theory using synthetic seismic data, and tested the method using synthetic data with 25% noise. We compared the matching pursuit results of the time-frequency dictionaries. The results indicated that the dictionary which matched the signal characteristics better would obtain better results, and can reflect the information of seismic data effectively. 展开更多
关键词 Matching pursuit seismic attenuation wavelet transform Wigner Ville distribution time- frequency dictionary
下载PDF
Fast M-fold matching pursuit algorithm for image approximation 被引量:1
15
作者 Gan Tao He Yanmin Zhu Weile 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第4期883-888,共6页
A simple and effective greedy algorithm for image approximation is proposed. Based on the matching pursuit approach, it is characterized by a reduced computational complexity benefiting from two major modifications. F... A simple and effective greedy algorithm for image approximation is proposed. Based on the matching pursuit approach, it is characterized by a reduced computational complexity benefiting from two major modifications. First, it iteratively finds an approximation by selecting M atoms instead of one at a time. Second, the inner product computations are confined within only a fraction of dictionary atoms at each iteration. The modifications are implemented very efficiently due to the spatial incoherence of the dictionary. Experimental results show that compared with full search matching pursuit, the proposed algorithm achieves a speed-up gain of 14.4-36.7 times while maintaining the approximation quality. 展开更多
关键词 greedy algorithm image approximation matching pursuit
下载PDF
Higher-order principal component pursuit via tensor approximation and convex optimization 被引量:1
16
作者 Sijia Cai Ping Wang +1 位作者 Linhao Li Chuhan Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第3期523-530,共8页
Recovering the low-rank structure of data matrix from sparse errors arises in the principal component pursuit (PCP). This paper exploits the higher-order generalization of matrix recovery, named higher-order princip... Recovering the low-rank structure of data matrix from sparse errors arises in the principal component pursuit (PCP). This paper exploits the higher-order generalization of matrix recovery, named higher-order principal component pursuit (HOPCP), since it is critical in multi-way data analysis. Unlike the convexification (nuclear norm) for matrix rank function, the tensorial nuclear norm is stil an open problem. While existing preliminary works on the tensor completion field provide a viable way to indicate the low complexity estimate of tensor, therefore, the paper focuses on the low multi-linear rank tensor and adopt its convex relaxation to formulate the convex optimization model of HOPCP. The paper further propose two algorithms for HOPCP based on alternative minimization scheme: the augmented Lagrangian alternating direction method (ALADM) and its truncated higher-order singular value decomposition (ALADM-THOSVD) version. The former can obtain a high accuracy solution while the latter is more efficient to handle the computationally intractable problems. Experimental results on both synthetic data and real magnetic resonance imaging data show the applicability of our algorithms in high-dimensional tensor data processing. 展开更多
关键词 tensor recovery principal component pursuit alternating direction method tensor approximation.
下载PDF
废弃PP纤维再生混凝土基本力学性能试验 被引量:1
17
作者 王建超 李梦飞 赵丰磊 《沈阳建筑大学学报(自然科学版)》 CAS 北大核心 2024年第1期105-113,共9页
目的 针对纤维体积掺量、长径比、再生骨料取代率等因素,探究废弃PP纤维对再生混凝土力学性能的影响,提高废弃纤维利用率。方法 以废弃PP打包带制成不同长径比的纤维作为筋材,以不同体积掺量与不同再生骨料取代率的再生混凝土混合制成1... 目的 针对纤维体积掺量、长径比、再生骨料取代率等因素,探究废弃PP纤维对再生混凝土力学性能的影响,提高废弃纤维利用率。方法 以废弃PP打包带制成不同长径比的纤维作为筋材,以不同体积掺量与不同再生骨料取代率的再生混凝土混合制成11组废弃PP纤维再生混凝土试块,对其进行抗压和抗拉试验。结果 立方体抗压、抗拉强度最佳时的废弃PP纤维体积掺量为1.5%,长径比为47.85;废弃PP纤维再生混凝土的立方体抗压、抗拉强度与再生骨料取代率有关,其强度与再生骨料取代率近似呈线性关系。结论 废弃PP纤维的掺入可以提高再生混凝土的立方体抗压强度和抗拉强度。 展开更多
关键词 再生混凝土 废弃pp纤维 再生骨料取代率 力学性能
下载PDF
生态翻译学视角下的电影片名翻译——以The Pursuit of Happyness汉译为例 被引量:1
18
作者 赵海娟 《重庆第二师范学院学报》 2015年第5期52-55,175,共4页
生态翻译学以探索普适翻译规律为目标,将翻译活动定义为译者在翻译生态环境中对各相关元素的适应选择行为,为电影片名翻译提供了全新的理论视角与实践方法。本文以美国影片The Pursuit of Happyness片名汉译为例,从语言维、文化维、交... 生态翻译学以探索普适翻译规律为目标,将翻译活动定义为译者在翻译生态环境中对各相关元素的适应选择行为,为电影片名翻译提供了全新的理论视角与实践方法。本文以美国影片The Pursuit of Happyness片名汉译为例,从语言维、文化维、交际维的三维适应性选择转换视角分析译者的整个翻译过程,借此管窥电影片名翻译的生态翻译学启示。 展开更多
关键词 生态翻译学 片名翻译 当幸福来敲门 三维转换
下载PDF
The application of projection pursuit classification in the process of strategy selection and evaluation based on the real coded accelerating genetic algorithm 被引量:1
19
作者 JIANG Fa-zhu YANG Xiu-feng 《Chinese Business Review》 2008年第1期40-44,64,共6页
During the process of enterprises' strategy evaluation and selection, there are many evaluating indicators, and among them there are some potential correlations and conflicts. Thus it poses the problems to the decisi... During the process of enterprises' strategy evaluation and selection, there are many evaluating indicators, and among them there are some potential correlations and conflicts. Thus it poses the problems to the decision-makers how to conduct correct evaluation on a business and how to make strategy adjustment and selection according to the evaluation. Based on the qualitative and quantitative method, the paper introduces the Projection Pursuit Classification (PPC) model based on the Real-coded Accelerating Genetic Algorithm (RAGA) into the process of enterprises' strategy evaluation and selection. The characteristic of PPC model is that it ultimately overcomes the influence of the proportion of subjectivity and avoids precocious convergence, thus providing a new objective method for strategy evaluation and selection by pursuing the most objective strategy evaluation to make the relatively sensible strategy portfolio and action. 展开更多
关键词 projection pursuit strategy evaluation accelerating genetic algorithm
下载PDF
自成核行为在CF/PPS复合材料中的差异性与普适性
20
作者 任毅 李洲洋 +3 位作者 李心果 周剑锋 朱姝 余木火 《合成纤维》 CAS 2024年第4期65-74,共10页
以半结晶高分子为基体的碳纤维增强热塑性复合材料,其基体的结晶行为将受到碳纤维表面性质与热历史的共同影响。当这种材料在经历反复加热冷却的热循环过程时,基体会产生自成核行为,其结晶过程变得更加复杂。通过三种T300级碳纤维分别... 以半结晶高分子为基体的碳纤维增强热塑性复合材料,其基体的结晶行为将受到碳纤维表面性质与热历史的共同影响。当这种材料在经历反复加热冷却的热循环过程时,基体会产生自成核行为,其结晶过程变得更加复杂。通过三种T300级碳纤维分别制备了碳纤维增强聚苯硫醚(CF/PPS)复合材料,并探究了二次熔融温度与CF/PPS复合材料结晶行为的关系,揭示了不同碳纤维表面性质对CF/PPS复合材料自成核行为的影响。在此基础上阐明了CF/PPS复合材料基体自成核与CF异相成核的竞争关系。最后,通过冲压成型制得具有自成核行为的CF/PPS复合材料角片,验证了自成核对于CF/PPS复合材料二次热成型技术的有效性与重要性。 展开更多
关键词 CF/ppS复合材料 自成核行为 碳纤维 冲压成型
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部