BACKGROUND The bowel preparation process prior to colonoscopy determines the quality of the bowel preparation,which in turn affects the quality of the colonoscopy.Colono-scopy is an essential procedure for postoperati...BACKGROUND The bowel preparation process prior to colonoscopy determines the quality of the bowel preparation,which in turn affects the quality of the colonoscopy.Colono-scopy is an essential procedure for postoperative follow-up monitoring of colorec-tal cancer(CRC)patients.Previous studies have shown that advanced age and a history of colorectal resection are both risk factors for inadequate bowel prepara-tion.However,little attention has been paid to the bowel preparation experiences and needs of predominantly older adult postoperative CRC patients.AIM To explore the experiences and needs of older adult postoperative CRC patients during bowel preparation for follow-up colonoscopy.METHODS Fifteen older adult postoperative CRC patients who underwent follow-up colonoscopy at a tertiary hospital in Shanghai were selected using purposive sampling from August 2023 to November 2023.The phenomenological method in qualitative research was employed to construct an interview outline and conduct semi-structured interviews with the patients.Colaizzi's seven-step analysis was utilized to organize,code,categorize,summarize,and verify the interview data.RESULTS The results of this study were summarized into four themes and eight sub-themes:(1)Inadequate knowledge about bowel preparation;(2)Decreased physiological comfort during bowel preparation(gastrointestinal discomfort and sleep deprivation caused by bowel cleansing agents,and hunger caused by dietary restrictions);(3)Psychological changes during different stages of bowel preparation(pre-preparation:Fear and resistance due to previous experiences;during preparation:Irritation and helplessness caused by taking bowel cleansing agents,and post-preparation:Anxiety and worry while waiting for the colonoscopy);and(4)Needs related to bowel preparation(detailed instructions from healthcare professionals;more ideal bowel cleansing agents;and shortened waiting times for colonoscopy).CONCLUSION Older adult postoperative CRC patients'knowledge of bowel preparation is not adequate,and they may encounter numerous difficulties and challenges during the process.Healthcare professionals should place great emphasis on providing instruction for their bowel preparation.展开更多
BACKGROUND This study employs a descriptive phenomenological approach to investigate the challenges anesthesia nurses face in managing emergence delirium(ED),a common and complex postoperative complication in the post...BACKGROUND This study employs a descriptive phenomenological approach to investigate the challenges anesthesia nurses face in managing emergence delirium(ED),a common and complex postoperative complication in the post-anesthesia care unit.The role of nurses in managing ED is critical,yet research on their understanding and management strategies for ED is lacking.AIM To investigate anesthetic nurses’cognition and management experiences of ED in hopes of developing a standardized management protocol.METHODS This study employed a descriptive phenomenological approach from qualitative research methodologies.Purposeful sampling was utilized to select 12 anesthetic nurses from a tertiary hospital in Shanghai as research subjects.Semi-structured interviews were conducted,and the data were organized and analyzed using Colaizzi’s seven-step analysis method,from which the final themes were extracted.RESULTS After analyzing the interview content,four main themes and eight subthemes were distilled:Inefficient cognition hinders the identification of ED(conceptual ambiguity,empirical identification),managing diversity and challenges(patientcentered safe care,low level of medical-nursing collaboration),work responsibilities and pressure coexist(heavy work responsibilities,occupational risks and stress),demand for high-quality management(expecting the construction of predictive assessment tools and prevention strategies,and pursuing standardized management processes to enhance management effectiveness).CONCLUSION Nursing managers should prioritize the needs and suggestions of nurses in order to enhance their nursing capabilities and provide guidance for standardized management processes.展开更多
The recent report of pressure-induced structural transition and signature of superconductivity with T_(c)≈80 K above 14 GPa in La_(3)Ni_(2)O_(7)crystals has garnered considerable attention.To further elaborate this d...The recent report of pressure-induced structural transition and signature of superconductivity with T_(c)≈80 K above 14 GPa in La_(3)Ni_(2)O_(7)crystals has garnered considerable attention.To further elaborate this discovery,we carried out comprehensive resistance measurements on La_(3)Ni_(2)O_(7)crystals grown in an optical-image floating zone furnace under oxygen pressure(15 bar)using a diamond anvil cell(DAC)and cubic anvil cell(CAC),which employ a solid(KBr)and liquid(glycerol)pressure-transmitting medium,respectively.Sample 1 measured in the DAC exhibits a semiconducting-like behavior with large resistance at low pressures and gradually becomes metallic upon compression.At pressures P 13.7 GPa we observed the appearance of a resistance drop of as much as~50%around 70 K,which evolves into a kink-like anomaly at pressures above 40 GPa and shifts to lower temperatures gradually with increasing magnetic field.These observations are consistent with the recent report mentioned above.On the other hand,sample 2 measured in the CAC retains metallic behavior in the investigated pressure range up to 15 GPa.The hump-like anomaly in resistance around~130 K at ambient pressure disappears at P≥2 GPa.In the pressure range of 11–15 GPa we observed the gradual development of a shoulder-like anomaly in resistance at low temperatures,which evolves into a pronounced drop of resistance of 98%below 62 K at 15 GPa,reaching a temperature-independent resistance of 20μΩbelow 20 K.Similarly,this resistance anomaly can be progressively shifted to lower temperatures by applying external magnetic fields,resembling a typical superconducting transition.Measurements on sample 3 in the CAC reproduce the resistance drop at pressures above 10 GPa and realize zero resistance below 10 K at 15 GPa even though an unusual semiconducting-like behavior is retained in the normal state.Based on these results,we constructed a dome-shaped superconducting phase diagram and discuss some issues regarding the sample-dependent behaviors on pressure-induced hightemperature superconductivity in the La_(3)Ni_(2)O_(7)crystals.展开更多
AIM To determine the distribution of rotavirus VP7 gene in hospitalized children in Yunnan, China. METHODS A total of 366 stool specimens were collected from hospitalized children in hospitals in Yunnan Province from ...AIM To determine the distribution of rotavirus VP7 gene in hospitalized children in Yunnan, China. METHODS A total of 366 stool specimens were collected from hospitalized children in hospitals in Yunnan Province from September 2010 to December 2013. The genomic RNA electropherotypes and the G genotypes of the rotaviruses were determined. A phylogenetic analysis of the VP7 gene was performed. Rotavirus isolation was performed, and characterized by plaque, minimum essential medium, and all genes sequence analysis. Quantification of antibodies for inactivated vaccine prepared with ZTR-68 was examined by enzyme-linked immunosorbent assay and microneutralization assay.RESULTS Group A human rotavirus was detected in 177 of 366(48.4%) stool samples using a colloidal gold device assay. The temporal distribution of rotavirus cases showed significant correlation with the mean air temperature. Rotaviruses were isolated from 13% of the rotavirus-positive samples. The predominant genotype was G1(43.5%), followed by G3(21.7%), G9(17.4%), G2(4.3%), G4(8.7%), and mixed(4.3%) among a total of 23 rotavirus isolates. A rotavirus strain was isolated from a rotavirus-positive stool sample of a 4-month-old child in The First People's Hospital of Zhaotong(2010) for use as a candidate human inactivated rotavirus vaccine strain and for further research, and was designated ZTR-68. The genotype of 11 gene segments of strain ZTR-68(RVA/Human-wt/CHN/ZTR-68/2010/G1P[8]) was characterized. The genotype constellation of strain ZTR-68 was identified as G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. The VP7 and VP4 genotypes of strain ZTR-68 were similar to Wa-like strains.CONCLUSIONS A high prevalence of the G1, G2, and G3 genotypes was detected from 2010 to 2012. However, a dominant prevalence of the G9 genotype was identified as the cause of gastroenteritis in children in Yunnan, China, in 2013. A candidate human inactivated rotavirus vaccine strain, designated ZTR-68 was isolated, characterized, and showed immunogenicity. Our data will be useful for the future formulation and development of a vaccine in China.展开更多
The Mott transition is one of the fundamental issues in condensed matter physics,especially in the system with antiferromagnetic long-range order.However,such a transition is rare in quantum spin liquid(QSL)systems wi...The Mott transition is one of the fundamental issues in condensed matter physics,especially in the system with antiferromagnetic long-range order.However,such a transition is rare in quantum spin liquid(QSL)systems without long-range order.Here we report the experimental pressure-induced insulator to metal transition followed by the emergence of superconductivity in the QSL candidate NaYbSe2 with a triangular lattice of 4 f Yb^3+ions.Detail analysis of transport properties in metallic state shows an evolution from non-Fermi liquid to Fermi liquid behavior when approaching the vicinity of superconductivity.An irreversible structure phase transition occurs around 11 GPa,which is revealed by the x-ray diffraction.These results shed light on the Mott transition in the QSL systems.展开更多
A random quantum circuit is a minimally structured model to study entanglement dynamics of many-body quantum systems.We consider a one-dimensional quantum circuit with noisy Haar-random unitary gates using density mat...A random quantum circuit is a minimally structured model to study entanglement dynamics of many-body quantum systems.We consider a one-dimensional quantum circuit with noisy Haar-random unitary gates using density matrix operator and tensor contraction methods.It is shown that the entanglement evolution of the random quantum circuits is properly characterized by the logarithmic entanglement negativity.By performing exact numerical calculations,we find that,as the physical error rate is decreased below a critical value p;≈0.056,the logarithmic entanglement negativity changes from the area law to the volume law,giving rise to an entanglement transition.The critical exponent of the correlation length can be determined from the finite-size scaling analysis,revealing the universal dynamic property of the noisy intermediate-scale quantum devices.展开更多
Objective: To explore the effects of Bailing capsule combined with irbesartan on oxidative stress, inflammatory response and immune function in patients with diabetic nephropathy. Methods: 142 patients with diabetic n...Objective: To explore the effects of Bailing capsule combined with irbesartan on oxidative stress, inflammatory response and immune function in patients with diabetic nephropathy. Methods: 142 patients with diabetic nephropathy admitted to our hospital from April 2017 to July 2018 were selected as the study subjects. 71 cases in the control group and 71 cases in the observation group were randomly assigned. The renal function, oxidative stress, inflammation and immune indexes of two groups of patients with diabetic nephropathy were compared and analyzed. Results: After treatment, the levels of BUN, SCr, UARE, ROS, AOPPS, TNF-α, CRP and CD8+ of DN patients in both groups decreased significantly compared with those before the treatment, while the levels of SOD, CD4+, CD4+/CD8+ increased significantly compared with those before the treatment;and the levels of BUN, SCr, UARE, ROS, AOPPS, TNF-α, CRP and CD8+ in the observation group were significantly lower than those in the control group, while the levels of SOD, CD4+, CD4+/CD8+ in the observation group were significantly higher than those in the control group. Conclusions: Bailing capsule combined with irbesartan in the treatment of diabetic nephropathy can effectively improve the renal function, oxidize inflammatory reaction and enhance the immune function of patients, which has clinical significance.展开更多
The oxidation morphologies of modified 310 steel exposed in 900 and 1 100 ℃ air were investigated. A double layer morphology consisting of a (Cr, Mn)-rich outer layer and a fine Cr-rich inner layer was formed at 90...The oxidation morphologies of modified 310 steel exposed in 900 and 1 100 ℃ air were investigated. A double layer morphology consisting of a (Cr, Mn)-rich outer layer and a fine Cr-rich inner layer was formed at 900℃. It was related to the breakaway oxidation induced by the Cr-depletion and the Mn-segregation in inner layer. Some Cr-rich oxides with amorphous state were formed along grain boundaries. And some new finer oxide grains, voids and Cr-rich precipitates were observed in spallation areas at 1 100℃. Correspondingly, the oxidation kinetic curve dropped with the spallation of scale and increased with the formation of some new oxide grains. It was caused by segregation of Cr and the transformation of oxides from Cr2O3 to the volatile oxides at elevated temperature. XRD analysis showed that the precipitates were mainly composed of CrO3. Segregation and depletion for solutions were also discussed by oxidation diffusion mechanisms.展开更多
Recent experiment has shown that the ABC-stacked trilayer graphene-boron nitride Moire super-lattice at half-filling is a Mort insulator. Based on symmetry analysis and effective band structure calculation, we propose...Recent experiment has shown that the ABC-stacked trilayer graphene-boron nitride Moire super-lattice at half-filling is a Mort insulator. Based on symmetry analysis and effective band structure calculation, we propose a valley-contrasting chiral tight-binding model with local Coulomb interaction to describe this Moire super-lattice system. By matching the positions of van Hove points in the low-energy effective bands, the valley-contrasting staggered flux per triangle is determined around π/2. When the valence band is half-filled, the Fermi surfaces are found to be perfectly nested between the two valleys. Such an effect can induce an inter-valley spiral order with a gap in the charge excitations, indicating that the Mott insulating behavior observed in the trilayer graphene-boron nitride Moire super-lattice results predominantly from the inter-valley scattering,展开更多
文摘BACKGROUND The bowel preparation process prior to colonoscopy determines the quality of the bowel preparation,which in turn affects the quality of the colonoscopy.Colono-scopy is an essential procedure for postoperative follow-up monitoring of colorec-tal cancer(CRC)patients.Previous studies have shown that advanced age and a history of colorectal resection are both risk factors for inadequate bowel prepara-tion.However,little attention has been paid to the bowel preparation experiences and needs of predominantly older adult postoperative CRC patients.AIM To explore the experiences and needs of older adult postoperative CRC patients during bowel preparation for follow-up colonoscopy.METHODS Fifteen older adult postoperative CRC patients who underwent follow-up colonoscopy at a tertiary hospital in Shanghai were selected using purposive sampling from August 2023 to November 2023.The phenomenological method in qualitative research was employed to construct an interview outline and conduct semi-structured interviews with the patients.Colaizzi's seven-step analysis was utilized to organize,code,categorize,summarize,and verify the interview data.RESULTS The results of this study were summarized into four themes and eight sub-themes:(1)Inadequate knowledge about bowel preparation;(2)Decreased physiological comfort during bowel preparation(gastrointestinal discomfort and sleep deprivation caused by bowel cleansing agents,and hunger caused by dietary restrictions);(3)Psychological changes during different stages of bowel preparation(pre-preparation:Fear and resistance due to previous experiences;during preparation:Irritation and helplessness caused by taking bowel cleansing agents,and post-preparation:Anxiety and worry while waiting for the colonoscopy);and(4)Needs related to bowel preparation(detailed instructions from healthcare professionals;more ideal bowel cleansing agents;and shortened waiting times for colonoscopy).CONCLUSION Older adult postoperative CRC patients'knowledge of bowel preparation is not adequate,and they may encounter numerous difficulties and challenges during the process.Healthcare professionals should place great emphasis on providing instruction for their bowel preparation.
文摘BACKGROUND This study employs a descriptive phenomenological approach to investigate the challenges anesthesia nurses face in managing emergence delirium(ED),a common and complex postoperative complication in the post-anesthesia care unit.The role of nurses in managing ED is critical,yet research on their understanding and management strategies for ED is lacking.AIM To investigate anesthetic nurses’cognition and management experiences of ED in hopes of developing a standardized management protocol.METHODS This study employed a descriptive phenomenological approach from qualitative research methodologies.Purposeful sampling was utilized to select 12 anesthetic nurses from a tertiary hospital in Shanghai as research subjects.Semi-structured interviews were conducted,and the data were organized and analyzed using Colaizzi’s seven-step analysis method,from which the final themes were extracted.RESULTS After analyzing the interview content,four main themes and eight subthemes were distilled:Inefficient cognition hinders the identification of ED(conceptual ambiguity,empirical identification),managing diversity and challenges(patientcentered safe care,low level of medical-nursing collaboration),work responsibilities and pressure coexist(heavy work responsibilities,occupational risks and stress),demand for high-quality management(expecting the construction of predictive assessment tools and prevention strategies,and pursuing standardized management processes to enhance management effectiveness).CONCLUSION Nursing managers should prioritize the needs and suggestions of nurses in order to enhance their nursing capabilities and provide guidance for standardized management processes.
基金supported by the Beijing Natural Science Foundation(Grant No.Z190008)the National Key Research and Development Program of China(Grant Nos.2018YFA0305700 and 2021YFA1400200)+6 种基金the National Natural Science Foundation of China(Grant Nos.12025408,11921004,11834016,and 11888101)supported by the National Natural Science Foundation of China(Grant No.12174454)the Strategic Priority Research Program of CAS(Grant No.XDB33000000)CAS Project for Young Scientists in Basic Research(Grant Nos.2022YSBR-047 and 2022YSBR-048)the Users with Excellence Program of Hefei Science Center CAS(Grant No.2021HSCUE008)Guangdong Basic and Applied Basic Research Funds(Grant No.2021B1515120015)Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)。
文摘The recent report of pressure-induced structural transition and signature of superconductivity with T_(c)≈80 K above 14 GPa in La_(3)Ni_(2)O_(7)crystals has garnered considerable attention.To further elaborate this discovery,we carried out comprehensive resistance measurements on La_(3)Ni_(2)O_(7)crystals grown in an optical-image floating zone furnace under oxygen pressure(15 bar)using a diamond anvil cell(DAC)and cubic anvil cell(CAC),which employ a solid(KBr)and liquid(glycerol)pressure-transmitting medium,respectively.Sample 1 measured in the DAC exhibits a semiconducting-like behavior with large resistance at low pressures and gradually becomes metallic upon compression.At pressures P 13.7 GPa we observed the appearance of a resistance drop of as much as~50%around 70 K,which evolves into a kink-like anomaly at pressures above 40 GPa and shifts to lower temperatures gradually with increasing magnetic field.These observations are consistent with the recent report mentioned above.On the other hand,sample 2 measured in the CAC retains metallic behavior in the investigated pressure range up to 15 GPa.The hump-like anomaly in resistance around~130 K at ambient pressure disappears at P≥2 GPa.In the pressure range of 11–15 GPa we observed the gradual development of a shoulder-like anomaly in resistance at low temperatures,which evolves into a pronounced drop of resistance of 98%below 62 K at 15 GPa,reaching a temperature-independent resistance of 20μΩbelow 20 K.Similarly,this resistance anomaly can be progressively shifted to lower temperatures by applying external magnetic fields,resembling a typical superconducting transition.Measurements on sample 3 in the CAC reproduce the resistance drop at pressures above 10 GPa and realize zero resistance below 10 K at 15 GPa even though an unusual semiconducting-like behavior is retained in the normal state.Based on these results,we constructed a dome-shaped superconducting phase diagram and discuss some issues regarding the sample-dependent behaviors on pressure-induced hightemperature superconductivity in the La_(3)Ni_(2)O_(7)crystals.
基金Supported by the CAMS Initiative for Innovative Medicine,No.2016-I2M-1-019 and No.2016-I2M-3-026National Natural Science Foundation of China,No.31700154+2 种基金Major Science and Technology Special Project of Yunnan Province(Biomedicine),No.2018ZF006Science and Technology Project of Yunnan Province-general program,No.2016FB034The State Project for Essential Drug Research and Development,the national "Twelfth Five-Year" plan,No.2014ZX09102041004
文摘AIM To determine the distribution of rotavirus VP7 gene in hospitalized children in Yunnan, China. METHODS A total of 366 stool specimens were collected from hospitalized children in hospitals in Yunnan Province from September 2010 to December 2013. The genomic RNA electropherotypes and the G genotypes of the rotaviruses were determined. A phylogenetic analysis of the VP7 gene was performed. Rotavirus isolation was performed, and characterized by plaque, minimum essential medium, and all genes sequence analysis. Quantification of antibodies for inactivated vaccine prepared with ZTR-68 was examined by enzyme-linked immunosorbent assay and microneutralization assay.RESULTS Group A human rotavirus was detected in 177 of 366(48.4%) stool samples using a colloidal gold device assay. The temporal distribution of rotavirus cases showed significant correlation with the mean air temperature. Rotaviruses were isolated from 13% of the rotavirus-positive samples. The predominant genotype was G1(43.5%), followed by G3(21.7%), G9(17.4%), G2(4.3%), G4(8.7%), and mixed(4.3%) among a total of 23 rotavirus isolates. A rotavirus strain was isolated from a rotavirus-positive stool sample of a 4-month-old child in The First People's Hospital of Zhaotong(2010) for use as a candidate human inactivated rotavirus vaccine strain and for further research, and was designated ZTR-68. The genotype of 11 gene segments of strain ZTR-68(RVA/Human-wt/CHN/ZTR-68/2010/G1P[8]) was characterized. The genotype constellation of strain ZTR-68 was identified as G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. The VP7 and VP4 genotypes of strain ZTR-68 were similar to Wa-like strains.CONCLUSIONS A high prevalence of the G1, G2, and G3 genotypes was detected from 2010 to 2012. However, a dominant prevalence of the G9 genotype was identified as the cause of gastroenteritis in children in Yunnan, China, in 2013. A candidate human inactivated rotavirus vaccine strain, designated ZTR-68 was isolated, characterized, and showed immunogenicity. Our data will be useful for the future formulation and development of a vaccine in China.
基金supported by the National Key R&D Program of China(Grant Nos.2016YFA0300504,2018YFE0202600 and2018YFA0305701)the National Natural Science Foundation of China(Grant Nos.11774423,11822412 and 11921004)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China(Grant Nos.18XNLG14and 19XNLG17)。
文摘The Mott transition is one of the fundamental issues in condensed matter physics,especially in the system with antiferromagnetic long-range order.However,such a transition is rare in quantum spin liquid(QSL)systems without long-range order.Here we report the experimental pressure-induced insulator to metal transition followed by the emergence of superconductivity in the QSL candidate NaYbSe2 with a triangular lattice of 4 f Yb^3+ions.Detail analysis of transport properties in metallic state shows an evolution from non-Fermi liquid to Fermi liquid behavior when approaching the vicinity of superconductivity.An irreversible structure phase transition occurs around 11 GPa,which is revealed by the x-ray diffraction.These results shed light on the Mott transition in the QSL systems.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0302902)。
文摘A random quantum circuit is a minimally structured model to study entanglement dynamics of many-body quantum systems.We consider a one-dimensional quantum circuit with noisy Haar-random unitary gates using density matrix operator and tensor contraction methods.It is shown that the entanglement evolution of the random quantum circuits is properly characterized by the logarithmic entanglement negativity.By performing exact numerical calculations,we find that,as the physical error rate is decreased below a critical value p;≈0.056,the logarithmic entanglement negativity changes from the area law to the volume law,giving rise to an entanglement transition.The critical exponent of the correlation length can be determined from the finite-size scaling analysis,revealing the universal dynamic property of the noisy intermediate-scale quantum devices.
文摘Objective: To explore the effects of Bailing capsule combined with irbesartan on oxidative stress, inflammatory response and immune function in patients with diabetic nephropathy. Methods: 142 patients with diabetic nephropathy admitted to our hospital from April 2017 to July 2018 were selected as the study subjects. 71 cases in the control group and 71 cases in the observation group were randomly assigned. The renal function, oxidative stress, inflammation and immune indexes of two groups of patients with diabetic nephropathy were compared and analyzed. Results: After treatment, the levels of BUN, SCr, UARE, ROS, AOPPS, TNF-α, CRP and CD8+ of DN patients in both groups decreased significantly compared with those before the treatment, while the levels of SOD, CD4+, CD4+/CD8+ increased significantly compared with those before the treatment;and the levels of BUN, SCr, UARE, ROS, AOPPS, TNF-α, CRP and CD8+ in the observation group were significantly lower than those in the control group, while the levels of SOD, CD4+, CD4+/CD8+ in the observation group were significantly higher than those in the control group. Conclusions: Bailing capsule combined with irbesartan in the treatment of diabetic nephropathy can effectively improve the renal function, oxidize inflammatory reaction and enhance the immune function of patients, which has clinical significance.
基金Item Sponsored by Key Projects Funded Program of Henan Province Education Department of China(I15A430012)
文摘The oxidation morphologies of modified 310 steel exposed in 900 and 1 100 ℃ air were investigated. A double layer morphology consisting of a (Cr, Mn)-rich outer layer and a fine Cr-rich inner layer was formed at 900℃. It was related to the breakaway oxidation induced by the Cr-depletion and the Mn-segregation in inner layer. Some Cr-rich oxides with amorphous state were formed along grain boundaries. And some new finer oxide grains, voids and Cr-rich precipitates were observed in spallation areas at 1 100℃. Correspondingly, the oxidation kinetic curve dropped with the spallation of scale and increased with the formation of some new oxide grains. It was caused by segregation of Cr and the transformation of oxides from Cr2O3 to the volatile oxides at elevated temperature. XRD analysis showed that the precipitates were mainly composed of CrO3. Segregation and depletion for solutions were also discussed by oxidation diffusion mechanisms.
基金supported by the National Key Research and Development Program of MOST of China(2017YFA0302900)the National Natural Science Foundation of China(11474331)
文摘Recent experiment has shown that the ABC-stacked trilayer graphene-boron nitride Moire super-lattice at half-filling is a Mort insulator. Based on symmetry analysis and effective band structure calculation, we propose a valley-contrasting chiral tight-binding model with local Coulomb interaction to describe this Moire super-lattice system. By matching the positions of van Hove points in the low-energy effective bands, the valley-contrasting staggered flux per triangle is determined around π/2. When the valence band is half-filled, the Fermi surfaces are found to be perfectly nested between the two valleys. Such an effect can induce an inter-valley spiral order with a gap in the charge excitations, indicating that the Mott insulating behavior observed in the trilayer graphene-boron nitride Moire super-lattice results predominantly from the inter-valley scattering,