While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drasti...While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract)展开更多
5G technology can greatly improve spectral efficiency(SE)and throughput of wireless communications.In this regard,multiple inputmultiple output(MIMO)technology has become the most influential technology using huge ant...5G technology can greatly improve spectral efficiency(SE)and throughput of wireless communications.In this regard,multiple inputmultiple output(MIMO)technology has become the most influential technology using huge antennas and user equipment(UE).However,the use of MIMO in 5G wireless technology will increase circuit power consumption and reduce energy efficiency(EE).In this regard,this article proposes an optimal solution for weighing SE and throughput tradeoff with energy efficiency.The research work is based on theWyner model of uplink(UL)and downlink(DL)transmission under the multi-cell model scenario.The SE-EE trade-off is carried out by optimizing the choice of antenna and UEs,while the approximation method based on the logarithmic function is used for optimization.In this paper,we analyzed the combination of UL and DL power consumption models and precoding schemes for all actual circuit power consumption models to optimize the trade-off between EE and throughput.The simulation results show that the SE-EE trade-off has been significantly improved by developing UL and DL transmission models with the approximation method based on logarithmic functions.It is also recognized that the throughput-EE trade-off can be improved by knowing the total actual power consumed by the entire network.展开更多
New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, ...New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, and biological activity. The analytical data showed that the Schiff base ligand acts as bidentate towards metal ions via the azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of M:L (1:2) to form metal complexes. NMR (1H, 13C and 119Sn) spectral data of the ligands and metal complex agree with proposed structures. The conductivity values between 14 - 27 ohm-1cm2mol-1 in DMF imply the presence of non-electrolyte species. 3D molecular modeling and analysis of bond lengths and bond angles have also been conducted for a representative compound, [Bu2Sn(L2)2], to substantiate the proposed structures. Antibacterial results indicate that the metal complexes are more active than the free ligands.展开更多
Many metal complexes of Schiff base derived from different amino acids are widely employed as biologically active materials, especially as antibacterial agents. Three new metal [Co(III), Mn(II) and La(III)] complexes ...Many metal complexes of Schiff base derived from different amino acids are widely employed as biologically active materials, especially as antibacterial agents. Three new metal [Co(III), Mn(II) and La(III)] complexes with the Schiff base (L) derived from salicylaldehyde and amino acid (methionine) were synthesized and investigated by using various physico-chemical techniques such as elemental analysis, FTIR, UV-visible spectroscopy, magnetic measurement, thermo gravimetric analysis (TGA) and X-ray powder diffraction (XRD) method. From spectral studies, it has been concluded that the synthesized ligand acts as a tetra-dentate molecule, coordinates metal through azomethine nitrogen, sulfur, phenolic oxygen and carboxylate oxygen. UV-visible spectrophotometry showed the characteristic absorption bands corresponding to a square planar geometry for La(III) and Mn(II) metal complexes and tetrahedral geometry for Co(III) complex. The XRD data demonstrated that the manganese and cobalt complexes were crystalline but the lanthanum complex was amorphous in nature. The empirical formula of the synthesized complexes based on analytical data were [Co(C12H13SNO3)]·(NO3), [La(C12H13SNO3)](Cl)(H2O) and [Mn (C12H13SNO3)].展开更多
In the present paper, we discuss some properties of piecewise linear spectral sequences introduced by Liu and Xu. We have a study on the pointwise and almost everywhere convergence of its corresponding series. Also, i...In the present paper, we discuss some properties of piecewise linear spectral sequences introduced by Liu and Xu. We have a study on the pointwise and almost everywhere convergence of its corresponding series. Also, it is shown that the set G constructed from piecewise linear spectral sequences are bases, but not unconditional bases, for LP（0, 1） where 1 〈 p 〈 ∞, p ≠2.展开更多
The coordination compounds of PdII, PtII, RhIII and IrIII metal ions with a Schiff base ligand (L) i.e. 2,6- diacetylpyridine bis(thiosemicarbazone) have been synthesized and characterized by elemental analyses, molar...The coordination compounds of PdII, PtII, RhIII and IrIII metal ions with a Schiff base ligand (L) i.e. 2,6- diacetylpyridine bis(thiosemicarbazone) have been synthesized and characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, NMR and electronic spectral studies. On the basis of molar conductance and elemental analyses the complexes were found to have composition [M(L)]Cl2 and [M’(L)Cl]Cl2, where M = Pd(II), Pt(II) and M’ = Rh(III), Ir(III). The spectral studies reveal that the complexes possess monomeric composition. Complexes of PdII and PtII were found to have four coordinated square planar geometry whereas the complexes of RhIII and IrIII posses six coordinated octahedral geometry. The ligand field parameters were calculated using various energy level diagrams. In vitro synthesized compounds and metal salts have been tested against some species of plant pathogenic fungi and bacteria in order to assess their antimicrobial properties.展开更多
探讨宝石能谱CT在鉴别诊断黏液性囊性肿瘤（mucinous cystic neoplasm,MCN）与浆液性囊腺瘤（serous cystadenoma,SCA）中的应用价值。方法回顾性分析2014年7月-2015年7月经手术病理证实的32例胰腺囊腺肿瘤临床资料,均给予宝石能谱CT检...探讨宝石能谱CT在鉴别诊断黏液性囊性肿瘤（mucinous cystic neoplasm,MCN）与浆液性囊腺瘤（serous cystadenoma,SCA）中的应用价值。方法回顾性分析2014年7月-2015年7月经手术病理证实的32例胰腺囊腺肿瘤临床资料,均给予宝石能谱CT检查,比较MCN与SCA的临床特征、不同能量水平CT值、不同扫描期下配对基物质浓度、宝石能谱CT检测与术后病理符合率。结果临床特征：MCN年龄、病灶直径、有症状例数明显高于SCA（t=6.472~8.284,P〈0.05）;不同能量水平CT值：MCN动脉期40 ke V、50 ke V、60 ke V、70 ke V时,门静脉期40 ke V、50 ke V、60 ke V时,CT值均明显高于SCA（t=2.093~6.785,P〈0.05）;配对基物质浓度：MCN动脉期钙（水）、水（钙）、碘（水）、水（碘）浓度均明显高于SCA,门静脉期钙（水）、碘（水）浓度均明显高于SCA（t=2.071~7.124,P〈0.05）;术后病理检测符合率：宝石能谱CT检出黏液性12例,检出浆液性20例,与术后病理检出相符30例,符合率93.75%（30/32）。结论胰腺MCN与SCA宝石能谱CT有明显的不同特征,通过对不同能量CT值、不同期相配对基物质浓度的比较,结合临床特征,有助于提高MCN与SCA诊断准确率。展开更多
基金supported by the key project of the National Natural Science Foundation of China(No.61431001)the 863 project No.2014AA01A701+4 种基金Program for New Century Excellent Talents in University(NECT12-0774)the open research fund of National Mobile Communications Research Laboratory Southeast University(No.2013D12)Fundamental Research Funds for the Central Universities(FRF-BD-15-012A)the Research Foundation of China Mobilethe Foundation of Beijing Engineering and Technology Center for Convergence Networks and Ubiquitous Services
文摘While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract)
文摘5G technology can greatly improve spectral efficiency(SE)and throughput of wireless communications.In this regard,multiple inputmultiple output(MIMO)technology has become the most influential technology using huge antennas and user equipment(UE).However,the use of MIMO in 5G wireless technology will increase circuit power consumption and reduce energy efficiency(EE).In this regard,this article proposes an optimal solution for weighing SE and throughput tradeoff with energy efficiency.The research work is based on theWyner model of uplink(UL)and downlink(DL)transmission under the multi-cell model scenario.The SE-EE trade-off is carried out by optimizing the choice of antenna and UEs,while the approximation method based on the logarithmic function is used for optimization.In this paper,we analyzed the combination of UL and DL power consumption models and precoding schemes for all actual circuit power consumption models to optimize the trade-off between EE and throughput.The simulation results show that the SE-EE trade-off has been significantly improved by developing UL and DL transmission models with the approximation method based on logarithmic functions.It is also recognized that the throughput-EE trade-off can be improved by knowing the total actual power consumed by the entire network.
文摘New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, and biological activity. The analytical data showed that the Schiff base ligand acts as bidentate towards metal ions via the azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of M:L (1:2) to form metal complexes. NMR (1H, 13C and 119Sn) spectral data of the ligands and metal complex agree with proposed structures. The conductivity values between 14 - 27 ohm-1cm2mol-1 in DMF imply the presence of non-electrolyte species. 3D molecular modeling and analysis of bond lengths and bond angles have also been conducted for a representative compound, [Bu2Sn(L2)2], to substantiate the proposed structures. Antibacterial results indicate that the metal complexes are more active than the free ligands.
文摘Many metal complexes of Schiff base derived from different amino acids are widely employed as biologically active materials, especially as antibacterial agents. Three new metal [Co(III), Mn(II) and La(III)] complexes with the Schiff base (L) derived from salicylaldehyde and amino acid (methionine) were synthesized and investigated by using various physico-chemical techniques such as elemental analysis, FTIR, UV-visible spectroscopy, magnetic measurement, thermo gravimetric analysis (TGA) and X-ray powder diffraction (XRD) method. From spectral studies, it has been concluded that the synthesized ligand acts as a tetra-dentate molecule, coordinates metal through azomethine nitrogen, sulfur, phenolic oxygen and carboxylate oxygen. UV-visible spectrophotometry showed the characteristic absorption bands corresponding to a square planar geometry for La(III) and Mn(II) metal complexes and tetrahedral geometry for Co(III) complex. The XRD data demonstrated that the manganese and cobalt complexes were crystalline but the lanthanum complex was amorphous in nature. The empirical formula of the synthesized complexes based on analytical data were [Co(C12H13SNO3)]·(NO3), [La(C12H13SNO3)](Cl)(H2O) and [Mn (C12H13SNO3)].
基金Supported by Prof.Y.Xu under his grant in program of"One Hundred Distingulshed Chi-nese Scientists"of the Chinese Academy of Sciences,the NNSF(10371122)of China and Poetgraduate Innovation Fund of Chinese Academy of Sciences.
文摘In the present paper, we discuss some properties of piecewise linear spectral sequences introduced by Liu and Xu. We have a study on the pointwise and almost everywhere convergence of its corresponding series. Also, it is shown that the set G constructed from piecewise linear spectral sequences are bases, but not unconditional bases, for LP（0, 1） where 1 〈 p 〈 ∞, p ≠2.
文摘The coordination compounds of PdII, PtII, RhIII and IrIII metal ions with a Schiff base ligand (L) i.e. 2,6- diacetylpyridine bis(thiosemicarbazone) have been synthesized and characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, NMR and electronic spectral studies. On the basis of molar conductance and elemental analyses the complexes were found to have composition [M(L)]Cl2 and [M’(L)Cl]Cl2, where M = Pd(II), Pt(II) and M’ = Rh(III), Ir(III). The spectral studies reveal that the complexes possess monomeric composition. Complexes of PdII and PtII were found to have four coordinated square planar geometry whereas the complexes of RhIII and IrIII posses six coordinated octahedral geometry. The ligand field parameters were calculated using various energy level diagrams. In vitro synthesized compounds and metal salts have been tested against some species of plant pathogenic fungi and bacteria in order to assess their antimicrobial properties.
文摘探讨宝石能谱CT在鉴别诊断黏液性囊性肿瘤（mucinous cystic neoplasm,MCN）与浆液性囊腺瘤（serous cystadenoma,SCA）中的应用价值。方法回顾性分析2014年7月-2015年7月经手术病理证实的32例胰腺囊腺肿瘤临床资料,均给予宝石能谱CT检查,比较MCN与SCA的临床特征、不同能量水平CT值、不同扫描期下配对基物质浓度、宝石能谱CT检测与术后病理符合率。结果临床特征：MCN年龄、病灶直径、有症状例数明显高于SCA（t=6.472~8.284,P〈0.05）;不同能量水平CT值：MCN动脉期40 ke V、50 ke V、60 ke V、70 ke V时,门静脉期40 ke V、50 ke V、60 ke V时,CT值均明显高于SCA（t=2.093~6.785,P〈0.05）;配对基物质浓度：MCN动脉期钙（水）、水（钙）、碘（水）、水（碘）浓度均明显高于SCA,门静脉期钙（水）、碘（水）浓度均明显高于SCA（t=2.071~7.124,P〈0.05）;术后病理检测符合率：宝石能谱CT检出黏液性12例,检出浆液性20例,与术后病理检出相符30例,符合率93.75%（30/32）。结论胰腺MCN与SCA宝石能谱CT有明显的不同特征,通过对不同能量CT值、不同期相配对基物质浓度的比较,结合临床特征,有助于提高MCN与SCA诊断准确率。
