Surface electromyography(sEMG)is widely used for analyzing and controlling lower limb assisted exoskeleton robots.Behavior intention recognition based on sEMG is of great significance for achieving intelligent prosthe...Surface electromyography(sEMG)is widely used for analyzing and controlling lower limb assisted exoskeleton robots.Behavior intention recognition based on sEMG is of great significance for achieving intelligent prosthetic and exoskeleton control.Achieving highly efficient recognition while improving performance has always been a significant challenge.To address this,we propose an sEMG-based method called Enhanced Residual Gate Network(ERGN)for lower-limb behavioral intention recognition.The proposed network combines an attention mechanism and a hard threshold function,while combining the advantages of residual structure,which maps sEMG of multiple acquisition channels to the lower limb motion states.Firstly,continuous wavelet transform(CWT)is used to extract signals features from the collected sEMG data.Then,a hard threshold function serves as the gate function to enhance signals quality,with an attention mechanism incorporated to improve the ERGN’s performance further.Experimental results demonstrate that the proposed ERGN achieves extremely high accuracy and efficiency,with an average recognition accuracy of 98.41%and an average recognition time of only 20 ms-outperforming the state-of-the-art research significantly.Our research provides support for the application of lower limb assisted exoskeleton robots.展开更多
The human pose paradigm is estimated using a transformer-based multi-branch multidimensional directed the three-dimensional(3D)method that takes into account self-occlusion,badly posedness,and a lack of depth data in ...The human pose paradigm is estimated using a transformer-based multi-branch multidimensional directed the three-dimensional(3D)method that takes into account self-occlusion,badly posedness,and a lack of depth data in the per-frame 3D posture estimation from two-dimensional(2D)mapping to 3D mapping.Firstly,by examining the relationship between the movements of different bones in the human body,four virtual skeletons are proposed to enhance the cyclic constraints of limb joints.Then,multiple parameters describing the skeleton are fused and projected into a high-dimensional space.Utilizing a multi-branch network,motion features between bones and overall motion features are extracted to mitigate the drift error in the estimation results.Furthermore,the estimated relative depth is projected into 3D space,and the error is calculated against real 3D data,forming a loss function along with the relative depth error.This article adopts the average joint pixel error as the primary performance metric.Compared to the benchmark approach,the estimation findings indicate an increase in average precision of 1.8 mm within the Human3.6M sample.展开更多
Purpose:To observe the efficacy of the combined treatment of carbamazepine and botulinum toxin A for blepharospasm and hemifacial spasm. Methods:Fifty-eight patients with either blepharospasm or hemifacial spasm were ...Purpose:To observe the efficacy of the combined treatment of carbamazepine and botulinum toxin A for blepharospasm and hemifacial spasm. Methods:Fifty-eight patients with either blepharospasm or hemifacial spasm were randomly divided into treatment and control groups. In the treatment group, 30 patients were administered with local intramuscular injections of botulinum toxin A and oral carbamazepine 100 mg/time,3 times/day for 60 days. Twenty-eight subjects in the control group under-went local intramuscular injections of botulinum toxin A only. Results:After combined treatment, the complete remission rate was 90%, which was significantly higher than that of the of the control group (67.9% , P<0.05,χ2 =4.733). However, no statistical significance was noted regarding the duration of therapeutic effects between the treatment group (range 14~40 weeks; 19.2 weeks on average) and control group (range 12~36 weeks; 18 weeks on average). Conclusion:The combined therapy of carbamazepine and topical injections of botulinum toxin A had increased efficacy in the treatment of blepharospasm or hemifacial spasm, but had no significant effect in terms of the duration of the therapeutic effect.展开更多
Objective:Explore the homogeneous management of appropri-ate technology for Traditional Chinese Medicine(TCM)care based on the county medical community platform.Methods:The hospital has formed a county medical communi...Objective:Explore the homogeneous management of appropri-ate technology for Traditional Chinese Medicine(TCM)care based on the county medical community platform.Methods:The hospital has formed a county medical community since 2020,based on which the platform develops homogeneous management of appropriate technologies for TCM nursing,establishes a medical training center,a remote consultation center and a TCM nursing quality control center,strengthens the construction of TCM nursing specialties,integrates TCM with public health and consolidates information support.The“321”model was developed,with January 2021 to December 2021 as the post-implementation period and January 2020 to December 2020 as the pre-implementation period,to compare the application of TCM nursing techniques before and after the implementation.Results:After the implementation of homogeneous management of TCM nursing techniques in the medical community units,the TCM nursing competence of primary care staff,patient compliance and satisfaction were significantly improved.Conclusion:The implementation of homogeneous management of TCM nursing techniques in the medical community units can enhance the TCM service capacity of primary care staff and improve the“sense of access to care”of patients.展开更多
Background:Although intensively studied in patients with cardiovascular diseases(CVDs),the prognostic value of diastolic blood pressure(DBP)has little been elucidated in patients with acute exacerbation of chronic obs...Background:Although intensively studied in patients with cardiovascular diseases(CVDs),the prognostic value of diastolic blood pressure(DBP)has little been elucidated in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).This study aimed to reveal the prognostic value of DBP in AECOPD patients.Methods:Inpatients with AECOPD were prospectively enrolled from 10 medical centers in China between September 2017 and July 2021.DBP was measured on admission.The primary outcome was all-cause in-hospital mortality;invasive mechanical ventilation and intensive care unit(ICU)admission were secondary outcomes.Least absolute shrinkage and selection operator(LASSO)and multivariable Cox regressions were used to identify independent prognostic factors and calculate the hazard ratio(HR)and 95%confidence interval(CI)for adverse outcomes.Results:Among 13,633 included patients with AECOPD,197(1.45%)died during their hospital stay.Multivariable Cox regression analysis showed that low DBP on admission(<70 mmHg)was associated with increased risk of in-hospital mortality(HR=2.16,95%CI:1.53–3.05,Z=4.37,P<0.01),invasive mechanical ventilation(HR=1.65,95%CI:1.32–2.05,Z=19.67,P<0.01),and ICU admission(HR=1.45,95%CI:1.24–1.69,Z=22.08,P<0.01)in the overall cohort.Similar findings were observed in subgroups with or without CVDs,except for invasive mechanical ventilation in the subgroup with CVDs.When DBP was further categorized in 5-mmHg increments from<50 mmHg to≥100 mmHg,and 75 to<80 mmHg was taken as reference,HRs for in-hospital mortality increased almost linearly with decreased DBP in the overall cohort and subgroups of patients with CVDs;higher DBP was not associated with the risk of in-hospital mortality.Conclusion:Low on-admission DBP,particularly<70 mmHg,was associated with an increased risk of adverse outcomes among inpatients with AECOPD,with or without CVDs,which may serve as a convenient predictor of poor prognosis in these patients.Clinical Trial Registration:Chinese Clinical Trail Registry,No.ChiCTR2100044625.展开更多
Lunar exploration is deemed crucial for uncovering the origins of the Earth-Moon system and is the first step for advancing humanity’s exploration of deep space.Over the past decade,the Chinese Lunar Exploration Prog...Lunar exploration is deemed crucial for uncovering the origins of the Earth-Moon system and is the first step for advancing humanity’s exploration of deep space.Over the past decade,the Chinese Lunar Exploration Program(CLEP),also known as the Chang’e(CE)Project,has achieved remarkable milestones.It has successfully developed and demonstrated the engineering capability required to reach and return from the lunar surface.Notably,the CE Project has made historic firsts with the landing and on-site exploration of the far side of the Moon,along with the collection of the youngest volcanic samples from the Procellarum KREEP Terrane.These achievements have significantly enhanced our understanding of lunar evolution.Building on this success,China has proposed an ambitious crewed lunar exploration strategy,aiming to return to the Moon for scientific exploration and utilization.This plan encompasses two primary phases:the first crewed lunar landing and exploration,followed by a thousand-kilometer scale scientific expedition to construct a geological cross-section across the lunar surface.Recognizing the limitations of current lunar exploration efforts and China’s engineering and technical capabilities,this paper explores the benefits of crewed lunar exploration while leveraging synergies with robotic exploration.The study refines fundamental lunar scientific questions that could lead to significant breakthroughs,considering the respective engineering and technological requirements.This research lays a crucial foundation for defining the objectives of future lunar exploration,emphasizing the importance of crewed missions and offering insights into potential advancements in lunar science.展开更多
A new stepwise dissolution scheme, involving acids with different properties, enables the selective recovery of radiogenic and common Pb from a mineral, and makes single-mineral Pb-Pb dating possible. Garnet from a gr...A new stepwise dissolution scheme, involving acids with different properties, enables the selective recovery of radiogenic and common Pb from a mineral, and makes single-mineral Pb-Pb dating possible. Garnet from a granulite sample from Huangtuling, northern Dabie Mountain yields a Pb-Pb isochron age of (1098 ± 35) Ma, which is interpreted as the timing of peak metamorphism of granulite facies.展开更多
Secondary ion mass spectrometry(SIMS) zircon U-Pb dating has been widely used to confine the absolute ages of the magmatic or metamorphic events and to distinguish multiple events.Here,a data set consisting of the zir...Secondary ion mass spectrometry(SIMS) zircon U-Pb dating has been widely used to confine the absolute ages of the magmatic or metamorphic events and to distinguish multiple events.Here,a data set consisting of the zircon standards dating data(~15 000 Ple?ovice and ~8 000 Qinghu items) accumulated for more than 8 years using the CAMECA IMS 1280 HR of the Institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS) is compiled to evaluate the long-term external reproducibility.With Ple?ovice zircon as the calibration standard and Qinghu zircon as an unknown sample,the analytical uncertainties for single-spot(n = 7 723) and session analyses(n = 691,with more than 7 single spot analyses in one session) are 2.6% and 0.9%(2 RSD,relative standard deviation),respectively.It means that single-spot U-Pb dating for a standard-level zircon sample could vary 5.2% at 95% confidence level,while the average value(n > 7) for each session may vary 1.8%.Thus,these values should be considered as the minimum uncertainty when comparing single spot and individual session analysis results for multiple dating works on a certain geological event.展开更多
In order to find the optimal combination method of secondary utilization of fly ash and graphite-phase carbon nitride(g-C_(3)N_(4))modification,an efficient composite photocatalyst of γ-Al_(2)O_(3)/g-C_(3)N_(4)was ob...In order to find the optimal combination method of secondary utilization of fly ash and graphite-phase carbon nitride(g-C_(3)N_(4))modification,an efficient composite photocatalyst of γ-Al_(2)O_(3)/g-C_(3)N_(4)was obtained by calcining the composite precursors of Al(OH)3/dicyandiamide(DCDA).The introduction of Al(OH)_(3)prepared by combining fly ash into the precursors causes hydrogen-bonding interactions between Al(OH)_(3)and DCDA,which facilitate the removal of N atoms from the edges of the CN framework of g-C_(3)N_(4)during condensation,and the composites prepared possess more cyano defects.In addition,γ-Al_(2)O_(3)and g-C_(3)N_(4)form a chemical bond at the interface,and this chemical bonding causes the density of the electron cloud in the vicinity of the N atoms to increase.Among them,the strongest chemical bonding between Al_(2)O_(3)and g-C_(3)N_(4)was observed in ACN-1,whereas the most cyanine defects were formed in ACN-1,which made ACN-1 exhibit the best photocatalytic degradation of methylene blue,which is 2.48 times higher than that of the pristine g-C_(3)N_(4).展开更多
Granite is the dominant rock type in Earth’s continental crust.The origin of granite can be directly or indirectly related to the fractional crystallization of mantle-derived basaltic melt or the reworking of pre-exi...Granite is the dominant rock type in Earth’s continental crust.The origin of granite can be directly or indirectly related to the fractional crystallization of mantle-derived basaltic melt or the reworking of pre-existing continental or oceanic crust, which contribute to the growth of continental crust. Among the various types of granites, the peraluminous leucogranites in the Himalayan orogen, which are high in SiO_2(>73%) and low in mafic minerals (<5%),展开更多
As an important post-collisional magmatic product in the orogenic belt, the Himalayan leucogranites are the critical host rocks for a number of rare-metal mineralization(such as Li, Be, Cs, Rb, Nb, Ta, and Sn).However...As an important post-collisional magmatic product in the orogenic belt, the Himalayan leucogranites are the critical host rocks for a number of rare-metal mineralization(such as Li, Be, Cs, Rb, Nb, Ta, and Sn).However, there is still a lack of good understanding on the formation and evolution of the leucogranites.Particularly, the role of the magmatic fluids in transporting and enriching the rare elements is not clear.Here we measure Ba isotope compositions for leucogranites from the Kampa Dome of the Himalayan belt to understand the fluid activity and behavior of fluid-mobile elements during leucogranite formation. Our results show that the δ138/134 Ba of leucogranites range from -1.32‰ to +0.12‰, much lower than the literature values for S-type granites and various sedimentary materials, suggesting that the Ba isotope compositions of the leucogranites does not reflect the sedimentary source signatures. Instead, their low δ138/134 Ba is accompanied by non-charge-and-radius-controlled(CHARAC) twin-element(such as Nb/Ta) behaviors, clearly showing the involvement of magmatic fluids during magma evolution.Experimental studies suggest that the low δ138/134 Ba of the magmatic fluids most likely results from exsolution from a large deep magma reservoir. Such fluids not only modified Ba isotope compositions of the leucogranites, but also transported many fluid-mobile metal elements which may help form the rare metal ore deposits. Therefore, Ba isotope data provide new insights into formation and evolution of magmatic fluids and exploration of the rare-metal mineralization.展开更多
High resolution Mg/Ca ratios in the skeleton of a Porites lutea from the coastal area in the North of the South China Sea were precisely analyzed by ICP-MS. Compared with the instrument measured SST records, the Mg/Ca...High resolution Mg/Ca ratios in the skeleton of a Porites lutea from the coastal area in the North of the South China Sea were precisely analyzed by ICP-MS. Compared with the instrument measured SST records, the Mg/Ca ratios strongly correlate with the SSTs, even in time of 1982/83 EI N(?)io. Therefore, a coral Mg/Ca thermometer for the North of the South China Sea was established.Based on ICP-MS technique it can report sea surface temperatures to an accuracy of±0.5℃.展开更多
Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient cont...Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient continental crust within young oceanic lithosphere. Almost all finds of ancient zircon xenocrysts within oceanic crust are from the Mid-Atlantic Ridge. For other localities, however, similar data are very limited. This report presents the first age determinations(U-Pb, SHRIMPII) and isotope-geochemical data(oxygen, trace and rare earth elements) for zircon xenocrysts from gabbro-diorites of the Shaka Ridge, in the vicinity of the Shaka fracture zone, near the western end of the Southwest Indian Ridge. The work is based on a study of bottom rock material dredged during expeditionary research on the R/V"Akademik Fedorov"(Russia) in 2016. The U-Pb isotope system of the zircon xenocrysts recorded a crystallization age of ~2.8 Ga at an upper discordia intercept and an age of ~600 Ma interpreted as the timing of a superimposed thermal event at a lower discordia intercept.The zircon xenocrysts show geochemical signatures of magmatic origin, i.e., fractionated REE distribution spectra with an increase in chondrite-normalized values from light to heavy REE, positive Ce anomalies and negative Eu anomalies, and high Th/U ratios(0.59-7.77). In discrimination diagrams based on a series of inter-element relationships, zircon compositions fall into the fields of zircons from rocks of continental crust, mostly granitoids. The Li content of the zircons is high(1.8 ppm-50 ppm),adding further evidence to their derivation from rocks of continental crust. During their residence within young oceanic crust, the zircon xenocrysts experienced alterations under the influence of submarine high-temperature hydrothermal fluids, which selectively affected the distribution of trace elements in the zircons and reduced the δ;O values to 1.75‰-3.15‰. The presence of obviously older zircons in Shaka gabbro-diorites clearly demonstrates the presence of ancient continental fragments and their recycling into the mantle at the western end of the Southwest Indian Ridge.展开更多
In order to study the dynamic characteristics of hydro-mechanical continuously variable transmission(HMCVT)under ploughing and sowing conditions,a complete simulation model of HMCVT is established based on AMESim soft...In order to study the dynamic characteristics of hydro-mechanical continuously variable transmission(HMCVT)under ploughing and sowing conditions,a complete simulation model of HMCVT is established based on AMESim software,including mechanical transmission model,pump controlled hydraulic motor speed control model and section changing hydraulic system model.In addition,the dynamic model of tractor is established.In order to verify the correctness of the simulation model,a test-bed is established.The test of tractor running speed and the test of pump controlled hydraulic motor system were carried out on the test-bed.The test results show that the simulation model of pump control hydraulic system can correctly reflect the change of transmission ratio of pump controlled hydraulic motor,and the simulation model can reflect the actual working condition change of clutch.Thus,the correctness of the previous simulation model based on AMESim is verified.Based on the simulation model established by AMESim,the dynamic characteristics of HMCVT under ploughing and sowing conditions are studied.The results show that:Under ploughing condition,the planetary platoon will have strong impact at the moment of throttle opening and changing section.Under sowing condition,the HMCVT will have a great impact at the time of variable cross section,but the variation range of rodent force decreases and the changing trend tends to be stable.展开更多
The highly depleted N-MORB-type volcanic rocks have been discovered in Mianlue mélange of Qinling orogenic belt, central China. These mafic rocks are associated with the meta-peridotites, showing LREE-depleted pa...The highly depleted N-MORB-type volcanic rocks have been discovered in Mianlue mélange of Qinling orogenic belt, central China. These mafic rocks are associated with the meta-peridotites, showing LREE-depleted pattern, similar to N-MORB and typical ophiolites. It is indicated that an ancient ocean existed in the Mianlue area of Qinling orogenic belt during the late Paleozoic.展开更多
Research on returned samples can provide ground truth for the study of the geological evolution history of the Moon.However,previous missions all collected samples from the near side of the Moon,which is significantly...Research on returned samples can provide ground truth for the study of the geological evolution history of the Moon.However,previous missions all collected samples from the near side of the Moon,which is significantly different from the far side of the Moon in terms of the thickness of the lunar crust,magma activity,and composition.Therefore,the samples from the far side of the Moon are of great significance for a comprehensive understanding of the history of the Moon.China’s Chang’e-6(CE-6)probe has successfully landed on the lunar far side and will return samples in the coming days.With the precise location of the CE-6 landing site,a detailed analysis of the geological background is conducted in this research.The landing site of CE-6 is within the Apollo crater,which is inside the largest impact basin on the Moon,i.e.,the South Pole-Aitken(SPA)basin.According to the numerical simulation of the formation process of the SPA basin,CE-6 landed at the edge of the SPA impact melting zone,which is presumably composed of impact melt of the lunar mantle.The Apollo crater subsequently excavated deep material again,which constitutes the basement of the CE-6 landing area.Later,erupted basalt covered these basement rocks,and they also constitute the main source of the CE-6 samples.Based on the dating method of crater size-frequency distribution,we find that the basalt is2.50 Ga.The CE-6 samples also possibly contain basement rocks as excavated and ejected by craters,and they can provide crucial information for our understanding of lunar geological history along with the basalt samples.展开更多
基金The Research and the Development Fund of the Institute of Environmental Friendly Materials and Occupational Health,Anhui University of Science and Technology,Grant/Award Number:ALW2022YF06Academic Support Project for Top-Notch Talents in Disciplines(Majors)of Colleges and Universities in Anhui Province,Grant/Award Number:gxbjZD2021052+1 种基金The University Synergy Innovation Program of Anhui Province,Grant/Award Number:GXXT-2022-053Anhui Province Key R&D Program of China,Grant/Award Number:2022i01020015.
文摘Surface electromyography(sEMG)is widely used for analyzing and controlling lower limb assisted exoskeleton robots.Behavior intention recognition based on sEMG is of great significance for achieving intelligent prosthetic and exoskeleton control.Achieving highly efficient recognition while improving performance has always been a significant challenge.To address this,we propose an sEMG-based method called Enhanced Residual Gate Network(ERGN)for lower-limb behavioral intention recognition.The proposed network combines an attention mechanism and a hard threshold function,while combining the advantages of residual structure,which maps sEMG of multiple acquisition channels to the lower limb motion states.Firstly,continuous wavelet transform(CWT)is used to extract signals features from the collected sEMG data.Then,a hard threshold function serves as the gate function to enhance signals quality,with an attention mechanism incorporated to improve the ERGN’s performance further.Experimental results demonstrate that the proposed ERGN achieves extremely high accuracy and efficiency,with an average recognition accuracy of 98.41%and an average recognition time of only 20 ms-outperforming the state-of-the-art research significantly.Our research provides support for the application of lower limb assisted exoskeleton robots.
基金supported by the Medical Special Cultivation Project of Anhui University of Science and Technology(Grant No.YZ2023H2B013)the Anhui Provincial Key Research and Development Project(Grant No.2022i01020015)the Open Project of Key Laboratory of Conveyance Equipment(East China Jiaotong University),Ministry of Education(KLCE2022-01).
文摘The human pose paradigm is estimated using a transformer-based multi-branch multidimensional directed the three-dimensional(3D)method that takes into account self-occlusion,badly posedness,and a lack of depth data in the per-frame 3D posture estimation from two-dimensional(2D)mapping to 3D mapping.Firstly,by examining the relationship between the movements of different bones in the human body,four virtual skeletons are proposed to enhance the cyclic constraints of limb joints.Then,multiple parameters describing the skeleton are fused and projected into a high-dimensional space.Utilizing a multi-branch network,motion features between bones and overall motion features are extracted to mitigate the drift error in the estimation results.Furthermore,the estimated relative depth is projected into 3D space,and the error is calculated against real 3D data,forming a loss function along with the relative depth error.This article adopts the average joint pixel error as the primary performance metric.Compared to the benchmark approach,the estimation findings indicate an increase in average precision of 1.8 mm within the Human3.6M sample.
基金The Science and Technology Projects of GuangdongProvince,China (2010B060500006)
文摘Purpose:To observe the efficacy of the combined treatment of carbamazepine and botulinum toxin A for blepharospasm and hemifacial spasm. Methods:Fifty-eight patients with either blepharospasm or hemifacial spasm were randomly divided into treatment and control groups. In the treatment group, 30 patients were administered with local intramuscular injections of botulinum toxin A and oral carbamazepine 100 mg/time,3 times/day for 60 days. Twenty-eight subjects in the control group under-went local intramuscular injections of botulinum toxin A only. Results:After combined treatment, the complete remission rate was 90%, which was significantly higher than that of the of the control group (67.9% , P<0.05,χ2 =4.733). However, no statistical significance was noted regarding the duration of therapeutic effects between the treatment group (range 14~40 weeks; 19.2 weeks on average) and control group (range 12~36 weeks; 18 weeks on average). Conclusion:The combined therapy of carbamazepine and topical injections of botulinum toxin A had increased efficacy in the treatment of blepharospasm or hemifacial spasm, but had no significant effect in terms of the duration of the therapeutic effect.
文摘Objective:Explore the homogeneous management of appropri-ate technology for Traditional Chinese Medicine(TCM)care based on the county medical community platform.Methods:The hospital has formed a county medical community since 2020,based on which the platform develops homogeneous management of appropriate technologies for TCM nursing,establishes a medical training center,a remote consultation center and a TCM nursing quality control center,strengthens the construction of TCM nursing specialties,integrates TCM with public health and consolidates information support.The“321”model was developed,with January 2021 to December 2021 as the post-implementation period and January 2020 to December 2020 as the pre-implementation period,to compare the application of TCM nursing techniques before and after the implementation.Results:After the implementation of homogeneous management of TCM nursing techniques in the medical community units,the TCM nursing competence of primary care staff,patient compliance and satisfaction were significantly improved.Conclusion:The implementation of homogeneous management of TCM nursing techniques in the medical community units can enhance the TCM service capacity of primary care staff and improve the“sense of access to care”of patients.
基金National Natural Science Foundation of China(No.82170013)Sichuan Science and Technology Program(No.2022YFS0262)National Key Research Program of China(No.2016YFC1304202)
文摘Background:Although intensively studied in patients with cardiovascular diseases(CVDs),the prognostic value of diastolic blood pressure(DBP)has little been elucidated in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).This study aimed to reveal the prognostic value of DBP in AECOPD patients.Methods:Inpatients with AECOPD were prospectively enrolled from 10 medical centers in China between September 2017 and July 2021.DBP was measured on admission.The primary outcome was all-cause in-hospital mortality;invasive mechanical ventilation and intensive care unit(ICU)admission were secondary outcomes.Least absolute shrinkage and selection operator(LASSO)and multivariable Cox regressions were used to identify independent prognostic factors and calculate the hazard ratio(HR)and 95%confidence interval(CI)for adverse outcomes.Results:Among 13,633 included patients with AECOPD,197(1.45%)died during their hospital stay.Multivariable Cox regression analysis showed that low DBP on admission(<70 mmHg)was associated with increased risk of in-hospital mortality(HR=2.16,95%CI:1.53–3.05,Z=4.37,P<0.01),invasive mechanical ventilation(HR=1.65,95%CI:1.32–2.05,Z=19.67,P<0.01),and ICU admission(HR=1.45,95%CI:1.24–1.69,Z=22.08,P<0.01)in the overall cohort.Similar findings were observed in subgroups with or without CVDs,except for invasive mechanical ventilation in the subgroup with CVDs.When DBP was further categorized in 5-mmHg increments from<50 mmHg to≥100 mmHg,and 75 to<80 mmHg was taken as reference,HRs for in-hospital mortality increased almost linearly with decreased DBP in the overall cohort and subgroups of patients with CVDs;higher DBP was not associated with the risk of in-hospital mortality.Conclusion:Low on-admission DBP,particularly<70 mmHg,was associated with an increased risk of adverse outcomes among inpatients with AECOPD,with or without CVDs,which may serve as a convenient predictor of poor prognosis in these patients.Clinical Trial Registration:Chinese Clinical Trail Registry,No.ChiCTR2100044625.
基金supported by the National Natural Science Foundation of China(L2224032)the Research Project on the Discipline Development Strategy of Academic Divisions of the Chinese Academy of Sciences(XK2022DXC004).
文摘Lunar exploration is deemed crucial for uncovering the origins of the Earth-Moon system and is the first step for advancing humanity’s exploration of deep space.Over the past decade,the Chinese Lunar Exploration Program(CLEP),also known as the Chang’e(CE)Project,has achieved remarkable milestones.It has successfully developed and demonstrated the engineering capability required to reach and return from the lunar surface.Notably,the CE Project has made historic firsts with the landing and on-site exploration of the far side of the Moon,along with the collection of the youngest volcanic samples from the Procellarum KREEP Terrane.These achievements have significantly enhanced our understanding of lunar evolution.Building on this success,China has proposed an ambitious crewed lunar exploration strategy,aiming to return to the Moon for scientific exploration and utilization.This plan encompasses two primary phases:the first crewed lunar landing and exploration,followed by a thousand-kilometer scale scientific expedition to construct a geological cross-section across the lunar surface.Recognizing the limitations of current lunar exploration efforts and China’s engineering and technical capabilities,this paper explores the benefits of crewed lunar exploration while leveraging synergies with robotic exploration.The study refines fundamental lunar scientific questions that could lead to significant breakthroughs,considering the respective engineering and technological requirements.This research lays a crucial foundation for defining the objectives of future lunar exploration,emphasizing the importance of crewed missions and offering insights into potential advancements in lunar science.
文摘A new stepwise dissolution scheme, involving acids with different properties, enables the selective recovery of radiogenic and common Pb from a mineral, and makes single-mineral Pb-Pb dating possible. Garnet from a granulite sample from Huangtuling, northern Dabie Mountain yields a Pb-Pb isochron age of (1098 ± 35) Ma, which is interpreted as the timing of peak metamorphism of granulite facies.
基金supported by the National Key R&D Program of China(No.2018YFA0702600)the National Natural Science Foundation of China(Nos.41773044,41773047)。
文摘Secondary ion mass spectrometry(SIMS) zircon U-Pb dating has been widely used to confine the absolute ages of the magmatic or metamorphic events and to distinguish multiple events.Here,a data set consisting of the zircon standards dating data(~15 000 Ple?ovice and ~8 000 Qinghu items) accumulated for more than 8 years using the CAMECA IMS 1280 HR of the Institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS) is compiled to evaluate the long-term external reproducibility.With Ple?ovice zircon as the calibration standard and Qinghu zircon as an unknown sample,the analytical uncertainties for single-spot(n = 7 723) and session analyses(n = 691,with more than 7 single spot analyses in one session) are 2.6% and 0.9%(2 RSD,relative standard deviation),respectively.It means that single-spot U-Pb dating for a standard-level zircon sample could vary 5.2% at 95% confidence level,while the average value(n > 7) for each session may vary 1.8%.Thus,these values should be considered as the minimum uncertainty when comparing single spot and individual session analysis results for multiple dating works on a certain geological event.
基金supported by the Medical Special Cultivation Project of Anhui University of Science and Technology(YZ2023H2B012,YZ2023H2B013)the Anhui Provincial Key Research and Development Project(2022i01020015)+1 种基金the University Synergy Innovation Program of Anhui Province(XT-2022-083,GXXT-2023-019)National Natural Science Foundation of China(52227901).
文摘In order to find the optimal combination method of secondary utilization of fly ash and graphite-phase carbon nitride(g-C_(3)N_(4))modification,an efficient composite photocatalyst of γ-Al_(2)O_(3)/g-C_(3)N_(4)was obtained by calcining the composite precursors of Al(OH)3/dicyandiamide(DCDA).The introduction of Al(OH)_(3)prepared by combining fly ash into the precursors causes hydrogen-bonding interactions between Al(OH)_(3)and DCDA,which facilitate the removal of N atoms from the edges of the CN framework of g-C_(3)N_(4)during condensation,and the composites prepared possess more cyano defects.In addition,γ-Al_(2)O_(3)and g-C_(3)N_(4)form a chemical bond at the interface,and this chemical bonding causes the density of the electron cloud in the vicinity of the N atoms to increase.Among them,the strongest chemical bonding between Al_(2)O_(3)and g-C_(3)N_(4)was observed in ACN-1,whereas the most cyanine defects were formed in ACN-1,which made ACN-1 exhibit the best photocatalytic degradation of methylene blue,which is 2.48 times higher than that of the pristine g-C_(3)N_(4).
基金supported by the National Natural Science Foundation of China(41772058 and 41402055)
文摘Granite is the dominant rock type in Earth’s continental crust.The origin of granite can be directly or indirectly related to the fractional crystallization of mantle-derived basaltic melt or the reworking of pre-existing continental or oceanic crust, which contribute to the growth of continental crust. Among the various types of granites, the peraluminous leucogranites in the Himalayan orogen, which are high in SiO_2(>73%) and low in mafic minerals (<5%),
基金supported by the National Natural Science Foundation of China(41803003).
文摘As an important post-collisional magmatic product in the orogenic belt, the Himalayan leucogranites are the critical host rocks for a number of rare-metal mineralization(such as Li, Be, Cs, Rb, Nb, Ta, and Sn).However, there is still a lack of good understanding on the formation and evolution of the leucogranites.Particularly, the role of the magmatic fluids in transporting and enriching the rare elements is not clear.Here we measure Ba isotope compositions for leucogranites from the Kampa Dome of the Himalayan belt to understand the fluid activity and behavior of fluid-mobile elements during leucogranite formation. Our results show that the δ138/134 Ba of leucogranites range from -1.32‰ to +0.12‰, much lower than the literature values for S-type granites and various sedimentary materials, suggesting that the Ba isotope compositions of the leucogranites does not reflect the sedimentary source signatures. Instead, their low δ138/134 Ba is accompanied by non-charge-and-radius-controlled(CHARAC) twin-element(such as Nb/Ta) behaviors, clearly showing the involvement of magmatic fluids during magma evolution.Experimental studies suggest that the low δ138/134 Ba of the magmatic fluids most likely results from exsolution from a large deep magma reservoir. Such fluids not only modified Ba isotope compositions of the leucogranites, but also transported many fluid-mobile metal elements which may help form the rare metal ore deposits. Therefore, Ba isotope data provide new insights into formation and evolution of magmatic fluids and exploration of the rare-metal mineralization.
文摘High resolution Mg/Ca ratios in the skeleton of a Porites lutea from the coastal area in the North of the South China Sea were precisely analyzed by ICP-MS. Compared with the instrument measured SST records, the Mg/Ca ratios strongly correlate with the SSTs, even in time of 1982/83 EI N(?)io. Therefore, a coral Mg/Ca thermometer for the North of the South China Sea was established.Based on ICP-MS technique it can report sea surface temperatures to an accuracy of±0.5℃.
基金funded by the National Key R & D Program of China(No.2016YFE0203000)the National Natural Science Foundation of China(No.41673018)+1 种基金conducted under state contract(Institute of Precambrian Geology and Geochronology of Russian Academy of Sciences)(No.FMNU-2022-0005)supported by the state assignment project of IGM SB RAS。
文摘Over the past two decades, a significant number of discoveries of ancient zircon xenocrysts in ocean-floor magmatic rocks have been reported. These findings provide compelling evidence for the presence of ancient continental crust within young oceanic lithosphere. Almost all finds of ancient zircon xenocrysts within oceanic crust are from the Mid-Atlantic Ridge. For other localities, however, similar data are very limited. This report presents the first age determinations(U-Pb, SHRIMPII) and isotope-geochemical data(oxygen, trace and rare earth elements) for zircon xenocrysts from gabbro-diorites of the Shaka Ridge, in the vicinity of the Shaka fracture zone, near the western end of the Southwest Indian Ridge. The work is based on a study of bottom rock material dredged during expeditionary research on the R/V"Akademik Fedorov"(Russia) in 2016. The U-Pb isotope system of the zircon xenocrysts recorded a crystallization age of ~2.8 Ga at an upper discordia intercept and an age of ~600 Ma interpreted as the timing of a superimposed thermal event at a lower discordia intercept.The zircon xenocrysts show geochemical signatures of magmatic origin, i.e., fractionated REE distribution spectra with an increase in chondrite-normalized values from light to heavy REE, positive Ce anomalies and negative Eu anomalies, and high Th/U ratios(0.59-7.77). In discrimination diagrams based on a series of inter-element relationships, zircon compositions fall into the fields of zircons from rocks of continental crust, mostly granitoids. The Li content of the zircons is high(1.8 ppm-50 ppm),adding further evidence to their derivation from rocks of continental crust. During their residence within young oceanic crust, the zircon xenocrysts experienced alterations under the influence of submarine high-temperature hydrothermal fluids, which selectively affected the distribution of trace elements in the zircons and reduced the δ;O values to 1.75‰-3.15‰. The presence of obviously older zircons in Shaka gabbro-diorites clearly demonstrates the presence of ancient continental fragments and their recycling into the mantle at the western end of the Southwest Indian Ridge.
基金The research is funded partially by the Jiangsu International Cooperation Project(Grant No.BZ2021007)the Modern Agricultural Machinery Equipment and Technology Promotion Project in Jiangsu Province(Grant No.NJ2021-06)+2 种基金the Nanjing International Science and Technology Cooperation Project(Grant No.202002049)the Xuzhou key research and development projects(Grant No.KC21136)The Fundamental Research Funds for the Central Universities(Grant No.KYGD202105).
文摘In order to study the dynamic characteristics of hydro-mechanical continuously variable transmission(HMCVT)under ploughing and sowing conditions,a complete simulation model of HMCVT is established based on AMESim software,including mechanical transmission model,pump controlled hydraulic motor speed control model and section changing hydraulic system model.In addition,the dynamic model of tractor is established.In order to verify the correctness of the simulation model,a test-bed is established.The test of tractor running speed and the test of pump controlled hydraulic motor system were carried out on the test-bed.The test results show that the simulation model of pump control hydraulic system can correctly reflect the change of transmission ratio of pump controlled hydraulic motor,and the simulation model can reflect the actual working condition change of clutch.Thus,the correctness of the previous simulation model based on AMESim is verified.Based on the simulation model established by AMESim,the dynamic characteristics of HMCVT under ploughing and sowing conditions are studied.The results show that:Under ploughing condition,the planetary platoon will have strong impact at the moment of throttle opening and changing section.Under sowing condition,the HMCVT will have a great impact at the time of variable cross section,but the variation range of rodent force decreases and the changing trend tends to be stable.
文摘The highly depleted N-MORB-type volcanic rocks have been discovered in Mianlue mélange of Qinling orogenic belt, central China. These mafic rocks are associated with the meta-peridotites, showing LREE-depleted pattern, similar to N-MORB and typical ophiolites. It is indicated that an ancient ocean existed in the Mianlue area of Qinling orogenic belt during the late Paleozoic.
基金supported by the National Key Research and Development Program of China(grant no.2022YFF0503100)the B-type Strategic Priority Program of the Chinese Academy of Sciences(grant no.XDB41000000)+2 种基金the Open Fund of the State Key Laboratory of Remote Sensing Science(grant no.OFSLRSS202206)the National Natural Science Foundation of China(grant no.62227901)the key research program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(grant no.IGGCAS-202401,IGGCAS-202204).
文摘Research on returned samples can provide ground truth for the study of the geological evolution history of the Moon.However,previous missions all collected samples from the near side of the Moon,which is significantly different from the far side of the Moon in terms of the thickness of the lunar crust,magma activity,and composition.Therefore,the samples from the far side of the Moon are of great significance for a comprehensive understanding of the history of the Moon.China’s Chang’e-6(CE-6)probe has successfully landed on the lunar far side and will return samples in the coming days.With the precise location of the CE-6 landing site,a detailed analysis of the geological background is conducted in this research.The landing site of CE-6 is within the Apollo crater,which is inside the largest impact basin on the Moon,i.e.,the South Pole-Aitken(SPA)basin.According to the numerical simulation of the formation process of the SPA basin,CE-6 landed at the edge of the SPA impact melting zone,which is presumably composed of impact melt of the lunar mantle.The Apollo crater subsequently excavated deep material again,which constitutes the basement of the CE-6 landing area.Later,erupted basalt covered these basement rocks,and they also constitute the main source of the CE-6 samples.Based on the dating method of crater size-frequency distribution,we find that the basalt is2.50 Ga.The CE-6 samples also possibly contain basement rocks as excavated and ejected by craters,and they can provide crucial information for our understanding of lunar geological history along with the basalt samples.