Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light (DL) could reset the circadian rhythm by activation of the suprachi...Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light (DL) could reset the circadian rhythm by activation of the suprachiasmatic nucleus to prevent delirium. Evidence regarding the effects of light therapy is predominantly focused on psychiatric disorders and circadian rhythm sleep disorders. In this study, we investi- gated the effect of DL on the total hospital length of stay (LOS) and occurrence of delirium in patients admitted to the Coronary Care Unit (CCU). Methods This was a retrospective cohort study. Patients older than 18 years, who were hospitalized longer than 12 h at the CCU and had a total hospital LOS for at least 24 h, were included. Patients were assigned to a room with DL (n = 369) or regular lighting condi- tions (n = 379). DL was administered at the CCU by two ceiling-mounted light panels delivering light with a colour temperature between 2700 and 6500 degrees Kelvin. Reported outcome data were: total hospital LOS, delirium incidence, consultation of a geriatrician and the amount of prescripted antipsychotics. Results Between May 2015 and May 2016, data from 748 patients were collected. Baseline charac- teristics, including risk factors provoking delirium, were equal in both groups. Median total hospital LOS in the DL group was 100.5 (70.8-186.0) and 101.0 (73.0-176.4) h in the control group (P = 0.935). The incidence of delirium in the DL and control group was 5.4% (20/369) and 5.0% (19/379), respectively (P = 0.802). No significant differences between the DL and control group were observed in secon- dary endpoints. Subgroup analysis based on age and CCU LOS also showed no differences. Conclusion Our study suggests exposure to DL as an early single approach does not result in a reduction of total hospital LOS or reduced incidence of delirium. When delirium was diagnosed, it was associated with poor hospital outcome.展开更多
The possible collapse of different circumstances is derived with the help of the limit analysis theory.Analytical equations related to collapsing mechanisms in deep tunnel with smooth three-centered arc cross sections...The possible collapse of different circumstances is derived with the help of the limit analysis theory.Analytical equations related to collapsing mechanisms in deep tunnel with smooth three-centered arc cross sections are derived on the basis of Hoek-Brown failure criterion and upper bound limit analysis.The pore water pressure is considered in the analysis,as a work rate of external force.Numerical results about the shape of detaching curve and the weight of collapsing block per unit length corresponding to different parameters are obtained with the help of mathematical software.The shapes of collapsing block are drawn with respected to different parameters.Furthermore,the effects of different parameters on the shape of detaching curve and the weight of the collapsing block are discussed.展开更多
With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) an...With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) and POR(Proofs of Retrievability) were proposed for this problem.Although many efficient schemes for static data have been constructed,only a few dynamic schemes exist,such as DPDP(Dynamic Provable Data Possession).But the DPDP scheme falls short when updates are not proportional to a fixed block size.The FlexList-based Dynamic Provable Data Possession(FlexDPDP) was an optimized scheme for DPDP.However,the update operations(insertion,remove,modification)in Flex DPDP scheme only apply to single node at a time,while multiple consecutive nodes operation is more common in practice.To solve this problem,we propose optimized algorithms for multiple consecutive nodes,which including MultiNodes Insert and Verification,MultiNodes Remove and Verification,MultiNodes Modify and Verification.The cost of our optimized algorithms is also analyzed.For m consecutive nodes,an insertion takes O(m) + O(log N) + O(log m),where N is the number of leaf nodes of FlexList,a remove takes O(log/V),and a modification is the same as the original algorithm.Finally,we compare the optimized algorithms with original FlexList through experiences,and the results show that our scheme has the higher efficiency of time and space.展开更多
As it is evident from the practice of construction and maintenance of thin retaining walls, the degree of developing of frictional forces in interlock connections of steel sheet U-shape piles essentially influences th...As it is evident from the practice of construction and maintenance of thin retaining walls, the degree of developing of frictional forces in interlock connections of steel sheet U-shape piles essentially influences the realization of the values of geometric characteristics of the piles cross-section (the moment of inertia and the section modulus) reduced to the length unit of the construction. The article offers new and simple solutions for realization and economically effective technological approaches to provide joint work of the sheet piles being considered, which improve the adequacy of design and reliability of maintenance of thin retaining walls.展开更多
Objective: To ascertain the variations of mitochondrion DNA (mtDNA) in mouse tumors and to inquire into the relationship between mutations of mtDNA and carcinogenesis Methods: The variations of D-loop, ND3 and tRN...Objective: To ascertain the variations of mitochondrion DNA (mtDNA) in mouse tumors and to inquire into the relationship between mutations of mtDNA and carcinogenesis Methods: The variations of D-loop, ND3 and tRNA^Met+Glu+Ile gene fragments of mtDNA from six tumor cell lines of mice were analyzed by PCR technology with restriction fragment length polymorphism analysis (polymerase chain reaction-restriction fragment length polymorphism, PCR-RFLP) and single strand conformation polymorphism analysis (SSCP-PCR) method. Results: ND3 and tRNA^Met+Glu+Ile gene fragments ofmtDNA from the tumors showed no variation in 27 endonuclease sites; D-loop ofmtDNA from Hca-F had an additional endonuclease sites of Hinf I in contrast to that of the inbred mouse. Deeply analyzed by PCR-SSCP, the D-loop ofmtDNA was found to possess mutations in 4 of 6 tumors. Conclusion: D-loop is the hot spot of tumor mtDNA mutation which can act as contributors to the carcinogenic展开更多
Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1...Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.展开更多
Based on the VHF lightning locating system,a three-dimensional-space cell-gridded approach is used to extract the lighting channel and calculate the length of the channel.Through clustering of the located radiation so...Based on the VHF lightning locating system,a three-dimensional-space cell-gridded approach is used to extract the lighting channel and calculate the length of the channel.Through clustering of the located radiation sources and then extracting the lightning channel,it can accurately obtain the length of the channel.To validate the feasibility of the approach,a simulation experiment is designed,and it shows the length error is no more than 10%.The relationship between the NO production of per unit arc length and atmospheric pressure obtained in laboratory is applied to the NOX production of per unit flash length at different altitudes in this paper.The channel length and the NOX production of 11 negative cloud-to-ground flashes and 59 intracloud flashes in an isolated thunderstorm in the northeastern Qinghai-Tibet Plateau are calculated.The results show that the average channel lengths of per cloud-to-ground and intracloud flash are 28.9 and 22.3 km respectively;the average NOX productions of per cloud-to-ground and intracloud flash are 1.89×1025 and 0.42×1025 molecules,respectively.展开更多
We have developed a process for chemical purification of carbon nanotubes for solution-processable thin-film transistors (TFTs) having high mobility. Films of the purified carbon nanotubes fabricated by simple drop ...We have developed a process for chemical purification of carbon nanotubes for solution-processable thin-film transistors (TFTs) having high mobility. Films of the purified carbon nanotubes fabricated by simple drop coating showed carrier mobilities as high as 164 cm2V-1s -1 normalized transconductances of 0.78 Sm-1 and on/off current ratios of 10^6. Such high performance requires the preparation of a suspension of micrometer-long and highly purified semiconducting single-walled carbon nanotubes (SWCNTs). Our purification process includes length and electronic-type selective trapping of SWCNTs using recycling gel filtration with a mixture of surfactants. The results provide an important milestone toward printed high-speed and large-area electronics with roll-to-roll and ink-jet device fabrication.展开更多
The direct electron transfer and adsorption behavior of hemoglobin(Hb) in a series of surfactants with different poly(ethylene oxide)(PEO) unit lengths on a glassy carbon electrode have been studied.With a surfactant ...The direct electron transfer and adsorption behavior of hemoglobin(Hb) in a series of surfactants with different poly(ethylene oxide)(PEO) unit lengths on a glassy carbon electrode have been studied.With a surfactant of appropriate PEO unit length,the surfactant film-modified electrode exhibited a more stable adsorption state with a larger surface coverage of Hb and a more positive formal potential,which can be attributed to the effect of hydrogen bonding between proteins and surfactants.The electrochemical behavior of surfactants with different PEO unit lengths is discussed in detail.Moreover,UV-visible spectroscopy demonstrated that the structure of Hb was not destroyed in the surfactant films.The electrocatalytic activity of hydrogen peroxide on three neutral surfactant-modified electrodes has also been investigated.展开更多
For a Riemann surface X of conformally finite type (g, n), let dT, dL and dpi (i = 1, 2) be the Teichmuller metric, the length spectrum metric and Thurston's pseudometrics on the Teichmutler space T(X), respect...For a Riemann surface X of conformally finite type (g, n), let dT, dL and dpi (i = 1, 2) be the Teichmuller metric, the length spectrum metric and Thurston's pseudometrics on the Teichmutler space T(X), respectively. The authors get a description of the Teichmiiller distance in terms of the Jenkins-Strebel differential lengths of simple closed curves. Using this result, by relatively short arguments, some comparisons between dT and dL, dpi (i = 1, 2) on Tε(X) and T(X) are obtained, respectively. These comparisons improve a corresponding result of Li a little. As applications, the authors first get an alternative proof of the topological equivalence of dT to any one of dL, dp1 and dp2 on T(X). Second, a new proof of the completeness of the length spectrum metric from the viewpoint of Finsler geometry is given. Third, a simple proof of the following result of Liu-Papadopoulos is given: a sequence goes to infinity in T(X) with respect to dT if and only if it goes to infinity with respect to dL (as well as dpi (i = 1, 2)).展开更多
Organic phototransistors based on high-quality 2,8-dichloro-5,11-dihexyl-indolo[3,2-b]carbazo(CHICZ)single crystals show the highest photoresponsivity of 3×10^3 A W^-1, photosensitivity of 2×10^4 and the det...Organic phototransistors based on high-quality 2,8-dichloro-5,11-dihexyl-indolo[3,2-b]carbazo(CHICZ)single crystals show the highest photoresponsivity of 3×10^3 A W^-1, photosensitivity of 2×10^4 and the detectivity can achieve 8.4×10^14 Jones. We also discovered good linear dependence of log(photosensitivity) versus the wavelength when the devices were illuminated with a series of sameintensity but different-wavelength lights. The organic phototransistors based on CHICZ single crystal have potential applications in wavelength-detection.展开更多
The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM an...The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM and Raman were used to characterize the length of nanotube bundles. The results show that the longer nanotubes were eluted out first, and then the shorter tubes were followed by the sodium dodecyl sulfate. However, the separated order was totally reversed by the sodium deoxycholate. By this method, the process generated nanotube fractions not only were narrower in length distributions, but also could control the separation orders by changing the eluents. Moreover, the separation principle was also discussed.展开更多
Using self-flux method,we have successfully grown the parent phase of the single crystals of CaFeAsF1-x.The X-ray di?raction indicates good crystallinity.In-plane resistivity shows a bad metallic behavior with a sharp...Using self-flux method,we have successfully grown the parent phase of the single crystals of CaFeAsF1-x.The X-ray di?raction indicates good crystallinity.In-plane resistivity shows a bad metallic behavior with a sharp drop of resistivity at about T SDW=119K.This anomaly is associated with the possible spin density wave(SDW)order.Interestingly near T SDW,the resistivity exhibits a cusp-like feature,which may be understood as the strong coupling effect between the electrons and the antiferromagnetic(AF)spin fluctuations.A reduction of fluorine or application of a high pressure will suppress the SDW feature and induce superconductivity.Hall effect measurements reveal a positive Hall coefficient below T SDW indicating a dominant role of the hole-like charge carriers in the parent phase.Strong magnetoresistance has been observed below T SDW suggesting multiple conduction channels of the charge carriers.展开更多
文摘Background Disturbed circadian rhythm is a potential cause of delirium and is linked to disorganisation of the circadian rhythmicity. Dynamic light (DL) could reset the circadian rhythm by activation of the suprachiasmatic nucleus to prevent delirium. Evidence regarding the effects of light therapy is predominantly focused on psychiatric disorders and circadian rhythm sleep disorders. In this study, we investi- gated the effect of DL on the total hospital length of stay (LOS) and occurrence of delirium in patients admitted to the Coronary Care Unit (CCU). Methods This was a retrospective cohort study. Patients older than 18 years, who were hospitalized longer than 12 h at the CCU and had a total hospital LOS for at least 24 h, were included. Patients were assigned to a room with DL (n = 369) or regular lighting condi- tions (n = 379). DL was administered at the CCU by two ceiling-mounted light panels delivering light with a colour temperature between 2700 and 6500 degrees Kelvin. Reported outcome data were: total hospital LOS, delirium incidence, consultation of a geriatrician and the amount of prescripted antipsychotics. Results Between May 2015 and May 2016, data from 748 patients were collected. Baseline charac- teristics, including risk factors provoking delirium, were equal in both groups. Median total hospital LOS in the DL group was 100.5 (70.8-186.0) and 101.0 (73.0-176.4) h in the control group (P = 0.935). The incidence of delirium in the DL and control group was 5.4% (20/369) and 5.0% (19/379), respectively (P = 0.802). No significant differences between the DL and control group were observed in secon- dary endpoints. Subgroup analysis based on age and CCU LOS also showed no differences. Conclusion Our study suggests exposure to DL as an early single approach does not result in a reduction of total hospital LOS or reduced incidence of delirium. When delirium was diagnosed, it was associated with poor hospital outcome.
基金Project(2013CB036004)supported by Basic Research Program of ChinaProjects(51378510,41302226)supported by National Natural Science Foundation of ChinaProject(2016zzts062)supported by Doctorial Innovation Foundation of Central South University,China
文摘The possible collapse of different circumstances is derived with the help of the limit analysis theory.Analytical equations related to collapsing mechanisms in deep tunnel with smooth three-centered arc cross sections are derived on the basis of Hoek-Brown failure criterion and upper bound limit analysis.The pore water pressure is considered in the analysis,as a work rate of external force.Numerical results about the shape of detaching curve and the weight of collapsing block per unit length corresponding to different parameters are obtained with the help of mathematical software.The shapes of collapsing block are drawn with respected to different parameters.Furthermore,the effects of different parameters on the shape of detaching curve and the weight of the collapsing block are discussed.
基金supported in part by the National Natural Science Foundation of China under Grant No.61440014&&No.61300196the Liaoning Province Doctor Startup Fundunder Grant No.20141012+2 种基金the Liaoning Province Science and Technology Projects under Grant No.2013217004the Shenyang Province Science and Technology Projects under Grant Nothe Fundamental Research Funds for the Central Universities under Grant No.N130317002 and No.N130317003
文摘With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) and POR(Proofs of Retrievability) were proposed for this problem.Although many efficient schemes for static data have been constructed,only a few dynamic schemes exist,such as DPDP(Dynamic Provable Data Possession).But the DPDP scheme falls short when updates are not proportional to a fixed block size.The FlexList-based Dynamic Provable Data Possession(FlexDPDP) was an optimized scheme for DPDP.However,the update operations(insertion,remove,modification)in Flex DPDP scheme only apply to single node at a time,while multiple consecutive nodes operation is more common in practice.To solve this problem,we propose optimized algorithms for multiple consecutive nodes,which including MultiNodes Insert and Verification,MultiNodes Remove and Verification,MultiNodes Modify and Verification.The cost of our optimized algorithms is also analyzed.For m consecutive nodes,an insertion takes O(m) + O(log N) + O(log m),where N is the number of leaf nodes of FlexList,a remove takes O(log/V),and a modification is the same as the original algorithm.Finally,we compare the optimized algorithms with original FlexList through experiences,and the results show that our scheme has the higher efficiency of time and space.
文摘As it is evident from the practice of construction and maintenance of thin retaining walls, the degree of developing of frictional forces in interlock connections of steel sheet U-shape piles essentially influences the realization of the values of geometric characteristics of the piles cross-section (the moment of inertia and the section modulus) reduced to the length unit of the construction. The article offers new and simple solutions for realization and economically effective technological approaches to provide joint work of the sheet piles being considered, which improve the adequacy of design and reliability of maintenance of thin retaining walls.
基金Supported by Natural Science Foundation of Chongqing in China(2009c195)
文摘Objective: To ascertain the variations of mitochondrion DNA (mtDNA) in mouse tumors and to inquire into the relationship between mutations of mtDNA and carcinogenesis Methods: The variations of D-loop, ND3 and tRNA^Met+Glu+Ile gene fragments of mtDNA from six tumor cell lines of mice were analyzed by PCR technology with restriction fragment length polymorphism analysis (polymerase chain reaction-restriction fragment length polymorphism, PCR-RFLP) and single strand conformation polymorphism analysis (SSCP-PCR) method. Results: ND3 and tRNA^Met+Glu+Ile gene fragments ofmtDNA from the tumors showed no variation in 27 endonuclease sites; D-loop ofmtDNA from Hca-F had an additional endonuclease sites of Hinf I in contrast to that of the inbred mouse. Deeply analyzed by PCR-SSCP, the D-loop ofmtDNA was found to possess mutations in 4 of 6 tumors. Conclusion: D-loop is the hot spot of tumor mtDNA mutation which can act as contributors to the carcinogenic
文摘Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.
基金supported by the National Natural Science Foundation of Chi-na(Grant Nos.41075002,40775004,41030960)R&D Special Fund for Public Welfare Industry(Meteorology)(Grant No.GYHY201006005-03)
文摘Based on the VHF lightning locating system,a three-dimensional-space cell-gridded approach is used to extract the lighting channel and calculate the length of the channel.Through clustering of the located radiation sources and then extracting the lightning channel,it can accurately obtain the length of the channel.To validate the feasibility of the approach,a simulation experiment is designed,and it shows the length error is no more than 10%.The relationship between the NO production of per unit arc length and atmospheric pressure obtained in laboratory is applied to the NOX production of per unit flash length at different altitudes in this paper.The channel length and the NOX production of 11 negative cloud-to-ground flashes and 59 intracloud flashes in an isolated thunderstorm in the northeastern Qinghai-Tibet Plateau are calculated.The results show that the average channel lengths of per cloud-to-ground and intracloud flash are 28.9 and 22.3 km respectively;the average NOX productions of per cloud-to-ground and intracloud flash are 1.89×1025 and 0.42×1025 molecules,respectively.
文摘We have developed a process for chemical purification of carbon nanotubes for solution-processable thin-film transistors (TFTs) having high mobility. Films of the purified carbon nanotubes fabricated by simple drop coating showed carrier mobilities as high as 164 cm2V-1s -1 normalized transconductances of 0.78 Sm-1 and on/off current ratios of 10^6. Such high performance requires the preparation of a suspension of micrometer-long and highly purified semiconducting single-walled carbon nanotubes (SWCNTs). Our purification process includes length and electronic-type selective trapping of SWCNTs using recycling gel filtration with a mixture of surfactants. The results provide an important milestone toward printed high-speed and large-area electronics with roll-to-roll and ink-jet device fabrication.
文摘The direct electron transfer and adsorption behavior of hemoglobin(Hb) in a series of surfactants with different poly(ethylene oxide)(PEO) unit lengths on a glassy carbon electrode have been studied.With a surfactant of appropriate PEO unit length,the surfactant film-modified electrode exhibited a more stable adsorption state with a larger surface coverage of Hb and a more positive formal potential,which can be attributed to the effect of hydrogen bonding between proteins and surfactants.The electrochemical behavior of surfactants with different PEO unit lengths is discussed in detail.Moreover,UV-visible spectroscopy demonstrated that the structure of Hb was not destroyed in the surfactant films.The electrocatalytic activity of hydrogen peroxide on three neutral surfactant-modified electrodes has also been investigated.
基金supported by the National Natural Science Foundation of China (No. 10871211)
文摘For a Riemann surface X of conformally finite type (g, n), let dT, dL and dpi (i = 1, 2) be the Teichmuller metric, the length spectrum metric and Thurston's pseudometrics on the Teichmutler space T(X), respectively. The authors get a description of the Teichmiiller distance in terms of the Jenkins-Strebel differential lengths of simple closed curves. Using this result, by relatively short arguments, some comparisons between dT and dL, dpi (i = 1, 2) on Tε(X) and T(X) are obtained, respectively. These comparisons improve a corresponding result of Li a little. As applications, the authors first get an alternative proof of the topological equivalence of dT to any one of dL, dp1 and dp2 on T(X). Second, a new proof of the completeness of the length spectrum metric from the viewpoint of Finsler geometry is given. Third, a simple proof of the following result of Liu-Papadopoulos is given: a sequence goes to infinity in T(X) with respect to dT if and only if it goes to infinity with respect to dL (as well as dpi (i = 1, 2)).
基金financial support from the Ministry of Science and Technology of China (2017YFA0204503 and 2016YFB0401100)the National Natural Science Foundation of China (51725304, 51633006, 51703159 and 51733004)the Strategic Priority Research Program (XDB12030300) of the Chinese Academy of Sciences
文摘Organic phototransistors based on high-quality 2,8-dichloro-5,11-dihexyl-indolo[3,2-b]carbazo(CHICZ)single crystals show the highest photoresponsivity of 3×10^3 A W^-1, photosensitivity of 2×10^4 and the detectivity can achieve 8.4×10^14 Jones. We also discovered good linear dependence of log(photosensitivity) versus the wavelength when the devices were illuminated with a series of sameintensity but different-wavelength lights. The organic phototransistors based on CHICZ single crystal have potential applications in wavelength-detection.
基金supported by the National Science & Technology Pillar Program of MOST (Grant No. 2011BAK15B04)
文摘The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM and Raman were used to characterize the length of nanotube bundles. The results show that the longer nanotubes were eluted out first, and then the shorter tubes were followed by the sodium dodecyl sulfate. However, the separated order was totally reversed by the sodium deoxycholate. By this method, the process generated nanotube fractions not only were narrower in length distributions, but also could control the separation orders by changing the eluents. Moreover, the separation principle was also discussed.
基金supported by the National Basic Research Program of China(Grant Nos.2011CBA00102,2010CB923002 and 2012CB821403)the National Natural Science Foundation of China and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Using self-flux method,we have successfully grown the parent phase of the single crystals of CaFeAsF1-x.The X-ray di?raction indicates good crystallinity.In-plane resistivity shows a bad metallic behavior with a sharp drop of resistivity at about T SDW=119K.This anomaly is associated with the possible spin density wave(SDW)order.Interestingly near T SDW,the resistivity exhibits a cusp-like feature,which may be understood as the strong coupling effect between the electrons and the antiferromagnetic(AF)spin fluctuations.A reduction of fluorine or application of a high pressure will suppress the SDW feature and induce superconductivity.Hall effect measurements reveal a positive Hall coefficient below T SDW indicating a dominant role of the hole-like charge carriers in the parent phase.Strong magnetoresistance has been observed below T SDW suggesting multiple conduction channels of the charge carriers.