BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptom...BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptoms,including severe headache,nausea,vomiting,transient or persistent loss of consciousness,limb weakness,and blurred vision.Ruptured aneurysms should be surgically treated as soon as possible.Intravascular electrocoagulation is becoming a promising treatment method for intracranial blister-like microaneurysms.The short-term follow-up results demonstrated that this method is safe and effective.This article presents a case of endovascular electrocoagulation for the treatment of a blisterlike microaneurysm.CASE SUMMARY This article reports the case of 71-year-old female patient with an intracranial aneurysm.The patient experienced a sudden headache with vomiting for 3 hours.Brain computed tomography(CT)scan showed a subarachnoid hemorrhage.She was diagnosed with rupture of an aneurysm and subarachnoid hemorrhage.The aneurysm was located in the choroidal segment of the right internal carotid artery.The size of the aneurysm was 2.00 mm×1.80 mm×1.97 mm,and the neck of the aneurysm was less than 0.5 mm wide.We successfully treated this aneurysm with endovascular electrocoagulation,and the patient was safely returned to the ward and discharged after subsequent supportive treatment.CT angiography reexamination 3 months after surgery revealed no contrast agent extravasation in the original lesion,with a good prognosis.CONCLUSION Endovascular electrocoagulation is an effective and safe method for the treatment of intracranial blister-like microaneurysms.展开更多
The Sichuan Basin(SCB),China has a high incidence of extremely persistent heavy rainfall(EPHR)events.The EPHR events from 2009 to 2019 in the SCB were mainly concentrated over the northern and northwestern windward sl...The Sichuan Basin(SCB),China has a high incidence of extremely persistent heavy rainfall(EPHR)events.The EPHR events from 2009 to 2019 in the SCB were mainly concentrated over the northern and northwestern windward slopes and the central basin.They occurred from June to September,but especially in July,and peaked at 0300 LST.ERA5 reanalysis data and objective classification were used to investigate the synoptic patterns and their effects.There were three synoptic patterns during EPHR events,all accompanied by a Southwest Vortex.The location and intensity of the Southwest Vortex,thermal forcing of the Tibetan Plateau(TP),and low-level winds can greatly affect the intensity and spatial distribution of EPHR.When the Southwest Vortex was located in the western SCB and there were southerly low-level jets(LLJs),convergence and upslope wind would lead to EPHR over the northwestern or northern windward slopes.If there was no LLJ and the whole SCB was under the center of the Southwest Vortex,nocturnal EPHR was controlled by the internal circulation of the Southwest Vortex and the updraft generated by the thermal forcing of the TP,and the rainfall was weaker.The southeastern entrance of the SCB was a key area where the low-level wind dominated the nocturnal peak of EPHR.The nocturnal strengthened southeasterly wind in the key area is attributable to inertial oscillation,and the topographic friction plays an essential role in transporting momentum and moisture into the basin by generating easterly and northeasterly ageostrophic winds.展开更多
In extremely close-distance coal seam(ECDCS)mining,section coal pillars remain after upper coal seam(UCS)extraction.Thus,for layout and support design of lower coal seam(LCS)mining roadways,it is critical to account f...In extremely close-distance coal seam(ECDCS)mining,section coal pillars remain after upper coal seam(UCS)extraction.Thus,for layout and support design of lower coal seam(LCS)mining roadways,it is critical to account for UCS goaf deterioration and residual coal pillar(RCP)-induced stress disturbance.Taking the 6.4 m layer spacing of ECDCS mining in Nanyangpo Coal Mine as a case study,this research aimed to determine the optimal layout and surrounding rock control method for the 24202-ventilation roadway in the RCP area.First,the challenges of roadway layout and support under RCP were clarified:three layout methods face distinct RCPinduced stress disturbances and goaf-related roof damage.A finite element model was established;the second invariant of deviatoric stress(J_(2))and horizontal stress index were introduced to analyze plastic zone and stress evolution after UCS mining.Results show that J_(2)distributes symmetrically,with its peak diffusing downward and attenuating in a“/”-shaped pattern.Six schemes were simulated to compare plastic zone distributions at different positions,revealing that the optimal layout consists of a roadway alignment with the RCP center.Based on roadway layout and roof conditions,a cooperative control scheme was proposed:deep,strong anchorage with long cables across the RCP,and shallow stable support with short bolts in the ECDCS.This scheme secures roof cables anchored to the UCS RCP roof to achieve cross-seam anchorage.On-site borehole peeping and loose circle tests confirm smooth surrounding rock hole walls and limited failure range.Specifically,surrounding rock deformation and roof separation were controlled within 200 mm and 80 mm,respectively,with stable bolt/cable support resistance.These results offer an innovative solution for roadway layout design and support strategies under RCP in ECDCS,with significant engineering application value.展开更多
Extremely large-scale array(XL-array)communications can significantly improve the transmission rate,spectral efficiency,and spatial resolution,and has great potential in next-generation mobile communication networks.A...Extremely large-scale array(XL-array)communications can significantly improve the transmission rate,spectral efficiency,and spatial resolution,and has great potential in next-generation mobile communication networks.A crucial problem in XLarray communications is to determine the boundary of applicable regions of the plane wave model(PWM)and spherical wave model(SWM).In this paper,we propose new PWM/SWM demarcations for XL-arrays from the viewpoint of channel gain and rank.Four sets of results are derived for four different array setups.First,an equi-power line is derived for a point-touniform linear array(ULA)scenario,where an inflection point is found at±π6 central incident angles.Second,an equi-power surface is derived for a point-touniform planar array(UPA)scenario,and it is proved that cos2(ϕ)cos2(φ)=12 is a dividing curve,where ϕ andφdenote the elevation and azimuth angles,respectively.Third,an accurate and explicit expression of the equi-rank surface is obtained for a ULA-to-ULA scenario.Finally,an approximated expression of the equirank surface is obtained for a ULA-to-UPA scenario.With the obtained closed-form expressions,the equirank surface for any antenna structure and any angle can be well estimated.Furthermore,the effect of scatterers is also investigated,from which some insights are drawn.展开更多
Under the influence of the upper coal pillars and dynamic pressure of coal mining,the roadway of the lower coal seam is prone to large deformation failure.In this paper,a novel control method and key technologies of a...Under the influence of the upper coal pillars and dynamic pressure of coal mining,the roadway of the lower coal seam is prone to large deformation failure.In this paper,a novel control method and key technologies of automatically formed roadway(AFR)by roof cutting and confined concrete column in extremely close-distance coal seam are proposed.Furthermore,a numerical model is established to analyze the structure characteristics of overlying roof strata.Based on numerical results,the roof structure model of“voussoir beam of upper layer+short cantilever beam of lower layer”of this method is proposed.What’s more,the calculation equation of the roof bending moment and evaluation indexes is established,and the influence of different factors on roof stability control of AFR is studied.Finally,a field test is conducted to verify the effectiveness of this novel method.Field results were as follows:1)The maximum and average support stress of working face obviously decreased;2)The confined concrete column can provide high-strength support in dynamic influence zone;3)The maximum deformation of AFR safety requirement can be met.This study can provide effective guidance for the application of this method in extremely close-distance coal seam.展开更多
This study focuses on steeply inclined and extremely thick coal seams(SIETCS)characterized by immense thickness,a steep inclination of coal seams(87°),and high horizontal stress.The geological conditions and mini...This study focuses on steeply inclined and extremely thick coal seams(SIETCS)characterized by immense thickness,a steep inclination of coal seams(87°),and high horizontal stress.The geological conditions and mining technology associated with SIETCS differ significantly from those of generally inclined coal seams,resulting in notable variations in roadway stress distributions.On SIETCS have predominantly examined the impact of rock layers flanking coal seams on rock bursts,with limited emphasis on SIETCS roadways.This study employs comprehensive methods,integrating numerical simulations,theoretical analyses,and field detections to investigate the stress distribution of SIETCS and the mechanisms of rock burst-induced vertical damage,subsequently validated in situ.The vertical stress in SIETCS is minimal,while horizontal stress is concentrated,leading to the formation of layered crack structures(LCS)that distribute above and below the roadways.Additionally,elastic energy significantly concentrates within the LCS.Axial dynamic compressive stress and vertical dynamic tensile stress along the LCS diminish its stability,readily triggering failure.During the LCS failure process,the stored energy is released,converting into kinetic energy required for coal body ejection after reaching the minimum energy for failure and dissipative energy,ultimately leading to rock burst-induced vertical damage in roadways.On-site detection and analysis within SIETCS,along with historical rock burst data,confirm the existence of LCS and its role in inducing vertical rock burst damage.This research establishes essential foundations for preventing rock bursts within SIETCS.展开更多
The implementation of the ecological protection red line serves as a crucial protective barrier for the conservation of wild plants with extremely small populations by delineating specific geographical areas designate...The implementation of the ecological protection red line serves as a crucial protective barrier for the conservation of wild plants with extremely small populations by delineating specific geographical areas designated for their conservation.The implementation of a comprehensive set of conservation measures aimed at establishing a biodiversity conservation network for wild plants with extremely small populations has laid the foundation for the health and stability of ecosystems,as well as the harmonious coexistence of humans and the natural environment.Research on the conservation of wild plants with extremely small populations serves as a critical foundation for informing and enhancing the effective conservation of such populations.This paper provides a systematic examination of the theoretical and practical conservation status of certain wild plants with extremely small populations and discusses the conservation trends of these populations within the framework of ecological protection red line delineation.In the future,strategies for the conservation of wild plants with extremely small populations should be integrated with an analysis of the causes of endangerment.This approach will provide a robust foundation for applied research focused on the conservation of these vulnerable plant populations.展开更多
Magnetoresistance(MR)is a pivotal transport phenomenon within the realm of condensed matter physics.In recent years,materials exhibiting extremely large unsaturated magnetoresistance(XMR),which are often potential top...Magnetoresistance(MR)is a pivotal transport phenomenon within the realm of condensed matter physics.In recent years,materials exhibiting extremely large unsaturated magnetoresistance(XMR),which are often potential topological materials,have garnered significant attention.In this study,we synthesized single crystals of ZrBi_(2) and performed electrical and specific heat measurements on them.The resistivity of ZrBi_(2) displays metallic behavior with a high residual resistance ratio.Notably,the MR of ZrBi_(2) reaches approximately 2.0×10^(3)%at 2 K and 16 T without saturation.Weak Shubnikov-de Haas oscillations with two frequencies were observed above 13.5 T,which correspond to 237 T and 663 T.Hall effect fitting yields nearly equal concentrations of electron and hole carriers with concentrations of approximately 10^(21)cm^(-3)and mobilities of approximately 5000 cm^(2)·V^(-1)·s^(-1)at 2 K.The XMR could be attributed to the electron-hole compensation with high mobility.展开更多
A numerical simulation was performed using the Thompson microphysics scheme to preliminarily investigate the features of the microphysical processes involved in the record-breaking rainfall event that occurred in Hena...A numerical simulation was performed using the Thompson microphysics scheme to preliminarily investigate the features of the microphysical processes involved in the record-breaking rainfall event that occurred in Henan Province,China,on 20 July 2021.The simulation results showed that a strong meso-𝛾-scale vortical updraft was concurrent with the torrential rainfall.The main finding is that this event was characterized by typical midlatitude warm-rain processes.The simulation with the Thompson microphysics scheme further indicated that highly efficient collision-coalescence of cloud water to rainwater resulted in a considerably active rain droplet growth,leading to this record-breaking rainfall event.展开更多
Introduction: The purpose of this retrospective study is to identify medical conditions impacting neurodevelopmental outcomes of extremely low birth weight and very low birth weight preterm infants at three years of a...Introduction: The purpose of this retrospective study is to identify medical conditions impacting neurodevelopmental outcomes of extremely low birth weight and very low birth weight preterm infants at three years of age. Methods: Infants born in Banner Diamond Children’s University Medical Center, receiving services in the Newborn Intensive Care Unit, and attending Neonatal Developmental Follow-Up Clinic were identified. Participants received developmental assessment and follow-up from August 2012 through December 2018. Relevant clinical conditions during initial hospital stay and up to three years of age were obtained by reviewing medical and developmental records. Bayley Scales of Infant Toddler Development (Bayley III) was used to evaluate skill development at 6, 9, 12, 18, 24, 30, 36 months. Results: Data analysis did not reveal significant p-values;it did demonstrate that some predictor variables impact neurodevelopmental outcomes in cognitive, language and motor skill development. Conclusion: This retrospective study reports significant association between birth weight and low cognitive scores. Correlations were also found between gestational age and Total Language, and the longer an infant stayed in the NICU, the poorer the Total Language Scaled Scores at 8 to 12 months, 15 to 18 months, and 24 to 36 months. Birth weight was found to be the greatest predictor of poor motor scores.展开更多
By selecting the daily maximum temperatures during 1961-2005 in 35 representative stations in Liaoning Province, the temporal and spatial distribution characteristics of extremely maximum temperature event were studie...By selecting the daily maximum temperatures during 1961-2005 in 35 representative stations in Liaoning Province, the temporal and spatial distribution characteristics of extremely maximum temperature event were studied. By using REOF, the mean-square deviation and so on, the variation and distribution situation of extremely maximum temperature in the different regions of Liaoning were reflected. The results showed that the extremely maximum temperature in Liaoning Province could be divided into 3 regions where were respectively the northeast area, the west and the northwest area, the south and the southeast area. The distribution characteristic of extremely maximum temperature threshold value in Liaoning Province was basically consistent with the distribution characteristic of average temperature. The zone where the extremely maximum temperature threshold was relatively high was in the northwest area of Liaoning, and the low threshold zone was in the southeast area and most areas in the east. The variation of extremely maximum temperature in winter was the greatest and in summer was the smallest. The variation of extremely maximum temperature days was the greatest in summer and wasn’t great in spring, autumn, winter.展开更多
AIM： Minimal deviation carcinoma of the uterine cervix, otherwise known as extremely well-differentiated adenocarcinoma （EWDA）, is characterized by its benign microscopic appearance in contrast to its aggressive be...AIM： Minimal deviation carcinoma of the uterine cervix, otherwise known as extremely well-differentiated adenocarcinoma （EWDA）, is characterized by its benign microscopic appearance in contrast to its aggressive behavior. In order to elucidate the clinicopathological features and biological behavior of the gastric counterpart of EWDA, we, using immunohistochemistry, analyzed nine lesions for the phenotypic expression, proliferative activity, and the expression of oncogene-associated products. METHODS： Clinicopathological features, including preoperative biopsy diagnosis, were reviewed. Using immunohitstochemistry, Ki-67 labeling index and expression of p53 and c-erbB-2 protein in the gastric lesions were detected.RESULT： Locations in the middle or upper third of the stomach and polypoid macroscopic features are characteristic of EWDA of the stomach. Although 4 of the 9 lesions showed only focal lymphatic or venous invasion, lymph node metastasis was not present and none of the patients died of the lesions （mean follow-up period, 56 too）. All 9 cases of EWDA could be classified into gastric phenotype （5 lesions） and intestinal phenotype （4 lesions）. The former resembled gastric foveolar epithelium, mucous neck cells or pyloric glands, but their papillary structures were frequently elongated and the tumor cellsand their nuclei were slightly larger and more hyperchromatic compared to normal epithelium. The latter resembled intestinal metaplasia with minimal nulcear atypia and irregular glands; two of these lesions demonstrated complete intestinal phenotype, while two demonstrated incomplete intestinal phenotype. Ki-67 labeling index was low and none of the cases revealed over-expression of p53 and c-erbB-2 protein. CONCLUSION： Unlike minimal deviation carcinoma of the cervix, these findings suggest that EWDA of the stomach is a lesion of low-grade malignancy. This favorable biological behavior is supported by the data of a low Ki-67 labeling index and a lack of p53 or c-erbB-2 protein over-expression. Because of its resemblance to normal gastric mucosa or mucosa with intestinal metaplasia, EWDA is often misdiagnosed. To prevent the misdiagnosis of such lesions, the clinical and pathologic characteristics should be taken into consideration.展开更多
In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La ...In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Niña event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid−high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Niña)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Niña prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.展开更多
An extremely heavy rainfall event lasting from 17 to 22 July 2021 occurred in Henan Province of China, with accumulated precipitation of more than 1000 mm over a 6-day period that exceeded its mean annual precipitatio...An extremely heavy rainfall event lasting from 17 to 22 July 2021 occurred in Henan Province of China, with accumulated precipitation of more than 1000 mm over a 6-day period that exceeded its mean annual precipitation. The present study examines the roles of persistent low-level jets(LLJs) in maintaining the precipitation using surface station observations and reanalysis datasets. The LLJs triggered strong ascending motions and carried moisture mainly from the outflow of Typhoon In-fa(2021). The varying directions of the LLJs well corresponded to the meridional shifts of the rainfall. The precipitation rate reached a maximum during 20-21 July as the LLJs strengthened and expanded vertically into double LLJs, including synoptic-weather-system-related LLJs(SLLJs) at 850–700 hPa and boundary-layer jets(BLJs)at ~950 hPa. The coupling of the SLLJ and BLJ provided strong mid-and low-level convergence on 20 July, whereas the SLLJ produced mid-level divergence at its entrance that coupled with low-level convergence at the terminus of the BLJ on21 July. The formation mechanisms of the two types of LLJs are further examined. The SLLJs and the low-pressure vortex(or inverted trough) varied synchronously as a whole and were affected by the southwestward movement of the WPSH in the rainiest period. The persistent large total pressure gradient force at low levels also maintained the strength of low-level geostrophic winds, thus sustaining the BLJs on the synoptic scale. The results based on a Du-Rotunno 1D model show that the Blackadar and Holton mechanisms jointly governed the BLJ dynamics on the diurnal scale.展开更多
A direct synthesis of methyl levulinate from cellulose alcoholysis in methanol medium under mild condition(180 210 C)catalyzed by extremely low concentration sulfuric acid(0.01 mol/L)and the product isolation were dev...A direct synthesis of methyl levulinate from cellulose alcoholysis in methanol medium under mild condition(180 210 C)catalyzed by extremely low concentration sulfuric acid(0.01 mol/L)and the product isolation were developed in this study.Effects of different process variables towards the catalytic performance were performed as a function of reaction time.The results indicated that sulfuric acid concentration,temperature and initial cellulose concentration had significant effects on the synthesis of methyl levulinate.An optimized yield of around 50%was achieved at 210 C for 120 min with sulfuric acid concentration of 0.01 mol/L and initial cellulose concentration below 100 g/L.The resulting product mixture was isolated by a distillation technique that combines an atmospheric distillation with a vacuum distillation where n-dodecane was added to help distill the heavy fraction.The light fraction including mainly methanol could be reused as the reaction medium without any substantial change in the yield of methyl levulinate.The chemical composition and structural of lower heavy fraction were characterized by GC/MS,FTIR,1H-NMR and13C-NMR techniques.Methyl levulinate was found to be a major ingredient of lower heavy fraction with the content over 96%.This pathway is efficient,environmentally benign and economical for the production of pure levulinate esters from cellulose.展开更多
Reconfigurable intelligent surface(RIS)is more likely to develop into extremely large-scale RIS(XL-RIS)to efficiently boost the system capacity for future 6 G communications.Beam training is an effective way to acquir...Reconfigurable intelligent surface(RIS)is more likely to develop into extremely large-scale RIS(XL-RIS)to efficiently boost the system capacity for future 6 G communications.Beam training is an effective way to acquire channel state information(CSI)for XL-RIS.Existing beam training schemes rely on the far-field codebook.However,due to the large aperture of XL-RIS,the scatters are more likely to be in the near-field region of XL-RIS.The far-field codebook mismatches the near-field channel model.Thus,the existing far-field beam training scheme will cause severe performance loss in the XL-RIS assisted nearfield communications.To solve this problem,we propose the efficient near-field beam training schemes by designing the near-field codebook to match the nearfield channel model.Specifically,we firstly design the near-field codebook by considering the near-field cascaded array steering vector of XL-RIS.Then,the optimal codeword for XL-RIS is obtained by the exhausted training procedure.To reduce the beam training overhead,we further design a hierarchical nearfield codebook and propose the corresponding hierarchical near-field beam training scheme,where different levels of sub-codebooks are searched in turn with reduced codebook size.Simulation results show the proposed near-field beam training schemes outperform the existing far-field beam training scheme.展开更多
When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stra...When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a ＂main key stratum＂, will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway （we can also drill them in the drilling field located high in an air gateway）. Given the practice in the Haizi mine, the gas drainage rate can reach 73% in the middie coal group, with a gas drainage radius over 100 m.展开更多
Assimilation of the Advanced Geostationary Radiance Imager(AGRI)clear-sky radiance in a regional model is performed.The forecasting effectiveness of the assimilation of two water vapor(WV)channels with conventional ob...Assimilation of the Advanced Geostationary Radiance Imager(AGRI)clear-sky radiance in a regional model is performed.The forecasting effectiveness of the assimilation of two water vapor(WV)channels with conventional observations for the“21·7”Henan extremely heavy rainfall is analyzed and compared with a baseline test that assimilates only conventional observations in this study.The results show that the 24-h cumulative precipitation forecast by the assimilation experiment with the addition of the AGRI exceeds 500 mm,compared to a maximum value of 532.6 mm measured by the national meteorological stations,and that the location of the maximum precipitation is consistent with the observations.The results for the short periods of intense precipitation processes are that the simulation of the location and intensity of the 3-h cumulative precipitation is also relatively accurate.The analysis increment shows that the main difference between the two sets of assimilation experiments is over the ocean due to the additional ocean observations provided by FY-4A,which compensates for the lack of ocean observations.The assimilation of satellite data adjusts the vertical and horizontal wind fields over the ocean by adjusting the atmospheric temperature and humidity,which ultimately results in a narrower and stronger WV transport path to the center of heavy precipitation in Zhengzhou in the lower troposphere.Conversely,the WV convergence and upward motion in the control experiment are more dispersed;therefore,the precipitation centers are also correspondingly more dispersed.展开更多
A record-breaking heavy rainfall event that occurred in Zhengzhou,Henan province during 19–21 July 2021 is simulated using the Weather Research and Forecasting Model,and the large-scale precipitation efficiency(LSPE)...A record-breaking heavy rainfall event that occurred in Zhengzhou,Henan province during 19–21 July 2021 is simulated using the Weather Research and Forecasting Model,and the large-scale precipitation efficiency(LSPE)and cloud-microphysical precipitation efficiency(CMPE)of the rainfall are analyzed based on the model results.Then,the key physical factors that influenced LSPE and CMPE,and the possible mechanisms for the extreme rainfall over Zhengzhou are explored.Results show that water vapor flux convergence was the key factor that influenced LSPE.Water vapor was transported by the southeasterly winds between Typhoon In-Fa(2021)and the subtropical high,and the southerly flow of Typhoon Cempaka(2021),and converged in Zhengzhou due to the blocking by the Taihang and Funiu Mountains in western Henan province.Strong moisture convergence centers were formed on the windward slope of the mountains,which led to high LSPE in Zhengzhou.From the perspective of CMPE,the net consumption of water vapor by microphysical processes was the key factor that influenced CMPE.Quantitative budget analysis suggests that water vapor was mainly converted to cloud water and ice-phase particles and then transformed to raindrops through melting of graupel and accretion of cloud water by rainwater during the heavy precipitation stage.The dry intrusion in the middle and upper levels over Zhengzhou made the high potential vorticity descend from the upper troposphere and enhanced the convective instability.Moreover,the intrusion of cold and dry air resulted in the supersaturation and condensation of water vapor,which contributed to the heavy rainfall in Zhengzhou.展开更多
AIM： To identify the clinical and prognostic features of patients with hepatocellular carcinoma （HCC） aged 80 years or more. METHODS： A total of 1310 patients with HCC were included in this study. Ninety-one patie...AIM： To identify the clinical and prognostic features of patients with hepatocellular carcinoma （HCC） aged 80 years or more. METHODS： A total of 1310 patients with HCC were included in this study. Ninety-one patients aged 80 years or more at the time of diagnosis of HCC were defined as the extremely elderly group. Two hundred and thirty-four patients aged 〉/ 50 years but less than 60 years were regarded as the non-elderly group. RESULTS： The sex ratio （male to female） was significantly lower in the extremely elderly group （0.90：1） than in the non-elderly group （3.9：1, P〈 0.001）. The positive rate for HBsAg was significantly lower in the extremely elderly group and the proportion of patients negative for HBsAg and HCVAb obviously increased in the extremely elderly group （P〈 0.001）. There were no significant differences in the following parameters： diameter and number of tumors, Child-Pugh grading, tumor staging, presence of portal thrombosis or ascites, and positive rate for HCVAb. Extremely elderly patients did not often receive surgical treatment （P 〈 0.001） and they were more likely to receive conservative treatment （P〈 0.01）. There were no significant differences in survival curves based on the Kaplan-Meier methods in comparison with the overall patients between the two groups. However, the survival curves were significantly worse in the extremely elderly patients with stage Ⅰ/Ⅱ, stage Ⅰ/Ⅱ and Child-Pugh grade A cirrhosis in comparison with the non-elderly group. The causes of death did not differ among the patients, and most cases died of liverrelated diseases even in the extremely elderly patients. CONCLUSION： In the patients with good liver functions and good performance status, aggressive treatment for HCC might improve the survival rate, even in extremely elderly patients.展开更多
文摘BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptoms,including severe headache,nausea,vomiting,transient or persistent loss of consciousness,limb weakness,and blurred vision.Ruptured aneurysms should be surgically treated as soon as possible.Intravascular electrocoagulation is becoming a promising treatment method for intracranial blister-like microaneurysms.The short-term follow-up results demonstrated that this method is safe and effective.This article presents a case of endovascular electrocoagulation for the treatment of a blisterlike microaneurysm.CASE SUMMARY This article reports the case of 71-year-old female patient with an intracranial aneurysm.The patient experienced a sudden headache with vomiting for 3 hours.Brain computed tomography(CT)scan showed a subarachnoid hemorrhage.She was diagnosed with rupture of an aneurysm and subarachnoid hemorrhage.The aneurysm was located in the choroidal segment of the right internal carotid artery.The size of the aneurysm was 2.00 mm×1.80 mm×1.97 mm,and the neck of the aneurysm was less than 0.5 mm wide.We successfully treated this aneurysm with endovascular electrocoagulation,and the patient was safely returned to the ward and discharged after subsequent supportive treatment.CT angiography reexamination 3 months after surgery revealed no contrast agent extravasation in the original lesion,with a good prognosis.CONCLUSION Endovascular electrocoagulation is an effective and safe method for the treatment of intracranial blister-like microaneurysms.
基金supported by the National Natural Science Foundation of China(Grant Nos.42330610 and 42075010)。
文摘The Sichuan Basin(SCB),China has a high incidence of extremely persistent heavy rainfall(EPHR)events.The EPHR events from 2009 to 2019 in the SCB were mainly concentrated over the northern and northwestern windward slopes and the central basin.They occurred from June to September,but especially in July,and peaked at 0300 LST.ERA5 reanalysis data and objective classification were used to investigate the synoptic patterns and their effects.There were three synoptic patterns during EPHR events,all accompanied by a Southwest Vortex.The location and intensity of the Southwest Vortex,thermal forcing of the Tibetan Plateau(TP),and low-level winds can greatly affect the intensity and spatial distribution of EPHR.When the Southwest Vortex was located in the western SCB and there were southerly low-level jets(LLJs),convergence and upslope wind would lead to EPHR over the northwestern or northern windward slopes.If there was no LLJ and the whole SCB was under the center of the Southwest Vortex,nocturnal EPHR was controlled by the internal circulation of the Southwest Vortex and the updraft generated by the thermal forcing of the TP,and the rainfall was weaker.The southeastern entrance of the SCB was a key area where the low-level wind dominated the nocturnal peak of EPHR.The nocturnal strengthened southeasterly wind in the key area is attributable to inertial oscillation,and the topographic friction plays an essential role in transporting momentum and moisture into the basin by generating easterly and northeasterly ageostrophic winds.
基金supported by the National Natural Science Foundation of China(No.52074296)。
文摘In extremely close-distance coal seam(ECDCS)mining,section coal pillars remain after upper coal seam(UCS)extraction.Thus,for layout and support design of lower coal seam(LCS)mining roadways,it is critical to account for UCS goaf deterioration and residual coal pillar(RCP)-induced stress disturbance.Taking the 6.4 m layer spacing of ECDCS mining in Nanyangpo Coal Mine as a case study,this research aimed to determine the optimal layout and surrounding rock control method for the 24202-ventilation roadway in the RCP area.First,the challenges of roadway layout and support under RCP were clarified:three layout methods face distinct RCPinduced stress disturbances and goaf-related roof damage.A finite element model was established;the second invariant of deviatoric stress(J_(2))and horizontal stress index were introduced to analyze plastic zone and stress evolution after UCS mining.Results show that J_(2)distributes symmetrically,with its peak diffusing downward and attenuating in a“/”-shaped pattern.Six schemes were simulated to compare plastic zone distributions at different positions,revealing that the optimal layout consists of a roadway alignment with the RCP center.Based on roadway layout and roof conditions,a cooperative control scheme was proposed:deep,strong anchorage with long cables across the RCP,and shallow stable support with short bolts in the ECDCS.This scheme secures roof cables anchored to the UCS RCP roof to achieve cross-seam anchorage.On-site borehole peeping and loose circle tests confirm smooth surrounding rock hole walls and limited failure range.Specifically,surrounding rock deformation and roof separation were controlled within 200 mm and 80 mm,respectively,with stable bolt/cable support resistance.These results offer an innovative solution for roadway layout design and support strategies under RCP in ECDCS,with significant engineering application value.
基金supported in part by the National Natural Science Foundation of China (NSFC) under Grants 62271310 and 62125108in part by the Fundamental Research Funds for the Central Universities of Chinain part by the NSFC under Grant 62431014
文摘Extremely large-scale array(XL-array)communications can significantly improve the transmission rate,spectral efficiency,and spatial resolution,and has great potential in next-generation mobile communication networks.A crucial problem in XLarray communications is to determine the boundary of applicable regions of the plane wave model(PWM)and spherical wave model(SWM).In this paper,we propose new PWM/SWM demarcations for XL-arrays from the viewpoint of channel gain and rank.Four sets of results are derived for four different array setups.First,an equi-power line is derived for a point-touniform linear array(ULA)scenario,where an inflection point is found at±π6 central incident angles.Second,an equi-power surface is derived for a point-touniform planar array(UPA)scenario,and it is proved that cos2(ϕ)cos2(φ)=12 is a dividing curve,where ϕ andφdenote the elevation and azimuth angles,respectively.Third,an accurate and explicit expression of the equi-rank surface is obtained for a ULA-to-ULA scenario.Finally,an approximated expression of the equirank surface is obtained for a ULA-to-UPA scenario.With the obtained closed-form expressions,the equirank surface for any antenna structure and any angle can be well estimated.Furthermore,the effect of scatterers is also investigated,from which some insights are drawn.
基金Projects(52074164,42077267)supported by the National Natural Science Foundation of ChinaProject(2023M742073)supported by the China Postdoctoral Science FoundationProject(SDCX-ZG-202303010)supported by the Shandong Postdoctora1 Science Foundation,China。
文摘Under the influence of the upper coal pillars and dynamic pressure of coal mining,the roadway of the lower coal seam is prone to large deformation failure.In this paper,a novel control method and key technologies of automatically formed roadway(AFR)by roof cutting and confined concrete column in extremely close-distance coal seam are proposed.Furthermore,a numerical model is established to analyze the structure characteristics of overlying roof strata.Based on numerical results,the roof structure model of“voussoir beam of upper layer+short cantilever beam of lower layer”of this method is proposed.What’s more,the calculation equation of the roof bending moment and evaluation indexes is established,and the influence of different factors on roof stability control of AFR is studied.Finally,a field test is conducted to verify the effectiveness of this novel method.Field results were as follows:1)The maximum and average support stress of working face obviously decreased;2)The confined concrete column can provide high-strength support in dynamic influence zone;3)The maximum deformation of AFR safety requirement can be met.This study can provide effective guidance for the application of this method in extremely close-distance coal seam.
基金support of the National Natural Science Foundation of China(52374180,52327804).
文摘This study focuses on steeply inclined and extremely thick coal seams(SIETCS)characterized by immense thickness,a steep inclination of coal seams(87°),and high horizontal stress.The geological conditions and mining technology associated with SIETCS differ significantly from those of generally inclined coal seams,resulting in notable variations in roadway stress distributions.On SIETCS have predominantly examined the impact of rock layers flanking coal seams on rock bursts,with limited emphasis on SIETCS roadways.This study employs comprehensive methods,integrating numerical simulations,theoretical analyses,and field detections to investigate the stress distribution of SIETCS and the mechanisms of rock burst-induced vertical damage,subsequently validated in situ.The vertical stress in SIETCS is minimal,while horizontal stress is concentrated,leading to the formation of layered crack structures(LCS)that distribute above and below the roadways.Additionally,elastic energy significantly concentrates within the LCS.Axial dynamic compressive stress and vertical dynamic tensile stress along the LCS diminish its stability,readily triggering failure.During the LCS failure process,the stored energy is released,converting into kinetic energy required for coal body ejection after reaching the minimum energy for failure and dissipative energy,ultimately leading to rock burst-induced vertical damage in roadways.On-site detection and analysis within SIETCS,along with historical rock burst data,confirm the existence of LCS and its role in inducing vertical rock burst damage.This research establishes essential foundations for preventing rock bursts within SIETCS.
基金Supported by 2024 Central Financial Comprehensive Protection Project for Abies chensiensis(610000242000000026647)2024 Provincial Forestry and Grassland Reform and Development Fund for the National Key Wild Plant Protection Project(610000242000000028574)2024 Biodiversity Conservation Project(610000242000000024911).
文摘The implementation of the ecological protection red line serves as a crucial protective barrier for the conservation of wild plants with extremely small populations by delineating specific geographical areas designated for their conservation.The implementation of a comprehensive set of conservation measures aimed at establishing a biodiversity conservation network for wild plants with extremely small populations has laid the foundation for the health and stability of ecosystems,as well as the harmonious coexistence of humans and the natural environment.Research on the conservation of wild plants with extremely small populations serves as a critical foundation for informing and enhancing the effective conservation of such populations.This paper provides a systematic examination of the theoretical and practical conservation status of certain wild plants with extremely small populations and discusses the conservation trends of these populations within the framework of ecological protection red line delineation.In the future,strategies for the conservation of wild plants with extremely small populations should be integrated with an analysis of the causes of endangerment.This approach will provide a robust foundation for applied research focused on the conservation of these vulnerable plant populations.
基金Project supported by the National Natural Science Foundation of China(Grant No.12274440)the National Key R&D Program of China(Grant No.2022YFA1403903)the Synergetic Extreme Condition User Facility(SECUF)。
文摘Magnetoresistance(MR)is a pivotal transport phenomenon within the realm of condensed matter physics.In recent years,materials exhibiting extremely large unsaturated magnetoresistance(XMR),which are often potential topological materials,have garnered significant attention.In this study,we synthesized single crystals of ZrBi_(2) and performed electrical and specific heat measurements on them.The resistivity of ZrBi_(2) displays metallic behavior with a high residual resistance ratio.Notably,the MR of ZrBi_(2) reaches approximately 2.0×10^(3)%at 2 K and 16 T without saturation.Weak Shubnikov-de Haas oscillations with two frequencies were observed above 13.5 T,which correspond to 237 T and 663 T.Hall effect fitting yields nearly equal concentrations of electron and hole carriers with concentrations of approximately 10^(21)cm^(-3)and mobilities of approximately 5000 cm^(2)·V^(-1)·s^(-1)at 2 K.The XMR could be attributed to the electron-hole compensation with high mobility.
基金jointly supported by the National Natural Science Foundation of China[grant numbers U2342202 and 42175005]the Qing Lan Project[grant number R2023Q06]。
文摘A numerical simulation was performed using the Thompson microphysics scheme to preliminarily investigate the features of the microphysical processes involved in the record-breaking rainfall event that occurred in Henan Province,China,on 20 July 2021.The simulation results showed that a strong meso-𝛾-scale vortical updraft was concurrent with the torrential rainfall.The main finding is that this event was characterized by typical midlatitude warm-rain processes.The simulation with the Thompson microphysics scheme further indicated that highly efficient collision-coalescence of cloud water to rainwater resulted in a considerably active rain droplet growth,leading to this record-breaking rainfall event.
文摘Introduction: The purpose of this retrospective study is to identify medical conditions impacting neurodevelopmental outcomes of extremely low birth weight and very low birth weight preterm infants at three years of age. Methods: Infants born in Banner Diamond Children’s University Medical Center, receiving services in the Newborn Intensive Care Unit, and attending Neonatal Developmental Follow-Up Clinic were identified. Participants received developmental assessment and follow-up from August 2012 through December 2018. Relevant clinical conditions during initial hospital stay and up to three years of age were obtained by reviewing medical and developmental records. Bayley Scales of Infant Toddler Development (Bayley III) was used to evaluate skill development at 6, 9, 12, 18, 24, 30, 36 months. Results: Data analysis did not reveal significant p-values;it did demonstrate that some predictor variables impact neurodevelopmental outcomes in cognitive, language and motor skill development. Conclusion: This retrospective study reports significant association between birth weight and low cognitive scores. Correlations were also found between gestational age and Total Language, and the longer an infant stayed in the NICU, the poorer the Total Language Scaled Scores at 8 to 12 months, 15 to 18 months, and 24 to 36 months. Birth weight was found to be the greatest predictor of poor motor scores.
文摘By selecting the daily maximum temperatures during 1961-2005 in 35 representative stations in Liaoning Province, the temporal and spatial distribution characteristics of extremely maximum temperature event were studied. By using REOF, the mean-square deviation and so on, the variation and distribution situation of extremely maximum temperature in the different regions of Liaoning were reflected. The results showed that the extremely maximum temperature in Liaoning Province could be divided into 3 regions where were respectively the northeast area, the west and the northwest area, the south and the southeast area. The distribution characteristic of extremely maximum temperature threshold value in Liaoning Province was basically consistent with the distribution characteristic of average temperature. The zone where the extremely maximum temperature threshold was relatively high was in the northwest area of Liaoning, and the low threshold zone was in the southeast area and most areas in the east. The variation of extremely maximum temperature in winter was the greatest and in summer was the smallest. The variation of extremely maximum temperature days was the greatest in summer and wasn’t great in spring, autumn, winter.
基金Supported by Grants-in-aid for Cancer Research from the Ministry of Education, Science and Culture, Japan and the Fukuoka Cancer Society, Fukuoka, Japan
文摘AIM： Minimal deviation carcinoma of the uterine cervix, otherwise known as extremely well-differentiated adenocarcinoma （EWDA）, is characterized by its benign microscopic appearance in contrast to its aggressive behavior. In order to elucidate the clinicopathological features and biological behavior of the gastric counterpart of EWDA, we, using immunohistochemistry, analyzed nine lesions for the phenotypic expression, proliferative activity, and the expression of oncogene-associated products. METHODS： Clinicopathological features, including preoperative biopsy diagnosis, were reviewed. Using immunohitstochemistry, Ki-67 labeling index and expression of p53 and c-erbB-2 protein in the gastric lesions were detected.RESULT： Locations in the middle or upper third of the stomach and polypoid macroscopic features are characteristic of EWDA of the stomach. Although 4 of the 9 lesions showed only focal lymphatic or venous invasion, lymph node metastasis was not present and none of the patients died of the lesions （mean follow-up period, 56 too）. All 9 cases of EWDA could be classified into gastric phenotype （5 lesions） and intestinal phenotype （4 lesions）. The former resembled gastric foveolar epithelium, mucous neck cells or pyloric glands, but their papillary structures were frequently elongated and the tumor cellsand their nuclei were slightly larger and more hyperchromatic compared to normal epithelium. The latter resembled intestinal metaplasia with minimal nulcear atypia and irregular glands; two of these lesions demonstrated complete intestinal phenotype, while two demonstrated incomplete intestinal phenotype. Ki-67 labeling index was low and none of the cases revealed over-expression of p53 and c-erbB-2 protein. CONCLUSION： Unlike minimal deviation carcinoma of the cervix, these findings suggest that EWDA of the stomach is a lesion of low-grade malignancy. This favorable biological behavior is supported by the data of a low Ki-67 labeling index and a lack of p53 or c-erbB-2 protein over-expression. Because of its resemblance to normal gastric mucosa or mucosa with intestinal metaplasia, EWDA is often misdiagnosed. To prevent the misdiagnosis of such lesions, the clinical and pathologic characteristics should be taken into consideration.
基金supported by the national key R&D Program of China(Grant No 2018YFC1505603)the Key Research Program of Frontier Sciences,CAS(Grant No.ZDBS-LY-DQC010)the National Natural Science Foundation of China(Grant Nos.41876012,41861144015).
文摘In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Niña event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid−high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Niña)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Niña prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.
基金supported by Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)the National Natural Science Foundation of China(Grant Nos.42122033,41875055,and 42075006)Guangzhou Science and Technology Plan Projects(202002030346 and 202002030196).
文摘An extremely heavy rainfall event lasting from 17 to 22 July 2021 occurred in Henan Province of China, with accumulated precipitation of more than 1000 mm over a 6-day period that exceeded its mean annual precipitation. The present study examines the roles of persistent low-level jets(LLJs) in maintaining the precipitation using surface station observations and reanalysis datasets. The LLJs triggered strong ascending motions and carried moisture mainly from the outflow of Typhoon In-fa(2021). The varying directions of the LLJs well corresponded to the meridional shifts of the rainfall. The precipitation rate reached a maximum during 20-21 July as the LLJs strengthened and expanded vertically into double LLJs, including synoptic-weather-system-related LLJs(SLLJs) at 850–700 hPa and boundary-layer jets(BLJs)at ~950 hPa. The coupling of the SLLJ and BLJ provided strong mid-and low-level convergence on 20 July, whereas the SLLJ produced mid-level divergence at its entrance that coupled with low-level convergence at the terminus of the BLJ on21 July. The formation mechanisms of the two types of LLJs are further examined. The SLLJs and the low-pressure vortex(or inverted trough) varied synchronously as a whole and were affected by the southwestward movement of the WPSH in the rainiest period. The persistent large total pressure gradient force at low levels also maintained the strength of low-level geostrophic winds, thus sustaining the BLJs on the synoptic scale. The results based on a Du-Rotunno 1D model show that the Blackadar and Holton mechanisms jointly governed the BLJ dynamics on the diurnal scale.
基金supported by the National Key Basic Research Program (2010CB732201) from the Ministry of Science and Technology of Chinathe State Key Laboratory Open Foundation of Pulp and Paper Engineering of China (201225)
文摘A direct synthesis of methyl levulinate from cellulose alcoholysis in methanol medium under mild condition(180 210 C)catalyzed by extremely low concentration sulfuric acid(0.01 mol/L)and the product isolation were developed in this study.Effects of different process variables towards the catalytic performance were performed as a function of reaction time.The results indicated that sulfuric acid concentration,temperature and initial cellulose concentration had significant effects on the synthesis of methyl levulinate.An optimized yield of around 50%was achieved at 210 C for 120 min with sulfuric acid concentration of 0.01 mol/L and initial cellulose concentration below 100 g/L.The resulting product mixture was isolated by a distillation technique that combines an atmospheric distillation with a vacuum distillation where n-dodecane was added to help distill the heavy fraction.The light fraction including mainly methanol could be reused as the reaction medium without any substantial change in the yield of methyl levulinate.The chemical composition and structural of lower heavy fraction were characterized by GC/MS,FTIR,1H-NMR and13C-NMR techniques.Methyl levulinate was found to be a major ingredient of lower heavy fraction with the content over 96%.This pathway is efficient,environmentally benign and economical for the production of pure levulinate esters from cellulose.
基金supported in part by the National Key Research and Development Program of China(Grant No.2020YFB1807205)in part by the National Natural Science Foundation of China(Grant No.62031019)in part by the European Commission through the H2020-MSCA-ITN META WIRELESS Research Project under Grant 956256。
文摘Reconfigurable intelligent surface(RIS)is more likely to develop into extremely large-scale RIS(XL-RIS)to efficiently boost the system capacity for future 6 G communications.Beam training is an effective way to acquire channel state information(CSI)for XL-RIS.Existing beam training schemes rely on the far-field codebook.However,due to the large aperture of XL-RIS,the scatters are more likely to be in the near-field region of XL-RIS.The far-field codebook mismatches the near-field channel model.Thus,the existing far-field beam training scheme will cause severe performance loss in the XL-RIS assisted nearfield communications.To solve this problem,we propose the efficient near-field beam training schemes by designing the near-field codebook to match the nearfield channel model.Specifically,we firstly design the near-field codebook by considering the near-field cascaded array steering vector of XL-RIS.Then,the optimal codeword for XL-RIS is obtained by the exhausted training procedure.To reduce the beam training overhead,we further design a hierarchical nearfield codebook and propose the corresponding hierarchical near-field beam training scheme,where different levels of sub-codebooks are searched in turn with reduced codebook size.Simulation results show the proposed near-field beam training schemes outperform the existing far-field beam training scheme.
基金Projects 2005CB221503 supported by the National Basic Research Program of China70533050 and 50674089 by the National Natural Science Foundation of China2005BA813B-3-06 by the National Tenth 5-Year Key Scientific and Technological Project
文摘When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a ＂main key stratum＂, will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway （we can also drill them in the drilling field located high in an air gateway）. Given the practice in the Haizi mine, the gas drainage rate can reach 73% in the middie coal group, with a gas drainage radius over 100 m.
基金supported by the National Key R&D Program of China(Grant Nos.2017YFC1501803 and 2017YFC1502102)。
文摘Assimilation of the Advanced Geostationary Radiance Imager(AGRI)clear-sky radiance in a regional model is performed.The forecasting effectiveness of the assimilation of two water vapor(WV)channels with conventional observations for the“21·7”Henan extremely heavy rainfall is analyzed and compared with a baseline test that assimilates only conventional observations in this study.The results show that the 24-h cumulative precipitation forecast by the assimilation experiment with the addition of the AGRI exceeds 500 mm,compared to a maximum value of 532.6 mm measured by the national meteorological stations,and that the location of the maximum precipitation is consistent with the observations.The results for the short periods of intense precipitation processes are that the simulation of the location and intensity of the 3-h cumulative precipitation is also relatively accurate.The analysis increment shows that the main difference between the two sets of assimilation experiments is over the ocean due to the additional ocean observations provided by FY-4A,which compensates for the lack of ocean observations.The assimilation of satellite data adjusts the vertical and horizontal wind fields over the ocean by adjusting the atmospheric temperature and humidity,which ultimately results in a narrower and stronger WV transport path to the center of heavy precipitation in Zhengzhou in the lower troposphere.Conversely,the WV convergence and upward motion in the control experiment are more dispersed;therefore,the precipitation centers are also correspondingly more dispersed.
基金supported by the National Key Research and Development Program of China(Grant Nos.2018YFC1506801 and 2018YFF0300102)the National Natural Science Foundation of China(NSFC)(Grant No.42105013).
文摘A record-breaking heavy rainfall event that occurred in Zhengzhou,Henan province during 19–21 July 2021 is simulated using the Weather Research and Forecasting Model,and the large-scale precipitation efficiency(LSPE)and cloud-microphysical precipitation efficiency(CMPE)of the rainfall are analyzed based on the model results.Then,the key physical factors that influenced LSPE and CMPE,and the possible mechanisms for the extreme rainfall over Zhengzhou are explored.Results show that water vapor flux convergence was the key factor that influenced LSPE.Water vapor was transported by the southeasterly winds between Typhoon In-Fa(2021)and the subtropical high,and the southerly flow of Typhoon Cempaka(2021),and converged in Zhengzhou due to the blocking by the Taihang and Funiu Mountains in western Henan province.Strong moisture convergence centers were formed on the windward slope of the mountains,which led to high LSPE in Zhengzhou.From the perspective of CMPE,the net consumption of water vapor by microphysical processes was the key factor that influenced CMPE.Quantitative budget analysis suggests that water vapor was mainly converted to cloud water and ice-phase particles and then transformed to raindrops through melting of graupel and accretion of cloud water by rainwater during the heavy precipitation stage.The dry intrusion in the middle and upper levels over Zhengzhou made the high potential vorticity descend from the upper troposphere and enhanced the convective instability.Moreover,the intrusion of cold and dry air resulted in the supersaturation and condensation of water vapor,which contributed to the heavy rainfall in Zhengzhou.
基金Supported by the grant of the Center of Excellence,Biomedical Research using accelerator technology
文摘AIM： To identify the clinical and prognostic features of patients with hepatocellular carcinoma （HCC） aged 80 years or more. METHODS： A total of 1310 patients with HCC were included in this study. Ninety-one patients aged 80 years or more at the time of diagnosis of HCC were defined as the extremely elderly group. Two hundred and thirty-four patients aged 〉/ 50 years but less than 60 years were regarded as the non-elderly group. RESULTS： The sex ratio （male to female） was significantly lower in the extremely elderly group （0.90：1） than in the non-elderly group （3.9：1, P〈 0.001）. The positive rate for HBsAg was significantly lower in the extremely elderly group and the proportion of patients negative for HBsAg and HCVAb obviously increased in the extremely elderly group （P〈 0.001）. There were no significant differences in the following parameters： diameter and number of tumors, Child-Pugh grading, tumor staging, presence of portal thrombosis or ascites, and positive rate for HCVAb. Extremely elderly patients did not often receive surgical treatment （P 〈 0.001） and they were more likely to receive conservative treatment （P〈 0.01）. There were no significant differences in survival curves based on the Kaplan-Meier methods in comparison with the overall patients between the two groups. However, the survival curves were significantly worse in the extremely elderly patients with stage Ⅰ/Ⅱ, stage Ⅰ/Ⅱ and Child-Pugh grade A cirrhosis in comparison with the non-elderly group. The causes of death did not differ among the patients, and most cases died of liverrelated diseases even in the extremely elderly patients. CONCLUSION： In the patients with good liver functions and good performance status, aggressive treatment for HCC might improve the survival rate, even in extremely elderly patients.
