Harmful algal blooms in eutrophic waters pose a serious threat to freshwater ecosystems and human health. In-situ light availability control is one of the most commonly used technologies to suppress algae in lakes and...Harmful algal blooms in eutrophic waters pose a serious threat to freshwater ecosystems and human health. In-situ light availability control is one of the most commonly used technologies to suppress algae in lakes and reservoirs. To develop a better understanding of the effects of light on algal growth, specific density, colony size and sinking loss, Anabaena flos-aquae(cyanobacteria) and Scenedesmus obliquus(green algae) were evaluated in varying light scenarios. The results showed that the specific density and colony size of these two species varied during growth, and there were obvious differences among the light scenarios. At the end of exponential phase, S. obliquus incubated under light-limited condition maintained a higher specific density and formed larger aggregates, whereas A. flos-aquae formed a longer filament length. Both species exhibited higher sinking loss rates with lower light availability. These results implied that the sinking loss rate was not always constant but should be considered as a variable response to the change of light availability, and in-situ light availability control might result in a significant increase of the sinking loss of algae due to the change of size and specific density, thereby further affecting the algal biomass in the water column.展开更多
Decomposition of dimethyl sulfide (DMS) in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge (DBD) reactor at room temperature and atmospheric pressure.A new type of high pulse ...Decomposition of dimethyl sulfide (DMS) in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge (DBD) reactor at room temperature and atmospheric pressure.A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network (BPFN) was adopted in our experiments.The maximum power output of the pulse voltage source and the maximum peak voltage were 1kW and 100kV,respectively.The important parameters affecting odor decomposition,including peak voltage,pulse frequency,gas flow rate,initial concentration,and humidity,which influenced the removal efficiency,were investigated.The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832mg/m3 and a gas flow rate of 1000ml/min.Humidity boosts the removal efficiency and improves the energy yield (EY) greatly.The EY of 832mg/m3 DMS was 2.87mg/kJ when the relative humidity was above 30%.In the case of DMS removal,the ozone and nitrogen oxides were observed in the exhaust gas.The carbon and sulfur elements of DMS were mainly converted to carbon dioxide,carbon monoxide and sulfur dioxide.Moreover,sulfur was discovered in the reactor.According to the results,the optimization design for the reactor and the matching of high pulse voltage source can be reckoned.展开更多
The hard - sphere three - parameter equation of state(CSPT) proposed in the previous paper(Li et al. 1991) was modified by a new temperature relation for the pseudo-critical compressibility ξc and the temperature cor...The hard - sphere three - parameter equation of state(CSPT) proposed in the previous paper(Li et al. 1991) was modified by a new temperature relation for the pseudo-critical compressibility ξc and the temperature correction factor α(Tr) of the attractive parameter. Vapor pressures and saturated liquid densities of 105 pure compounds were calculated by the modified version. Results show that correlations of saturated properties at low reduced temperatures and thermodynamic properties in the vicinity of critical region were significantly improved. Furthermore, characteristic parameters of this modified version were generalized by acentric factor ω and critical compressibility Zc to predict saturated liquid densities of 72 polar substances and the latent heat of vaporization for 151 substances including strongly polar compounds with satisfactory results.展开更多
Britholite-Y is milkwhite, rosy in colour. The measured specific gravity is 4.35, with Ng′ = 1.791, Np′ = 1.784. As determined by electron microprobe, its crystal formula is (Y2.82Ca1.58Ce0.27Dy0.21Er0.11)5 [(Si2.95...Britholite-Y is milkwhite, rosy in colour. The measured specific gravity is 4.35, with Ng′ = 1.791, Np′ = 1.784. As determined by electron microprobe, its crystal formula is (Y2.82Ca1.58Ce0.27Dy0.21Er0.11)5 [(Si2.95P0.05)3O12](OH,F), space group = C22-P21, a = (0.9504±0.0005) nm, b = (0.9414±0.0004) nm, c = (0.6922±0.0002) nm, r = (119.71±0.04)°, V = (53.79±0.04) nm3, Z = 2. Least-squares refinements with 2272 independent reflection (F0>3σ|F0|) yielded R = 0.111. The change of symmetry group P63/m of apatite to P21 of britholite-Y results from the shifts of Y, Ca, Si, O and (OH) atoms (anions) from the pseudohexagonal P63/m equivalent positions (6h), (4f), (12i) and (2a) as produced by distortion of the polyhedra with 7-, 9-, and 4-corners. The substitution of Ca in apatite for Y and the order distribution of atoms Y and Ca on the equivalent positions (6h) and (4f) have contributed to the distortion of 7- and 9- cornered polyhedra. The substitutions of Si4+ for P5+ and OH- for F- may also be effected. The crystal chemistry of apatite-group minerals is also discussed.展开更多
OBJECTIVE To investigate the relationship between the clinicopatho- logical stage and serum prostate specific antigen(PSA)concentration and PSAdensity(PSAD)in patients with prostate cancer. METHODS The clinicopatholog...OBJECTIVE To investigate the relationship between the clinicopatho- logical stage and serum prostate specific antigen(PSA)concentration and PSAdensity(PSAD)in patients with prostate cancer. METHODS The clinicopathological stage was determined on the basis of a pathological examination and clinical data in 65 prostate cancer patients treated by radical prostatectomy.PSA and PSAD were measured before the operation.The Spearman rank correlation was applied to evaluate the relationship between the clinicopathological stage,serum PSAconcentration and PSAD. RESULTS Patients with higher PSA and PSAD were significantly more likely to have higher clinical stages,a higher Gleason score,positive surgical margins,capsular penetration,and seminal vesicle invasion(each P<0.05). But there was no significant association between PSA and lymph node metastasis(P=0.053).The levels of serum PSA concentration and PSAD were significantly correlated with the clinical stage(P<0.05)in the prostate cancer patients. CONCLUSION The level of both PSA and PSAD were significantly correlated with the clinical stage(P<0.05)in the prostate cancer patients.But PSAD may be a more powerful predictor of clinical stage and prognosis than PSA.展开更多
CONSPECTUS:Lithium−sulfur(Li-S)batteries have emerged as a promising energy storage technology driven by their potential to reach very high theoretical specific energy densities of up to 2600 Wh·kg^(−1).This rema...CONSPECTUS:Lithium−sulfur(Li-S)batteries have emerged as a promising energy storage technology driven by their potential to reach very high theoretical specific energy densities of up to 2600 Wh·kg^(−1).This remarkably high energy density directly results from the reversible,multi-electron-transfer reactions between sulfur and lithium metal taking place during the charge and discharge cycles.However,the charge/discharge processes of Li-S batteries are invariably accompanied by changes in both the composition and the structure of the sulfur species in the cathode,all of which result in sluggish and incomplete sulfur transformation.It has been demonstrated that the application of electrocatalysts is an effective strategy to accelerate the sulfur reduction reaction(SRR).Recognizing this challenge,researchers worldwide have tried to develop efficient catalysts to accelerate the kinetics of the SRR and boost the overall performance of Li-S batteries.However,this goal necessitates an in-depth understanding of the intricate catalytic processes in the Li-S battery cathode.The effective characterization of the catalysts and a thorough investigation of the SRR process are essential steps to unraveling the underlying catalytic mechanism of sulfur reduction and to compare the performances of the different electrocatalysts.Nonetheless,this pursuit is hindered by the inherent complexity of the SRR process,which remains uniquely specific to the Li-S system under study.Throughout the SRR process,a multitude of intermediate products are created through catalytic conversions between liquid−solid and solid−solid phases.This complexity is markedly different from established heterogeneous catalytic processes,such as water-splitting reactions,where reactants,products,and reaction phases are relatively simple.Given these challenges,our response has been to design a series of catalysts with controlled structures to gain an in-depth understanding of the intricate reaction processes within Li-S catalysis.In this Account,we have undertaken a comprehensive analysis of the structure−function relationships governing the active sites of electrocatalysts in SRR.Our work thus encompasses three aspects-catalytic sites:their geometry and evolution during the reaction,catalytic mechanisms:a key factor that determines SRR kinetics,and catalytic materials:intelligent design toward optimized performance.Also presented in this Account is a brief discussion covering the broader domain of other electrocatalysts and sulfurbased electrochemical systems.Drawing upon the insights obtained from these works,we present future perspectives on potential opportunities and hurdles in the wider application of sulfur cathode electrocatalysts.展开更多
Ni-rich layered cathodes have become the promising candidates for the next-generation high-energy Liion batteries due to their high energy density and competitive cost.However,they suffer from rapidcapacity fading due...Ni-rich layered cathodes have become the promising candidates for the next-generation high-energy Liion batteries due to their high energy density and competitive cost.However,they suffer from rapidcapacity fading due to the structural and interfacial instability upon long-term operation.Herein,the Tidoped and LiYO2-coated Ni-rich layered cathode has been synthesized via a facile one-step sinteringstrategy,which significantly restrains the interfacial parasitic side reactions and enhances the structuralstability.Specifically,the trace Ti^(4+)doping greatly stabilizes the lattice oxygen and alleviates the Li/Nidisorder while the LiYO_(2) coating layer can prevent the erosion of the cathode by the electrolyte duringcycles.As a result,the Ti-NCM83@LYO delivers a high specific capacity of 135 mAh g^(-1) even at 10C andthere is almost no capacity loss at 1C for 100 cycles.This work provides a simple one-step dual-modification strategy to meet the commercial requirements of Ni-rich cathodes.展开更多
The influence of atomic densities on the propagation property for ultrashort pulses in a two-level atom (TLA) medium is investigated. With higher atomic densities, the self-induced transparency (SIT) cannot be recover...The influence of atomic densities on the propagation property for ultrashort pulses in a two-level atom (TLA) medium is investigated. With higher atomic densities, the self-induced transparency (SIT) cannot be recovered even for 2πultrashort pulses. New features such as pulse splitting, red-shift and blue-shift of the corresponding spectra arise, and the component of central frequency gradually disappears.展开更多
基金Supported by the National Natural Science Foundation of China(No.41471393)the Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration(No.SHUES2016B03)
文摘Harmful algal blooms in eutrophic waters pose a serious threat to freshwater ecosystems and human health. In-situ light availability control is one of the most commonly used technologies to suppress algae in lakes and reservoirs. To develop a better understanding of the effects of light on algal growth, specific density, colony size and sinking loss, Anabaena flos-aquae(cyanobacteria) and Scenedesmus obliquus(green algae) were evaluated in varying light scenarios. The results showed that the specific density and colony size of these two species varied during growth, and there were obvious differences among the light scenarios. At the end of exponential phase, S. obliquus incubated under light-limited condition maintained a higher specific density and formed larger aggregates, whereas A. flos-aquae formed a longer filament length. Both species exhibited higher sinking loss rates with lower light availability. These results implied that the sinking loss rate was not always constant but should be considered as a variable response to the change of light availability, and in-situ light availability control might result in a significant increase of the sinking loss of algae due to the change of size and specific density, thereby further affecting the algal biomass in the water column.
基金Project(No.20576121)supported by the National Natural Science Foundation of China
文摘Decomposition of dimethyl sulfide (DMS) in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge (DBD) reactor at room temperature and atmospheric pressure.A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network (BPFN) was adopted in our experiments.The maximum power output of the pulse voltage source and the maximum peak voltage were 1kW and 100kV,respectively.The important parameters affecting odor decomposition,including peak voltage,pulse frequency,gas flow rate,initial concentration,and humidity,which influenced the removal efficiency,were investigated.The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832mg/m3 and a gas flow rate of 1000ml/min.Humidity boosts the removal efficiency and improves the energy yield (EY) greatly.The EY of 832mg/m3 DMS was 2.87mg/kJ when the relative humidity was above 30%.In the case of DMS removal,the ozone and nitrogen oxides were observed in the exhaust gas.The carbon and sulfur elements of DMS were mainly converted to carbon dioxide,carbon monoxide and sulfur dioxide.Moreover,sulfur was discovered in the reactor.According to the results,the optimization design for the reactor and the matching of high pulse voltage source can be reckoned.
基金Supported by the National Natural Science Foundation of China
文摘The hard - sphere three - parameter equation of state(CSPT) proposed in the previous paper(Li et al. 1991) was modified by a new temperature relation for the pseudo-critical compressibility ξc and the temperature correction factor α(Tr) of the attractive parameter. Vapor pressures and saturated liquid densities of 105 pure compounds were calculated by the modified version. Results show that correlations of saturated properties at low reduced temperatures and thermodynamic properties in the vicinity of critical region were significantly improved. Furthermore, characteristic parameters of this modified version were generalized by acentric factor ω and critical compressibility Zc to predict saturated liquid densities of 72 polar substances and the latent heat of vaporization for 151 substances including strongly polar compounds with satisfactory results.
文摘Britholite-Y is milkwhite, rosy in colour. The measured specific gravity is 4.35, with Ng′ = 1.791, Np′ = 1.784. As determined by electron microprobe, its crystal formula is (Y2.82Ca1.58Ce0.27Dy0.21Er0.11)5 [(Si2.95P0.05)3O12](OH,F), space group = C22-P21, a = (0.9504±0.0005) nm, b = (0.9414±0.0004) nm, c = (0.6922±0.0002) nm, r = (119.71±0.04)°, V = (53.79±0.04) nm3, Z = 2. Least-squares refinements with 2272 independent reflection (F0>3σ|F0|) yielded R = 0.111. The change of symmetry group P63/m of apatite to P21 of britholite-Y results from the shifts of Y, Ca, Si, O and (OH) atoms (anions) from the pseudohexagonal P63/m equivalent positions (6h), (4f), (12i) and (2a) as produced by distortion of the polyhedra with 7-, 9-, and 4-corners. The substitution of Ca in apatite for Y and the order distribution of atoms Y and Ca on the equivalent positions (6h) and (4f) have contributed to the distortion of 7- and 9- cornered polyhedra. The substitutions of Si4+ for P5+ and OH- for F- may also be effected. The crystal chemistry of apatite-group minerals is also discussed.
文摘OBJECTIVE To investigate the relationship between the clinicopatho- logical stage and serum prostate specific antigen(PSA)concentration and PSAdensity(PSAD)in patients with prostate cancer. METHODS The clinicopathological stage was determined on the basis of a pathological examination and clinical data in 65 prostate cancer patients treated by radical prostatectomy.PSA and PSAD were measured before the operation.The Spearman rank correlation was applied to evaluate the relationship between the clinicopathological stage,serum PSAconcentration and PSAD. RESULTS Patients with higher PSA and PSAD were significantly more likely to have higher clinical stages,a higher Gleason score,positive surgical margins,capsular penetration,and seminal vesicle invasion(each P<0.05). But there was no significant association between PSA and lymph node metastasis(P=0.053).The levels of serum PSA concentration and PSAD were significantly correlated with the clinical stage(P<0.05)in the prostate cancer patients. CONCLUSION The level of both PSA and PSAD were significantly correlated with the clinical stage(P<0.05)in the prostate cancer patients.But PSAD may be a more powerful predictor of clinical stage and prognosis than PSA.
基金financial support from the Natural Science Foundation of China(22125902,21975243,and U2032202)the Anhui Science Fund for Distinguished Young Scholars(2208085J15)+2 种基金the National Key R&D Program of China(2022YFA1504101)Users with Excellence Program of Hefei Science Center CAS(2021HSC-UE002)the USTC Research Funds of the Double First-Class Initiative(YD2060002030).
文摘CONSPECTUS:Lithium−sulfur(Li-S)batteries have emerged as a promising energy storage technology driven by their potential to reach very high theoretical specific energy densities of up to 2600 Wh·kg^(−1).This remarkably high energy density directly results from the reversible,multi-electron-transfer reactions between sulfur and lithium metal taking place during the charge and discharge cycles.However,the charge/discharge processes of Li-S batteries are invariably accompanied by changes in both the composition and the structure of the sulfur species in the cathode,all of which result in sluggish and incomplete sulfur transformation.It has been demonstrated that the application of electrocatalysts is an effective strategy to accelerate the sulfur reduction reaction(SRR).Recognizing this challenge,researchers worldwide have tried to develop efficient catalysts to accelerate the kinetics of the SRR and boost the overall performance of Li-S batteries.However,this goal necessitates an in-depth understanding of the intricate catalytic processes in the Li-S battery cathode.The effective characterization of the catalysts and a thorough investigation of the SRR process are essential steps to unraveling the underlying catalytic mechanism of sulfur reduction and to compare the performances of the different electrocatalysts.Nonetheless,this pursuit is hindered by the inherent complexity of the SRR process,which remains uniquely specific to the Li-S system under study.Throughout the SRR process,a multitude of intermediate products are created through catalytic conversions between liquid−solid and solid−solid phases.This complexity is markedly different from established heterogeneous catalytic processes,such as water-splitting reactions,where reactants,products,and reaction phases are relatively simple.Given these challenges,our response has been to design a series of catalysts with controlled structures to gain an in-depth understanding of the intricate reaction processes within Li-S catalysis.In this Account,we have undertaken a comprehensive analysis of the structure−function relationships governing the active sites of electrocatalysts in SRR.Our work thus encompasses three aspects-catalytic sites:their geometry and evolution during the reaction,catalytic mechanisms:a key factor that determines SRR kinetics,and catalytic materials:intelligent design toward optimized performance.Also presented in this Account is a brief discussion covering the broader domain of other electrocatalysts and sulfurbased electrochemical systems.Drawing upon the insights obtained from these works,we present future perspectives on potential opportunities and hurdles in the wider application of sulfur cathode electrocatalysts.
基金This work was supported by the National Natural ScienceFoundation of China(grant No.21975074)the Innovation Programof Shanghai Municipal Education Commission,and the Fundamental Research Funds for the Central Universities.
文摘Ni-rich layered cathodes have become the promising candidates for the next-generation high-energy Liion batteries due to their high energy density and competitive cost.However,they suffer from rapidcapacity fading due to the structural and interfacial instability upon long-term operation.Herein,the Tidoped and LiYO2-coated Ni-rich layered cathode has been synthesized via a facile one-step sinteringstrategy,which significantly restrains the interfacial parasitic side reactions and enhances the structuralstability.Specifically,the trace Ti^(4+)doping greatly stabilizes the lattice oxygen and alleviates the Li/Nidisorder while the LiYO_(2) coating layer can prevent the erosion of the cathode by the electrolyte duringcycles.As a result,the Ti-NCM83@LYO delivers a high specific capacity of 135 mAh g^(-1) even at 10C andthere is almost no capacity loss at 1C for 100 cycles.This work provides a simple one-step dual-modification strategy to meet the commercial requirements of Ni-rich cathodes.
基金The work was supported by the National Natural Science Foundation of China (No. 60478002) and the Natural Science Key Foundation of Shanghai (No. 04JC14036).
文摘The influence of atomic densities on the propagation property for ultrashort pulses in a two-level atom (TLA) medium is investigated. With higher atomic densities, the self-induced transparency (SIT) cannot be recovered even for 2πultrashort pulses. New features such as pulse splitting, red-shift and blue-shift of the corresponding spectra arise, and the component of central frequency gradually disappears.
