An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement ...An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement by a new calibration method.In theory,the measuring range of the measurement system is only determined by the measuring range of the instruments network analyzer and photo detector.Diodes' bandwidth of 7 5GHz and 10GHz is measured.The results reveal that the method is feasible and comparing with other method,it is more precise and easier to use.展开更多
The growing complexity of System on Chip （SOC） requres a system level specicanon and design approach. High-level languages such as C＋＋/SystemC can play multiple roles in system design as target languages. There ar...The growing complexity of System on Chip （SOC） requres a system level specicanon and design approach. High-level languages such as C＋＋/SystemC can play multiple roles in system design as target languages. There are many practical problems in the application of object-oriented methods for this goal. Based on the analysis of traditional and system-level design methodology, a new object-oriented SOC design methodology with object-oriented design patterns is proposed, which emphasizes high-level design and verification. Aiming at the final goal of developing design patterns specific to SOC design, the reuse of design patterns in SOC systems and the capability of new SOC design patterns are discussed. With the illustration of some concrete examples of SOC design patterns, the application of object-oriented design methodology in the SOC design process is presented.展开更多
The paper deals with unusual use of one kind of ECA （electrically conductive adhesive）---the ICA （isotropic conductive adhesive）. The main sphere of ECA application is electronic assembly, e.g., it is bonding of s...The paper deals with unusual use of one kind of ECA （electrically conductive adhesive）---the ICA （isotropic conductive adhesive）. The main sphere of ECA application is electronic assembly, e.g., it is bonding of semiconductor microchips on printed circuits boards. In this sphere, the ECA compete with soft solder. In spite of this fact, the author utilized of two main ECA characteristics--good electrical conductivity and excellent adhesion to material surfaces to make the fiat thermocouples. Both the design of thermocouples and the measuring device and the measuring workplace arrangement are described. The measured data of thermoelectric voltages are plotted. The thermoelectric （Seebeck＇s） coefficients were calculated from obtained dependences of thermoelectric voltage versus the temperature differences.展开更多
In this report we illustrate our application of soft lithography-based microfabrication,surface modification,and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual ...In this report we illustrate our application of soft lithography-based microfabrication,surface modification,and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual forebrain neurons from Day 7 embryonic chicks into two rows of eight in a silicon microstructure aligned over a microelectrode array (MEA). The polydimethylsiloxane (PDMS) membrane with microstructures to confine cells and guide network connectivity was aligned to the electrodes of a MEA. Both the MEA and the PDMS membrane were treated with O2 plasma,Poly-L-Lysine,and Laminin to aid in cell attachment and survival. The primary advantage of our process is that it is quicker and simpler than previous cell-placement methods and may make highly defined neuronal network biochips more practical.展开更多
A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system contr...A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system control parts. In the proposed AFC block, both analog and digital modes were designed to complete the AFC process. In analog mode, the analog part sampled and detected the charge pump output tuning voltage, which would give the indicator to digital part to adjust the voltage control oscillator(VCO) capacitor bank. In digital mode, the digital part counted the phase lock loop(PLL) divided clock to judge whether VCO frequency was fast or slow. The analog and digital modes completed the auto frequency calibration function independently by internal switch. By designing a special switching algorithm, the switch of the digital and analog mode could be realized anytime during the lock and unlock detecting process for faster and more stable locking. This chip is fabricated in 0.13 μm RF complementary metal oxide semiconductor(CMOS) process, and the VCO supports the frequency range from 2.7 to 4.0 GHz. Tested 3.96 GHz frequency phase noise is -90 d Bc/Hz@100 k Hz frequency offset and -120 d Bc/Hz@1 MHz frequency offset. By using the analog mode in lock detection and digital mode in unlock detection, tested AFC time is less than 9 μs and the total PLL lock time is less than 19 μs. The SoC acquisition and tracking sensitivity are about-142 d Bm and-155 d Bm, respectively. The area of the proposed PLL is 0.35 mm^2 and the total SoC area is about 9.6 mm^2.展开更多
A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials, bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency ide...A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials, bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency identification(RFID) inlay. The optimization condition for flip-chip bonding was determined from the behavior of bonding strength. Under the optimized condition, the shear strength for the antenna printed with paste-type Ag ink was larger than that for Cu antenna. Furthermore, an identification distance was varied from the antenna materials. Comparing with the Ag antenna pattern, the as-bonded die on Cu antenna showed a larger distance of identification. However, the long-term reliability of inlay using the Cu antenna was decreased significantly as a function of aging time at room temperature because of the bended shape of Cu antenna formed during the flip-chip bonding process.展开更多
We used yttrium acetate, barium acetate, and copper acetate as the starting materials, benzalacetone (BzAcH) as chemical modifier, and methanol (MEOH) as solvent to synthesize a stable fluorine-free YBCO precursor sol...We used yttrium acetate, barium acetate, and copper acetate as the starting materials, benzalacetone (BzAcH) as chemical modifier, and methanol (MEOH) as solvent to synthesize a stable fluorine-free YBCO precursor sol. The coated YBCO gel film using this precursor sol exhibited photosensitivity to UV irradiation at a wavelength of 330 nm. After the subsequent exposing, the YBCO gel film showed a decreased solubility in several organic solvents. Based on the photosensitivity of the YBCO/BzAcH gel film, YBCO superconducting microarray with the pitch of 5 μm was fabricated by irradiating the gel film with UV light through a mask, followed by leaching the unirradiated area in a mixture solvent of methanol and n-butyl alcohol with the volume ratio of 1:1. After proper heat treatment the x-ray diffraction result showed that the as-prepared arrays were highly c-axis oriented and with a high T c by this new photosensitive sol-gel process.展开更多
Over the past half century,the semiconductor chips have deeply influenced our everyday life through increasingly sophisticated electronic products.The central driving force underlying the remarkable evolution in semic...Over the past half century,the semiconductor chips have deeply influenced our everyday life through increasingly sophisticated electronic products.The central driving force underlying the remarkable evolution in semiconductor industry is Moore’s Law,nowadays referring to a doubling of transistor counts per chip every 18 months.Sustaining Moore’s Law is economically beneficial;while the manufacturing cost per chip has been held constant,展开更多
We investigate the possibility of observing in integrated solid-state systems the dynamical Casimir effect,in which photons are created out of vacuum.We use a transmission line resonator on a superconducting chip as t...We investigate the possibility of observing in integrated solid-state systems the dynamical Casimir effect,in which photons are created out of vacuum.We use a transmission line resonator on a superconducting chip as the microwave cavity and modulate its properties by coupling it to carefully designed Josephson devices.We evaluate the effect of main decoherence sources and show that our design offers a promising system for experimentally demonstrating the dynamical Casimir effect.Moreover,we also study the squeezing properties of the created photon field and how they depend on the dissipation.展开更多
The broad class of explosives includes nitro aromatics as well as challenging aliphatic nitro-organics whose detection is important from counter-terrorism and national security perspectives.Here we report a turn-on fl...The broad class of explosives includes nitro aromatics as well as challenging aliphatic nitro-organics whose detection is important from counter-terrorism and national security perspectives.Here we report a turn-on fluorescent sensor array based on aggregation-induced emission(AIE)fluorophores as receptors.To achieve a good sensing system with fast response,good sensitivity and low detection limit,three receptors with abundant chemical diversities for target analytes were synthesized.The turn-on response of the individual receptor showed highly variable and cross-reactive analyte-dependent changes in fluorescence.The excellent ability to identify a variety of explosives,especially the challenging aliphatic nitro-organics(2,3-dimethyl-2,3-dinitrobutane(DMNB),1,3,5-trinitro-1,3,5-triazinane(RDX),cyclotetramethylene tetranitramine(HMX)and entaerythritol tetranitrate(PETN)),was demonstrated in qualitative and quantitative analyses with 100%accuracy.The fluorescence signal amplification in the presence of explosives allows for application of these receptors in a sensor microarray suitable for high-throughput screening.These results suggested that the cross-reactive sensor array based on AIE fluorophores could find a wide range of applications for sensing various analytes or complex mixtures.展开更多
The effects of Aspirin on tumor chemoprevention and inhibition have been debated and researched in recent years and its effects on colorectal cancer are quite clear.For breast cancer,however,conclusions are inconsiste...The effects of Aspirin on tumor chemoprevention and inhibition have been debated and researched in recent years and its effects on colorectal cancer are quite clear.For breast cancer,however,conclusions are inconsistent and the anti-tumor mechanism of Aspirin is not clear yet.In our study,we used DMBA-induced mammary gland carcinogenesis model to assess the chemoprevention effect of Aspirin on mammary precancerous lesions.After SD rats were treated with Aspirin,the total numbers of precancerous lesion in experimental groups were 16（40 mg/kg Aspirin） and 13（20 mg/kg Aspirin）,while the number in control group was 35.In vitro,we found that Aspirin inhibited cell proliferation in human breast cancer cell line MCF-7 by SRB assay with no apparent cytotoxity under the doses of 10,8,6,4 and 2 mM,the inhibitory rates were 86.96%,54.56%,24.83%,14.24% and 4.49%,respectively.In mechanism research,the results of gene microarray assay demonstrated that 4 mM and 2 mM Aspirin were effective in changing gene expression profile in MCF-7 cells.The expression of cell cycle regulator,cyclin A,was significantly down-regulated under the same doses,while the down-regulation of Cdk2 was only remarkable at 4 mM.Our findings reveal that Aspirin is effective in tumor inhibition during initial phase in rats.In MCF-7 cells,Aspirin reduces cell proliferation without significant cytotoxity and its possible mechanism involves altering tumor-related gene expression and regulating cell cycle process.展开更多
Microarray technology has been proved to be greatly helpful for biomedical and biological diagnosis. And the evaluation of its biological applications lies in the detection sensitivity, which requires high intensity a...Microarray technology has been proved to be greatly helpful for biomedical and biological diagnosis. And the evaluation of its biological applications lies in the detection sensitivity, which requires high intensity and stability of the signal. Recently, several nanomaterials, especially semiconductor nanomaterials, due to their excellent fluorescence properties, have been widely used to construct microarrays for biosensors. Here, we presented an approach for constructing CdSe/ZnS quantum dot (QD) microarray in microfluidic channels on a glass slide by photolithography. The conditions for immobilizing stable and uniform QD microarray on the glass slide were optimized. Several types of QD microarrays with different emission wavelengths and modified groups were constructed using silanization and lithography technology. Based on the fluorescence quenching effect of Cu2+ on QDs, the microfluidic chip with QD microarray was applied for the determination of Cu2+. 1 nmol/L Cu2+ could be detected by this method.展开更多
文摘An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement by a new calibration method.In theory,the measuring range of the measurement system is only determined by the measuring range of the instruments network analyzer and photo detector.Diodes' bandwidth of 7 5GHz and 10GHz is measured.The results reveal that the method is feasible and comparing with other method,it is more precise and easier to use.
文摘The growing complexity of System on Chip （SOC） requres a system level specicanon and design approach. High-level languages such as C＋＋/SystemC can play multiple roles in system design as target languages. There are many practical problems in the application of object-oriented methods for this goal. Based on the analysis of traditional and system-level design methodology, a new object-oriented SOC design methodology with object-oriented design patterns is proposed, which emphasizes high-level design and verification. Aiming at the final goal of developing design patterns specific to SOC design, the reuse of design patterns in SOC systems and the capability of new SOC design patterns are discussed. With the illustration of some concrete examples of SOC design patterns, the application of object-oriented design methodology in the SOC design process is presented.
文摘The paper deals with unusual use of one kind of ECA （electrically conductive adhesive）---the ICA （isotropic conductive adhesive）. The main sphere of ECA application is electronic assembly, e.g., it is bonding of semiconductor microchips on printed circuits boards. In this sphere, the ECA compete with soft solder. In spite of this fact, the author utilized of two main ECA characteristics--good electrical conductivity and excellent adhesion to material surfaces to make the fiat thermocouples. Both the design of thermocouples and the measuring device and the measuring workplace arrangement are described. The measured data of thermoelectric voltages are plotted. The thermoelectric （Seebeck＇s） coefficients were calculated from obtained dependences of thermoelectric voltage versus the temperature differences.
基金South Carolina Spinal Cord Injury Association (Grant No.SCIRF 0303)AHA (0565445U)+2 种基金NIH SC INBRE (Grant No.2p20RR16461-05)DoD Era of Hope Award (BC044778)NIH Career Award (1K25HL088262-01)
文摘In this report we illustrate our application of soft lithography-based microfabrication,surface modification,and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual forebrain neurons from Day 7 embryonic chicks into two rows of eight in a silicon microstructure aligned over a microelectrode array (MEA). The polydimethylsiloxane (PDMS) membrane with microstructures to confine cells and guide network connectivity was aligned to the electrodes of a MEA. Both the MEA and the PDMS membrane were treated with O2 plasma,Poly-L-Lysine,and Laminin to aid in cell attachment and survival. The primary advantage of our process is that it is quicker and simpler than previous cell-placement methods and may make highly defined neuronal network biochips more practical.
基金Project(2011912004)supported by the Major Program of the Economic & Information Commission Program of Guangdong Province,ChinaProjects(2011B010700065,2011A090200106)supported by the Major Program of the Department of Science and Technology of Guangdong Province,China
文摘A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system control parts. In the proposed AFC block, both analog and digital modes were designed to complete the AFC process. In analog mode, the analog part sampled and detected the charge pump output tuning voltage, which would give the indicator to digital part to adjust the voltage control oscillator(VCO) capacitor bank. In digital mode, the digital part counted the phase lock loop(PLL) divided clock to judge whether VCO frequency was fast or slow. The analog and digital modes completed the auto frequency calibration function independently by internal switch. By designing a special switching algorithm, the switch of the digital and analog mode could be realized anytime during the lock and unlock detecting process for faster and more stable locking. This chip is fabricated in 0.13 μm RF complementary metal oxide semiconductor(CMOS) process, and the VCO supports the frequency range from 2.7 to 4.0 GHz. Tested 3.96 GHz frequency phase noise is -90 d Bc/Hz@100 k Hz frequency offset and -120 d Bc/Hz@1 MHz frequency offset. By using the analog mode in lock detection and digital mode in unlock detection, tested AFC time is less than 9 μs and the total PLL lock time is less than 19 μs. The SoC acquisition and tracking sensitivity are about-142 d Bm and-155 d Bm, respectively. The area of the proposed PLL is 0.35 mm^2 and the total SoC area is about 9.6 mm^2.
基金supported by the Ministry of Commerce, Industry and Energy (MOCIE) of Korea (10031777)
文摘A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials, bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency identification(RFID) inlay. The optimization condition for flip-chip bonding was determined from the behavior of bonding strength. Under the optimized condition, the shear strength for the antenna printed with paste-type Ag ink was larger than that for Cu antenna. Furthermore, an identification distance was varied from the antenna materials. Comparing with the Ag antenna pattern, the as-bonded die on Cu antenna showed a larger distance of identification. However, the long-term reliability of inlay using the Cu antenna was decreased significantly as a function of aging time at room temperature because of the bended shape of Cu antenna formed during the flip-chip bonding process.
基金supported by the National Natural Science Foundation of China (Grant No. 51072163)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20096118110002)the Special Funds for the Construction of Key Disciplines Project of Shanxi Province
文摘We used yttrium acetate, barium acetate, and copper acetate as the starting materials, benzalacetone (BzAcH) as chemical modifier, and methanol (MEOH) as solvent to synthesize a stable fluorine-free YBCO precursor sol. The coated YBCO gel film using this precursor sol exhibited photosensitivity to UV irradiation at a wavelength of 330 nm. After the subsequent exposing, the YBCO gel film showed a decreased solubility in several organic solvents. Based on the photosensitivity of the YBCO/BzAcH gel film, YBCO superconducting microarray with the pitch of 5 μm was fabricated by irradiating the gel film with UV light through a mask, followed by leaching the unirradiated area in a mixture solvent of methanol and n-butyl alcohol with the volume ratio of 1:1. After proper heat treatment the x-ray diffraction result showed that the as-prepared arrays were highly c-axis oriented and with a high T c by this new photosensitive sol-gel process.
文摘Over the past half century,the semiconductor chips have deeply influenced our everyday life through increasingly sophisticated electronic products.The central driving force underlying the remarkable evolution in semiconductor industry is Moore’s Law,nowadays referring to a doubling of transistor counts per chip every 18 months.Sustaining Moore’s Law is economically beneficial;while the manufacturing cost per chip has been held constant,
基金supported by the National Natural Science Foundation of China(Grant No.11174270)the National Basic Research Program of China(Grant Nos.2011CB921204 and 2011CBA00200)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB01000000)ZHOU Zheng Wei gratefully acknowledges the support of theK.C.Wong Education Foundation,Hong Kong
文摘We investigate the possibility of observing in integrated solid-state systems the dynamical Casimir effect,in which photons are created out of vacuum.We use a transmission line resonator on a superconducting chip as the microwave cavity and modulate its properties by coupling it to carefully designed Josephson devices.We evaluate the effect of main decoherence sources and show that our design offers a promising system for experimentally demonstrating the dynamical Casimir effect.Moreover,we also study the squeezing properties of the created photon field and how they depend on the dissipation.
基金the National Natural Science Foundation of China(50873051,205333050)National High Technology Research and Development Program of China(2007AA03Z307)Transregional Project(TRR61)
文摘The broad class of explosives includes nitro aromatics as well as challenging aliphatic nitro-organics whose detection is important from counter-terrorism and national security perspectives.Here we report a turn-on fluorescent sensor array based on aggregation-induced emission(AIE)fluorophores as receptors.To achieve a good sensing system with fast response,good sensitivity and low detection limit,three receptors with abundant chemical diversities for target analytes were synthesized.The turn-on response of the individual receptor showed highly variable and cross-reactive analyte-dependent changes in fluorescence.The excellent ability to identify a variety of explosives,especially the challenging aliphatic nitro-organics(2,3-dimethyl-2,3-dinitrobutane(DMNB),1,3,5-trinitro-1,3,5-triazinane(RDX),cyclotetramethylene tetranitramine(HMX)and entaerythritol tetranitrate(PETN)),was demonstrated in qualitative and quantitative analyses with 100%accuracy.The fluorescence signal amplification in the presence of explosives allows for application of these receptors in a sensor microarray suitable for high-throughput screening.These results suggested that the cross-reactive sensor array based on AIE fluorophores could find a wide range of applications for sensing various analytes or complex mixtures.
基金The Comprehensive Center for Drug Discovery and Development,Peking University(Grant No.2009ZX09301-010)
文摘The effects of Aspirin on tumor chemoprevention and inhibition have been debated and researched in recent years and its effects on colorectal cancer are quite clear.For breast cancer,however,conclusions are inconsistent and the anti-tumor mechanism of Aspirin is not clear yet.In our study,we used DMBA-induced mammary gland carcinogenesis model to assess the chemoprevention effect of Aspirin on mammary precancerous lesions.After SD rats were treated with Aspirin,the total numbers of precancerous lesion in experimental groups were 16（40 mg/kg Aspirin） and 13（20 mg/kg Aspirin）,while the number in control group was 35.In vitro,we found that Aspirin inhibited cell proliferation in human breast cancer cell line MCF-7 by SRB assay with no apparent cytotoxity under the doses of 10,8,6,4 and 2 mM,the inhibitory rates were 86.96%,54.56%,24.83%,14.24% and 4.49%,respectively.In mechanism research,the results of gene microarray assay demonstrated that 4 mM and 2 mM Aspirin were effective in changing gene expression profile in MCF-7 cells.The expression of cell cycle regulator,cyclin A,was significantly down-regulated under the same doses,while the down-regulation of Cdk2 was only remarkable at 4 mM.Our findings reveal that Aspirin is effective in tumor inhibition during initial phase in rats.In MCF-7 cells,Aspirin reduces cell proliferation without significant cytotoxity and its possible mechanism involves altering tumor-related gene expression and regulating cell cycle process.
基金supported by the National Basic Research Program of China (2011CB933600)the Science Fund for Creative Research Groups (20921062)+1 种基金the National Natural Science Foundation of China (21175100)the Program for New Century Excellent Talents in University (NCET-10-0656)
文摘Microarray technology has been proved to be greatly helpful for biomedical and biological diagnosis. And the evaluation of its biological applications lies in the detection sensitivity, which requires high intensity and stability of the signal. Recently, several nanomaterials, especially semiconductor nanomaterials, due to their excellent fluorescence properties, have been widely used to construct microarrays for biosensors. Here, we presented an approach for constructing CdSe/ZnS quantum dot (QD) microarray in microfluidic channels on a glass slide by photolithography. The conditions for immobilizing stable and uniform QD microarray on the glass slide were optimized. Several types of QD microarrays with different emission wavelengths and modified groups were constructed using silanization and lithography technology. Based on the fluorescence quenching effect of Cu2+ on QDs, the microfluidic chip with QD microarray was applied for the determination of Cu2+. 1 nmol/L Cu2+ could be detected by this method.
