This study explores the 2D stretching flow of a hybrid nanofluid over a curved surface influenced by a magnetic field and reactions. A steady laminar flow model is created with curvilinear coordinates, considering the...This study explores the 2D stretching flow of a hybrid nanofluid over a curved surface influenced by a magnetic field and reactions. A steady laminar flow model is created with curvilinear coordinates, considering thermal radiation, suction, and magnetic boundary conditions. The nanofluid is made of water with copper and MWCNTs as nanoparticles. The equations are transformed into nonlinear ODEs and solved numerically. The model’s accuracy is confirmed by comparing it with published data. Results show that fluid velocity increases, temperature decreases, and concentration increases with the curvature radius parameter. The hybrid nanofluid is more sensitive to magnetic field changes in velocity, while the nanofluid is more sensitive to magnetic boundary coefficient changes. These insights can optimize heat and mass transfer in industrial processes like chemical reactors and wastewater treatment.展开更多
In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_...In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.展开更多
With the advent of the Industry 5.0 era,the Internet of Things(IoT)devices face unprecedented proliferation,requiring higher communications rates and lower transmission delays.Considering its high spectrum efficiency,...With the advent of the Industry 5.0 era,the Internet of Things(IoT)devices face unprecedented proliferation,requiring higher communications rates and lower transmission delays.Considering its high spectrum efficiency,the promising filter bank multicarrier(FBMC)technique using offset quadrature amplitude modulation(OQAM)has been applied to Beyond 5G(B5G)industry IoT networks.However,due to the broadcasting nature of wireless channels,the FBMC-OQAMindustry IoT network is inevitably vulnerable to adversary attacks frommalicious IoT nodes.The FBMC-OQAMindustry cognitive radio network(ICRNet)is proposed to ensure security at the physical layer to tackle the above challenge.As a pivotal step of ICRNet,blind modulation recognition(BMR)can detect and recognize the modulation type of malicious signals.The previous works need to accomplish the BMR task of FBMC-OQAM signals in ICRNet nodes.A novel FBMC BMR algorithm is proposed with the transform channel convolution network(TCCNet)rather than a complicated two-dimensional convolution.Firstly,this is achieved by designing a low-complexity binary constellation diagram(BCD)gridding matrix as the input of TCCNet.Then,a transform channel convolution strategy is developed to convert the image-like BCD matrix into a serieslike data format,accelerating the BMR process while keeping discriminative features.Monte Carlo experimental results demonstrate that the proposed TCCNet obtains a performance gain of 8%and 40%over the traditional inphase/quadrature(I/Q)-based and constellation diagram(CD)-based methods at a signal noise ratio(SNR)of 12 dB,respectively.Moreover,the proposed TCCNet can achieve around 29.682 and 2.356 times faster than existing CD-Alex Network(CD-AlexNet)and I/Q-Convolutional Long Deep Neural Network(I/Q-CLDNN)algorithms,respectively.展开更多
LiCoO_(2)is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density,good thermal stability,and stable voltage platform.Recent works on LiCoO_(2)have focus...LiCoO_(2)is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density,good thermal stability,and stable voltage platform.Recent works on LiCoO_(2)have focused on the realization of higher charging voltages to fully utilize its high theoretical capacity.However,an unambiguous atomic-level local probe is essential for the understanding of structure-function correlation.Here we employ highresolution solid-state nuclear magnetic resonance(NMR)spectroscopy to study the local atomic environments in LiCoO_(2)synthesized with three common sintering methods.While one-dimensional 7Li NMR shows distinct linewidth and subtle dependence on lithium over-stoichiometry,both 7Li and 59Co relaxation times are highly dependent on the sintering method.We prove that the two-step sintering method favors the elimination of unreacted Co3O4,thereby enabling the best discharge capacity in all-solid-state lithium batteries assembled with LiCoO_(2)/LGPS/LiIn,which is in accordance with its narrowest 7Li linewidth and the longest 7Li/59Co T1.展开更多
Dual-mode electron paramagnetic resonance(EPR)spectroscopy was employed to analyze redox mechanisms in lithium cobalt oxide LiCoO_(2)(LCO)cathode material during delithiation and lithiation.It was found that the O_(3)...Dual-mode electron paramagnetic resonance(EPR)spectroscopy was employed to analyze redox mechanisms in lithium cobalt oxide LiCoO_(2)(LCO)cathode material during delithiation and lithiation.It was found that the O_(3)-II could not fully convert back to the pristine O_(3) -I phase while oxygen vacancies quickly generate and accumulate during the cycling.Our study paves the way for better understanding the doping effects of different elements on LiCoO_(2) in the future.展开更多
AIM: To identify cancer stern cells (CSCs) in human gallbladder carcinomas (GBCs). METHODS: Primary GBC cells were cultured under serum-free conditions to produce floating spheres. The stem-cell properties of th...AIM: To identify cancer stern cells (CSCs) in human gallbladder carcinomas (GBCs). METHODS: Primary GBC cells were cultured under serum-free conditions to produce floating spheres. The stem-cell properties of the sphere-forming cells, including self-renewal, differentiation potential, chemoresistance and tumorigenicity, were determined in vitro or in vivo. Cell surface expression of CD133 was investigated in primary tumors and in spheroid cells using flow cytometry. The sphere-colony-formation ability and tumorigenicity of CD133+ cells were assayed.floating spheroids were generated from primary GBC cells, and these sphere-forming cells could generate new progeny spheroids in serum-free media. Spheroid cells were differentiated under serum-containing conditions with downregulation of the stem cell markers Oct-4, Nanog, and nestin (P 〈 0.05). The differentiated cells showed lower spheroid-colony-formation ability than the original spheroid cells (P 〈 0.05). Spheroid ceils were more resistant to chemotherapeutic reagents than the congenetic adherent cells (P 〈 0.05). Flow cytometry showed enriched CD133+ population in sphereforming cells (P 〈 0.05). CD133+ cells possessed high colony-formation ability than the CD133 population (P 〈 0.01). CD133+ cells injected into nude mice revealed higher tumorigenicity than their antigen-negative counterparts (P 〈 0.05). CONCLUSION: CD133 may be a cell surface marker for CSCs in GBC.展开更多
To provide an anatomical basis for clinical implant esthetics,we evaluated the morphology of the nasopalatine canal(NPC) and analyzed labial and interproximal bone anatomy at the maxillary anterior region.We sought ...To provide an anatomical basis for clinical implant esthetics,we evaluated the morphology of the nasopalatine canal(NPC) and analyzed labial and interproximal bone anatomy at the maxillary anterior region.We sought to investigate the effect of maxillary protrusion and tooth labiolingual inclination on labial bone anatomy in Chinese adults.Three dimensional(3D) images were reconstructed using cone-beam computed tomography(CBCT) images from 80 Chinese subjects and by SimPlant 11.04.The dimensions of the NPC,the thickness and profile of the labial bone,the width and height of the interproximal bone,angle sella-nasion-subspinale(SNA) and angle upper central incisor-nasion,subspinale(U1-NA) were measured.The incisive foramen of the NPC was markedly wider than its nasal foramen.The dimension of its labial bone wall demonstrated an increasing width from the crestal to apical measurements.The labial bone at the maxillary anterior region was rather thin,especially at 3 mm below the cemento-enamel junction(CEJ) and the mid-root level;the profile of the labial bone was more curved at the central incisor,and the interproximal bone became wider and shorter posteriorly.There were significant relationships between maxillary protrusion and labial bone profile,tooth labiolingual inclination and labial bone thickness(P 〈 0.02).To achieve optimal esthetic outcome of implant,bone augmentation is necessary at the maxillary anterior region.For immediate or early placement at the maxillary anterior region,the implant should be located palatally to reduce labial bone resorption and marginal recession;its apex should be angulated palatally to avoid labial perforation at the apical region.To protect the NPC,implants at the central incisor region should be placed away from NPC.展开更多
BACKGROUND: The treatment of borderline resectable pancreatic head cancer(BRPHC) is still controversial and challenging. The artery-first approaches are described to be the important options for the early determina...BACKGROUND: The treatment of borderline resectable pancreatic head cancer(BRPHC) is still controversial and challenging. The artery-first approaches are described to be the important options for the early determination. Whether these approaches can achieve an increase R0 rate, better bleeding control and increasing long-term survival for BRPHC are still controversial. We compared a previously reported technique, a modified artery-first approach(MAFA), with conventional techniques for the surgical treatment of BRPHC.METHODS: A total of 117 patients with BRPHC undergone pancreaticoduodenectomy(PD) from January 2013 to June 2015 were included. They were divided into an MAFA group(n=78) and a conventional-technique group(n=39). Background characteristics, operative data and complications were compared between the two groups.RESULTS: Mean operation time was significantly shorter in the MAFA group than that in the conventional-technique group(313 vs 384 min; P=0.014); mean volume of intraoperative blood loss was significantly lower in the MAFA group than that in the conventional-technique group(534 vs 756 m L; P=0.043); and mean rate of venous resection was significantly higher in the conventional-technique group than that in the MAFA group(61.5% vs 35.9%; P=0.014). Pathologic data, early mortality and morbidity were not different significantly between the two groups.CONCLUSIONS: MAFA is safe, simple, less time-consuming, less intraoperative blood loss and less venous resection, and therefore, may become a standard surgical approach to PD for BRPHC with the superior mesenteric vein-portal vein involvement but without superior mesenteric artery invasion.展开更多
Herein,we develop cost-efficient superhigh-performance of engineering carbonaceous adsorbent from cigarette butts using combined wet-impregnated and re-dispersed method of KOH,which optimizes the implant approach of a...Herein,we develop cost-efficient superhigh-performance of engineering carbonaceous adsorbent from cigarette butts using combined wet-impregnated and re-dispersed method of KOH,which optimizes the implant approach of activator,breaking the restriction of selective capture of toluene using traditional activated carbon.The Brunauer-Emmett-Teller(BET)surface area and pore volume of targeted adsorbent can attain 3088 m^(2)·g^(-1) and 1.61 cm^(3)·g^(-1),respectively,by optimizing the temperaturedependent synthetic factor effect of the adsorbent.The adsorption capacity of resultant adsorbent for presenting volatile benzene and toluene shows a positive correlation with increasing carbonization temperature of carbon precursor.Besides,we demonstrated the unsmoked and smoked butts derived adsorbents afford feeble difference in saturated adsorbed capacity of volatile organic compounds(VOCs).The highest adsorption capacity of sample CF-800 for benzene and toluene in CF group is as high as 1268.1 and 1181.6 mg·g^(-1) respectively,slightly higher than that of sample UF-800,but far outperforming reported other adsorbents.The predicted adsorption selectivity of CF-800 and UF-800 for C_(7)H_(8)/H_(2)O(g)using the DIH(difference of isosteric heats)equation reach up to ca.3800 and 7500 respectively,indicating the weak adsorbability of water vapor on the developed adsorbent and greater superiority of the smoked butts derived adsorbents in selective capture of VOCs at low relative humidity in the competitive adsorption process for practical mixed VOCs.展开更多
BACKGROUND: Postoperative pancreatic fistula remains the most common complication of pancreaticoduodenectomy (PD) and is potentially lethal. It contributes significantly to prolonged hospitalization and mortality. ...BACKGROUND: Postoperative pancreatic fistula remains the most common complication of pancreaticoduodenectomy (PD) and is potentially lethal. It contributes significantly to prolonged hospitalization and mortality. In this study, we introduced a new technical approach, a modified Roux-en-Y reconstruction and evaluated its safety and feasibility. METHODS: We retrospectively reviewed the patients who had undergone PD with the modified Roux-en-Y reconstructive technique for periampullary malignancies from January 2011 to June 2012. The data on complications, hospital stay and outcomes after the modified Roux-en-Y reconstruction were analyzed. RESULTS: The reconstruction was performed in 171 patients, of whom 92 received pancreaticogastrostomy and 79 received pancreaticojejunostomy. The median duration of surgery was 4.0 hours (range 3.1-6.9) in all patients, and the median blood loss was 530 mL (range 200-2000). Sixty-nine patients were subjected to transfusions, with a median transfusion volume of 430 mL (range 200-1400). The median hospital stay of the patients was 14 days (range 11-38). Their operative mortality was zero and overall morbidity was 18.1% (31 patients). Only four patients (2.3%) developed pancreatic fistulas (grade A fistulas in two patients and grade B in two patients); no patients developed grade C fistula. None of the patients developed bile reflux gastritis. CONCLUSIONS: The modified Roux-en-Y reconstruction, which isolates biliary anastomosis from pancreatic, gastric or jejunalanastomosis, is a safe, reliable, and favorable technique. But it needs further investigation in randomized controlled trials.展开更多
Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static b...Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static background subtraction based on a median image technique has been used to extract moving space objects prior to the tracking operation, as this is computationally efficient. The main disadvantage of this technique is that it is not robust to variable illumination conditions. In this article, we propose an approach for tracking small and dim space debris in the context of a dynamic background via one of the optical telescopes that is part of the space surveillance network project, named the Asia- Pacific ground-based Optical Space Observation System or APOSOS. The approach combines a fuzzy running Gaussian average for robust moving-object extraction with dim-target tracking using a particle- filter-based track-before-detect method. The performance of the proposed algorithm is experimentally evaluated, and the results show that the scheme achieves a satisfactory level of accuracy for space debris tracking.展开更多
Ridge cultivation can effectively enhance soil permeability,promote root development and improve fruit quality. Based on the characteristics of Lane Late navel orange,this paper summarizes the technical points related...Ridge cultivation can effectively enhance soil permeability,promote root development and improve fruit quality. Based on the characteristics of Lane Late navel orange,this paper summarizes the technical points related to ridge cultivation and compares the effects of ridge cultivation and conventional cultivation on the growth,so as to provide guidance for better production practices.展开更多
As of April 2017,the planting area of Citrus grandis in Ruili City was 594. 3 ha. Among it,the area of fruiting trees was 267. 2 ha,and they were mainly owned by small growers. In view of the serious fragmentation of ...As of April 2017,the planting area of Citrus grandis in Ruili City was 594. 3 ha. Among it,the area of fruiting trees was 267. 2 ha,and they were mainly owned by small growers. In view of the serious fragmentation of pomelos,the large investment in fertilizers,and the unsatisfactory production efficiency of C. grandis in Ruili,the fertilization technology for C. grandis was discussed. The problems in the fertilization process,as well as the principles and modes of fertilization were analyzed briefly. The fertilization methods for saplings and fruiting trees were introduced,in order to promote the improvement of the fertilization and management level of local pomelo growers.展开更多
The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from les...The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from less than (3.0 to 52.1) ng·L-1, with an average level of less than 11.1 ng.L-1. The annual average content was less than 7.9 ng.L-1, 13.9 ng.L-1, and 12.3 ng.L-1 in 2011, 2012, and 2013, respectively. The concentrations of diuron in marine sediments also varied from less than (0.3 to 3.9) ng.g-1 (dry weight), with an average concentration of less than 1.13 ng g-1 (dry weight). The annual average concentration was less than 0.851 ng.g-1, 1.328 ng.g-1, and 1.202 ng.g-1 in 2011, 2012, and 2013, respectively. The accumulation of diuron in seawater and sediments may pose a potential risk to the marine ecosystem of the investigated sea area.展开更多
The high energy density and stability of solid-state lithium metal batteries(SSLMBs)have garnered great attention.Garnet-type oxides,especially Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO),with high ionic conductivity,...The high energy density and stability of solid-state lithium metal batteries(SSLMBs)have garnered great attention.Garnet-type oxides,especially Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO),with high ionic conductivity,wide electrochemical window,and stability to Li metal anode,are promising solid-state electrolyte(SSEs)materials for SSLMBs.However,Li/LLZTO interface issues including high interface resistance,inhomogeneous Li deposition,and Li dendrite growth have hindered the practical application of SSLMBs.Herein,a multi-functional Li–SnF_(2) composite anode with Li,LiF,and Li-Sn alloy was specifically designed and prepared.The composite anode improves the wettability to LLZTO,constructing an intimate contact interface between it and LLZTO.Meanwhile,ionic/electronic conductive paths in situ formed at the interface can effectively uniform Li deposition and suppress Li dendrite.The solid-state symmetric cell exhibits low interface resistance(11Ω·cm^(2)) and high critical current density(1.3 mA·cm^(−2))at 25℃.The full SSLMB based on LiFePO_(4) or LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathode also shows stable cycling performance and high rate capability.This work provides a new composite anode strategy for achieving high-energy density and high-safety SSLMBs.展开更多
Ground-and space-based optical observation is an efficient way to catalog objects in the cislunar space.Initial orbit determination based on optical data is still an open problem for cislunar objects.The motion of the...Ground-and space-based optical observation is an efficient way to catalog objects in the cislunar space.Initial orbit determination based on optical data is still an open problem for cislunar objects.The motion of these objects usually follows the law of three bodies instead of the two-body one,so current algorithms based on the two-body relation should be revised.Moreover,due to the long duration of most cislunar objects,optical observations of even hours can cover only a small fraction of one orbit,making the initial orbit determination of these objects a typical too-short-arc problem,which is difficult.A way to address this problem is to use the admissible region.In this study,an efficient algorithm constrained by the admissible region is proposed.It is easy to implement because it uses only simple iterations.Its efficiency is proven by comparing it with that of one traditional initial orbit determination algorithm.展开更多
The transmission properties in Fibonacci quasi-periodic photonic crystals containing negative-zero-positive index metamaterials(NZPIM)are investigated systematically.Because of linear dispersion,an asymmetric band gap...The transmission properties in Fibonacci quasi-periodic photonic crystals containing negative-zero-positive index metamaterials(NZPIM)are investigated systematically.Because of linear dispersion,an asymmetric band gap appears near the optical Dirac point(DP)only at an oblique incidence.Zero-n gaps and Bragg gaps exist when the refractive indexes of NZPIM are negative and positive,respectively.We also obtain gaps induced by total reflection on both sides of the DP gap.The corresponding Goos-Hänchen(GH)shifts and phase variations are also demonstrated in detail.It is shown that the characteristics of the band gaps,GH shifts,and phase variations depend crucially on the incident angle,number of periods,and layer thickness.展开更多
Sediment in rivers plays an essential role in the river and watershed ecosystem.Recently,Dethier et al.[1]used an empirical model,which was developed using the data in America and Taiwan Province in China,to estimate ...Sediment in rivers plays an essential role in the river and watershed ecosystem.Recently,Dethier et al.[1]used an empirical model,which was developed using the data in America and Taiwan Province in China,to estimate suspended sediment concentration(SSC)and generate a long-term record of SSC and sediment fluxes in 414 major rivers worldwide since 1984.The authors concluded that the widespread decreases in river sediment fluxes in the North Hemisphere(NH)resulted from the dams,while the increases in river sediment fluxes in the South Hemisphere were possibly related to changes in land use.Regardless of the discussion on whether such an empirical model could be extrapolated to the global rivers for accurately retrieving SSC from Landsat imagery,the elucidation of the continuous declines in SSC in the NH rivers since1980s was incomplete.As Dethier et al.[1]demonstrated,the spatial and temporal variations in river sediment were regulated by climate change and human activities[2],including precipitation,land cover and land use,damming,and dredging activities[3-6].展开更多
文摘This study explores the 2D stretching flow of a hybrid nanofluid over a curved surface influenced by a magnetic field and reactions. A steady laminar flow model is created with curvilinear coordinates, considering thermal radiation, suction, and magnetic boundary conditions. The nanofluid is made of water with copper and MWCNTs as nanoparticles. The equations are transformed into nonlinear ODEs and solved numerically. The model’s accuracy is confirmed by comparing it with published data. Results show that fluid velocity increases, temperature decreases, and concentration increases with the curvature radius parameter. The hybrid nanofluid is more sensitive to magnetic field changes in velocity, while the nanofluid is more sensitive to magnetic boundary coefficient changes. These insights can optimize heat and mass transfer in industrial processes like chemical reactors and wastewater treatment.
基金supported by grants from the National Natural Science Foundation of China(No.22272055)multifunctional platform for innovation of ECNU(EPR).
文摘In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.
基金supported by the National Natural Science Foundation of China(Nos.61671095,61371164)the Project of Key Laboratory of Signal and Information Processing of Chongqing(No.CSTC2009CA2003).
文摘With the advent of the Industry 5.0 era,the Internet of Things(IoT)devices face unprecedented proliferation,requiring higher communications rates and lower transmission delays.Considering its high spectrum efficiency,the promising filter bank multicarrier(FBMC)technique using offset quadrature amplitude modulation(OQAM)has been applied to Beyond 5G(B5G)industry IoT networks.However,due to the broadcasting nature of wireless channels,the FBMC-OQAMindustry IoT network is inevitably vulnerable to adversary attacks frommalicious IoT nodes.The FBMC-OQAMindustry cognitive radio network(ICRNet)is proposed to ensure security at the physical layer to tackle the above challenge.As a pivotal step of ICRNet,blind modulation recognition(BMR)can detect and recognize the modulation type of malicious signals.The previous works need to accomplish the BMR task of FBMC-OQAM signals in ICRNet nodes.A novel FBMC BMR algorithm is proposed with the transform channel convolution network(TCCNet)rather than a complicated two-dimensional convolution.Firstly,this is achieved by designing a low-complexity binary constellation diagram(BCD)gridding matrix as the input of TCCNet.Then,a transform channel convolution strategy is developed to convert the image-like BCD matrix into a serieslike data format,accelerating the BMR process while keeping discriminative features.Monte Carlo experimental results demonstrate that the proposed TCCNet obtains a performance gain of 8%and 40%over the traditional inphase/quadrature(I/Q)-based and constellation diagram(CD)-based methods at a signal noise ratio(SNR)of 12 dB,respectively.Moreover,the proposed TCCNet can achieve around 29.682 and 2.356 times faster than existing CD-Alex Network(CD-AlexNet)and I/Q-Convolutional Long Deep Neural Network(I/Q-CLDNN)algorithms,respectively.
基金supported by grants from the National Natural Science Foundation of China(Nos.22172049,21874045)Shanghai Science and Technology Innovation Action Plan(No.19142202900)+1 种基金Fundamental Research Funds for Central Universities and Open Foundation of ECNU(42125102)ECNU multifunctional platform for innovation(EPR).
文摘LiCoO_(2)is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density,good thermal stability,and stable voltage platform.Recent works on LiCoO_(2)have focused on the realization of higher charging voltages to fully utilize its high theoretical capacity.However,an unambiguous atomic-level local probe is essential for the understanding of structure-function correlation.Here we employ highresolution solid-state nuclear magnetic resonance(NMR)spectroscopy to study the local atomic environments in LiCoO_(2)synthesized with three common sintering methods.While one-dimensional 7Li NMR shows distinct linewidth and subtle dependence on lithium over-stoichiometry,both 7Li and 59Co relaxation times are highly dependent on the sintering method.We prove that the two-step sintering method favors the elimination of unreacted Co3O4,thereby enabling the best discharge capacity in all-solid-state lithium batteries assembled with LiCoO_(2)/LGPS/LiIn,which is in accordance with its narrowest 7Li linewidth and the longest 7Li/59Co T1.
基金the National Natural Science Foundation of China(Nos.21872055,22172049,21874045)Shanghai Science and technology innovation action plan(No.19142202900)+1 种基金BASF,Fundamental Research Funds for Central Universities and Open Foundation of ECNU(42125102)ECNU multifunctional platform for innovation(EPR).
文摘Dual-mode electron paramagnetic resonance(EPR)spectroscopy was employed to analyze redox mechanisms in lithium cobalt oxide LiCoO_(2)(LCO)cathode material during delithiation and lithiation.It was found that the O_(3)-II could not fully convert back to the pristine O_(3) -I phase while oxygen vacancies quickly generate and accumulate during the cycling.Our study paves the way for better understanding the doping effects of different elements on LiCoO_(2) in the future.
文摘AIM: To identify cancer stern cells (CSCs) in human gallbladder carcinomas (GBCs). METHODS: Primary GBC cells were cultured under serum-free conditions to produce floating spheres. The stem-cell properties of the sphere-forming cells, including self-renewal, differentiation potential, chemoresistance and tumorigenicity, were determined in vitro or in vivo. Cell surface expression of CD133 was investigated in primary tumors and in spheroid cells using flow cytometry. The sphere-colony-formation ability and tumorigenicity of CD133+ cells were assayed.floating spheroids were generated from primary GBC cells, and these sphere-forming cells could generate new progeny spheroids in serum-free media. Spheroid cells were differentiated under serum-containing conditions with downregulation of the stem cell markers Oct-4, Nanog, and nestin (P 〈 0.05). The differentiated cells showed lower spheroid-colony-formation ability than the original spheroid cells (P 〈 0.05). Spheroid ceils were more resistant to chemotherapeutic reagents than the congenetic adherent cells (P 〈 0.05). Flow cytometry showed enriched CD133+ population in sphereforming cells (P 〈 0.05). CD133+ cells possessed high colony-formation ability than the CD133 population (P 〈 0.01). CD133+ cells injected into nude mice revealed higher tumorigenicity than their antigen-negative counterparts (P 〈 0.05). CONCLUSION: CD133 may be a cell surface marker for CSCs in GBC.
文摘To provide an anatomical basis for clinical implant esthetics,we evaluated the morphology of the nasopalatine canal(NPC) and analyzed labial and interproximal bone anatomy at the maxillary anterior region.We sought to investigate the effect of maxillary protrusion and tooth labiolingual inclination on labial bone anatomy in Chinese adults.Three dimensional(3D) images were reconstructed using cone-beam computed tomography(CBCT) images from 80 Chinese subjects and by SimPlant 11.04.The dimensions of the NPC,the thickness and profile of the labial bone,the width and height of the interproximal bone,angle sella-nasion-subspinale(SNA) and angle upper central incisor-nasion,subspinale(U1-NA) were measured.The incisive foramen of the NPC was markedly wider than its nasal foramen.The dimension of its labial bone wall demonstrated an increasing width from the crestal to apical measurements.The labial bone at the maxillary anterior region was rather thin,especially at 3 mm below the cemento-enamel junction(CEJ) and the mid-root level;the profile of the labial bone was more curved at the central incisor,and the interproximal bone became wider and shorter posteriorly.There were significant relationships between maxillary protrusion and labial bone profile,tooth labiolingual inclination and labial bone thickness(P 〈 0.02).To achieve optimal esthetic outcome of implant,bone augmentation is necessary at the maxillary anterior region.For immediate or early placement at the maxillary anterior region,the implant should be located palatally to reduce labial bone resorption and marginal recession;its apex should be angulated palatally to avoid labial perforation at the apical region.To protect the NPC,implants at the central incisor region should be placed away from NPC.
基金supported by grants from The National Natural Science Foundation of China(81071775,81272659,81101621,81172064,81001068 and 81272425)Key Projects of Science Foundation of Hubei Province(2011CDA030)Research Fund of Young Scholars for the Doctoral Program of Higher Education of China(20110142120014)
文摘BACKGROUND: The treatment of borderline resectable pancreatic head cancer(BRPHC) is still controversial and challenging. The artery-first approaches are described to be the important options for the early determination. Whether these approaches can achieve an increase R0 rate, better bleeding control and increasing long-term survival for BRPHC are still controversial. We compared a previously reported technique, a modified artery-first approach(MAFA), with conventional techniques for the surgical treatment of BRPHC.METHODS: A total of 117 patients with BRPHC undergone pancreaticoduodenectomy(PD) from January 2013 to June 2015 were included. They were divided into an MAFA group(n=78) and a conventional-technique group(n=39). Background characteristics, operative data and complications were compared between the two groups.RESULTS: Mean operation time was significantly shorter in the MAFA group than that in the conventional-technique group(313 vs 384 min; P=0.014); mean volume of intraoperative blood loss was significantly lower in the MAFA group than that in the conventional-technique group(534 vs 756 m L; P=0.043); and mean rate of venous resection was significantly higher in the conventional-technique group than that in the MAFA group(61.5% vs 35.9%; P=0.014). Pathologic data, early mortality and morbidity were not different significantly between the two groups.CONCLUSIONS: MAFA is safe, simple, less time-consuming, less intraoperative blood loss and less venous resection, and therefore, may become a standard surgical approach to PD for BRPHC with the superior mesenteric vein-portal vein involvement but without superior mesenteric artery invasion.
基金This work was financially supported by the National Natural Science Foundation of China(51672114,21908085,21806077)Natural Science Foundation of Jiangsu Province(BK20190961)+2 种基金Foundation from Marine Equipment and Technology Institute for Jiangsu University of Science and Technology(HZ20190004)Postdoctoral Research Foundation of Jiangsu Province(2020Z291)High-tech Ship Research Project of the Ministry of Industry and Information Technology(No.[2017]614).
文摘Herein,we develop cost-efficient superhigh-performance of engineering carbonaceous adsorbent from cigarette butts using combined wet-impregnated and re-dispersed method of KOH,which optimizes the implant approach of activator,breaking the restriction of selective capture of toluene using traditional activated carbon.The Brunauer-Emmett-Teller(BET)surface area and pore volume of targeted adsorbent can attain 3088 m^(2)·g^(-1) and 1.61 cm^(3)·g^(-1),respectively,by optimizing the temperaturedependent synthetic factor effect of the adsorbent.The adsorption capacity of resultant adsorbent for presenting volatile benzene and toluene shows a positive correlation with increasing carbonization temperature of carbon precursor.Besides,we demonstrated the unsmoked and smoked butts derived adsorbents afford feeble difference in saturated adsorbed capacity of volatile organic compounds(VOCs).The highest adsorption capacity of sample CF-800 for benzene and toluene in CF group is as high as 1268.1 and 1181.6 mg·g^(-1) respectively,slightly higher than that of sample UF-800,but far outperforming reported other adsorbents.The predicted adsorption selectivity of CF-800 and UF-800 for C_(7)H_(8)/H_(2)O(g)using the DIH(difference of isosteric heats)equation reach up to ca.3800 and 7500 respectively,indicating the weak adsorbability of water vapor on the developed adsorbent and greater superiority of the smoked butts derived adsorbents in selective capture of VOCs at low relative humidity in the competitive adsorption process for practical mixed VOCs.
基金supported by grants from the National Natural Science Foundation of China (81272659, 81101621 and 81372353)
文摘BACKGROUND: Postoperative pancreatic fistula remains the most common complication of pancreaticoduodenectomy (PD) and is potentially lethal. It contributes significantly to prolonged hospitalization and mortality. In this study, we introduced a new technical approach, a modified Roux-en-Y reconstruction and evaluated its safety and feasibility. METHODS: We retrospectively reviewed the patients who had undergone PD with the modified Roux-en-Y reconstructive technique for periampullary malignancies from January 2011 to June 2012. The data on complications, hospital stay and outcomes after the modified Roux-en-Y reconstruction were analyzed. RESULTS: The reconstruction was performed in 171 patients, of whom 92 received pancreaticogastrostomy and 79 received pancreaticojejunostomy. The median duration of surgery was 4.0 hours (range 3.1-6.9) in all patients, and the median blood loss was 530 mL (range 200-2000). Sixty-nine patients were subjected to transfusions, with a median transfusion volume of 430 mL (range 200-1400). The median hospital stay of the patients was 14 days (range 11-38). Their operative mortality was zero and overall morbidity was 18.1% (31 patients). Only four patients (2.3%) developed pancreatic fistulas (grade A fistulas in two patients and grade B in two patients); no patients developed grade C fistula. None of the patients developed bile reflux gastritis. CONCLUSIONS: The modified Roux-en-Y reconstruction, which isolates biliary anastomosis from pancreatic, gastric or jejunalanastomosis, is a safe, reliable, and favorable technique. But it needs further investigation in randomized controlled trials.
基金support from The World Academy of Sciences(TWAS)the Chinese Academy of Sciences(CAS)+1 种基金the AsiaPacific Space Cooperation Organization(APSCO)supported as part of a national major scientific research equipment development project of China(No.ZDYZ2013-2)
文摘Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static background subtraction based on a median image technique has been used to extract moving space objects prior to the tracking operation, as this is computationally efficient. The main disadvantage of this technique is that it is not robust to variable illumination conditions. In this article, we propose an approach for tracking small and dim space debris in the context of a dynamic background via one of the optical telescopes that is part of the space surveillance network project, named the Asia- Pacific ground-based Optical Space Observation System or APOSOS. The approach combines a fuzzy running Gaussian average for robust moving-object extraction with dim-target tracking using a particle- filter-based track-before-detect method. The performance of the proposed algorithm is experimentally evaluated, and the results show that the scheme achieves a satisfactory level of accuracy for space debris tracking.
文摘Ridge cultivation can effectively enhance soil permeability,promote root development and improve fruit quality. Based on the characteristics of Lane Late navel orange,this paper summarizes the technical points related to ridge cultivation and compares the effects of ridge cultivation and conventional cultivation on the growth,so as to provide guidance for better production practices.
文摘As of April 2017,the planting area of Citrus grandis in Ruili City was 594. 3 ha. Among it,the area of fruiting trees was 267. 2 ha,and they were mainly owned by small growers. In view of the serious fragmentation of pomelos,the large investment in fertilizers,and the unsatisfactory production efficiency of C. grandis in Ruili,the fertilization technology for C. grandis was discussed. The problems in the fertilization process,as well as the principles and modes of fertilization were analyzed briefly. The fertilization methods for saplings and fruiting trees were introduced,in order to promote the improvement of the fertilization and management level of local pomelo growers.
文摘The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from less than (3.0 to 52.1) ng·L-1, with an average level of less than 11.1 ng.L-1. The annual average content was less than 7.9 ng.L-1, 13.9 ng.L-1, and 12.3 ng.L-1 in 2011, 2012, and 2013, respectively. The concentrations of diuron in marine sediments also varied from less than (0.3 to 3.9) ng.g-1 (dry weight), with an average concentration of less than 1.13 ng g-1 (dry weight). The annual average concentration was less than 0.851 ng.g-1, 1.328 ng.g-1, and 1.202 ng.g-1 in 2011, 2012, and 2013, respectively. The accumulation of diuron in seawater and sediments may pose a potential risk to the marine ecosystem of the investigated sea area.
基金This study was financially supported by the National Natural Science Foundation of China(Nos.52177208,52171202,51971055 and 51871046)the National Safety Academic Fund(Nos.U1930208,U2030206 and U1730136).
文摘The high energy density and stability of solid-state lithium metal batteries(SSLMBs)have garnered great attention.Garnet-type oxides,especially Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO),with high ionic conductivity,wide electrochemical window,and stability to Li metal anode,are promising solid-state electrolyte(SSEs)materials for SSLMBs.However,Li/LLZTO interface issues including high interface resistance,inhomogeneous Li deposition,and Li dendrite growth have hindered the practical application of SSLMBs.Herein,a multi-functional Li–SnF_(2) composite anode with Li,LiF,and Li-Sn alloy was specifically designed and prepared.The composite anode improves the wettability to LLZTO,constructing an intimate contact interface between it and LLZTO.Meanwhile,ionic/electronic conductive paths in situ formed at the interface can effectively uniform Li deposition and suppress Li dendrite.The solid-state symmetric cell exhibits low interface resistance(11Ω·cm^(2)) and high critical current density(1.3 mA·cm^(−2))at 25℃.The full SSLMB based on LiFePO_(4) or LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathode also shows stable cycling performance and high rate capability.This work provides a new composite anode strategy for achieving high-energy density and high-safety SSLMBs.
基金supported by the National Natural Science Foundation of China(No.12233003)The author Xiyun Hou also wishes to thank support from the Space Debris and Near-Earth Asteroid Defense Research Project of China(No.KJSP2020020205)support from the Laboratory of Pinghu,Pinghu,China.
文摘Ground-and space-based optical observation is an efficient way to catalog objects in the cislunar space.Initial orbit determination based on optical data is still an open problem for cislunar objects.The motion of these objects usually follows the law of three bodies instead of the two-body one,so current algorithms based on the two-body relation should be revised.Moreover,due to the long duration of most cislunar objects,optical observations of even hours can cover only a small fraction of one orbit,making the initial orbit determination of these objects a typical too-short-arc problem,which is difficult.A way to address this problem is to use the admissible region.In this study,an efficient algorithm constrained by the admissible region is proposed.It is easy to implement because it uses only simple iterations.Its efficiency is proven by comparing it with that of one traditional initial orbit determination algorithm.
基金supported by the National Natural Science Foundation of China(No.61975109)the Science and Technology Commission of Shanghai Municipal(No.19ZR1417900)。
文摘The transmission properties in Fibonacci quasi-periodic photonic crystals containing negative-zero-positive index metamaterials(NZPIM)are investigated systematically.Because of linear dispersion,an asymmetric band gap appears near the optical Dirac point(DP)only at an oblique incidence.Zero-n gaps and Bragg gaps exist when the refractive indexes of NZPIM are negative and positive,respectively.We also obtain gaps induced by total reflection on both sides of the DP gap.The corresponding Goos-Hänchen(GH)shifts and phase variations are also demonstrated in detail.It is shown that the characteristics of the band gaps,GH shifts,and phase variations depend crucially on the incident angle,number of periods,and layer thickness.
基金supported by the National Natural Science Foundation of China(U2243205 and 42101378)the Natural Science Foundation of Jiangsu Province(BK20210989)。
文摘Sediment in rivers plays an essential role in the river and watershed ecosystem.Recently,Dethier et al.[1]used an empirical model,which was developed using the data in America and Taiwan Province in China,to estimate suspended sediment concentration(SSC)and generate a long-term record of SSC and sediment fluxes in 414 major rivers worldwide since 1984.The authors concluded that the widespread decreases in river sediment fluxes in the North Hemisphere(NH)resulted from the dams,while the increases in river sediment fluxes in the South Hemisphere were possibly related to changes in land use.Regardless of the discussion on whether such an empirical model could be extrapolated to the global rivers for accurately retrieving SSC from Landsat imagery,the elucidation of the continuous declines in SSC in the NH rivers since1980s was incomplete.As Dethier et al.[1]demonstrated,the spatial and temporal variations in river sediment were regulated by climate change and human activities[2],including precipitation,land cover and land use,damming,and dredging activities[3-6].