期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
DADS联合P-gp抑制剂比立考达协同逆转A549/DDP多药耐药性的研究
1
作者 廖明初 陈洁海 +2 位作者 曹振华 陈聪 艾小红 《中国医药指南》 2016年第26期17-19,共3页
目的为研究DADS(二烯丙基二硫)联合第二代P-gp抑制剂比立考是否可协同逆转肺癌耐顺铂细胞株A549/DDP的多药耐药,增强化疗敏感性。方法 MTT进行药物毒性试验,Western和RT-PCR检测P-gp及其编码基因MDR-1表达变化。结果非细胞毒性剂量的8 m... 目的为研究DADS(二烯丙基二硫)联合第二代P-gp抑制剂比立考是否可协同逆转肺癌耐顺铂细胞株A549/DDP的多药耐药,增强化疗敏感性。方法 MTT进行药物毒性试验,Western和RT-PCR检测P-gp及其编码基因MDR-1表达变化。结果非细胞毒性剂量的8 mg/L DADS和2.3μmol/L的比立考达都可以增加CDDP(顺铂)对A549/DDP细胞毒性,且二者联合具有协同作用。并通过Western和PCR验证经8 mg/L DADS作用后耐药细胞系A549/DDP后P-gp与MDR-1表达明显降低,经8 mg/L DADS和2.3μmol/L的比立考达共同作用后A549/DDP后P-gp与MDR-1表达进一步降低。结论 DADS与比立考达在逆转肺癌多药耐药具有协同作用。 展开更多
关键词 肺癌 DADS(二烯丙基二硫) 比立考达 多药耐药 P–gp
下载PDF
比立和恩丹西酮预防顺铂所致恶心、呕吐的临床观察
2
作者 袁晓明 陈其友 +1 位作者 吴清泉 施建华 《医学理论与实践》 2006年第4期424-425,共2页
目的:通过交叉对照方法,观察比立和恩丹西酮的止吐效果与毒性。方法:60例接受顺铂每日35—45mg/m^2,连续2d的联合化疗患者,采用交叉对照方法,分别给予比立(盐酸格拉司琼)3mg或恩丹西酮8mg连续2d静滴。结果:对恶心,比立和恩... 目的:通过交叉对照方法,观察比立和恩丹西酮的止吐效果与毒性。方法:60例接受顺铂每日35—45mg/m^2,连续2d的联合化疗患者,采用交叉对照方法,分别给予比立(盐酸格拉司琼)3mg或恩丹西酮8mg连续2d静滴。结果:对恶心,比立和恩丹西酮有效率分别为90%和62.5%,差异有统计学意义(P〈0.01);呕吐控制率分别为96%和78%,差异有统计学意义(P〈0.01)。两药副作用轻微,均可耐受.结论:比立预防和控制恶心、呕吐的作用,比恩丹西酮强,可以减轻顺铂所致胃肠道反应,提高患者生存质量。 展开更多
关键词 比立 恩丹西酮 恶心 呕吐
下载PDF
Rice Crop Digital Image Compression Technology Based on Discrete Fourier Transform 被引量:1
3
作者 黄新民 姚军财 +2 位作者 何军锋 申静 黄晓洲 《Agricultural Science & Technology》 CAS 2012年第3期634-637,共4页
[Objective] To study the digital image compression technology in rice monitoring system. [Method] A digital image compression technology program based on the discrete Fourier transform was proposed, and simulation exp... [Objective] To study the digital image compression technology in rice monitoring system. [Method] A digital image compression technology program based on the discrete Fourier transform was proposed, and simulation experiments were carried out to compress the image at different compression ratios. [Result] When com- pression ratios were less than 30, the compression ratio, image entropy, average codeword length, coding efficiency and redundancy which reflected the quality of the coding, and the parameter PSNR which estimated the fidelity of the compressed im- age were all achieved good results that human eye could barely percept the differ- ence between the original image and decompressed image; and when the compres- sion ratios were more than 30, there was a certain distortion in the decompressed image. And when the compression ratio was 91.516 3, although the image had some distortion, the PSNR was still achieved to 21.528 2, and human eye could accept the decompressed image intuitively within the acceptable error range. [Conclusion] The results show that the proposed image compression program is a viable, effective, and better image compression technology which can satisfy the requirements of the crop monitoring system on image storage, transforming and transporting. 展开更多
关键词 Digital image Compression Fourier Transform Peak Signal-to-Noise Ratio
下载PDF
Morphological Comparison between Chinese Ayu and Japanese Ayu and Establishment of Plecoglossus altivelis chinensis Wu&Shan subsp.nov. 被引量:2
4
作者 SHANXiujuan WUYunfei KANGBin 《Journal of Ocean University of China》 SCIE CAS 2005年第1期61-66,共6页
The countable characters of Qingdao, Zhejiang, Liaoning and Japanese Ayu arecompared. There are no substantial different characters among the former three Ayu, so thecomprehensive values of them are taken as represent... The countable characters of Qingdao, Zhejiang, Liaoning and Japanese Ayu arecompared. There are no substantial different characters among the former three Ayu, so thecomprehensive values of them are taken as representative of Chinese Ayu, which is in turn comparedwith Japanese Ayu ( Plecoglossus altivelis altivelis and Plecoglossus altivelis ryukyuensis). By thecoefficient of difference test, 3 and 4 characters are found to be beyond the subspecies levelbetween Chinese Ayu and nominate subspecies (Plecoglossus altivelis altivelis) and between ChineseAyu (Plecoglossus altivelis chinensis) and Ryukyus subspecies (Plecoglossus altivelis ryukyuensis),respectively, which shows that they belong to different subspecies. The China mainland Ayu is a newsubspecies, Plecoglossus altivelis chinensis Wu and Shan, the establishment of which and its formingcauses are discussed. 展开更多
关键词 morphological comparison plecoglossus altivelis chinensis wu and shan geographic isolation population subspecies differentiation
下载PDF
A SIZE-REDUCED LOG PERIODIC DIPOLE ANTENNA 被引量:1
5
作者 Yang Zhengguang Su Donglin Lü Shanwei 《Journal of Electronics(China)》 2006年第6期913-914,共2页
A rectangle capacity patch was adopted as the resonance unit of the Log Periodic Dipole Antenna (LPDA) so as to realize the miniaturization of this aerial in this paper. Fifteen rectangle capacity patch units of diffe... A rectangle capacity patch was adopted as the resonance unit of the Log Periodic Dipole Antenna (LPDA) so as to realize the miniaturization of this aerial in this paper. Fifteen rectangle capacity patch units of different parameters were analyzed in this paper and three design laws of size-reduction were found. Accord-ing to these design laws, a 70% miniaturization ratio LPDA was designed and fabricated. The Voltage Standing Wave Ratio (VSWR) and pattern of the fabricated LPDA were measured. The results indicate that this size-reduction method do not deteriorate performance. 展开更多
关键词 Log Periodic Dipole Antenna (LPDA) size-reduction Voltage Standing Wave Ratio (VSWR)
下载PDF
Comparative Study of the Modification of Coal Tar Pitch for Higher Carbonization Yield and Better Properties 被引量:2
6
作者 张文娟 李铁虎 +1 位作者 卢萌 侯翠岭 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第12期1391-1396,共6页
Parent coal tar pitch(CTP)was modified with boric acid(BA),cinnamaldehyde(CMA)and the mixture of BA and CMA,respectively.The parent CTP and three modified CTPs were characterized by elemental analysis,thermogravimetri... Parent coal tar pitch(CTP)was modified with boric acid(BA),cinnamaldehyde(CMA)and the mixture of BA and CMA,respectively.The parent CTP and three modified CTPs were characterized by elemental analysis,thermogravimetric analysis,Fourier transform infrared(FT-IR)spectroscopy and scanning electron microscopy.The four samples were carbonized at different temperatures and resultant carbonized products were characterized by FT-IR spectroscopy,X-ray diffraction and polarized-light microscopy.The results show that the morphologies and carbonization behaviors of the parent CTP and modified CTPs are quite different.The carbonization yield of the CTP modified with the mixture of BA and CMA is higher than that of CTP modified with BA or CMA only.In addition,the modification of CTP with 7 g of BA and 10 ml of CMA results in an increase in carbonization yield by5.64%.During the pyrolysis of modified CTPs,the dehydration of BA or the distillation of CMA occurs at the temperature lower than 300°C,and methyl and methylene groups of the modified CTPs disappear gradually as temperature rises.Furthermore,the modification of CTP by the mixture of BA and CMA results in more intensive mesophase spheres than other modified CTPs,and the modified CTP is easier to be carbonized to form graphitic carbon. 展开更多
关键词 coal tar pitch CINNAMALDEHYDE boric acid CARBONIZATION
下载PDF
Sustainable Construction --An International Comparison of Civil Engineering Students
7
作者 Thanh Trung Le Chris Ian Goodier +2 位作者 Hanh Huu Pham Marios N. Soutsos Kien Ton Tong 《Journal of Civil Engineering and Architecture》 2012年第12期1648-1653,共6页
Sustainable construction in the future will be influenced significantly by the beliefs and actions of civil engineering students studying at university today. A comparative investigation of the appreciation and attitu... Sustainable construction in the future will be influenced significantly by the beliefs and actions of civil engineering students studying at university today. A comparative investigation of the appreciation and attitudes regarding sustainable construction of civil engineering students at The NUCE (National University of Civil Engineering) in Vietnam, and the Universities of Loughborough and Liverpool in the UK were therefore conducted. Results indicate that students at all three universities appreciate the importance of the development of sustainable construction and have positive attitudes with regards to sustainability. Construction design and appropriate use of materials were two issues generally considered the most important with regards to sustainability, but were also thought to be adequately covered on the courses in all three institutions. 展开更多
关键词 Sustainable construction EDUCATION SUSTAINABILITY civil engineering VIETNAM UK.
下载PDF
Quadrature formulas for Fourier-Chebyshev coefficients
8
作者 杨士俊 《Journal of Zhejiang University Science》 CSCD 2002年第3期326-331,共6页
The aim of this work is to construct a new quadrature formula for Fourier Chebyshev coef ficients based on the divided differences of the integrand at points 1, 1 and the zeros of the n th Chebyshev polynomial o... The aim of this work is to construct a new quadrature formula for Fourier Chebyshev coef ficients based on the divided differences of the integrand at points 1, 1 and the zeros of the n th Chebyshev polynomial of the second kind. The interesting thing is that this quadrature rule is closely related to the well known Gauss Turn quadrature formula and similar to a recent result of Micchelli and Sharma, extending a particular case due to Micchelli and Rivlin. 展开更多
关键词 Divided differences QUADRATURE Chebyshev polynomials Fourier Chebyshev coefficient
下载PDF
Variable Separation Approach to Solve (2 + 1)-Dimensional Generalized Burgers System: Solitary Wave and Jacobi Periodic Wave Excitations
9
作者 ZHENGChun-Long 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期391-396,共6页
By means of the standard truncated Painlevé expansion and a variable separation approach, a general variable separation solution of the generalized Burgers system is derived. In addition to the usual localized co... By means of the standard truncated Painlevé expansion and a variable separation approach, a general variable separation solution of the generalized Burgers system is derived. In addition to the usual localized coherent soliton excitations like dromions, lumps, rings, breathers, instantons, oscillating soliton excitations, peakons, foldons, and previously revealed chaotic and fractal localized solutions, some new types of excitations — compacton and Jacobi periodic wave solutions are obtained by introducing appropriate lower dimensional piecewise smooth functions and Jacobi elliptic functions. 展开更多
关键词 generalized Burgers system variable separation approach solitary wave Jacobi periodic wave
下载PDF
A fast acquisition method of DSSS signals using differential decoding and fast Fourier transform 被引量:2
10
作者 杨伟君 张朝杰 +2 位作者 金小军 金仲和 徐兆斌 《Journal of Central South University》 SCIE EI CAS 2013年第5期1285-1291,共7页
In low earth orbit (LEO) satellite or missile communication scenarios, signals may experience extremely large Doppler shifts and have short visual time. Thus, direct sequence spread spectrum (DSSS) systems should be a... In low earth orbit (LEO) satellite or missile communication scenarios, signals may experience extremely large Doppler shifts and have short visual time. Thus, direct sequence spread spectrum (DSSS) systems should be able to achieve acquisition in a very short time in spite of large Doppler frequencies. However, the traditional methods cannot solve it well. This work describes a new method that uses a differential decoding technique for Doppler mitigation and a batch process of FFT (fast Fourier transform) and IFFT (invert FFT) for the purpose of parallel code phase search by frequency domain correlation. After the code phase is estimated, another FFT process is carried out to search the Doppler frequency. Since both code phase and Doppler frequency domains are searched in parallel, this architecture can provide acquisition fifty times faster than conventional FFT methods. The performance in terms of the probability of detection and false alarm are also analyzed and simulated, showing that a signal-to-noise ratio (SNR) loss of 3 dB is introduced by the differential decoding. The proposed method is an efficient way to shorten the acquisition time with slightly hardware increasing. 展开更多
关键词 low earth orbit (LEO) satellite spread spectrum fast acquisition fast Fourier transform (FFT) Doppler mitigation
下载PDF
Simple Scheme for Realizing the General Conditional Phase Shift Gate and a Simulation of Quantum Fourier Transform in Circuit QED
11
作者 吴春旺 韩阳 +3 位作者 邓志姣 李虹轶 陈平形 李承祖 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第9期435-439,共5页
We propose a theoretical scheme for realizing the general conditional phase shift gate of charge qubits situated in a high-Q superconducting transmission line resonator. The phase shifting angle can be tuned from 0 to... We propose a theoretical scheme for realizing the general conditional phase shift gate of charge qubits situated in a high-Q superconducting transmission line resonator. The phase shifting angle can be tuned from 0 to 27r by simply adjusting the qubit-resonator detuning and the interaction time. Based on this gate proposal, we give a detailed procedure to implement the three-qubit quantum Fourier transform with circuit quantum eleetrodynamics (QED). A careful analysis of the decoherence sources shows that the algorithm can be achieved with a high fidelity using current circuit QED techniques. 展开更多
关键词 circuit QED conditional phase shift gate quantum Fourier transform
下载PDF
A novel Haar wavelet-based precoded BPSK-OFDM system with reduced PAPR
12
作者 黄新林 Wang Gang +1 位作者 Liao Quanrui Sun Qingquan 《High Technology Letters》 EI CAS 2011年第1期25-31,共7页
The performance of OFDM systems may be degraded when intersymbol interference (ISI) channels have spectral nulls. Recently, the precoded OFDM was proposed to combat this problem. However, due to inserting (M- K) z... The performance of OFDM systems may be degraded when intersymbol interference (ISI) channels have spectral nulls. Recently, the precoded OFDM was proposed to combat this problem. However, due to inserting (M- K) zeros between each two sets of K consecutive information symbols, the average transmitting power of the precoded OFDM system reduces by 10log10(M/K) dB compared with the conventional OFDM system. Under the same points inverse fast Fourier transformation (IFFF), the precoded OFDM system has a higher peak-to-average power ratio (PAPR) compared with the conventional OFDM system. This paper proposes a novel precoded BPSK-OFDM system based on Haar wavelet transformation. The Haar wavelet transformation operating decomposition over the vector information symbols produced by a precoder shows that half of the information symbols are zeros and the rest are either √2- or √2. Then, we have the peak power and PAPR reduced by 10log1002=3dB at most compared with the precoded OFDM system. Finally, we compare PAPR of the proposed OFDM system with the precoded OFDM and the conventional OFDM system. 展开更多
关键词 peak-to-average power ratio (PAPR) Haar wavelet BPSK precoded OFDM.
下载PDF
On the Ratio Between 2-Domination and Total Outer-Independent Domination Numbers of Trees
13
作者 Marcin KRZYWKOWSKI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第5期765-776,共12页
A 2-dominating set of a graph G is a set D of vertices of G such that every vertex of V(G)\D has at least two neighbors in D.A total outer-independent dominating set of a graph G is a set D of vertices of G such that ... A 2-dominating set of a graph G is a set D of vertices of G such that every vertex of V(G)\D has at least two neighbors in D.A total outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of G has a neighbor in D,and the set V(G)\D is independent.The 2-domination(total outer-independent domination,respectively)number of a graph G is the minimum cardinality of a 2-dominating(total outer-independent dominating,respectively)set of G.We investigate the ratio between2-domination and total outer-independent domination numbers of trees. 展开更多
关键词 2-Domination Total domination Total outer-independent domination Tree
原文传递
Promoting Reform of Chinese Forest Sector Legislation:Some observations from Analysis and Comparison of a Sample of Forest Laws
14
作者 MANN Stefan 《Chinese Forestry Science and Technology》 2006年第4期46-62,共17页
The paper introduces and outlines the outcome of the analysis and comparison of a sample of forest sector laws from 12 countries. The selection of both the key-topics for the analysis, and the sample of laws was done ... The paper introduces and outlines the outcome of the analysis and comparison of a sample of forest sector laws from 12 countries. The selection of both the key-topics for the analysis, and the sample of laws was done in response to concrete requests by the State Forestry Administration of the P.R. China. The analysis, prepared over a period of five months, produced country case-studies and a final report, and concluded with a workshop hosted by the Chinese Academy of Forestry in late November 2006. The findings consistently indicate that forest sector laws, of necessity, closely reflect a given country’s historical development, socio-political reality, and governance system. Consequently, there exists no blue-print for, or “model-approach” to forest sector legislation. In reviewing the effective Chinese forest sector laws, examples from third countries should be considered only with due caution, in respect of clear-cut & consistent Chinese forest policy objectives, and only after careful consideration of their applicability and transferability in the Chinese political as well as social context. The comparison of a sample of forest sector laws nevertheless enables the identification of several basic approaches to promoting sustainable forest management by public as well as non-public stakeholders, as well as a number of reform trends (particularly in regard to the restructuring of public sector administrations). On this basis, generalised conclusions are drawn and recommendations made for the forthcoming review of Chinese forest sector laws. 展开更多
关键词 forest sector laws comparative analysis legal review sustainable forest sector development
原文传递
Dynamical separation of rigid bodies in supersonic flow 被引量:1
15
作者 LI Tao SUI JingXia +1 位作者 GONG Sheng WU ChuiJie 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第12期2110-2121,共12页
A computational investigation of the unsteady separation behavior of rigid bodies in Mach-4 flow is carried out. Two rigid bodies, a sphere and a cube, initially stationary, centroid axially aligned, are released and ... A computational investigation of the unsteady separation behavior of rigid bodies in Mach-4 flow is carried out. Two rigid bodies, a sphere and a cube, initially stationary, centroid axially aligned, are released and thereafter fly freely according to the aerodynamic forces experienced. During the separation process, the smaller cube can experience different types of movement and our principal interest here is the non-dimensional transverse velocity of it. The separation behavior is investigated for interactions between a sphere and a cube with different mass ratio and a constant initial distance between them. The qualitative separation behavior and the final transverse velocity of the small body are found to vary strongly with the mass ratio but less sensitive to the initial distance between the two bodies. At a critical mass ratio for a given distance, the smaller body transit from entrainment within the flow region bounded by the larger body's shock to expulsion and the accumulated transverse velocity of the small body is close to maximum. This phenomenon is the so-called ‘shock-wave surfing' phenomenon noted by Laurence & Deiterding for two spheres at hypersonic Mach numbers. Then we investigate the separation behavior of a sphere interaction with a rotary cube and with a non-rotary cube for a given mass ratio and different distance between them. The rotary is found to increase the likelihood of ‘surfing'. Only at a certain initial distance for a given mass ratio the rotary effect of cube can be neglectable. 展开更多
关键词 separation behavior flow-structure interactions shock waves
原文传递
Near-equiatomic high-entropy decagonal quasicrystal in Al20Si20Mn20Fe20Ga20
16
作者 Haikun Ma Liangqun Zhao +8 位作者 Zhi-Yi Hu Dinghao Miao Ruixuan Li Tulai Sun He Tian Tiantian Zhang Hua Li Yong Zhang Zhanbing He 《Science China Materials》 SCIE EI CSCD 2021年第2期440-447,共8页
High-entropy alloys(HEAs)contain multiple principal alloying elements,but usually with simple crystal structures.Quasicrystals are structurally complex phases,but are generally dominated by only one element.However,ne... High-entropy alloys(HEAs)contain multiple principal alloying elements,but usually with simple crystal structures.Quasicrystals are structurally complex phases,but are generally dominated by only one element.However,nearequiatomic high-entropy quasicrystals have rarely been reported because they are difficult to prepare experimentally and predict theoretically.Therefore,the preparation and crystal structures of near-equiatomic high-entropy quasicrystals have drawn much interest.We report a quinary decagonal quasicrystal(DQC)with near-equiatomic alloying elements in Al20Si20Mn20Fe20Ga20 melt-spun ribbons,which is the first to our knowledge.Meanwhile,the structural features of the DQC are characterized in detail.The configurational entropy of both the alloy and DQC satisfies the entropy-based criterion for HEAs,suggesting a high-entropy DQC.Our findings provide a new strategy to develop high-entropy quasicrystals. 展开更多
关键词 high-entropy alloys decagonal quasicrystal high-entropy quasicrystals melt-spun ribbons high-angle annular dark-field scanning transmission electron microscopy
原文传递
Qubit Systems from Colored Toric Geometry and Hypercube Graph Theory 被引量:1
17
作者 Y.Aadel A.Belhaj +3 位作者 M.Bensed Z.Benslimane M.B.Sedra A.Segui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第9期285-289,共5页
We develop a new geometric approach to deal with qubit information systems using colored graph theory. More precisely, we present a one to one correspondence between graph theory, and qubit systems, which may be explo... We develop a new geometric approach to deal with qubit information systems using colored graph theory. More precisely, we present a one to one correspondence between graph theory, and qubit systems, which may be explored to attack qubit information problems using torie geometry considered as a powerful tool to understand modern physics including string theory. Concretely, we examine in some details the cases of one, two, and three qubits, and we find that they are associated with CP1, CP1×CP1 and CP1×CP1× CP1 toric varieties respectively. Using a geometric procedure referred to as a colored toric geometry, we show that the qubit physics can be converted into a scenario handling toric data of such manifolds by help of hypercube graph theory. Operations on toric information can produce universal quantum gates. 展开更多
关键词 toric geometry information theory and graph theory
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部