期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
含两参数的二阶常微分方程Cauchy问题解的多重层性质
1
作者 林苏榕 《大学数学》 2010年第2期94-98,共5页
研究含两参数的二阶常微分方程Cauchy问题解的多重层性质,根据不同层次引用不同的伸长变量,分别构造了具有不同量级的边界层校正项,从而证得关于解的一致有效的渐近展开式和有关的余项估计.
关键词 双参数 CAUCHY问题 多重层性质
下载PDF
煤层群多重保护层开采防突技术的研究 被引量:25
2
作者 刘林 《矿业安全与环保》 2001年第5期1-4,共4页
通过理论分析与现场试验研究,丰富和发展了保护层开采的基本理论,建立了保护层开采效果考察及评价体系,确定出了合理超前距、走向、倾向卸压保护角等技术参数。
关键词 多重保护开采 煤突出 瓦斯突出 除突技术 防突效果
下载PDF
近距离煤层群开采瓦斯综合治理技术研究与应用
3
作者 李德成 王欣茂 随贺 《能源技术与管理》 2012年第4期38-40,共3页
祁东煤矿8224工作面回采过程中,受到近距离邻近煤层81、9煤的瓦斯大量涌出及本煤层煤与瓦斯突出等灾害威胁,通过采取"Y"型通风、保护层开采、顶板预裂爆破、立体抽采等综合治理措施取得显著效果。
关键词 近距离邻近 多重保护开采 顶板预裂爆破 立体抽采
下载PDF
白皎矿2443工作面瓦斯治理 被引量:1
4
作者 刘盛东 魏进涛 《煤炭技术》 CAS 北大核心 2016年第3期199-201,共3页
结合白皎矿2443工作面的实际情况,利用多重上保护层开采技术和底板道穿层网格钻孔有效消除了2443工作面的突出危险,同时结合均压通风控制工作面瓦斯浓度和"U+L"形通风方式治理上隅角瓦斯,使得2443工作面瓦斯的治理取得了良好... 结合白皎矿2443工作面的实际情况,利用多重上保护层开采技术和底板道穿层网格钻孔有效消除了2443工作面的突出危险,同时结合均压通风控制工作面瓦斯浓度和"U+L"形通风方式治理上隅角瓦斯,使得2443工作面瓦斯的治理取得了良好的效果。 展开更多
关键词 突出 多重上保护开采 底板穿钻孔 上隅角
下载PDF
长篇小说的总体把握功力
5
《文艺理论研究》 CSSCI 北大核心 1991年第6期96-96,共1页
黄毓璜在《长篇小说的整体把握》(《文学评论》1991年4期)一文中指出: 把种种差异参照起来加以思考,我的感受不能不集中到长篇小说的整体把握这一也许算不得新鲜的问题上。可以从多重角度、多重层面上指认长篇区别于中短篇的特质。但最... 黄毓璜在《长篇小说的整体把握》(《文学评论》1991年4期)一文中指出: 把种种差异参照起来加以思考,我的感受不能不集中到长篇小说的整体把握这一也许算不得新鲜的问题上。可以从多重角度、多重层面上指认长篇区别于中短篇的特质。但最基本最关涉根本的恐怕在于容量规范。亦即长篇是以大格局、大篇制、大容量、大境界的特质是称。无论是着力“再现”外部世界还是侧重“表现”比天空、海洋更广袤的心灵世界。长篇都不是直线的、平面的、单义的,而是展现为多层、多维、多义的有机复合体。这就使得一个长篇作家从林林总总、千头万绪、纷纭杂沓中实施整体把握的功力上升到决定性的位置。舍此,任何机巧、变化、从容、闪光。 展开更多
关键词 长篇小说 整体把握 天空 总体把握 文学评论 外部世界 功力 心灵世界 多重层 大境界
下载PDF
一种三维手性声子晶体的横波偏振特性研究
6
作者 严谋 曹瑞芳 杨涛 《梧州学院学报》 2016年第3期27-33,共7页
构造了一种具有完整螺旋结构的三维手性声子晶体,并用层多重散射方法计算了其能带结构,发现这类结构可以实现横波左右旋偏振态的分离。然后详细考察了各种非完整螺旋结构的能带图。其中,具有三层周期的非完整螺旋结构可分为A、B和C型空... 构造了一种具有完整螺旋结构的三维手性声子晶体,并用层多重散射方法计算了其能带结构,发现这类结构可以实现横波左右旋偏振态的分离。然后详细考察了各种非完整螺旋结构的能带图。其中,具有三层周期的非完整螺旋结构可分为A、B和C型空间结构,A型结构对应的横波偏振仍然简并,无法分裂,B和C型结构则可以实现完全相同的横波带分裂,即分离横波左右旋偏振态。通过平移实现的两层斜方晶体结构,尽管并不是严格意义上的手性螺旋结构,但同样可以实现横波的偏振分裂。 展开更多
关键词 声子晶体 手性 偏振 多重散射
下载PDF
FAULT DETECTION FOR MULTIPLE-VALUED LOGIC CIRCUITS WITH FANOUT-FREE 被引量:1
7
作者 PanZhongliang 《Journal of Electronics(China)》 2004年第5期376-383,共8页
The single fault and multiple fault detections for multiple-valued logic circuits are studied in this paper. Firstly, it is shown that the cardinality of optimal single fault test set for fanout-free m-valued circuits... The single fault and multiple fault detections for multiple-valued logic circuits are studied in this paper. Firstly, it is shown that the cardinality of optimal single fault test set for fanout-free m-valued circuits with n primary inputs is not more than n + 1, for linear tree circuits is two, and for multiplication modulo circuits is two if n is an odd number or if n is an even number and m > 3, where the optimal test set of a circuit has minimal number of test vectors. Secondly,it is indicated that the cardinality of optimal multiple fault test set for linear tree circuits with n primary inputs is 1 + [n/(m - 1)], for multiplication modulo circuits is n+ 1, for fanout-free circuits that consist of 2-input linear tree circuits and 2-input multiplication modulo circuits is not greater than n+ 1, where [x] denotes the smallest integer greater than or equal to x. Finally,the single fault location approaches of linear tree circuits and multiplication modulo circuits are presented, and all faults in the two types of circuits can be located by using a test set with n + 1 vectors. 展开更多
关键词 Multiple-valued logic Digital circuits Fault detection Single fault Multiple faults
下载PDF
Production of Entanglement of Multiple Three-Level Atoms with a Two-Mode Cavity
8
作者 ZHENG Shi-Biao 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期539-541,共3页
A scheme is proposed for generating maximally entangled states for two or more three-level atoms. In the scheme the atoms are sent through a two-mode cavity one by one and interact with the two-cavity modes sequential... A scheme is proposed for generating maximally entangled states for two or more three-level atoms. In the scheme the atoms are sent through a two-mode cavity one by one and interact with the two-cavity modes sequentially. The required experimental techniques are within the scope of what can be obtained in the microwave cavity QED setup. 展开更多
关键词 ENTANGLEMENT three-level atoms two-mode cavity
下载PDF
Benefit of everolimus as a monotherapy for a refractory breast cancer patient bearing multiple genetic mutations in the PI3K/AKT/mTOR signaling pathway 被引量:6
9
作者 Yehui Shi Wenwen Zhang +6 位作者 Yingnan Ye Yanan Cheng Lei Han Pengpeng Liu Weipeng Zhao Zhongsheng Tong Jinpu Yu 《Cancer Biology & Medicine》 SCIE CAS CSCD 2018年第3期314-321,共8页
A postmenopausal patient with a diagnosis of estrogen receptor(ER)(+), progesterone receptor(PR)(+), and human epidermal growth factor receptor-2(HER2)(-) breast cancer was reported. The patient refused surgery and wa... A postmenopausal patient with a diagnosis of estrogen receptor(ER)(+), progesterone receptor(PR)(+), and human epidermal growth factor receptor-2(HER2)(-) breast cancer was reported. The patient refused surgery and was resistant to conventional chemotherapy regimens. Computed tomography and the circulating tumor cell test indicated that the patient's tumor burden increased rapidly even after several chemotherapy sessions. Multiple genetic aberrances in the phosphatidylinositol3-kinases(PI3 K) signaling pathway were detected via next-generation sequencing(NGS)-based liquid biopsy, including a p. G1007 R missense mutation in exon 21 of PIK3 CA(33.61%), a p.L70 fs frameshift mutation in exon 3 of phosphatase and tension homolog deleted on chromosome ten(PTEN)(49.14%), and a p. D1542 Y missense mutation in exon 32 of mammalian target of rapamycin(m TOR)(1.66%). Therefore, only the m TOR inhibitor everolimus was administered to the patient. Partial remission(PR) was observed after 2 months, and sustained stable disease(SD) was observed after a year and a half. Subsequent sequencing showed that the mutation ratio of PIK3 CA decreased to 4.17%, and that the PTEN and m TOR mutations disappeared, which revealed the significant curative effect of everolimus. We report the first case of successful monotherapy treatment using everolimus in a patient with advanced breast cancer bearing mutations in genes involved in the PI3 K/ARK/m TOR signaling pathway. The success of this case highlights the invaluable clinical contribution of NGS-based liquid biopsy, as it successfully provided an optimal therapeutic target for the patient with advanced breast cancer. 展开更多
关键词 Breast cancer EVEROLIMUS next-generation sequencing liquid biopsy PI3K/AKT/MTOR
下载PDF
Rate decline analysis of multiple fractured horizontal well in shale reservoir with triple continuum 被引量:1
10
作者 王军磊 闫存章 +3 位作者 贾爱林 何东博 位云生 齐亚东 《Journal of Central South University》 SCIE EI CAS 2014年第11期4320-4329,共10页
Multiple fractured horizontal well(MFHW) is widely applied in the development of shale gas. To investigate the gas flow characteristics in shale, based on a new dual mechanism triple continuum model, an analytical sol... Multiple fractured horizontal well(MFHW) is widely applied in the development of shale gas. To investigate the gas flow characteristics in shale, based on a new dual mechanism triple continuum model, an analytical solution for MFHW surrounded by stimulated reservoir volume(SRV) was presented. Pressure and pressure derivative curves were used to identify the characteristics of flow regimes in shale. Blasingame type curves were established to evaluate the effects of sensitive parameters on rate decline curves, which indicates that the whole flow regimes could be divided into transient flow, feeding flow, and pseudo steady state flow. In feeding flow regime, the production of gas well is gradually fed by adsorbed gases in sub matrix, and free gases in matrix. The proportion of different gas sources to well production is determined by such parameters as storability ratios of triple continuum, transmissibility coefficients controlled by dual flow mechanism and fracture conductivity. 展开更多
关键词 triple continuum desorption and diffusion Darcy flow multiple finite conductivity fractures pressure blasingame type curves
下载PDF
Influence of brittleness and confining stress on rock cuttability based on rock indentation tests 被引量:6
11
作者 WANG Shao-feng TANG Yu WANG Shan-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第9期2786-2800,共15页
In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utili... In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utilized to take regression analysis.The eight sets of normalized regression models were established for reflecting the relationships of peak indentation force(PIF)and specific energy(SE)with brittleness index and uniaxial confining stress.The regression analyses present that these regression models have good prediction performance.The regressive results indicate that brittleness indices and uniaxial confining stress conditions have non-linear effects on the rock cuttability that is determined by PIF and SE.Finally,the multilayer perceptual neural network was used to measure the importance weights of brittleness index and uniaxial confining stress upon the influence for rock cuttability.The results indicate that the uniaxial confining stress is more significant than brittleness index for influencing the rock cuttability. 展开更多
关键词 rock cuttability brittleness index uniaxial confining pressures regression analysis multilayer perceptual neural network importance analysis
下载PDF
废弃物管理词汇对照(二十三)
12
作者 于欣丽 《术语标准化与信息技术》 2002年第2期37-38,共2页
关键词 废弃物管理 科技术语 空气污染 批量废弃物 多重 多路系统
下载PDF
Electronic Properties in a Hierarchical Multilayer Structure
13
作者 ZHUChen-Ping XIONGShi-Jie 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第3期339-346,共8页
We investigate electronic properties of a hierarchical multilayer structure consisting of stacking of barriers and wells. The structure is formed in a sequence of generations, each of which is constructed with the sam... We investigate electronic properties of a hierarchical multilayer structure consisting of stacking of barriers and wells. The structure is formed in a sequence of generations, each of which is constructed with the same pattern but with the previous generation as the basic building blocks. We calculate the transmission spectrum which shows the multifractal behavior for systems with large generation index. From the analysis of the average resistivity and the multifractal structure of the wavefunctions, we show that there exist different types of states exhibiting extended, localized and intermediate characteristics. The degree of localization is sensitive to the variation of the structural parameters.Suggestion of the possible experimental realization is discussed. 展开更多
关键词 hierarchical structure MULTILAYER MULTIFRACTAL
下载PDF
MULTISTAGE SUPERIMPOSED DEFORMATION AND THE EVOLUTION OF THE NORTHEASTERN MARGIN OF YANGTZEBLOCK 被引量:2
14
作者 HOUMingjin TANGJiafu +1 位作者 LIHuaikun WUYuedong 《Geotectonica et Metallogenia》 2003年第1期33-54,共22页
Multistage superimposed deformation has been discussed systematically based on the progress of the stratigraphic sequences of the northeastern margin of Yangtze Block.The new-discovered first stage deformation of thos... Multistage superimposed deformation has been discussed systematically based on the progress of the stratigraphic sequences of the northeastern margin of Yangtze Block.The new-discovered first stage deformation of those sequences occurred from the middle Triassic to the end of early Jurassic together with development of regional folding, which was resulted from the deep detachment shearing tending toward NW-WNW. The folds dip to east and fall down toward west, and were superimposed by the main stage folding.Thereafter, a series of folds were developed with axes trending toward northeast.Consequently normal folds occurred on the normal limbs while overturned fold on the overturned limbs during the first stage folding. The detachment or thrust was formed from late Jurassic to early Cretaceous. Due to the uplifting of Dabie and the Wannan Mountains in the north and south sides, the bi-directional thrusting belt was formed by gravity flowing from the Mountains toward the center of the basin along the north side of Xuancheng and south side of Guichi. The deformation geodynamics was discussed simply based on the newly recognized information about the tectonic evolution. 展开更多
关键词 Yangtze Block multistage superimposed deformation gravity gliding THRUSTING INDOSINIAN YANSHANIAN
下载PDF
Multifractal Characteristics of Intermittent Turbulence in the Urban Canopy Layer 被引量:1
15
作者 XU Jing-Jing HU Fei 《Atmospheric and Oceanic Science Letters》 CSCD 2015年第2期72-77,共6页
The multifractality of energy and thermal dissipation of fully developed intermittent turbulence is investigated in the urban canopy layer under unstable conditions by the singularity spectrum for the fractal dimensio... The multifractality of energy and thermal dissipation of fully developed intermittent turbulence is investigated in the urban canopy layer under unstable conditions by the singularity spectrum for the fractal dimensions of sets of singularities characterizing multifractals. In order to obtain high-order moment properties of smallscale turbulent dissipation in the inertial range, an ultrasonic anemometer with a high sampling frequency of 100 Hz was used. The authors found that the turbulent signal could be singular everywhere. Moreover, the singular exponents of energy and thermal dissipation rates are most frequently encountered at around 0.2, which is significantly smaller than the singular exponents for a wind tunnel at a moderate Reynolds number. The evidence indicates a higher intermittency of turbulence in the urban canopy layer at a high Reynolds number, which is demonstrated by the data with high temporal resolution. Furthermore, the temperature field is more intermittent than the velocity field. In addition, a large amount of samples could be used for verification of the results. 展开更多
关键词 urban canopy layer intermittent turbulence turbulent dissipation MULTIFRACTALITY singularity spectrum
下载PDF
AN ENHANCED DETECTION ALGORITHM FOR V-BLAST SYSTEM
16
作者 Su Xin Yi Kechu Tian Bin Sun Yongjun 《Journal of Electronics(China)》 2006年第5期773-776,共4页
A decoding method complemented by Maximum Likelihood (ML) detection for V-BLAST (Verti- cal Bell Labs Layered Space-Time) system is presented. The ranked layers are divided into several groups. ML decoding is performe... A decoding method complemented by Maximum Likelihood (ML) detection for V-BLAST (Verti- cal Bell Labs Layered Space-Time) system is presented. The ranked layers are divided into several groups. ML decoding is performed jointly for the layers within the same group while the Decision Feedback Equalization (DFE) is performed for groups. Based on the assumption of QPSK modulation and the quasi-static flat fading channel, simulations are made to testify the performance of the proposed algorithm. The results show that the algorithm outperforms the original V-BLAST detection dramatically in Symbol Error Probability (SEP) per- formance. Specifically, Signal-to-Noise Ratio (SNR) improvement of 3.4dB is obtained for SEP of 10?2 (4×4 case), with a reasonable complexity maintained. 展开更多
关键词 Multi-Input Multi-Output (MIMO) Vertical Bell Labs Layered Space-Time (V-BLAST) Maximum Likelihood (ML) detection Decision Feedback Equalization (DFE)
下载PDF
Searching Multiple Structural Changes of Chinese Stock Market via GMDH
17
作者 Yixiang Tian Li Zhou 《Journal of Systems Science and Information》 2009年第3期193-200,共8页
This paper analyzes multiple structural changes by GMDH (Group Meth- ods of Data Handling), which have obvious advantages. Our method extends the model of Lumsdaine & Papell[1] (1997), and it could be applied to ... This paper analyzes multiple structural changes by GMDH (Group Meth- ods of Data Handling), which have obvious advantages. Our method extends the model of Lumsdaine & Papell[1] (1997), and it could be applied to the case of more than two structural changes. Because of simultaneously considering every structural change of the hypothesis, it is likely to be of particular relevance in practice. And it can decrease large investigation costs by MATLAB programming. What is more, we can select the criterion value of F incremental statistic to control the significance of the breaks, based on kinds of investigation intentions. And the empirical evidences on Shenzhen Composite Index are presented to illustrate the usefulness of our method. 展开更多
关键词 GMDH multiple structural changes F incremental statistic
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部