The donor-acceptor hydrogen bonding strategy has been proposed to enforce coplanar packing of anisotropic π-conjugated units, thereby maximizing the material's achievable birefringence. Herein, employing this str...The donor-acceptor hydrogen bonding strategy has been proposed to enforce coplanar packing of anisotropic π-conjugated units, thereby maximizing the material's achievable birefringence. Herein, employing this strategy, we successfully obtain two highly coplanar birefringent crystals, FAHC_(2)O_(4) and FAH_(2)C_(3)N_(3)S_(3) (FA+: CH5N2, for-mamidinium). FAHC_(2)O_(4) shows a wide bandgap (4.20 eV), while FAH_(2)C_(3)N_(3)S_(3) exhibits a narrower bandgap (2.96 eV) due to the involvement of sulfur atom. Both crystals display notable birefringence in their respective material classes: 0.275@546 nm and 0.504@546 nm, respectively. X-ray crystallography and computational studies attribute the pronounced birefringence to their π-conjugated moieties and their near-coplanar configu-rations. Comparative analysis of FAHC_(2)O_(4) and FAH_(2)C_(3)N_(3)S_(3) further establishes that the hydrogen bond strength directly influences the molecular coplanarity degree. These findings provide new insights for applying the donor-acceptor hydrogen bonding strategy in the rational design of high-performance birefringent materials.展开更多
During the excavation of large-scale rock slopes and deep hard rock engineering,the induced rapid unloading serves as the primary cause of rock mass deformation and failure.The essence of this phenomenon lies in the o...During the excavation of large-scale rock slopes and deep hard rock engineering,the induced rapid unloading serves as the primary cause of rock mass deformation and failure.The essence of this phenomenon lies in the opening-shear failure process triggered by the normal stress unloading of fractured rock mass.In this study,we focus on local-scale rock fracture and conduct direct shear tests under different normal stress unloading rates on five types of non-persistent fractured hard rocks.The aim is to analyze the influence of normal stress unloading rates on the failure modes and shear mechanical characteristics of non-persistent fractured rocks.The results indicate that the normal unloading displacement decreases gradually with increasing normal stress unloading rate,while the influence of normal stress unloading rate on shear displacement is not significant.As the normal stress unloading rate increases,the rocks brittle failure process accelerates,and the degree of rocks damage decreases.Analysis of the stress state on rock fracture surfaces reveals that increasing the normal stress unloading rate enhances the compressive stress on rocks,leading to a transition in the failure mode from shear failure to tensile failure.A negative exponential strength formula was proposed,which effectively fits the relationship between failure normal stress and normal stress unloading rate.The findings enrich the theoretical foundation of unloading rock mechanics and provide theoretical support for disasters prevention and control in rock engineering excavations.展开更多
Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resi...Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resistivity silicon （HRS） substrate. The results show that the microwave loss of a CPW on LRS is too high to be used, but it can be greatly reduced by adding a thick interlayer of silicon oxide between the CPW transmission lines and the LRS.A CPW directly on HRS shows a loss lower than 2dB/cm in the range of 0-26GHz and the process is simple,so HRS is a more suitable CPW substrate.展开更多
Purpose: To compare the dosimetric impact of coplanar intensity modulated radiation therapy (IMRT) and non-coplanar IMRT for the esophageal carcinoma. Methods: There are forty-five esophageal carcinoma patients, fifte...Purpose: To compare the dosimetric impact of coplanar intensity modulated radiation therapy (IMRT) and non-coplanar IMRT for the esophageal carcinoma. Methods: There are forty-five esophageal carcinoma patients, fifteen of whom were cervical and upper thoracic (Group 1) and thirty were middle and lower thoracic (Group 2). Gross tumor volume (GTV), clinical target volume (CTV), and organs at risk (OAR) were contoured by the chief physician in the CMS-XiO treatment planning system. For each patient, one coplanar plan and two non-coplanar plans have been created using the same physical objective function. A detailed dose-volume histogram (DVH) comparison among three plans was then carried out in a tabulated format. Results: 1) In Group 1 patients with PTV volume less than 100cc, the mean dose and dose gradient of non-coplanar plan were much better than those in coplanar plan. 2) In Group 2 patients, the conformity index (CI) for coplanar and two non-coplanar plans were 0.69 ± 0.13, 0.41 ± 0.13, and 0.68 ± 0.15, respectively. The V5, V10, V20, and the mean dose to the lung were lower in the non-coplanar plans compared to ones in coplanar plan. However, the non-coplanar plans resulted in an increase in a dose to the heart, but the dose was still within heart toxicity tolerance. Conclusion: For Group 1 patients, the non-coplanar IMRT plan had less dose gradient and better mean dose than the coplanar IMRT plan. For Group 2 patients, the non-coplanar IMRT could the decrease dose to the lung tissue, thus lowering the probability of radiation pneumonia to esophageal cancer patients. The drawback of non-coplanar IMRT is that, even within toxicity tolerance, it could deliver a higher dose to the heart and spinal cord compared to the coplanar plan. Therefore, for patients with cardiology and neurology concern, non-coplanar IMRT should be used with caution.展开更多
Fluctuated loadings from currents,waves and sea ground motions are observed on offshore steel pipelines,and they will result in small cracks to propagate continuously and cause unexpected damage to offshore/geotechnic...Fluctuated loadings from currents,waves and sea ground motions are observed on offshore steel pipelines,and they will result in small cracks to propagate continuously and cause unexpected damage to offshore/geotechnical infrastructures.In spite of the availability of efficient techniques and high-power computers for solving crack problems,investigations on the fatigue life of offshore pipelines with 3D interacting cracks are still rarely found in open literature.In the current study,systematic numerical investigations are performed on fatigue crack growth behaviours of offshore pipelines containing coplanar and non-coplanar cracks.Extended finite element method(XFEM)is adopted to simulate the fatigue crack growth.The qualitative validations of numerical results are made for certain cases with available experimental results.Parametric studies are conducted to investigate the influences of various important parameters on fatigue crack growth.The results will be helpful to assess the fatigue behaviours of steel pipeline with 3D interacting cracks.展开更多
In order to broaden the bandwidth of a tapered slot- line antenna （TSA）, a bilateral tapered slot-line antenna （BTSA） with a new feeding structure of coplanar waveguide （CPW） is developed. Based on the fact that...In order to broaden the bandwidth of a tapered slot- line antenna （TSA）, a bilateral tapered slot-line antenna （BTSA） with a new feeding structure of coplanar waveguide （CPW） is developed. Based on the fact that the bandwidth limitation of TSA mainly depends on its feeding structure, an improved CPW-based feed structure etched on the backboard of the BTSA is adopted to perform traveling-wave transition. Both the simulation results and measurement data verify that the proposed feeding structure results in ＂high-pass＂ frequency response for antenna impedance matching. The voltage standing wave ratio （VSWR） is less than 2：1 when the frequency is higher than 3 GHz. The antenna gain exceeds 7 dBi with good radiation patterns when the bandwidth is from 4 to 16 GHz. This ultra wideband （UWB） antenna with a compact size is specially available for the electronic systems of counter-measure and microwave imaging.展开更多
The transient response of two coplanar cracks in a piezoelectric ceramic under antiplane mechanical and inplane electric impacting loads is investigated in the present paper. Laplace and Fourier transforms are used to...The transient response of two coplanar cracks in a piezoelectric ceramic under antiplane mechanical and inplane electric impacting loads is investigated in the present paper. Laplace and Fourier transforms are used to reduce the mixed boundary value problems to Cauchy-type singular integral equations in Laplace transform domain, which are solved numerically. The dynamic stress and electric displacement factors are obtained as the functions of time and geometry parameters. The present study shows that the presence of the dynamic electric field will impede or enhance the propagation of the crack in piezoelectric ceramics at different stages of the dynamic electromechanical load. Moreover, the electromechanical response is greatly affected by the ratio of the space of the cracks and the crack length.展开更多
We discuss the characterization and modeling of coplanar waveguides （CPW） realized in TSMC 0. 13μm CMOS process. EM-field simulations with momentum are performed to estimate the important parameters of the transmis...We discuss the characterization and modeling of coplanar waveguides （CPW） realized in TSMC 0. 13μm CMOS process. EM-field simulations with momentum are performed to estimate the important parameters of the transmission lines, such as characteristic impedance and propagation loss. Coplanar waveguide libraries are designed with Z values of 30,50,70, and 100Ω. Finally, the propagation constant and the characteristic impedance are measured in a frequency range from 0. 1 to 40GHz with a vector-network analyzer,using the short-open-loadthru （SOLT） de-embedding technique. The distributed parameters of the CPWs are extracted from the measured S-parameters.展开更多
In this paper, the authors present an analytical model for coplanar waveguide on silicon-on-insulator substrate. The four-element topological network and the conformal mapping technique are used to analyse the capacit...In this paper, the authors present an analytical model for coplanar waveguide on silicon-on-insulator substrate. The four-element topological network and the conformal mapping technique are used to analyse the capacitance and the conductance of the sandwich substrate. The validity of the model is verified by the full-wave method and the experimental data. It is found that the inductance, the resistance, the capacitance and the conductance from the analytical model show they are in good agreement with the corresponding values extracted from experimental Sparameter until 10 GHz.展开更多
The skin effect is an electromagnetic phenomenon that makes the current flows only on the surface of the conductors at high frequency. This article is based on the phenomenon to model a structure made in coplanar tech...The skin effect is an electromagnetic phenomenon that makes the current flows only on the surface of the conductors at high frequency. This article is based on the phenomenon to model a structure made in coplanar technology. In reality, these types of structures integrated metal layers of different thickness of copper (9 μm, 18 μm, 35 μm, 70 μm). The neglect of this parameter introduces errors, sometimes significant, in the numerical calculations. This is why an iterative method (FWCIP) based on the wave concept was restated. Validation of results was carried out by comparison with those calculated by Ansoft HFSS software and Agilent ADS Technology. They show a good matching.展开更多
We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Th...We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Then, the smoothly blending of two cylinders whose axes are non-coplanar is realized by taking intersecting line of conical surface as axes.展开更多
YBa2Cu3O7（YBCO） thin films have been prepared by thermal coevaporation on LaAlO3（LAO） substrates, and Tl2Ba2CaCu2O8（TBCCO） thin films are synthesized by magnetron sputtering method on LAO substrates. The transit...YBa2Cu3O7（YBCO） thin films have been prepared by thermal coevaporation on LaAlO3（LAO） substrates, and Tl2Ba2CaCu2O8（TBCCO） thin films are synthesized by magnetron sputtering method on LAO substrates. The transition temperature Tc is 90 K forYBCO/LAO and 104 K for TBCCO/LAO. Microwave responses of the films are studied systematically by coplanar resonator technique. Energy gaps of the films obtained are △0 = 1.04kBTc for YBCO films and △0 =0.84kBTc for TBCCO films by analysing the temperature dependence of resonant frequencies of coplanar resonator. Penetration depth at 0 K A0 = 198.nm for YBCO films and A0 = 200 nm for TBCCO films could also be obtained by using the weak coupling theory and two fluid theory. Results of penetration depth and energy gap confirm the weak coupling properties of the films. In addition, microwave surface resistances Rs of YBCO/LAO and TBCCO/LAO are also investigated by analysing the quality factor and insert loss of the coplanar resonator. Surface resistance of TBCCO/LAO is less than that of YBCO/LAO, so that TBCCO/LAO films may have more potential applications.展开更多
A tunable superconducting half-wavelength coplanar waveguide resonator （CPWR） with Nb parallel nanowires - 300 nm in width embedded in the center conductor was designed, fabricated, and measured. The frequency shift...A tunable superconducting half-wavelength coplanar waveguide resonator （CPWR） with Nb parallel nanowires - 300 nm in width embedded in the center conductor was designed, fabricated, and measured. The frequency shift and the amplitude attenuation of the resonance peak under irradiation of 404-nm pulse laser were observed with different light powers at 4.2 K. The RF power supplied to such a CPWR can serve as current bias, which will affect the light response of the resonator.展开更多
In this paper we propose a two-pole varactor-tuned superconducting filter using coplanar waveguide （CPW） spiralin-spiral-out （SISO） resonators. Novel internal and external coupling structures are introduced to mee...In this paper we propose a two-pole varactor-tuned superconducting filter using coplanar waveguide （CPW） spiralin-spiral-out （SISO） resonators. Novel internal and external coupling structures are introduced to meet the requirements for a tunable filter with a constant absolute bandwidth. The fabricated device has a frequency tuning range of 14.4% at frequencies ranging from 274.1 MHz to 317.7 MHz, a 3-dB bandwidth of 5.14±0.06 MHz, and an insertion loss of 0.08 dB-0.70 dB. The simulated and measured results are in excellent agreement with each other.展开更多
This paper proposes an antenna design concept to achieve a multi-reconfigurable band-notch antenna by using a set of microswitches. The proposed idea was proved by the design of the coplanar waveguide(CPW)-fed slot an...This paper proposes an antenna design concept to achieve a multi-reconfigurable band-notch antenna by using a set of microswitches. The proposed idea was proved by the design of the coplanar waveguide(CPW)-fed slot antenna. The sample design gives a wideband antenna the impedance bandwidth of which covers the frequency ranged from 1.9 GHz to 6.55 GHz.The antenna could be configured to work either in single-band mode or in one of the defined dual-band modes.展开更多
The （e, 2e） triple-differential cross sections of Ag＋ （4p, 4s） are calculated based on the three-body distorted-wave Born approximation considering post-collision interaction in coplanar symmetric geometry. The e...The （e, 2e） triple-differential cross sections of Ag＋ （4p, 4s） are calculated based on the three-body distorted-wave Born approximation considering post-collision interaction in coplanar symmetric geometry. The energy of the outgoing electron is set to be 50, 70, 100, 200, 300,500, 700, and 1000 eV, and the intensity and splitting of forward and backward peaks are discussed in detail. Some new structures are observed around 15° and 85° for 4p and 4s orbitals. Structures in triple-differential cross sections at 15° are reported for the first time. A double-binary collision is proposed to explain the formation of such structures. The structures at 85° are also considered as the result of one kind of double-binary collision.展开更多
A coplanar dicage pentaprismane molecule C16H12 has been studied by using DFT at B3LYP/D95* level and ab initio method at MP2/D95* level, and the vibrational frequencies of the molecule have been calculated at B3LYP/D...A coplanar dicage pentaprismane molecule C16H12 has been studied by using DFT at B3LYP/D95* level and ab initio method at MP2/D95* level, and the vibrational frequencies of the molecule have been calculated at B3LYP/D95* level too. The results show that the molecule is thermodynamically stable. Some physico-chemical properties, such as geometry, simulated IR spectrum and heat of formation, have been reported.展开更多
Superconducting coplanar waveguide（CPW） can be widely used as two-dimensional（2 D） resonator, transmission line or feedline, providing an important component for superconducting quantum circuit which is a promisin...Superconducting coplanar waveguide（CPW） can be widely used as two-dimensional（2 D） resonator, transmission line or feedline, providing an important component for superconducting quantum circuit which is a promising candidate for quantum information processing. Due to the discontinuities and asymmetries in the ground planes, CPW usually exhibits the spurious resonance, which is a common source of decoherence in circuit quantum electrodynamics experiments. To mitigate the spurious resonance, we fabricated superconducting aluminum air-bridges on Nb CPW. The fabricated airbridges are approximately 3 m high and up to 120 m long. Compared with other methods, the fabrication procedures of our air-bridges are simpler, and the air-bridge can withstand strong ultrasound.展开更多
The dynamic response of multiple coplanar interface cracks between two dissimilar piezoelectric strips subjected to mechanical and electrical impacts is investigated.Solutions to two kinds of electric boundary conditi...The dynamic response of multiple coplanar interface cracks between two dissimilar piezoelectric strips subjected to mechanical and electrical impacts is investigated.Solutions to two kinds of electric boundary conditions on crack surfaces,i.e.electric impermeable and electric permeable,are obtained.Laplace and Fourier transforms and dislocation density functions are employed to reduce the mixed boundary value problem to Cauchy singular integral equations, which can be solved numerically.The effects of electrical load,geometry criterion of piezoelectric strips,relative location of cracks and material properties on the dynamic energy release rate are examined.展开更多
Polymorphism makes it possible to clarify the relationship between emission property and crystal structure.However,based on the exact molecular conformation in tetraphenylethene polymorphisms,it is still challenging t...Polymorphism makes it possible to clarify the relationship between emission property and crystal structure.However,based on the exact molecular conformation in tetraphenylethene polymorphisms,it is still challenging to evaluate the difference of intramolecular coplanarity without the support of calculation because of the complex combination of four different torsion angles between four peripheral benzenes and the central ethylene plane.Here,by using a di-formyl-functionalized tetraphenylethene derivative,two ideal polymorphisms with a consistent trend of the corresponding torsion angles have been obtained.For the first time,we explicitly demonstrated that intramolecular coplanarity is the underlying cause of the polymorphism-dependent emission of tetraphenylethene derivatives.展开更多
基金the National Natural Science Foundation of China(22193043).
文摘The donor-acceptor hydrogen bonding strategy has been proposed to enforce coplanar packing of anisotropic π-conjugated units, thereby maximizing the material's achievable birefringence. Herein, employing this strategy, we successfully obtain two highly coplanar birefringent crystals, FAHC_(2)O_(4) and FAH_(2)C_(3)N_(3)S_(3) (FA+: CH5N2, for-mamidinium). FAHC_(2)O_(4) shows a wide bandgap (4.20 eV), while FAH_(2)C_(3)N_(3)S_(3) exhibits a narrower bandgap (2.96 eV) due to the involvement of sulfur atom. Both crystals display notable birefringence in their respective material classes: 0.275@546 nm and 0.504@546 nm, respectively. X-ray crystallography and computational studies attribute the pronounced birefringence to their π-conjugated moieties and their near-coplanar configu-rations. Comparative analysis of FAHC_(2)O_(4) and FAH_(2)C_(3)N_(3)S_(3) further establishes that the hydrogen bond strength directly influences the molecular coplanarity degree. These findings provide new insights for applying the donor-acceptor hydrogen bonding strategy in the rational design of high-performance birefringent materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.42372326 and 42090054)supported by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(SKLGP2023Z015).
文摘During the excavation of large-scale rock slopes and deep hard rock engineering,the induced rapid unloading serves as the primary cause of rock mass deformation and failure.The essence of this phenomenon lies in the opening-shear failure process triggered by the normal stress unloading of fractured rock mass.In this study,we focus on local-scale rock fracture and conduct direct shear tests under different normal stress unloading rates on five types of non-persistent fractured hard rocks.The aim is to analyze the influence of normal stress unloading rates on the failure modes and shear mechanical characteristics of non-persistent fractured rocks.The results indicate that the normal unloading displacement decreases gradually with increasing normal stress unloading rate,while the influence of normal stress unloading rate on shear displacement is not significant.As the normal stress unloading rate increases,the rocks brittle failure process accelerates,and the degree of rocks damage decreases.Analysis of the stress state on rock fracture surfaces reveals that increasing the normal stress unloading rate enhances the compressive stress on rocks,leading to a transition in the failure mode from shear failure to tensile failure.A negative exponential strength formula was proposed,which effectively fits the relationship between failure normal stress and normal stress unloading rate.The findings enrich the theoretical foundation of unloading rock mechanics and provide theoretical support for disasters prevention and control in rock engineering excavations.
文摘Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resistivity silicon （HRS） substrate. The results show that the microwave loss of a CPW on LRS is too high to be used, but it can be greatly reduced by adding a thick interlayer of silicon oxide between the CPW transmission lines and the LRS.A CPW directly on HRS shows a loss lower than 2dB/cm in the range of 0-26GHz and the process is simple,so HRS is a more suitable CPW substrate.
文摘Purpose: To compare the dosimetric impact of coplanar intensity modulated radiation therapy (IMRT) and non-coplanar IMRT for the esophageal carcinoma. Methods: There are forty-five esophageal carcinoma patients, fifteen of whom were cervical and upper thoracic (Group 1) and thirty were middle and lower thoracic (Group 2). Gross tumor volume (GTV), clinical target volume (CTV), and organs at risk (OAR) were contoured by the chief physician in the CMS-XiO treatment planning system. For each patient, one coplanar plan and two non-coplanar plans have been created using the same physical objective function. A detailed dose-volume histogram (DVH) comparison among three plans was then carried out in a tabulated format. Results: 1) In Group 1 patients with PTV volume less than 100cc, the mean dose and dose gradient of non-coplanar plan were much better than those in coplanar plan. 2) In Group 2 patients, the conformity index (CI) for coplanar and two non-coplanar plans were 0.69 ± 0.13, 0.41 ± 0.13, and 0.68 ± 0.15, respectively. The V5, V10, V20, and the mean dose to the lung were lower in the non-coplanar plans compared to ones in coplanar plan. However, the non-coplanar plans resulted in an increase in a dose to the heart, but the dose was still within heart toxicity tolerance. Conclusion: For Group 1 patients, the non-coplanar IMRT plan had less dose gradient and better mean dose than the coplanar IMRT plan. For Group 2 patients, the non-coplanar IMRT could the decrease dose to the lung tissue, thus lowering the probability of radiation pneumonia to esophageal cancer patients. The drawback of non-coplanar IMRT is that, even within toxicity tolerance, it could deliver a higher dose to the heart and spinal cord compared to the coplanar plan. Therefore, for patients with cardiology and neurology concern, non-coplanar IMRT should be used with caution.
基金The authors would like to acknowledge the financial support for this project under Nanyang Technological University,Singapore’s Academic Research Fund(AcRF)Tier 1 Grant No.RG 168/16.
文摘Fluctuated loadings from currents,waves and sea ground motions are observed on offshore steel pipelines,and they will result in small cracks to propagate continuously and cause unexpected damage to offshore/geotechnical infrastructures.In spite of the availability of efficient techniques and high-power computers for solving crack problems,investigations on the fatigue life of offshore pipelines with 3D interacting cracks are still rarely found in open literature.In the current study,systematic numerical investigations are performed on fatigue crack growth behaviours of offshore pipelines containing coplanar and non-coplanar cracks.Extended finite element method(XFEM)is adopted to simulate the fatigue crack growth.The qualitative validations of numerical results are made for certain cases with available experimental results.Parametric studies are conducted to investigate the influences of various important parameters on fatigue crack growth.The results will be helpful to assess the fatigue behaviours of steel pipeline with 3D interacting cracks.
基金The National High Technology Research and Development Program of China(863 Program)(No.2007AA01Z264)
文摘In order to broaden the bandwidth of a tapered slot- line antenna （TSA）, a bilateral tapered slot-line antenna （BTSA） with a new feeding structure of coplanar waveguide （CPW） is developed. Based on the fact that the bandwidth limitation of TSA mainly depends on its feeding structure, an improved CPW-based feed structure etched on the backboard of the BTSA is adopted to perform traveling-wave transition. Both the simulation results and measurement data verify that the proposed feeding structure results in ＂high-pass＂ frequency response for antenna impedance matching. The voltage standing wave ratio （VSWR） is less than 2：1 when the frequency is higher than 3 GHz. The antenna gain exceeds 7 dBi with good radiation patterns when the bandwidth is from 4 to 16 GHz. This ultra wideband （UWB） antenna with a compact size is specially available for the electronic systems of counter-measure and microwave imaging.
文摘The transient response of two coplanar cracks in a piezoelectric ceramic under antiplane mechanical and inplane electric impacting loads is investigated in the present paper. Laplace and Fourier transforms are used to reduce the mixed boundary value problems to Cauchy-type singular integral equations in Laplace transform domain, which are solved numerically. The dynamic stress and electric displacement factors are obtained as the functions of time and geometry parameters. The present study shows that the presence of the dynamic electric field will impede or enhance the propagation of the crack in piezoelectric ceramics at different stages of the dynamic electromechanical load. Moreover, the electromechanical response is greatly affected by the ratio of the space of the cracks and the crack length.
文摘We discuss the characterization and modeling of coplanar waveguides （CPW） realized in TSMC 0. 13μm CMOS process. EM-field simulations with momentum are performed to estimate the important parameters of the transmission lines, such as characteristic impedance and propagation loss. Coplanar waveguide libraries are designed with Z values of 30,50,70, and 100Ω. Finally, the propagation constant and the characteristic impedance are measured in a frequency range from 0. 1 to 40GHz with a vector-network analyzer,using the short-open-loadthru （SOLT） de-embedding technique. The distributed parameters of the CPWs are extracted from the measured S-parameters.
基金Project supported by the National Natural Science Foundation of China(Grant No.10775166)the Zhejiang Provincial Science Technology Foundation,China(Grant No.2008C31002)
文摘In this paper, the authors present an analytical model for coplanar waveguide on silicon-on-insulator substrate. The four-element topological network and the conformal mapping technique are used to analyse the capacitance and the conductance of the sandwich substrate. The validity of the model is verified by the full-wave method and the experimental data. It is found that the inductance, the resistance, the capacitance and the conductance from the analytical model show they are in good agreement with the corresponding values extracted from experimental Sparameter until 10 GHz.
文摘The skin effect is an electromagnetic phenomenon that makes the current flows only on the surface of the conductors at high frequency. This article is based on the phenomenon to model a structure made in coplanar technology. In reality, these types of structures integrated metal layers of different thickness of copper (9 μm, 18 μm, 35 μm, 70 μm). The neglect of this parameter introduces errors, sometimes significant, in the numerical calculations. This is why an iterative method (FWCIP) based on the wave concept was restated. Validation of results was carried out by comparison with those calculated by Ansoft HFSS software and Agilent ADS Technology. They show a good matching.
文摘We construct two conical surfaces which take non-coplanar lines as generatrix and rational Bezier curve as ridge-line, and prove that the intersecting line of conical surface has similar properties to Bezier curve. Then, the smoothly blending of two cylinders whose axes are non-coplanar is realized by taking intersecting line of conical surface as axes.
基金Project supported by the National Natural Science Foundation of China （Grant No 10474121）.
文摘YBa2Cu3O7（YBCO） thin films have been prepared by thermal coevaporation on LaAlO3（LAO） substrates, and Tl2Ba2CaCu2O8（TBCCO） thin films are synthesized by magnetron sputtering method on LAO substrates. The transition temperature Tc is 90 K forYBCO/LAO and 104 K for TBCCO/LAO. Microwave responses of the films are studied systematically by coplanar resonator technique. Energy gaps of the films obtained are △0 = 1.04kBTc for YBCO films and △0 =0.84kBTc for TBCCO films by analysing the temperature dependence of resonant frequencies of coplanar resonator. Penetration depth at 0 K A0 = 198.nm for YBCO films and A0 = 200 nm for TBCCO films could also be obtained by using the weak coupling theory and two fluid theory. Results of penetration depth and energy gap confirm the weak coupling properties of the films. In addition, microwave surface resistances Rs of YBCO/LAO and TBCCO/LAO are also investigated by analysing the quality factor and insert loss of the coplanar resonator. Surface resistance of TBCCO/LAO is less than that of YBCO/LAO, so that TBCCO/LAO films may have more potential applications.
基金Project supported by the National Basic Research Program of China(Grant Nos.2011CB922104 and 2011CBA00200)the National Natural Science Foundation of China(Grant No.11474154)+1 种基金the Jiangsu Natural Science Fund for Distinguished Young Scholars(Grant No.BK2012013)a Doctoral Program(Grant No.20120091110030)
文摘A tunable superconducting half-wavelength coplanar waveguide resonator （CPWR） with Nb parallel nanowires - 300 nm in width embedded in the center conductor was designed, fabricated, and measured. The frequency shift and the amplitude attenuation of the resonance peak under irradiation of 404-nm pulse laser were observed with different light powers at 4.2 K. The RF power supplied to such a CPWR can serve as current bias, which will affect the light response of the resonator.
基金supported by the National Natural Science Foundation of China(Grant No.61371009)the National High Technology Research and Development Program of China(Grant No.2014AA032703)
文摘In this paper we propose a two-pole varactor-tuned superconducting filter using coplanar waveguide （CPW） spiralin-spiral-out （SISO） resonators. Novel internal and external coupling structures are introduced to meet the requirements for a tunable filter with a constant absolute bandwidth. The fabricated device has a frequency tuning range of 14.4% at frequencies ranging from 274.1 MHz to 317.7 MHz, a 3-dB bandwidth of 5.14±0.06 MHz, and an insertion loss of 0.08 dB-0.70 dB. The simulated and measured results are in excellent agreement with each other.
文摘This paper proposes an antenna design concept to achieve a multi-reconfigurable band-notch antenna by using a set of microswitches. The proposed idea was proved by the design of the coplanar waveguide(CPW)-fed slot antenna. The sample design gives a wideband antenna the impedance bandwidth of which covers the frequency ranged from 1.9 GHz to 6.55 GHz.The antenna could be configured to work either in single-band mode or in one of the defined dual-band modes.
基金Project supported by the Natural Science Foundation of Shandong Province, China (Grant No. Q2008A07)
文摘The （e, 2e） triple-differential cross sections of Ag＋ （4p, 4s） are calculated based on the three-body distorted-wave Born approximation considering post-collision interaction in coplanar symmetric geometry. The energy of the outgoing electron is set to be 50, 70, 100, 200, 300,500, 700, and 1000 eV, and the intensity and splitting of forward and backward peaks are discussed in detail. Some new structures are observed around 15° and 85° for 4p and 4s orbitals. Structures in triple-differential cross sections at 15° are reported for the first time. A double-binary collision is proposed to explain the formation of such structures. The structures at 85° are also considered as the result of one kind of double-binary collision.
基金by NNSFC (60071006) and the Natural Science Foundation of Shandong Province (Y2002G11)
文摘A coplanar dicage pentaprismane molecule C16H12 has been studied by using DFT at B3LYP/D95* level and ab initio method at MP2/D95* level, and the vibrational frequencies of the molecule have been calculated at B3LYP/D95* level too. The results show that the molecule is thermodynamically stable. Some physico-chemical properties, such as geometry, simulated IR spectrum and heat of formation, have been reported.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301802)the National Natural Science Foundation of China(Grant Nos.11474152,11274156,11504165,and 61521001)
文摘Superconducting coplanar waveguide（CPW） can be widely used as two-dimensional（2 D） resonator, transmission line or feedline, providing an important component for superconducting quantum circuit which is a promising candidate for quantum information processing. Due to the discontinuities and asymmetries in the ground planes, CPW usually exhibits the spurious resonance, which is a common source of decoherence in circuit quantum electrodynamics experiments. To mitigate the spurious resonance, we fabricated superconducting aluminum air-bridges on Nb CPW. The fabricated airbridges are approximately 3 m high and up to 120 m long. Compared with other methods, the fabrication procedures of our air-bridges are simpler, and the air-bridge can withstand strong ultrasound.
基金Project supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(No.HKUT014/00E)the National Natural Science Foundation of China(No.19772029).
文摘The dynamic response of multiple coplanar interface cracks between two dissimilar piezoelectric strips subjected to mechanical and electrical impacts is investigated.Solutions to two kinds of electric boundary conditions on crack surfaces,i.e.electric impermeable and electric permeable,are obtained.Laplace and Fourier transforms and dislocation density functions are employed to reduce the mixed boundary value problem to Cauchy singular integral equations, which can be solved numerically.The effects of electrical load,geometry criterion of piezoelectric strips,relative location of cracks and material properties on the dynamic energy release rate are examined.
基金the National Natural Science Foundation of China(Nos.21708039,21878286,21908216,21835001,21875085,51773080,21674041)the Program for Changbaishan Scholars of Jilin Province。
文摘Polymorphism makes it possible to clarify the relationship between emission property and crystal structure.However,based on the exact molecular conformation in tetraphenylethene polymorphisms,it is still challenging to evaluate the difference of intramolecular coplanarity without the support of calculation because of the complex combination of four different torsion angles between four peripheral benzenes and the central ethylene plane.Here,by using a di-formyl-functionalized tetraphenylethene derivative,two ideal polymorphisms with a consistent trend of the corresponding torsion angles have been obtained.For the first time,we explicitly demonstrated that intramolecular coplanarity is the underlying cause of the polymorphism-dependent emission of tetraphenylethene derivatives.
