Introducing heavy halogen atoms into organic small molecules is a practical strategy for efficient singlet oxygen(^(1)O_(2))generation.Generally,bromine or iodine atoms are introduced on the aza-borondipyrromethene(az...Introducing heavy halogen atoms into organic small molecules is a practical strategy for efficient singlet oxygen(^(1)O_(2))generation.Generally,bromine or iodine atoms are introduced on the aza-borondipyrromethene(aza-BODIPY)core,rather than on the periphery aryl rings for efficient~1O_(2) generation.Herein,an aza-BODIPY dye NBDPBr with unexpected bromination on the periphery aryl rings was synthesized for photoacoustic(PA)imaging-guided synergistic photothermal therapy(PTT)and photodynamic therapy(PDT)in tumor cells.Owing to unexcepted bromination at the periphery aryl rings,NBDPBr demonstrated an outstanding singlet oxygen quantum yield(Φ_(Δ))of 66% which was superior to similar brominated photosensitizers previously reported.After encapsulation with amphiphilic polymer F-127,hydrophilic NBDPBr nanoparticles(NPs)were fabricated and exhibited an excellent photothermal conversion efficiency(η)of 43.0% under 660 nm photoirradiation.In vivo PA imaging results demonstrated that NBDPBr NPs could specifically accumulate at tumor sites and realized the maximum tumor retention at 7 h post-injection.All the in vitro and in vivo results indicated the significant potence of NBDPBr with unexpected bis-bromination for PA imaging-guided synergetic PDT/PTT.展开更多
Cooling tower is crucial equipment in the cool-end system of power plant and the natural draft counter-flow wet cooling tower(NDWCT)gets wide application.The artificial neural network(ANN)technique is becoming an effe...Cooling tower is crucial equipment in the cool-end system of power plant and the natural draft counter-flow wet cooling tower(NDWCT)gets wide application.The artificial neural network(ANN)technique is becoming an effective method for the thermal performance investigation of cooling towers.However,the neural network research on the energy efficiency performance of NDWCTs is not sufficient.In this paper,a novel approach was proposed to predict energy efficiency of various NDWCTs by using Back Propagation(BP)neural network:Firstly,based on 638 sets of field test data within 36 diverse NDWCTs in power plant,a three-layer BP neural network model with structure of 8-14-2 was developed.Then the cooling number and evaporation loss of water of different NDWCTs were predicted adopting the BP model.The results show that the established BP neural network has preferable prediction accuracy for the heat and mass transfer performance of NDWCT with various scales.The predicted cooling number and evaporative loss proportion of the testing cooling towers are in good agreement with experimental values with the mean relative error in the range of 2.11%–4.45%and 1.04%–4.52%,respectively.Furthermore,the energy efficiency of different NDWCTs can also be predicted by the proposed BP model with consideration of evaporation loss of water in cooling tower.At last,a novel method for energy efficiency prediction of various NDWCTs using the developed ANN model was proposed.The energy efficiency index(EEI)of different NDWCTs can be achieved readily without measuring the temperature as well as velocity of the outlet air.展开更多
In collisions between energetic highly charged ions and atoms,the ions could remove the electrons of the target atoms,or be excited into high-level states.In the first case,the target electrons not only be captured in...In collisions between energetic highly charged ions and atoms,the ions could remove the electrons of the target atoms,or be excited into high-level states.In the first case,the target electrons not only be captured into ground and excited states of the projectile ions,but also be ionized to free.Non-radiative capture(NRC)and radiative electron capture(REC)are two competing mechanisms in fast collisions[1].NRC means electron transfer from a bound state of the target to a bound states of the projectile without the emission of radiation;REC is produced with simultaneous the emission of photon for satisfying energy and momentum conservation laws.The physical essence is the competition between the“electron-nucleus”interaction and the“electron-vacuum”interaction.NRC is dominant in collisions of high-Z ions with heavy target atoms at moderate energies.REC entirely determine the electron capture channel for high collision velocities and light targets[1].Measuring the relative strength of the projectile x-ray emission associated with electron capture could determine state-selective population,angular distribution of single capture Ly 1 or double capture Kα1 and Kα2,would provide new detailed information on the dynamics of ion-atom collisions and atomic structure studies[1].展开更多
This paper focused on nitrate fate in the vadose zone(VZ)and its implications for groundwater vulnerability under different soil types in the agricultural area of Huaihe River Basin,China.Isotopic compositions of nitr...This paper focused on nitrate fate in the vadose zone(VZ)and its implications for groundwater vulnerability under different soil types in the agricultural area of Huaihe River Basin,China.Isotopic compositions of nitrate(δ15N andδ18O)along with NO3-and Cl-concentrations were determined in the VZ-shallow groundwater continuum beneath silty-loam and silty-clay-loam,which are distinctive in texture and organic carbon(OC).In the soil zone(<1 m in depth),measuredδ18O-NO3-suggested the ubiquitous of nitrification regardless of soil types.In the subsoil zone(>1 m in depth),however,the concurrent enrichment ofδ15N-NO3-andδ18O-NO3-indicated the occurrence of denitrification,which showed a dependence on subsoil properties.Specifically,during wheat and maize land uses,denitrification removed as much as 76%-88%of the total nitrate where the subsoil was dominated by stratified OC-rich silty-clay-loam.In contrast,only 0%-28%of the nitrate was degraded via denitrification where the subsoil was composed of uniform,OC-depleted silty-loam.Furthermore,inactive denitrification and higher permeability in the silty-loam VZ implied higher groundwater vulnerability.This observation was consistent with the fact that groundwater NO3--N concentration beneath silty-loam(11.24 mg L-1)was over two times higher than that of the silty-clay-loam(5.32 mg L-1),where stricter fertilization management and conservation strategies should be applied to protect groundwater quality.展开更多
Radiative electron capture(REC)and nonradiative capture(NRC)are two competing mechanisms in relativistic collisions of highly charged ions with atoms[1].REC means electron transfer from target to projectile with the e...Radiative electron capture(REC)and nonradiative capture(NRC)are two competing mechanisms in relativistic collisions of highly charged ions with atoms[1].REC means electron transfer from target to projectile with the emission of one photon for satisfying energy and momentum conservation laws.展开更多
In highly charged ions(HCI)-atom collisions, many electrons are active and much more channels are opened, and the collision dynamics therefore is much more complicated. Because of the complexity originated from many a...In highly charged ions(HCI)-atom collisions, many electrons are active and much more channels are opened, and the collision dynamics therefore is much more complicated. Because of the complexity originated from many active electrons which are involved in HCI and atoms collisions, the full quantum treatment is rather difficult, whereas the simple classical over-the-barrier models and semiempirical展开更多
The cluster target system was installed to the due position last year. Several test experiments such as the test of vacuum system, the calibration of the flux and the stability of system have been done after the insta...The cluster target system was installed to the due position last year. Several test experiments such as the test of vacuum system, the calibration of the flux and the stability of system have been done after the installation and collimation of cluster internal target. However, there are two problems which hinder us from going further. One is the blocking of nozzle which results in the failure of a long-term system running; the other is the low pumping power for Hydrogen gases in the first stage of the cluster source cham-展开更多
Highly charged Arq+ (q=13, 14, 15, 16) ions were provided by a 14.5 GHz ECR ion source. Highly charged ions were extracted and m/q-selected (where m is the ion mass and q is the ion charge) by an analyzing magnet. The...Highly charged Arq+ (q=13, 14, 15, 16) ions were provided by a 14.5 GHz ECR ion source. Highly charged ions were extracted and m/q-selected (where m is the ion mass and q is the ion charge) by an analyzing magnet. The ion beams were charge state-selected again before entering into the target chamber by a 64°coaxial展开更多
基金supported by NSF of Jiangsu Province(No.BK20200092)。
文摘Introducing heavy halogen atoms into organic small molecules is a practical strategy for efficient singlet oxygen(^(1)O_(2))generation.Generally,bromine or iodine atoms are introduced on the aza-borondipyrromethene(aza-BODIPY)core,rather than on the periphery aryl rings for efficient~1O_(2) generation.Herein,an aza-BODIPY dye NBDPBr with unexpected bromination on the periphery aryl rings was synthesized for photoacoustic(PA)imaging-guided synergistic photothermal therapy(PTT)and photodynamic therapy(PDT)in tumor cells.Owing to unexcepted bromination at the periphery aryl rings,NBDPBr demonstrated an outstanding singlet oxygen quantum yield(Φ_(Δ))of 66% which was superior to similar brominated photosensitizers previously reported.After encapsulation with amphiphilic polymer F-127,hydrophilic NBDPBr nanoparticles(NPs)were fabricated and exhibited an excellent photothermal conversion efficiency(η)of 43.0% under 660 nm photoirradiation.In vivo PA imaging results demonstrated that NBDPBr NPs could specifically accumulate at tumor sites and realized the maximum tumor retention at 7 h post-injection.All the in vitro and in vivo results indicated the significant potence of NBDPBr with unexpected bis-bromination for PA imaging-guided synergetic PDT/PTT.
基金supported by the National Key R&D Program of China(Grant No.2017YFF0209803)。
文摘Cooling tower is crucial equipment in the cool-end system of power plant and the natural draft counter-flow wet cooling tower(NDWCT)gets wide application.The artificial neural network(ANN)technique is becoming an effective method for the thermal performance investigation of cooling towers.However,the neural network research on the energy efficiency performance of NDWCTs is not sufficient.In this paper,a novel approach was proposed to predict energy efficiency of various NDWCTs by using Back Propagation(BP)neural network:Firstly,based on 638 sets of field test data within 36 diverse NDWCTs in power plant,a three-layer BP neural network model with structure of 8-14-2 was developed.Then the cooling number and evaporation loss of water of different NDWCTs were predicted adopting the BP model.The results show that the established BP neural network has preferable prediction accuracy for the heat and mass transfer performance of NDWCT with various scales.The predicted cooling number and evaporative loss proportion of the testing cooling towers are in good agreement with experimental values with the mean relative error in the range of 2.11%–4.45%and 1.04%–4.52%,respectively.Furthermore,the energy efficiency of different NDWCTs can also be predicted by the proposed BP model with consideration of evaporation loss of water in cooling tower.At last,a novel method for energy efficiency prediction of various NDWCTs using the developed ANN model was proposed.The energy efficiency index(EEI)of different NDWCTs can be achieved readily without measuring the temperature as well as velocity of the outlet air.
文摘In collisions between energetic highly charged ions and atoms,the ions could remove the electrons of the target atoms,or be excited into high-level states.In the first case,the target electrons not only be captured into ground and excited states of the projectile ions,but also be ionized to free.Non-radiative capture(NRC)and radiative electron capture(REC)are two competing mechanisms in fast collisions[1].NRC means electron transfer from a bound state of the target to a bound states of the projectile without the emission of radiation;REC is produced with simultaneous the emission of photon for satisfying energy and momentum conservation laws.The physical essence is the competition between the“electron-nucleus”interaction and the“electron-vacuum”interaction.NRC is dominant in collisions of high-Z ions with heavy target atoms at moderate energies.REC entirely determine the electron capture channel for high collision velocities and light targets[1].Measuring the relative strength of the projectile x-ray emission associated with electron capture could determine state-selective population,angular distribution of single capture Ly 1 or double capture Kα1 and Kα2,would provide new detailed information on the dynamics of ion-atom collisions and atomic structure studies[1].
文摘目的探讨不同频次的青藤碱注射治疗膝骨关节炎的疗效。方法选取陕西中医药大学第二附属医院2021年11月-2022年1月诊治的60例膝骨关节炎患者,随机分为每日组和隔日组,每组30例。每日组给予青藤碱35 mg关节腔内注射,每日1次,共10次;隔日组给予青藤碱35 mg关节腔内注射,每2 d 1次,共5次。观察2组治疗前后西安大略和麦克马斯特大学骨关节炎指数评分(WOMAC)、疼痛视觉模拟评分法(VAS)评分和血清中白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)水平变化,记录2组不良反应发生情况。结果治疗后,2组患者WOMAC评分、VAS评分及血清中IL-1β和TNF-α水平均较治疗前显著降低(P均<0.05),每日组的WOMAC评分、VAS评分与隔日组比较差异均无统计学意义(P均>0.05),但每日组血清IL-1β和TNF-α水平显著低于隔日组(P均<0.05)。2组均无明显不良反应发生。结论不同频次的青藤碱注射治疗膝骨关节炎均能改善患者的症状并降低血清炎性因子水平,但每日注射下调血清炎性因子水平作用更显著。临床中可根据患者具体情况选取更为合适的治疗方法。
基金This work was supported by the Key Program of the National Natural Science Foundation of China(41230640)Major Science and Technology Program for Water Pollution Control and Treatment(2017ZX07602003).
文摘This paper focused on nitrate fate in the vadose zone(VZ)and its implications for groundwater vulnerability under different soil types in the agricultural area of Huaihe River Basin,China.Isotopic compositions of nitrate(δ15N andδ18O)along with NO3-and Cl-concentrations were determined in the VZ-shallow groundwater continuum beneath silty-loam and silty-clay-loam,which are distinctive in texture and organic carbon(OC).In the soil zone(<1 m in depth),measuredδ18O-NO3-suggested the ubiquitous of nitrification regardless of soil types.In the subsoil zone(>1 m in depth),however,the concurrent enrichment ofδ15N-NO3-andδ18O-NO3-indicated the occurrence of denitrification,which showed a dependence on subsoil properties.Specifically,during wheat and maize land uses,denitrification removed as much as 76%-88%of the total nitrate where the subsoil was dominated by stratified OC-rich silty-clay-loam.In contrast,only 0%-28%of the nitrate was degraded via denitrification where the subsoil was composed of uniform,OC-depleted silty-loam.Furthermore,inactive denitrification and higher permeability in the silty-loam VZ implied higher groundwater vulnerability.This observation was consistent with the fact that groundwater NO3--N concentration beneath silty-loam(11.24 mg L-1)was over two times higher than that of the silty-clay-loam(5.32 mg L-1),where stricter fertilization management and conservation strategies should be applied to protect groundwater quality.
基金National Natural Science Foundation of China(11604345,11611530684,11674333,11774356)。
文摘Radiative electron capture(REC)and nonradiative capture(NRC)are two competing mechanisms in relativistic collisions of highly charged ions with atoms[1].REC means electron transfer from target to projectile with the emission of one photon for satisfying energy and momentum conservation laws.
基金Supported by the National Natural Science Foundation of China under Grant No.10304019,No.10134010 and No. 103750
文摘In highly charged ions(HCI)-atom collisions, many electrons are active and much more channels are opened, and the collision dynamics therefore is much more complicated. Because of the complexity originated from many active electrons which are involved in HCI and atoms collisions, the full quantum treatment is rather difficult, whereas the simple classical over-the-barrier models and semiempirical
基金Supported by the National Natural Science Foundation of China (10304019, 10134010 and 10375080)
文摘The cluster target system was installed to the due position last year. Several test experiments such as the test of vacuum system, the calibration of the flux and the stability of system have been done after the installation and collimation of cluster internal target. However, there are two problems which hinder us from going further. One is the blocking of nozzle which results in the failure of a long-term system running; the other is the low pumping power for Hydrogen gases in the first stage of the cluster source cham-
基金Supported by NSFC under the contract numbers of 10134010, 10375080, 10304019 and 10274088.
文摘Highly charged Arq+ (q=13, 14, 15, 16) ions were provided by a 14.5 GHz ECR ion source. Highly charged ions were extracted and m/q-selected (where m is the ion mass and q is the ion charge) by an analyzing magnet. The ion beams were charge state-selected again before entering into the target chamber by a 64°coaxial
