Vertically oriented carbon structures constructed from low-dimen-sional carbon materials are ideal frameworks for high-performance thermal inter-face materials(TIMs).However,improving the interfacial heat-transfer eff...Vertically oriented carbon structures constructed from low-dimen-sional carbon materials are ideal frameworks for high-performance thermal inter-face materials(TIMs).However,improving the interfacial heat-transfer efficiency of vertically oriented carbon structures is a challenging task.Herein,an orthotropic three-dimensional(3D)hybrid carbon network(VSCG)is fabricated by depositing vertically aligned carbon nanotubes(VACNTs)on the surface of a horizontally oriented graphene film(HOGF).The interfacial interaction between the VACNTs and HOGF is then optimized through an annealing strategy.After regulating the orientation structure of the VACNTs and filling the VSCG with polydimethylsi-loxane(PDMS),VSCG/PDMS composites with excellent 3D thermal conductive properties are obtained.The highest in-plane and through-plane thermal conduc-tivities of the composites are 113.61 and 24.37 W m^(-1)K^(-1),respectively.The high contact area of HOGF and good compressibility of VACNTs imbue the VSCG/PDMS composite with low thermal resistance.In addition,the interfacial heat-transfer efficiency of VSCG/PDMS composite in the TIM performance was improved by 71.3%compared to that of a state-of-the-art thermal pad.This new structural design can potentially realize high-performance TIMs that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.展开更多
Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CP...Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic Box.This onboard software has the following features:high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation,dedicated localization algorithm optimized for both short and long bursts,and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation system.This paper provides a detailed description of the design and development of the trigger and localization software system for GECAM.It covers the general design,workflow,the main functions,and the algorithms used in the system.The paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube,as well as an overview of the performance for real celestial bursts during its in-orbit operation.展开更多
In recent years,distributed photovoltaics(DPV)has ushered in a good development situation due to the advantages of pollution-free power generation,full utilization of the ground or roof of the installation site,and ba...In recent years,distributed photovoltaics(DPV)has ushered in a good development situation due to the advantages of pollution-free power generation,full utilization of the ground or roof of the installation site,and balancing a large number of loads nearby.However,under the background of a large-scale DPV grid-connected to the county distribution network,an effective analysis method is needed to analyze its impact on the voltage of the distribution network in the early development stage of DPV.Therefore,a DPV orderly grid-connected method based on photovoltaics grid-connected order degree(PGOD)is proposed.This method aims to orderly analyze the change of voltage in the distribution network when large-scale DPV will be connected.Firstly,based on the voltagemagnitude sensitivity(VMS)index of the photovoltaics permitted grid-connected node and the acceptance of grid-connected node(AoGCN)index of other nodes in the network,thePGODindex is constructed to determine the photovoltaics permitted grid-connected node of the current photovoltaics grid-connected state network.Secondly,a photovoltaics orderly grid-connected model with a continuous updating state is constructed to obtain an orderly DPV grid-connected order.The simulation results illustrate that the photovoltaics grid-connected order determined by this method based on PGOD can effectively analyze the voltage impact of large-scale photovoltaics grid-connected,and explore the internal factors and characteristics of the impact.展开更多
Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the ...Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the operating costs of the power system.This paper proposes a two-stage planning method for distributed generation and energy storage systems that considers the hierarchical partitioning of source-storage-load.Firstly,an electrical distance structural index that comprehensively considers active power output and reactive power output is proposed to divide the distributed generation voltage regulation domain and determine the access location and number of distributed power sources.Secondly,a two-stage planning is carried out based on the zoning results.In the phase 1 distribution network-zoning optimization layer,the network loss is minimized so that the node voltage in the area does not exceed the limit,and the distributed generation configuration results are initially determined;in phase 2,the partition-node optimization layer is planned with the goal of economic optimization,and the distance-based improved ant lion algorithm is used to solve the problem to obtain the optimal distributed generation and energy storage systemconfiguration.Finally,the IEEE33 node systemwas used for simulation.The results showed that the voltage quality was significantly improved after optimization,and the overall revenue increased by about 20.6%,verifying the effectiveness of the two-stage planning.展开更多
Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H ...Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.展开更多
The overuse of nitrogen(N)fertilizer in fields has increased production costs and raised environmental concerns.Increasing the N use efficiency(NUE)of rice varieties is crucial for sustainable agriculture.Here we repo...The overuse of nitrogen(N)fertilizer in fields has increased production costs and raised environmental concerns.Increasing the N use efficiency(NUE)of rice varieties is crucial for sustainable agriculture.Here we report the cloning and characterization of OsNPF3.1,a gene that controls rice NUE.An amino acid mutation in the OsNPF3.1 coding region caused different NUEs in wild and cultivated rice.OsNPF3.1,which is expressed mainly in the aerial parts of rice,also affects rice plant height,heading date,and thousand-grain weight.The OsNPF3.1 protein is located in the plasma membrane.When OsNPF3.1 was subjected to artificial selection,two naturally varying loci were associated with NUE,of which OsNPF3.1Chr6_8741040differed between indica and japonica rice.OsNPF3.1 can be used as a new target gene for breeding rice varieties with high NUE.展开更多
Plant height(PH)is a complex trait regulated by the environment and multiple genes.PH directly affects crop yield,harvest index,and lodging resistance.From plant dwarf mutants,many genes related to PH have been identi...Plant height(PH)is a complex trait regulated by the environment and multiple genes.PH directly affects crop yield,harvest index,and lodging resistance.From plant dwarf mutants,many genes related to PH have been identified and described.Nonetheless,the molecular mechanism of height regulation in high-culm rice mutants has not been well studied.By using transcriptome and weighted gene co-expression network analysis(WGCNA),we identified the differentially expressed genes(DEGs)between high-culm rice mutants(MUT)and wild-type(WT)and explored the key pathways and potential candidate genes involved in PH regulation.Transcriptome analysis identified a total of 2,184 DEGs,of which 1,317 were identified at the jointing stage and 1,512 were identified at the heading stage.Kyoto Encyclopedia of Genes and Genomes enrichment showed that the enrichment pathways were mainly involved in plant hormone signal transduction,ABC transportation,and steroid hormone biosynthesis.Among these metabolic pathways,LOC_Os05g43910 and LOC_Os01g35030 were auxin(IAA)-related genes,up-regulated in MUT and LOC_Os02g08500(LEPTO1),LOC_Os11g04720,and LOC_Os12g04500 were cytokinin(CK)-related genes,downregulated in MUT.The WGCNA identified four modules(light cyan,dark grey,grey,and pale turquoise)closely related to PH,and seven key genes were screened from these modules,of which two were up-regulated cell wallrelated genes(LOC_Os01g26174(OsWAK5),LOC_Os06g05050)in MUT,and one gibberellic acid(GA)gene(LOC_Os06g37364,OsKO2)was also up-regulated.These genes might be closely related to PH regulation.These findings help us better understand the transcriptional regulation of rice plant growth and development and provide a theoretical basis for mapping and cloning the PH regulatory genes.展开更多
Urban rail transit loops are essential in urban rail transit systems and transportation networks.However,precise requirements and reference standards for rail transit loop design have yet to be established.There are c...Urban rail transit loops are essential in urban rail transit systems and transportation networks.However,precise requirements and reference standards for rail transit loop design have yet to be established.There are certain areas for improvement in planning,construction,and operation.In the planning and design of urban rail transit loops,the scale of the city and the relationship between line operations should be considered to ensure that the line conforms to the city’s operating traffic conditions and can effectively cater to peak passenger flow requirements.This article presents strategies for planning,constructing,and operating urban rail transit loops,laying the foundation for the healthy operation of urban rail transit.展开更多
The importance of public transportation in social and economic development is undeniable.With the rising concerns of environmental pollution and resource depletion in recent times,China has made significant efforts to...The importance of public transportation in social and economic development is undeniable.With the rising concerns of environmental pollution and resource depletion in recent times,China has made significant efforts to transition towards a low-carbon economy.To advance this transition,it is imperative to confront the obstacles faced by public transportation and enact effective management strategies that promote both economic and environmental sustainability.In this regard,the author has evaluated the existing status of public transit within the context of a low-carbon economy and put forth targeted management approaches.This research is expected to make a valuable contribution towards enhancing the quality of public transportation management.展开更多
In order to make rail transit smart stations serve passengers better,the potential of smart stations should be optimized to reduce time cost,and relieve traffic congestion.In this paper,the construction of smart stati...In order to make rail transit smart stations serve passengers better,the potential of smart stations should be optimized to reduce time cost,and relieve traffic congestion.In this paper,the construction of smart stations based on the management experience of a subway station and the benefits of smart stations were analyzed and discussed.The construction of smart stations,as well as the key technologies for the construction of smart stations,will aid in the automation and intelligent management of subway stations.展开更多
Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects.However,in view of the complexity of composite structure and composition,its self-heal is faci...Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects.However,in view of the complexity of composite structure and composition,its self-heal is facing challenges.In this article,supramolecular effect is proposed to repair the multistage structure,mechanical and thermal properties of composite materials.A stiff and tough supramolecular frameworks of 2-[[(butylamino)carbonyl]oxy]ethyl ester(PBA)–polydimethylsiloxane(PDMS)were established using a chain extender with double amide bonds in a side chain to extend prepolymers through copolymerization.Then,by introducing the copolymer into a folded graphene film(FGf),a highly thermally conductive composite of PBA–PDMS/FGf with self-healing capacity was fabricated.The ratio of crosslinking and hydrogen bonding was optimized to ensure that PBA–PDMS could completely self-heal at room temperature in 10 min.Additionally,PBA–PDMS/FGf exhibits a high tensile strength of 2.23±0.15 MPa at break and high thermal conductivity of 13±0.2 W m^(−1)K^(−1);of which the self-healing efficiencies were 100%and 98.65%at room temperature for tensile strength and thermal conductivity,respectively.The excellent self-healing performance comes from the efficient supramolecular interaction between polymer molecules,as well as polymer molecule and graphene.This kind of thermal conductive self-healing composite has important application prospects in the heat dissipation field of next generation electronic devices in the future.展开更多
Pulmonary arterial hypertension (PAH) is a progressive disease associated with increased constriction and remodeling of the pulmonary vasculature. Quercetin is a natural fiavonoid and has a variety of pharmacologica...Pulmonary arterial hypertension (PAH) is a progressive disease associated with increased constriction and remodeling of the pulmonary vasculature. Quercetin is a natural fiavonoid and has a variety of pharmacological effects including improvement of endothelial cell function. However, its pharmacological effects on pulmonary hypertension have been rarely reported. We sought to observe the protective effect of quercetin in rats with monocrotaline induced PAH. We divided 30 male Sprague-Dawley rats randomly into three groups with ten rats in each group: the monocrotaline group, the quercetin group and the control group. We found that, compared with the controls, the mean pulmonary artery pressure (mPAP) and the right ventricular hypertrophy index in the monocrotaline group were significantly higher (P 〈 0.01). Quercetin caused a significant reduction both in the mPAP and fight ventricular hypertrophy index compared with the monocrotaline group (P 〈 0.01) while no difference was found between the quercefin group and the control group (P 〉 0.05). Monocrotaline induced a marked increase in the wall thickness (WT) in small and mid-sized pulmonary arteries compared with the controls (P 〈 0.01). Monocrotaline also induced a marked increase in the wall area (WA) in small [(56.38 ±6.65)% in monocrotaline vs. (19.80±4.63)% in control] and mid-sized [(43.71± 5.38)% in monocrotaline vs. (14.24± 3.66)% in control] pulmonary arteries (P 〈 0.01). Quercefin treatment markedly reduced monocrotaline induced increase in both WT and WA (P 〈 0.01), which, however, still remained significantly elevated compared with those of the controls (P 〈 0.01). Furthermore, compared with controls, proliferating cell nuclear antigen (PCNA) expression in the pulmonary artery tissues was markedly increased by monocrotaline [(45.59± 1.27) in monocrotaline vs. (9.64± 0.69) in controls], which was significantly attenuated by quercetin. Our animal experiment indicated that quercetin could have protective effects on monocrotaline-induced PAH.展开更多
BACKGROUND Computed tomography(CT)-guided percutaneous lung biopsy is a common protocol in the context of diagnostic thoracic oncology,but entails a risk of complications including systematic air embolism(SAE).While S...BACKGROUND Computed tomography(CT)-guided percutaneous lung biopsy is a common protocol in the context of diagnostic thoracic oncology,but entails a risk of complications including systematic air embolism(SAE).While SAE is often well tolerated,it can be difficult to treat and may result in rapid mortality in some cases.CASE SUMMARY We report a rare case of left atrial SAE in a 71-year-old woman who underwent a CT-guided lung biopsy of a pulmonary nodule in the posterior basal segment of the right lower lobe.Shortly following needle extraction,she experienced a mild cough,hemoptysis,rapid-onset unconsciousness,and cardiopulmonary arrest.Cardiopulmonary resuscitation was immediately performed,but the patient died 40 min after the procedure.A closer review of collected CT scans revealed the presence of a large volume of air within the left atrium.CONCLUSION Although SAE is generally well tolerated and asymptomatic,interventional radiologists must be aware of the risk of fatal outcomes and establish appropriate emergency management protocols.In this report,the characteristics,mechanisms,and treatment recommendations associated with SAE are discussed in an effort to improve the survival of affected patients.展开更多
Au nanoparticles dispersed NiO composite films were prepared by a chemical solution method.The phase structure,microstructure,surface chemical state,and optical absorption properties of the films were characterized by...Au nanoparticles dispersed NiO composite films were prepared by a chemical solution method.The phase structure,microstructure,surface chemical state,and optical absorption properties of the films were characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,and Uv-vis spectrometer.The results indicate that Au particles with the average diameters of 35-42 nm are approximately spherical and disperse in the NiO matrix.The optical absorption peaks due to the surface plasmon resonance of Au particles shift to the shorter wavelength and intensify with the increase of Au content.The bandwidth narrows when the Au content increases from 8.4wt% to 45.2wt%,but widens by further increasing the Au content from 45.2wt% to 60.5wt%.The band gap Eg increases with the increase of Au contents from 8.4wt% to 45.2wt%,but decreases by further increasing the Au content.展开更多
Natural dyestuff of luteolin was isolated and used to dye wool fabric in this paper. Ethanol extraction and high-speed countercurrent chromatography (HSCCC) were used to extract and purify the luteolin from the peanut...Natural dyestuff of luteolin was isolated and used to dye wool fabric in this paper. Ethanol extraction and high-speed countercurrent chromatography (HSCCC) were used to extract and purify the luteolin from the peanut shell, and the structure of the isolated luteolin was characterized with FTIR techniques. The interaction between dyestuff and fiber was preliminarily discussed through thermodynamic study and supramolecular structure simulation to explain the intrinsic reasons why the color fastness was low when luteolin was applied to dyeing wool fabric. The extraction condition and purification parameter were as follows: 65% ethanol, ratio of material to liquid 1:20, 80°C, 3 h, chloroform-methanol-water (4/3/2, V/V), 800 rmp/min, 2.0 Mkpa, 0.5 mL/ min and 280 nm. The results of dyeing thermodynamics showed that the sorption isotherm of luteolin on wool fabric was consistent with Nernst model and similar to the disperse dyestuff. With molecular simulation, luteolin and glycin composed 8 stable complexes whose Laplacian values all were greater than 0, which suggested typical hydrogen bonds existing. The complex with three hydrogen bonds was proved the most stable. Both studies on thermodynamics and supramolecular simulation revealed that luteolin on wool fabric mainly depended on the weak hydrogen bonds interaction that determined the low dyefastness.展开更多
BACKGROUND Pulmonary alveolar proteinosis(PAP)is a rare condition that can cause progressive symptoms including dyspnea,cough and respiratory insufficiency.Secondary PAP is generally associated with hematological mali...BACKGROUND Pulmonary alveolar proteinosis(PAP)is a rare condition that can cause progressive symptoms including dyspnea,cough and respiratory insufficiency.Secondary PAP is generally associated with hematological malignancies including chronic myelomonocytic leukemia(CMML).To the best of our knowledge,this is the first reported case of PAP occurring secondary to CMML.CASE SUMMARY We report the case of a 63-year-old male who presented with a recurrent cough and gradually progressive dyspnea in the absence of fever.Based upon clinical symptoms,computed tomography findings,bone marrow aspiration,flow cytometry studies and cytogenetic analyses,the patient was diagnosed with PAP secondary to CMML.He underwent whole lung lavage in March 2016 to alleviate his dyspnea,after which he began combined chemotherapeutic treatment with decitabine and cytarabine.The patient died in January 2020 as a consequence of severe pulmonary infection.CONCLUSION This case offers insight regarding the mechanistic basis for PAP secondary to CMML and highlights potential risk factors.展开更多
With the shortage of energy and the rise of crude oil in the world, the development of oil shale is gaining more attention globally. To solve the problem of traditional heat conduction with low efficiency and high cos...With the shortage of energy and the rise of crude oil in the world, the development of oil shale is gaining more attention globally. To solve the problem of traditional heat conduction with low efficiency and high cost for oil shale, a new technology called radio frequency (RF) heating (microwave heating) is introduced in this paper. Radio frequency electromagnetic (microwave) can do work directly on medium molecule of oil shale and change into heat energy, the transmission of which allows both inner and outer molecules heating simultaneously without heat conduction. Meanwhile, oil shale is a poor microwave absorbing material and microwave absorbents must be added to reach pyrolysis temperature. By this means, shale oil could be heated at a higher speed and kerogen will gradually be cracked into gas and oil. Then shale oil and gas will flow into the production wells through fractures generated by heating and be pumped up to the surface.展开更多
The emergency treatment of thoracic injuries varies of general conditions and modern warfare. However, there are no unified battlefield treatment guidelines for thoracic injuries in the Chinese People's Liberation...The emergency treatment of thoracic injuries varies of general conditions and modern warfare. However, there are no unified battlefield treatment guidelines for thoracic injuries in the Chinese People's Liberation Army(PLA). An expert consensus has been reached based on the epidemiology of thoracic injuries and the concept of battlefield treatment combined with the existing levels of military medical care in modern warfare. Since there are no differences in the specialized treatment for thoracic injuries between general conditions and modern warfare, first aid, emergency treatment, and early treatment of thoracic injuries are introduced separately in three levels in this consensus. At Level Ⅰfacilities, tension pneumothorax and open pneumothorax are recommended for initial assessment during the first aid stage. Re-evaluation and further treatment for hemothorax, flail chest, and pericardial tamponade are recommended at Level Ⅱ facilities. At Level Ⅲ facilities, simple surgical operations such as emergency thoracotomy and debridement surgery for open pneumothorax are recommended. The grading standard for evidence evaluation and recommendation was used to reach this expert consensus.展开更多
It is critical to understand how forests regenerate after the exclusion of human induced disturbances because the regenerating species drive the renewal of resources and ecosystems,which in turn support human beings l...It is critical to understand how forests regenerate after the exclusion of human induced disturbances because the regenerating species drive the renewal of resources and ecosystems,which in turn support human beings locally and globally.This study of forest regeneration was conducted in the tropical coastal forest ecosystems of Tanzania at Uzigua Forest Reserve(24,730 ha)in the Pwani Region.We collected data from adult trees in 47 sampling plots(25×25 m)randomly established in closed forest sites(control)and in sites disturbed by farming and livestock grazing.Sapling and seedling data were collected and analyzed in 2×2 m nested subplots.Plots in the closed forest had higher mean basal area and volume for adult trees than those in sites disturbed by farming and livestock grazing.Plots in sites disturbed by farming had the highest Shannon–Wiener index for seedlings and saplings,followed by closed forest and livestock grazed sites.Closed plots and farmed plots had higher Simpson’s index for seedlings and saplings than in grazed sites.Plots in farmed and livestock-grazed sites had a higher Simpson index for adult trees than in closed sites.Equitability of seedlings and saplings was highest in closed forest sites,followed by farmed and livestock grazed sites.Plots disturbed by farming had higher equitability for adult trees than in livestock-grazed and closed sites.Moreover,plots disturbed by farming and grazing had a higher importance value index for seedlings than in closed sites.Plots in closed forests had higher sapling importance values than in farmed and grazed sites.Again,plots in closed forest had a higher importance value for adult trees than in farmed and grazed sites.The differences in tree species subcategories of regeneration across land-use indicates that farming and livestock grazing disturbances create heterogeneous microhabitats,which positively or negatively affects regeneration capacity of species after exclusion.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52130303,52327802,52303101,52173078,51973158)the China Postdoctoral Science Foundation(2023M732579)+2 种基金Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)National Key R&D Program of China(No.2022YFB3805702)Joint Funds of Ministry of Education(8091B032218).
文摘Vertically oriented carbon structures constructed from low-dimen-sional carbon materials are ideal frameworks for high-performance thermal inter-face materials(TIMs).However,improving the interfacial heat-transfer efficiency of vertically oriented carbon structures is a challenging task.Herein,an orthotropic three-dimensional(3D)hybrid carbon network(VSCG)is fabricated by depositing vertically aligned carbon nanotubes(VACNTs)on the surface of a horizontally oriented graphene film(HOGF).The interfacial interaction between the VACNTs and HOGF is then optimized through an annealing strategy.After regulating the orientation structure of the VACNTs and filling the VSCG with polydimethylsi-loxane(PDMS),VSCG/PDMS composites with excellent 3D thermal conductive properties are obtained.The highest in-plane and through-plane thermal conduc-tivities of the composites are 113.61 and 24.37 W m^(-1)K^(-1),respectively.The high contact area of HOGF and good compressibility of VACNTs imbue the VSCG/PDMS composite with low thermal resistance.In addition,the interfacial heat-transfer efficiency of VSCG/PDMS composite in the TIM performance was improved by 71.3%compared to that of a state-of-the-art thermal pad.This new structural design can potentially realize high-performance TIMs that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.
基金supported by the Strategic Priority Research Program on Space Science of the Chinese Academy of Sciences,the support from the Strategic Priority Research Program on Space Science(grant Nos.XDA15360300,XDA15360000,XDA15360102,XDA15052700 and E02212A02S)of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(NSFC,Grant No.12173038)and BeiDou navigation system。
文摘Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December 10.We developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic Box.This onboard software has the following features:high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation,dedicated localization algorithm optimized for both short and long bursts,and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation system.This paper provides a detailed description of the design and development of the trigger and localization software system for GECAM.It covers the general design,workflow,the main functions,and the algorithms used in the system.The paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube,as well as an overview of the performance for real celestial bursts during its in-orbit operation.
基金supported by North China Electric Power Research Institute’s Self-Funded Science and Technology Project“Research on Distributed Energy Storage Optimal Configuration and Operation Control Technology for Photovoltaic Promotion in the Entire County”(KJZ2022049).
文摘In recent years,distributed photovoltaics(DPV)has ushered in a good development situation due to the advantages of pollution-free power generation,full utilization of the ground or roof of the installation site,and balancing a large number of loads nearby.However,under the background of a large-scale DPV grid-connected to the county distribution network,an effective analysis method is needed to analyze its impact on the voltage of the distribution network in the early development stage of DPV.Therefore,a DPV orderly grid-connected method based on photovoltaics grid-connected order degree(PGOD)is proposed.This method aims to orderly analyze the change of voltage in the distribution network when large-scale DPV will be connected.Firstly,based on the voltagemagnitude sensitivity(VMS)index of the photovoltaics permitted grid-connected node and the acceptance of grid-connected node(AoGCN)index of other nodes in the network,thePGODindex is constructed to determine the photovoltaics permitted grid-connected node of the current photovoltaics grid-connected state network.Secondly,a photovoltaics orderly grid-connected model with a continuous updating state is constructed to obtain an orderly DPV grid-connected order.The simulation results illustrate that the photovoltaics grid-connected order determined by this method based on PGOD can effectively analyze the voltage impact of large-scale photovoltaics grid-connected,and explore the internal factors and characteristics of the impact.
基金supported by North China Electric Power Research Institute’s Self-Funded Science and Technology Project“Research on Distributed Energy Storage Optimal Configuration and Operation Control Technology for Photovoltaic Promotion in the Entire County”(KJZ2022049).
文摘Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the operating costs of the power system.This paper proposes a two-stage planning method for distributed generation and energy storage systems that considers the hierarchical partitioning of source-storage-load.Firstly,an electrical distance structural index that comprehensively considers active power output and reactive power output is proposed to divide the distributed generation voltage regulation domain and determine the access location and number of distributed power sources.Secondly,a two-stage planning is carried out based on the zoning results.In the phase 1 distribution network-zoning optimization layer,the network loss is minimized so that the node voltage in the area does not exceed the limit,and the distributed generation configuration results are initially determined;in phase 2,the partition-node optimization layer is planned with the goal of economic optimization,and the distance-based improved ant lion algorithm is used to solve the problem to obtain the optimal distributed generation and energy storage systemconfiguration.Finally,the IEEE33 node systemwas used for simulation.The results showed that the voltage quality was significantly improved after optimization,and the overall revenue increased by about 20.6%,verifying the effectiveness of the two-stage planning.
基金supported by the National Natural Science Foundation of China (Grant Nos.81874006,82172399,81902222,82060395,81902277,82072504,82000845)the Hunan Province Natural Science Foundation of China (Grant Nos.2020JJ4928,2020JJ4897,2021JJ30038,2021JJ40492)the Independent Exploration and Innovation Project of Central South University (Grant Nos.2020zzts255)。
文摘Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.
基金supported by the National Natural Science Foundation of China(32060476 and 31860371)Guangxi Department of Science and Technology(AA22068087-4)+3 种基金Guangxi Natural Science Foundation of China(2015GXNSFAA139054,2018GXNSFAA138124,and 2020GXNSFAA259041)Guangxi Ministry of Science and Technology(AB21238009)Special Fund of Local Science and Technology Development for the Central Guidance(ZY21195034)Guangxi Academy of Agricultural Sciences(2021JM04,2021JM49,2021YT030,QN-25,and QN-35)。
文摘The overuse of nitrogen(N)fertilizer in fields has increased production costs and raised environmental concerns.Increasing the N use efficiency(NUE)of rice varieties is crucial for sustainable agriculture.Here we report the cloning and characterization of OsNPF3.1,a gene that controls rice NUE.An amino acid mutation in the OsNPF3.1 coding region caused different NUEs in wild and cultivated rice.OsNPF3.1,which is expressed mainly in the aerial parts of rice,also affects rice plant height,heading date,and thousand-grain weight.The OsNPF3.1 protein is located in the plasma membrane.When OsNPF3.1 was subjected to artificial selection,two naturally varying loci were associated with NUE,of which OsNPF3.1Chr6_8741040differed between indica and japonica rice.OsNPF3.1 can be used as a new target gene for breeding rice varieties with high NUE.
基金supported by the National Natural Science Foundation of China(31760428,31860371,and 32060476)Guangxi Natural Science Foundation of China(2020GXNSFAA259041)+1 种基金Guangxi Science and Technology Project(Guike AB21238009)Guangxi Academy of Agricultural Sciences Foundation(2021JM04,JM49,YT030,QN-11,14,20,29,and 35).
文摘Plant height(PH)is a complex trait regulated by the environment and multiple genes.PH directly affects crop yield,harvest index,and lodging resistance.From plant dwarf mutants,many genes related to PH have been identified and described.Nonetheless,the molecular mechanism of height regulation in high-culm rice mutants has not been well studied.By using transcriptome and weighted gene co-expression network analysis(WGCNA),we identified the differentially expressed genes(DEGs)between high-culm rice mutants(MUT)and wild-type(WT)and explored the key pathways and potential candidate genes involved in PH regulation.Transcriptome analysis identified a total of 2,184 DEGs,of which 1,317 were identified at the jointing stage and 1,512 were identified at the heading stage.Kyoto Encyclopedia of Genes and Genomes enrichment showed that the enrichment pathways were mainly involved in plant hormone signal transduction,ABC transportation,and steroid hormone biosynthesis.Among these metabolic pathways,LOC_Os05g43910 and LOC_Os01g35030 were auxin(IAA)-related genes,up-regulated in MUT and LOC_Os02g08500(LEPTO1),LOC_Os11g04720,and LOC_Os12g04500 were cytokinin(CK)-related genes,downregulated in MUT.The WGCNA identified four modules(light cyan,dark grey,grey,and pale turquoise)closely related to PH,and seven key genes were screened from these modules,of which two were up-regulated cell wallrelated genes(LOC_Os01g26174(OsWAK5),LOC_Os06g05050)in MUT,and one gibberellic acid(GA)gene(LOC_Os06g37364,OsKO2)was also up-regulated.These genes might be closely related to PH regulation.These findings help us better understand the transcriptional regulation of rice plant growth and development and provide a theoretical basis for mapping and cloning the PH regulatory genes.
文摘Urban rail transit loops are essential in urban rail transit systems and transportation networks.However,precise requirements and reference standards for rail transit loop design have yet to be established.There are certain areas for improvement in planning,construction,and operation.In the planning and design of urban rail transit loops,the scale of the city and the relationship between line operations should be considered to ensure that the line conforms to the city’s operating traffic conditions and can effectively cater to peak passenger flow requirements.This article presents strategies for planning,constructing,and operating urban rail transit loops,laying the foundation for the healthy operation of urban rail transit.
文摘The importance of public transportation in social and economic development is undeniable.With the rising concerns of environmental pollution and resource depletion in recent times,China has made significant efforts to transition towards a low-carbon economy.To advance this transition,it is imperative to confront the obstacles faced by public transportation and enact effective management strategies that promote both economic and environmental sustainability.In this regard,the author has evaluated the existing status of public transit within the context of a low-carbon economy and put forth targeted management approaches.This research is expected to make a valuable contribution towards enhancing the quality of public transportation management.
文摘In order to make rail transit smart stations serve passengers better,the potential of smart stations should be optimized to reduce time cost,and relieve traffic congestion.In this paper,the construction of smart stations based on the management experience of a subway station and the benefits of smart stations were analyzed and discussed.The construction of smart stations,as well as the key technologies for the construction of smart stations,will aid in the automation and intelligent management of subway stations.
基金financially supported by National Natural Science Foundation of China (Grant Nos. 52173078, 52130303, 51973158, 51803151, and 51973152)the Science Foundation for Distinguished Young Scholars in Tianjin (No. 19JCJQJC61700)Tianjin Postgraduate Scientific Research Innovation Project in 2019 (2019YJSB181)
文摘Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects.However,in view of the complexity of composite structure and composition,its self-heal is facing challenges.In this article,supramolecular effect is proposed to repair the multistage structure,mechanical and thermal properties of composite materials.A stiff and tough supramolecular frameworks of 2-[[(butylamino)carbonyl]oxy]ethyl ester(PBA)–polydimethylsiloxane(PDMS)were established using a chain extender with double amide bonds in a side chain to extend prepolymers through copolymerization.Then,by introducing the copolymer into a folded graphene film(FGf),a highly thermally conductive composite of PBA–PDMS/FGf with self-healing capacity was fabricated.The ratio of crosslinking and hydrogen bonding was optimized to ensure that PBA–PDMS could completely self-heal at room temperature in 10 min.Additionally,PBA–PDMS/FGf exhibits a high tensile strength of 2.23±0.15 MPa at break and high thermal conductivity of 13±0.2 W m^(−1)K^(−1);of which the self-healing efficiencies were 100%and 98.65%at room temperature for tensile strength and thermal conductivity,respectively.The excellent self-healing performance comes from the efficient supramolecular interaction between polymer molecules,as well as polymer molecule and graphene.This kind of thermal conductive self-healing composite has important application prospects in the heat dissipation field of next generation electronic devices in the future.
文摘Pulmonary arterial hypertension (PAH) is a progressive disease associated with increased constriction and remodeling of the pulmonary vasculature. Quercetin is a natural fiavonoid and has a variety of pharmacological effects including improvement of endothelial cell function. However, its pharmacological effects on pulmonary hypertension have been rarely reported. We sought to observe the protective effect of quercetin in rats with monocrotaline induced PAH. We divided 30 male Sprague-Dawley rats randomly into three groups with ten rats in each group: the monocrotaline group, the quercetin group and the control group. We found that, compared with the controls, the mean pulmonary artery pressure (mPAP) and the right ventricular hypertrophy index in the monocrotaline group were significantly higher (P 〈 0.01). Quercetin caused a significant reduction both in the mPAP and fight ventricular hypertrophy index compared with the monocrotaline group (P 〈 0.01) while no difference was found between the quercefin group and the control group (P 〉 0.05). Monocrotaline induced a marked increase in the wall thickness (WT) in small and mid-sized pulmonary arteries compared with the controls (P 〈 0.01). Monocrotaline also induced a marked increase in the wall area (WA) in small [(56.38 ±6.65)% in monocrotaline vs. (19.80±4.63)% in control] and mid-sized [(43.71± 5.38)% in monocrotaline vs. (14.24± 3.66)% in control] pulmonary arteries (P 〈 0.01). Quercefin treatment markedly reduced monocrotaline induced increase in both WT and WA (P 〈 0.01), which, however, still remained significantly elevated compared with those of the controls (P 〈 0.01). Furthermore, compared with controls, proliferating cell nuclear antigen (PCNA) expression in the pulmonary artery tissues was markedly increased by monocrotaline [(45.59± 1.27) in monocrotaline vs. (9.64± 0.69) in controls], which was significantly attenuated by quercetin. Our animal experiment indicated that quercetin could have protective effects on monocrotaline-induced PAH.
基金Supported by the Science and Technology Development Project of Hangzhou,No.202004A15.
文摘BACKGROUND Computed tomography(CT)-guided percutaneous lung biopsy is a common protocol in the context of diagnostic thoracic oncology,but entails a risk of complications including systematic air embolism(SAE).While SAE is often well tolerated,it can be difficult to treat and may result in rapid mortality in some cases.CASE SUMMARY We report a rare case of left atrial SAE in a 71-year-old woman who underwent a CT-guided lung biopsy of a pulmonary nodule in the posterior basal segment of the right lower lobe.Shortly following needle extraction,she experienced a mild cough,hemoptysis,rapid-onset unconsciousness,and cardiopulmonary arrest.Cardiopulmonary resuscitation was immediately performed,but the patient died 40 min after the procedure.A closer review of collected CT scans revealed the presence of a large volume of air within the left atrium.CONCLUSION Although SAE is generally well tolerated and asymptomatic,interventional radiologists must be aware of the risk of fatal outcomes and establish appropriate emergency management protocols.In this report,the characteristics,mechanisms,and treatment recommendations associated with SAE are discussed in an effort to improve the survival of affected patients.
基金supported by the Major State Basic Research Development Program of China(No.2007CB613301)the National Natural Science Foundation of China(Nos.50842028 and 50972012)
文摘Au nanoparticles dispersed NiO composite films were prepared by a chemical solution method.The phase structure,microstructure,surface chemical state,and optical absorption properties of the films were characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,and Uv-vis spectrometer.The results indicate that Au particles with the average diameters of 35-42 nm are approximately spherical and disperse in the NiO matrix.The optical absorption peaks due to the surface plasmon resonance of Au particles shift to the shorter wavelength and intensify with the increase of Au content.The bandwidth narrows when the Au content increases from 8.4wt% to 45.2wt%,but widens by further increasing the Au content from 45.2wt% to 60.5wt%.The band gap Eg increases with the increase of Au contents from 8.4wt% to 45.2wt%,but decreases by further increasing the Au content.
文摘Natural dyestuff of luteolin was isolated and used to dye wool fabric in this paper. Ethanol extraction and high-speed countercurrent chromatography (HSCCC) were used to extract and purify the luteolin from the peanut shell, and the structure of the isolated luteolin was characterized with FTIR techniques. The interaction between dyestuff and fiber was preliminarily discussed through thermodynamic study and supramolecular structure simulation to explain the intrinsic reasons why the color fastness was low when luteolin was applied to dyeing wool fabric. The extraction condition and purification parameter were as follows: 65% ethanol, ratio of material to liquid 1:20, 80°C, 3 h, chloroform-methanol-water (4/3/2, V/V), 800 rmp/min, 2.0 Mkpa, 0.5 mL/ min and 280 nm. The results of dyeing thermodynamics showed that the sorption isotherm of luteolin on wool fabric was consistent with Nernst model and similar to the disperse dyestuff. With molecular simulation, luteolin and glycin composed 8 stable complexes whose Laplacian values all were greater than 0, which suggested typical hydrogen bonds existing. The complex with three hydrogen bonds was proved the most stable. Both studies on thermodynamics and supramolecular simulation revealed that luteolin on wool fabric mainly depended on the weak hydrogen bonds interaction that determined the low dyefastness.
基金Supported by The Medical and Health Technology Project of Zhejiang Province,No.2018KY567and the Hangzhou Municipal Science and Technology Development Program,No.20142013A61.
文摘BACKGROUND Pulmonary alveolar proteinosis(PAP)is a rare condition that can cause progressive symptoms including dyspnea,cough and respiratory insufficiency.Secondary PAP is generally associated with hematological malignancies including chronic myelomonocytic leukemia(CMML).To the best of our knowledge,this is the first reported case of PAP occurring secondary to CMML.CASE SUMMARY We report the case of a 63-year-old male who presented with a recurrent cough and gradually progressive dyspnea in the absence of fever.Based upon clinical symptoms,computed tomography findings,bone marrow aspiration,flow cytometry studies and cytogenetic analyses,the patient was diagnosed with PAP secondary to CMML.He underwent whole lung lavage in March 2016 to alleviate his dyspnea,after which he began combined chemotherapeutic treatment with decitabine and cytarabine.The patient died in January 2020 as a consequence of severe pulmonary infection.CONCLUSION This case offers insight regarding the mechanistic basis for PAP secondary to CMML and highlights potential risk factors.
文摘With the shortage of energy and the rise of crude oil in the world, the development of oil shale is gaining more attention globally. To solve the problem of traditional heat conduction with low efficiency and high cost for oil shale, a new technology called radio frequency (RF) heating (microwave heating) is introduced in this paper. Radio frequency electromagnetic (microwave) can do work directly on medium molecule of oil shale and change into heat energy, the transmission of which allows both inner and outer molecules heating simultaneously without heat conduction. Meanwhile, oil shale is a poor microwave absorbing material and microwave absorbents must be added to reach pyrolysis temperature. By this means, shale oil could be heated at a higher speed and kerogen will gradually be cracked into gas and oil. Then shale oil and gas will flow into the production wells through fractures generated by heating and be pumped up to the surface.
基金supported by the "Thirteenth Five-Year Plan" Special Project in Military Logistics Scientific Program(AWS16J032)the Innovation Project of Military Medicine(16CXZ017)
文摘The emergency treatment of thoracic injuries varies of general conditions and modern warfare. However, there are no unified battlefield treatment guidelines for thoracic injuries in the Chinese People's Liberation Army(PLA). An expert consensus has been reached based on the epidemiology of thoracic injuries and the concept of battlefield treatment combined with the existing levels of military medical care in modern warfare. Since there are no differences in the specialized treatment for thoracic injuries between general conditions and modern warfare, first aid, emergency treatment, and early treatment of thoracic injuries are introduced separately in three levels in this consensus. At Level Ⅰfacilities, tension pneumothorax and open pneumothorax are recommended for initial assessment during the first aid stage. Re-evaluation and further treatment for hemothorax, flail chest, and pericardial tamponade are recommended at Level Ⅱ facilities. At Level Ⅲ facilities, simple surgical operations such as emergency thoracotomy and debridement surgery for open pneumothorax are recommended. The grading standard for evidence evaluation and recommendation was used to reach this expert consensus.
基金supported by National Key Research and Development Project(2017YFD060130403)Fujian Forestry Science and Technology Research Project(2018FSR04008)International Science and Technology Cooperation Program of Fujian Agriculture and Forestry University(KXB16008A)
文摘It is critical to understand how forests regenerate after the exclusion of human induced disturbances because the regenerating species drive the renewal of resources and ecosystems,which in turn support human beings locally and globally.This study of forest regeneration was conducted in the tropical coastal forest ecosystems of Tanzania at Uzigua Forest Reserve(24,730 ha)in the Pwani Region.We collected data from adult trees in 47 sampling plots(25×25 m)randomly established in closed forest sites(control)and in sites disturbed by farming and livestock grazing.Sapling and seedling data were collected and analyzed in 2×2 m nested subplots.Plots in the closed forest had higher mean basal area and volume for adult trees than those in sites disturbed by farming and livestock grazing.Plots in sites disturbed by farming had the highest Shannon–Wiener index for seedlings and saplings,followed by closed forest and livestock grazed sites.Closed plots and farmed plots had higher Simpson’s index for seedlings and saplings than in grazed sites.Plots in farmed and livestock-grazed sites had a higher Simpson index for adult trees than in closed sites.Equitability of seedlings and saplings was highest in closed forest sites,followed by farmed and livestock grazed sites.Plots disturbed by farming had higher equitability for adult trees than in livestock-grazed and closed sites.Moreover,plots disturbed by farming and grazing had a higher importance value index for seedlings than in closed sites.Plots in closed forests had higher sapling importance values than in farmed and grazed sites.Again,plots in closed forest had a higher importance value for adult trees than in farmed and grazed sites.The differences in tree species subcategories of regeneration across land-use indicates that farming and livestock grazing disturbances create heterogeneous microhabitats,which positively or negatively affects regeneration capacity of species after exclusion.