In 2018,Baige,Xizang,witnessed two consecutive large-scale landslides,causing significant damage and drawing widespread attention.From March 2011 to February 2018,the Baige landslide exhibited a 50-m displacement with...In 2018,Baige,Xizang,witnessed two consecutive large-scale landslides,causing significant damage and drawing widespread attention.From March 2011 to February 2018,the Baige landslide exhibited a 50-m displacement without complete failure,culminating in a collapse in October 2018.The mechanisms behind its resistance to failure despite substantial deformation and the influence of the complex geo-structure within the tectonic mélange belt remain unclear.To address these questions,this study utilized a multidisciplinary approach,integrating on-site geological field mapping,surface deformation monitoring,multielectrode resistivity method,and deep displacement analysis.The aim was to evaluate the impact of the intricate geo-structure within the tectonic mélange belt on the Baige landslide events.Findings reveal that the landslide's geo-structure consists of structurally fractured,mesh-like rock masses,including heterogeneous lenticular rock masses and intermittent brittle shear zones distributed around the lens-shaped rock masses.The study underscores that the inhomogeneous and weakly deformed lenticular rock masses function as natural locked segments,governing the stability of the Baige landslide.Specifically,the relatively intact and hard granodiorite porphyry play a crucial role in locking the landslide's deformation.Deep displacement analysis indicates that the brittle shear zones act as the sliding surfaces.The progressive destruction of the locked segments and the gradual penetration of brittle shear zones,driven by gravitational potential energy,contribute to the landslide occurrence.This research provides critical insights into the formation mechanisms of large-scale landslides within tectonic mélange belts.展开更多
Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing,recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages.Here,we study the...Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing,recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages.Here,we study the structure and properties of a new type of thermoplastic polyurethanes(TPUs)with trapped dynamic covalent bonds in the hard-phase domain and report the frustrated relaxation of TPUs containing weak dynamic bond andπ-πinteraction in hard segments.As detected by rheometry,the aromatic TPUs with alkyl disulfide in the hard segments possess the maximum network relaxation time in contrast to those without dynamic bonds and alicyclic TPUs.In situ FTIR and small-angle scattering results reveal that the alkyl disulfide facilitates stronger intermolecular interaction and more stable micro-phase morphology inπ-πinteraction based aromatic TPUs.Molecular dynamics simulation for pure hard segments of model molecules verify that the presence of disulfide bonds leads to strongerπ-πstacking of aromatic rings due to both enhanced assembling thermodynamics and kinetics.The enhancedπ-πpacking and micro-phase structure in TPUs further kinetically immobilize the dynamic bond.This kinetically interlocking between the weak dynamic bonds and strong molecular interaction in hard segments leads to much slower network relaxation of TPU.This work provides a new insight in tuning the network relaxation and heat resistance as well as molecular self-assembly in stimulus-responsive dynamic polymers by both molecular design and micro-phase control toward the functional applications of advanced materials.展开更多
Purpose:To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods:The study group is treated...Purpose:To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods:The study group is treated with PFNA internal fixation.The control group is treated by internal fixation with anatomical locking plate of proximal femur.Results:The time of operation,the amount of intraoperative bleeding and the time of fracture healing in the study group are significantly less than those in the control group.The incidence rate of complication in the study group(3.23%)is significantly lower than that in the control group(17.2%).Data comparison shows P<0.05.Conclusion:The curative effect and prognosis for patients with intertrochanteric fracture of femur treated by PFNA internal fixation are more ideal.展开更多
Purpose To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods The study group is treated...Purpose To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods The study group is treated with PFNA internal fixation.The control group is treated by internal fixation with anatomical locking plate of proximal femur.Results The time of operation,the amount of intraoperative bleeding and the time of fracture healing in the study group are significantly less than those in the control group.The incidence rate of complication in the study group(3.23%)is significantly lower than that in the control group(17.2%).Data comparison shows P<0.05.Conclusion The curative effect and prognosis for patients with intertrochanteric fracture of femur treated by PFNA internal fixation are more ideal.展开更多
Objective:To analyze the effect of locking compression plate on the success rate of operation and the time of postoperative recovery.Methods:120 patients with limb fractures from March 2018 to March 2020 were randomly...Objective:To analyze the effect of locking compression plate on the success rate of operation and the time of postoperative recovery.Methods:120 patients with limb fractures from March 2018 to March 2020 were randomly divided into control group(60 cases)and observation group(60 cases).The control group was treated with plate screw internal fixation,The observation group used locking compression plate internal fixation,Compare the effect of treatment,the success rate of operation and the time of postoperative recovery.results:compared the effective rate of the two groups,the observation group(93.33%)was significantly higher than the control group(75.00%).Compared with the two groups,the success rate of operation and the time of postoperative recovery,the observed composition power was higher than that of the control group,and the postoperative recovery time was lower than that of the control group,P<0.05.Conclusion:The use of locking compression plate for the treatment of limb fracture can significantly increase the probability of successful operation,shorten the recovery time after operation,the overall curative effect is ideal,and the clinical popularization value is high.展开更多
Objective: to analyze the clinical effect of locking compression plate on limb fractures. Methods: 130 patients with limb fractures received in our hospital from June 2021 to July 2022 were selected for the study. The...Objective: to analyze the clinical effect of locking compression plate on limb fractures. Methods: 130 patients with limb fractures received in our hospital from June 2021 to July 2022 were selected for the study. They were randomly divided into the control group (ordinary plate and screw internal fixation) and the observation group (locking compression plate treatment), 65 patients in each group. The clinical effects were compared. Results: the clinical effective rate of the observation group was significantly better than that of the control group (P < 0.05);the operation time, fracture healing time, X-ray callus score, VAS score and complication rate in the observation group were significantly lower than those in the control group (P < 0.05). Conclusion: the clinical effect of locking compression plate for limb fracture is significant, which can promote patients to obtain better treatment effect, significantly shorten the operation time of patients, promote fracture healing, further reduce the body pain of patients, reduce the pain of patients, and the probability of adverse reactions of patients is relatively low, which has high safety in clinical application. It also shows that this treatment method has a better significance of popularization and application.展开更多
Objective: to evaluate the effect of anatomical locking plate and retrograde intramedullary nail in the diagnosis and treatment of femoral supracondylar fracture. Methods: the clinical records of 45 patients with femo...Objective: to evaluate the effect of anatomical locking plate and retrograde intramedullary nail in the diagnosis and treatment of femoral supracondylar fracture. Methods: the clinical records of 45 patients with femoral supracondylar fracture previously diagnosed and treated in our hospital were selected and divided into two groups according to different treatment methods: the relevant reinforcement group (20 cases) for analyzing locking plate and the relevant internal fixation group (25 cases) for retrograde intramedullary nail. To observe the clinical effects of operation time, bleeding value and fracture healing time of patients with supracondylar fracture disease in both groups. Results: the operation time and fracture healing time of the patients in the treatment group with internal screw fixation corresponding to the retrograde medullary position were shorter than those in the treatment group with anatomical locking plate, and the bleeding value was smaller than that in the treatment group with anatomical locking plate, the difference was statistically significant (P < 0.05). Conclusion: the diagnosis and treatment of retrograde intramedullary nail internal fixation is less harmful to the patients with femoral supracondylar fracture, the operation time is shorter, and the prognosis is good. It can be widely applied in clinical practice.展开更多
Reform and opening up has made China’s economy develop faster than ever. But it has not succeeded in changing the regional disparity in China. In this article, we establish a model factor input called the "lock-...Reform and opening up has made China’s economy develop faster than ever. But it has not succeeded in changing the regional disparity in China. In this article, we establish a model factor input called the "lock-in effect" and analyze the channel of the lock-in effect and how it influences the regional economy. On the analyses of thirty provinces’ panel data in China from 1990 to 2005, we find that the lock-in effect of factor inputs further exacerbates the developmental imbalance among regions.展开更多
Mode locking can be effectively achieved by using the thermo-optic effects in the whispering gallery mode(WGM)optical microcavity,without the help of external equipment.Therefore,it has the advantages of small size,lo...Mode locking can be effectively achieved by using the thermo-optic effects in the whispering gallery mode(WGM)optical microcavity,without the help of external equipment.Therefore,it has the advantages of small size,low integration costs,and self-locking,which shows great potential for application.However,the conventional single-channel microcavity thermal-locking method that relies solely on internal thermal balance will inevitably be disturbed by the external environment.This limitation affects the locking time and stability.Therefore,in this paper,we propose a new method for closed-loop thermal locking of a dual-channel microcavity.The thermal locking of the signal laser and the thermal regulation of the control laser are carried out respectively by synchronously drawing a dual-path tapered fiber.The theoretical model of the thermal dynamics of the dual-channel microcavity system is established,and the influence of the control-laser power on the thermal locking of the signal laser is confirmed.The deviation between the locking voltage of the signal laser and the set point value is used as a closed-loop feedback parameter to achieve long-term and highly stable mode locking of the signal laser.The results show that in the 2.63 h thermal-locking test,the locking stability is an order of magnitude higher than that of the single tapered fiber.This solution addresses the issue of thermal locking being disrupted by the external environment,and offers new possibilities for important applications such as spectroscopy and micro-optical sensor devices.展开更多
Objective: to analyze and study the therapeutic effect of locking bone plate internal fixation stent system for osteoporotic fracture, hoping to provide certain reference for the treatment of osteoporotic fracture thr...Objective: to analyze and study the therapeutic effect of locking bone plate internal fixation stent system for osteoporotic fracture, hoping to provide certain reference for the treatment of osteoporotic fracture through this study. Methods: for research materials into the group stipulated time in March 2020 to March 2021, choose 80 patients in our hospital for treatment of patients with osteoporotic fractures, and They have been divided into 40 cases accepted by the computer random locking plate internal fixation treatment of supporting system of the experimental group and 40 anatomical steel treated with a control group. After treatment by different ways of treatment and the amount of blood loss, postoperative complications, treatment costs and functional status of joints were compared between the two groups. Results: after data statistics, the amount of blood loss in the experimental group was less than the control group. The postoperative complications were lower than those in the control group. The treatment cost of the experimental group was higher. The functional status of joints in the experimental group was significantly better. The above data showed significant differences between the experimental group and the control group. Conclusion: although the cost of locking plate internal fixation stent system in the treatment of osteoporotic fracture is higher than that of anatomical plate treatment, the clinical treatment indicators of patients with locking plate internal fixation stent system are better, so it is worthy of use and promotion in the treatment of patients with osteoporotic fracture.展开更多
The applications of magnetrons are greatly limited because of the poor output spectrum of the free-running magnetron.Currently, one of the best ways to solve this problem is injection locking. However, the injection l...The applications of magnetrons are greatly limited because of the poor output spectrum of the free-running magnetron.Currently, one of the best ways to solve this problem is injection locking. However, the injection locking theory which is widely used nowadays is based on the simplified oscillator, which does not include the frequency pushing effect of the magnetron. In this paper, the theory of injection locking magnetrons with frequency pushing effect is systematically studied.Analytical analysis shows that the locking bandwidth turns larger with the consideration of the pushing parameter(α), and the increase of locking bandwidth is expanded with α increasing. Experimental results show that the locking bandwidth is expanded by 0.3 MHz, 1 MHz, and 1.6 MHz compared with the locking bandwidth from the conventional locking theory under an injection ratio(ρ) of 0.05, 0.075, and 0.1, respectively. This research provides a more accurate prediction of the properties of the injection-locked magnetron.展开更多
We present a compact passively mode-locked semiconductor disk laser at 1045 nm. The gain chip without any post processing consists of 16 compressively strained In Ga As symmetrical step quantum wells in the active reg...We present a compact passively mode-locked semiconductor disk laser at 1045 nm. The gain chip without any post processing consists of 16 compressively strained In Ga As symmetrical step quantum wells in the active region. 3-GHz repetition rate, 4.9-ps pulse duration, and 30-mW average output power are obtained with 1.4 W of 808-nm incident pump power. The temperature stability of the laser is demonstrated to have an ideal shift rate of 0.035 nm/K of the lasing wavelength.展开更多
In this study, two-section mode-locked semiconductor lasers with different numbers of quantum wells and different types of waveguide structures are made. Their ultrashort pulse features are presented. The spectral dyn...In this study, two-section mode-locked semiconductor lasers with different numbers of quantum wells and different types of waveguide structures are made. Their ultrashort pulse features are presented. The spectral dynamical behaviors in these lasers are studied in detail. In the simulation part, a two-band compressive-strained quantum well（QW） model is used to study thermally induced band-edge detuning in the amplifier and saturable absorber（SA）. A sudden blue shift in laser spectrum is expected by calculating the peak of the net gain. In the experiment part, the sudden blue shift in the emission spectrum is observed in triple QW samples under certain operating conditions but remains absent in single QW samples.Experimental results reveal that blue shift phenomenon is connected with the difference between currents in two sections.Additionally, a threshold current ratio for blue-shift is also demonstrated.展开更多
Using a newly reported Pacific sea surface temperature data set, we extend a prior study that assigned El Niño episodes to distinct sequences. Within these sequences the episodes are phase-locked to subharmoni...Using a newly reported Pacific sea surface temperature data set, we extend a prior study that assigned El Niño episodes to distinct sequences. Within these sequences the episodes are phase-locked to subharmonics of the annual solar irradiance cycle having two- or three-year periodicity. There are 40 El Niño episodes occurring since 1872, each found within one of eighteen such sequences. Our list includes all previously reported events. Three El Niño episodes have already been observed in boreal winters of 2009, 2012 and 2015, illustrating a sequence of 3-year intervals that began in 2008. If the climate system remains in this state, the next El Niño is likely to occur in boreal winter of 2018.展开更多
In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequ...In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequencies are designed and fabricated in 0.5 μm n-well CMOS process. Cadence/Spectre simulations show that the frequency range of the switchable phased-locked loop is between 320 MHz to 1.15 GHz. The experimental results show that the RMS jitter of the phase-locked loop changes from 26 ps to 123 ps as output frequency varies. For 700 MHz carrier frequency, the phase noise of the phase-locked loop reaches as low as ?81 dBc/Hz at 10 kHz offset frequency and ?104 dBc/Hz at 1 MHz offset frequency. A device degradation model due to hot carrier effects has been used to analyze the jitter and phase noise performance in an open loop voltage-controlled oscillator. The oscillation frequency of the voltage-controlled oscillator decreases by approximately 100 to 200 MHz versus the bias voltage and the RMS jitter increases by 40 ps under different phase-locked loop output frequencies after 4 hours of stress time.展开更多
基金supported by the National Major Scientific Instruments and Equipment Development Projects of China(No.41827808)the Major Program of the National Natural Science Foundation of China(No.42090055)Supported by Science and Technology Projects of Xizang Autonomous Region,China(No.XZ202402ZD0001)。
文摘In 2018,Baige,Xizang,witnessed two consecutive large-scale landslides,causing significant damage and drawing widespread attention.From March 2011 to February 2018,the Baige landslide exhibited a 50-m displacement without complete failure,culminating in a collapse in October 2018.The mechanisms behind its resistance to failure despite substantial deformation and the influence of the complex geo-structure within the tectonic mélange belt remain unclear.To address these questions,this study utilized a multidisciplinary approach,integrating on-site geological field mapping,surface deformation monitoring,multielectrode resistivity method,and deep displacement analysis.The aim was to evaluate the impact of the intricate geo-structure within the tectonic mélange belt on the Baige landslide events.Findings reveal that the landslide's geo-structure consists of structurally fractured,mesh-like rock masses,including heterogeneous lenticular rock masses and intermittent brittle shear zones distributed around the lens-shaped rock masses.The study underscores that the inhomogeneous and weakly deformed lenticular rock masses function as natural locked segments,governing the stability of the Baige landslide.Specifically,the relatively intact and hard granodiorite porphyry play a crucial role in locking the landslide's deformation.Deep displacement analysis indicates that the brittle shear zones act as the sliding surfaces.The progressive destruction of the locked segments and the gradual penetration of brittle shear zones,driven by gravitational potential energy,contribute to the landslide occurrence.This research provides critical insights into the formation mechanisms of large-scale landslides within tectonic mélange belts.
基金financially supported by the National Natural Science Foundation of China(No.21774135)。
文摘Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing,recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages.Here,we study the structure and properties of a new type of thermoplastic polyurethanes(TPUs)with trapped dynamic covalent bonds in the hard-phase domain and report the frustrated relaxation of TPUs containing weak dynamic bond andπ-πinteraction in hard segments.As detected by rheometry,the aromatic TPUs with alkyl disulfide in the hard segments possess the maximum network relaxation time in contrast to those without dynamic bonds and alicyclic TPUs.In situ FTIR and small-angle scattering results reveal that the alkyl disulfide facilitates stronger intermolecular interaction and more stable micro-phase morphology inπ-πinteraction based aromatic TPUs.Molecular dynamics simulation for pure hard segments of model molecules verify that the presence of disulfide bonds leads to strongerπ-πstacking of aromatic rings due to both enhanced assembling thermodynamics and kinetics.The enhancedπ-πpacking and micro-phase structure in TPUs further kinetically immobilize the dynamic bond.This kinetically interlocking between the weak dynamic bonds and strong molecular interaction in hard segments leads to much slower network relaxation of TPU.This work provides a new insight in tuning the network relaxation and heat resistance as well as molecular self-assembly in stimulus-responsive dynamic polymers by both molecular design and micro-phase control toward the functional applications of advanced materials.
文摘Purpose:To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods:The study group is treated with PFNA internal fixation.The control group is treated by internal fixation with anatomical locking plate of proximal femur.Results:The time of operation,the amount of intraoperative bleeding and the time of fracture healing in the study group are significantly less than those in the control group.The incidence rate of complication in the study group(3.23%)is significantly lower than that in the control group(17.2%).Data comparison shows P<0.05.Conclusion:The curative effect and prognosis for patients with intertrochanteric fracture of femur treated by PFNA internal fixation are more ideal.
文摘Purpose To investigate the clinical value of proximal femoral nail antirotation and anatomical locking plate of proximal femur in the treatment of intertrochanteric fracture of femur.Methods The study group is treated with PFNA internal fixation.The control group is treated by internal fixation with anatomical locking plate of proximal femur.Results The time of operation,the amount of intraoperative bleeding and the time of fracture healing in the study group are significantly less than those in the control group.The incidence rate of complication in the study group(3.23%)is significantly lower than that in the control group(17.2%).Data comparison shows P<0.05.Conclusion The curative effect and prognosis for patients with intertrochanteric fracture of femur treated by PFNA internal fixation are more ideal.
文摘Objective:To analyze the effect of locking compression plate on the success rate of operation and the time of postoperative recovery.Methods:120 patients with limb fractures from March 2018 to March 2020 were randomly divided into control group(60 cases)and observation group(60 cases).The control group was treated with plate screw internal fixation,The observation group used locking compression plate internal fixation,Compare the effect of treatment,the success rate of operation and the time of postoperative recovery.results:compared the effective rate of the two groups,the observation group(93.33%)was significantly higher than the control group(75.00%).Compared with the two groups,the success rate of operation and the time of postoperative recovery,the observed composition power was higher than that of the control group,and the postoperative recovery time was lower than that of the control group,P<0.05.Conclusion:The use of locking compression plate for the treatment of limb fracture can significantly increase the probability of successful operation,shorten the recovery time after operation,the overall curative effect is ideal,and the clinical popularization value is high.
文摘Objective: to analyze the clinical effect of locking compression plate on limb fractures. Methods: 130 patients with limb fractures received in our hospital from June 2021 to July 2022 were selected for the study. They were randomly divided into the control group (ordinary plate and screw internal fixation) and the observation group (locking compression plate treatment), 65 patients in each group. The clinical effects were compared. Results: the clinical effective rate of the observation group was significantly better than that of the control group (P < 0.05);the operation time, fracture healing time, X-ray callus score, VAS score and complication rate in the observation group were significantly lower than those in the control group (P < 0.05). Conclusion: the clinical effect of locking compression plate for limb fracture is significant, which can promote patients to obtain better treatment effect, significantly shorten the operation time of patients, promote fracture healing, further reduce the body pain of patients, reduce the pain of patients, and the probability of adverse reactions of patients is relatively low, which has high safety in clinical application. It also shows that this treatment method has a better significance of popularization and application.
文摘Objective: to evaluate the effect of anatomical locking plate and retrograde intramedullary nail in the diagnosis and treatment of femoral supracondylar fracture. Methods: the clinical records of 45 patients with femoral supracondylar fracture previously diagnosed and treated in our hospital were selected and divided into two groups according to different treatment methods: the relevant reinforcement group (20 cases) for analyzing locking plate and the relevant internal fixation group (25 cases) for retrograde intramedullary nail. To observe the clinical effects of operation time, bleeding value and fracture healing time of patients with supracondylar fracture disease in both groups. Results: the operation time and fracture healing time of the patients in the treatment group with internal screw fixation corresponding to the retrograde medullary position were shorter than those in the treatment group with anatomical locking plate, and the bleeding value was smaller than that in the treatment group with anatomical locking plate, the difference was statistically significant (P < 0.05). Conclusion: the diagnosis and treatment of retrograde intramedullary nail internal fixation is less harmful to the patients with femoral supracondylar fracture, the operation time is shorter, and the prognosis is good. It can be widely applied in clinical practice.
文摘Reform and opening up has made China’s economy develop faster than ever. But it has not succeeded in changing the regional disparity in China. In this article, we establish a model factor input called the "lock-in effect" and analyze the channel of the lock-in effect and how it influences the regional economy. On the analyses of thirty provinces’ panel data in China from 1990 to 2005, we find that the lock-in effect of factor inputs further exacerbates the developmental imbalance among regions.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB3203400)the National Natural Science Foundation of China(Grant Nos.U21A20141,62273314,and 51821003)+1 种基金the Fundamental Research Program of Shanxi Province(Grant No.202303021223001)Shanxi Province Key Laboratory of Quantum Sensing and Precision Measurement(Grant No.201905D121001)。
文摘Mode locking can be effectively achieved by using the thermo-optic effects in the whispering gallery mode(WGM)optical microcavity,without the help of external equipment.Therefore,it has the advantages of small size,low integration costs,and self-locking,which shows great potential for application.However,the conventional single-channel microcavity thermal-locking method that relies solely on internal thermal balance will inevitably be disturbed by the external environment.This limitation affects the locking time and stability.Therefore,in this paper,we propose a new method for closed-loop thermal locking of a dual-channel microcavity.The thermal locking of the signal laser and the thermal regulation of the control laser are carried out respectively by synchronously drawing a dual-path tapered fiber.The theoretical model of the thermal dynamics of the dual-channel microcavity system is established,and the influence of the control-laser power on the thermal locking of the signal laser is confirmed.The deviation between the locking voltage of the signal laser and the set point value is used as a closed-loop feedback parameter to achieve long-term and highly stable mode locking of the signal laser.The results show that in the 2.63 h thermal-locking test,the locking stability is an order of magnitude higher than that of the single tapered fiber.This solution addresses the issue of thermal locking being disrupted by the external environment,and offers new possibilities for important applications such as spectroscopy and micro-optical sensor devices.
文摘Objective: to analyze and study the therapeutic effect of locking bone plate internal fixation stent system for osteoporotic fracture, hoping to provide certain reference for the treatment of osteoporotic fracture through this study. Methods: for research materials into the group stipulated time in March 2020 to March 2021, choose 80 patients in our hospital for treatment of patients with osteoporotic fractures, and They have been divided into 40 cases accepted by the computer random locking plate internal fixation treatment of supporting system of the experimental group and 40 anatomical steel treated with a control group. After treatment by different ways of treatment and the amount of blood loss, postoperative complications, treatment costs and functional status of joints were compared between the two groups. Results: after data statistics, the amount of blood loss in the experimental group was less than the control group. The postoperative complications were lower than those in the control group. The treatment cost of the experimental group was higher. The functional status of joints in the experimental group was significantly better. The above data showed significant differences between the experimental group and the control group. Conclusion: although the cost of locking plate internal fixation stent system in the treatment of osteoporotic fracture is higher than that of anatomical plate treatment, the clinical treatment indicators of patients with locking plate internal fixation stent system are better, so it is worthy of use and promotion in the treatment of patients with osteoporotic fracture.
基金Project supported by the Sichuan Science and Technology Program,China(Grant No.2019YFG0419)the National Natural Science Foundation of China(Grant No.61601312)
文摘The applications of magnetrons are greatly limited because of the poor output spectrum of the free-running magnetron.Currently, one of the best ways to solve this problem is injection locking. However, the injection locking theory which is widely used nowadays is based on the simplified oscillator, which does not include the frequency pushing effect of the magnetron. In this paper, the theory of injection locking magnetrons with frequency pushing effect is systematically studied.Analytical analysis shows that the locking bandwidth turns larger with the consideration of the pushing parameter(α), and the increase of locking bandwidth is expanded with α increasing. Experimental results show that the locking bandwidth is expanded by 0.3 MHz, 1 MHz, and 1.6 MHz compared with the locking bandwidth from the conventional locking theory under an injection ratio(ρ) of 0.05, 0.075, and 0.1, respectively. This research provides a more accurate prediction of the properties of the injection-locked magnetron.
基金supported by the National Natural Science Foundation of China(Grant No.61177047)the Key Project of the National Natural Science Foundation of China(Grant No.61235010)
文摘We present a compact passively mode-locked semiconductor disk laser at 1045 nm. The gain chip without any post processing consists of 16 compressively strained In Ga As symmetrical step quantum wells in the active region. 3-GHz repetition rate, 4.9-ps pulse duration, and 30-mW average output power are obtained with 1.4 W of 808-nm incident pump power. The temperature stability of the laser is demonstrated to have an ideal shift rate of 0.035 nm/K of the lasing wavelength.
基金Project supported by the National Basic Research Program of China(Grant Nos.2013CB933304 and 2012CB932701)the National Natural Science Foundation of China(Grant Nos.61274125 and 61435012)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB01010200)
文摘In this study, two-section mode-locked semiconductor lasers with different numbers of quantum wells and different types of waveguide structures are made. Their ultrashort pulse features are presented. The spectral dynamical behaviors in these lasers are studied in detail. In the simulation part, a two-band compressive-strained quantum well（QW） model is used to study thermally induced band-edge detuning in the amplifier and saturable absorber（SA）. A sudden blue shift in laser spectrum is expected by calculating the peak of the net gain. In the experiment part, the sudden blue shift in the emission spectrum is observed in triple QW samples under certain operating conditions but remains absent in single QW samples.Experimental results reveal that blue shift phenomenon is connected with the difference between currents in two sections.Additionally, a threshold current ratio for blue-shift is also demonstrated.
文摘Using a newly reported Pacific sea surface temperature data set, we extend a prior study that assigned El Niño episodes to distinct sequences. Within these sequences the episodes are phase-locked to subharmonics of the annual solar irradiance cycle having two- or three-year periodicity. There are 40 El Niño episodes occurring since 1872, each found within one of eighteen such sequences. Our list includes all previously reported events. Three El Niño episodes have already been observed in boreal winters of 2009, 2012 and 2015, illustrating a sequence of 3-year intervals that began in 2008. If the climate system remains in this state, the next El Niño is likely to occur in boreal winter of 2018.
文摘In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequencies are designed and fabricated in 0.5 μm n-well CMOS process. Cadence/Spectre simulations show that the frequency range of the switchable phased-locked loop is between 320 MHz to 1.15 GHz. The experimental results show that the RMS jitter of the phase-locked loop changes from 26 ps to 123 ps as output frequency varies. For 700 MHz carrier frequency, the phase noise of the phase-locked loop reaches as low as ?81 dBc/Hz at 10 kHz offset frequency and ?104 dBc/Hz at 1 MHz offset frequency. A device degradation model due to hot carrier effects has been used to analyze the jitter and phase noise performance in an open loop voltage-controlled oscillator. The oscillation frequency of the voltage-controlled oscillator decreases by approximately 100 to 200 MHz versus the bias voltage and the RMS jitter increases by 40 ps under different phase-locked loop output frequencies after 4 hours of stress time.
