The third paragraph in Sec.IV REGENERATIVE AMPLIFICATION erroneously states“In other words,the distribution of spectral components is time-dependent,and the spectral distortion in the amplification process will not c...The third paragraph in Sec.IV REGENERATIVE AMPLIFICATION erroneously states“In other words,the distribution of spectral components is time-dependent,and the spectral distortion in the amplification process will not change the time-domain shape.”展开更多
Broadband low-coherence light is considered to be an effective way to suppress laser plasma instability.Recent studies have demonstrated the ability of low-coherence laser facilities to reduce back-scattering during b...Broadband low-coherence light is considered to be an effective way to suppress laser plasma instability.Recent studies have demonstrated the ability of low-coherence laser facilities to reduce back-scattering during beam–target coupling.However,to ensure simultaneous low coherence and high energy,complex spectral modulation methods and amplification routes have to be adopted.In this work,we propose the use of a random fiber laser(RFL)as the seed source.The spectral features of this RFL can be carefully tailored to provide a good match with the gain characteristics of the laser amplification medium,thus enabling efficient amplification while maintaining low coherence.First,a theoretical model is constructed to give a comprehensive description of the output characteristics of the spectrum-tailored RFL,after which the designed RFL is experimentally realized as a seed source.Through precise pulse shaping and efficient regenerative amplification,a shaped random laser pulse output of 28 mJ is obtained,which is the first random laser system with megawatt-class peak power that is able to achieve low coherence and efficient spectrum-conformal regenerative amplification.展开更多
The coevolution and coexistence of bacterial–fungal consortium have been widely reported in various natural ecosystems. The transboundary communication mediated by bacterial acyl–homoserine lactone signals probably ...The coevolution and coexistence of bacterial–fungal consortium have been widely reported in various natural ecosystems. The transboundary communication mediated by bacterial acyl–homoserine lactone signals probably is the driving force of fungal spore germination. This study aimed to report a functional bacterial signal molecule, C10-acyl homoserine lactone, which could be sensed by Galactomyces geotrichum. The spore germination rates of G. geotrichum increased by 22%. Meanwhile, carbohydrate production improved by 1.0-to 2.5-fold. G. geotrichum signaled to C10-HSL through receptor gene Rho1and made a response in cell wall assembly and carbohydrate biosynthesis by the upregulated expression(above 1-fold) of functional genes, such as Smi1, Utr2, and Chs2. It contributed to spore germination and morphology transformation together. This study provides a novel perspective for understating the transboundary cooperation between fungi and bacteria by cell-to-cell communication.展开更多
Climate affects the natural landscape,the economic productivity of societies,and the lifestyles of its inhabitants.It also influences municipal wastewater treatment.Biological processes are widely employed in municipa...Climate affects the natural landscape,the economic productivity of societies,and the lifestyles of its inhabitants.It also influences municipal wastewater treatment.Biological processes are widely employed in municipal wastewater treatment plants(WWTPs),and the prolonged cold conditions brought by the winter months each year pose obstacles to meeting the national standards in relatively cold regions.Therefore,both a systematic analysis of existing technical bottlenecks as well as promising novel technologies are urgently needed for these cold regions.Taking North-east China as a case,this review studied and analyzed the main challenges affecting 20 municipal WWTPs.Moreover,we outlined the currently employed strategies and research issues pertaining to low temperature conditions.Low temperatures have been found to reduce the metabolism of microbes by 58%or more,thereby leading to chemical oxygen demand(COD)and NH_(4)^(-)-N levels that have frequently exceeded the national standard during the winter months.Furthermore,the extracellular matrix tends to lead to activated sludge bulking issues.Widely employed strategies to combat these issues include increasing the aeration intensity,reflux volume,and flocculant addition;however,these strategies increase electricity consumption by>42%in the winter months.Internationally,the processes of anaerobic ammonium oxidation(anammox),granular sludge,and aerobic denitrification have become the focus of research for overcoming low temperature.These have inspired us to review and propose directions for the further development of novel technologies suitable for cold regions,thereby overcoming the issues inherent in traditional processes that have failed to meet the presently reformed WWTP requirements.展开更多
The isotherms of original AC (activated carbon) and photocatalysts (TiO2-AC) calcined at 500℃ for phenol were measured. The results showed a reversible adsorption of phenol onto both kinds of particles at 25℃, and c...The isotherms of original AC (activated carbon) and photocatalysts (TiO2-AC) calcined at 500℃ for phenol were measured. The results showed a reversible adsorption of phenol onto both kinds of particles at 25℃, and could be fitted well to the Freundlich adsorption equation for the dilute solution. Five oxidation processes, namely O3 , O3 /UV, O3 /UV/AC, O2 /UV/TiO2 and O3 /UV/TiO2 , for phenol degradation in fluidized bed were evaluated and compared, and the photocatalytic ozonation was found to give the highest phenol conversion because of the combined actions of homogenous ozonation in the liquid phase, heterogeneous ozonation on the surface of the catalyst support, i.e. activated carbon, and heterogeneous photocatalytic oxidation on the TiO2 catalyst surface. With the simplified kinetic model, photolytic ozonation was confirmed to predominantly take place on the particle surface in comparison with the heterogeneous and homogeneous photolytic ozonation. Additionally, the heterogeneous photocatalytic oxidation constant was found to be enhanced by 3.73 times in photocatlaytic ozonation process with ozone as the scavenger compared to the photocatalytic oxidation process with oxygen as the scavenger.展开更多
The efficiency of a fluidized-bed flocculator with 800- m particles of 1360 kg/m3 in density was studied, and the anti-shock capability of the unit was estimated for three kinds of industrial wastewater: heavy turbidi...The efficiency of a fluidized-bed flocculator with 800- m particles of 1360 kg/m3 in density was studied, and the anti-shock capability of the unit was estimated for three kinds of industrial wastewater: heavy turbidity wastewater, dispersed dyeing wastewater and starch wastewater. Steady removal efficiency was contributed by the following characteristics of the flocculator: (1) the dynamic conditions, flocculation time and velocity gradient, which were stabilized at a steady level as the loading rate changed; (2) hydrodynamic characteristics, especially the considerable rise of expanded bed height with increasing superficial velocity when small and light particles were employed as the solid phase; (3) flocs growth characteristics in the fluidized bed, which caused the density and size of the flocs being maintained at a compensational relationship, resulted the stabilized settling velocity of the flocs.展开更多
With the random movement of silica gel beads in a conical fluidized bed, micro-vortices resulting from the fluidization promoted the collision and aggregation of suspended fine kaolin powders. The abatement efficienci...With the random movement of silica gel beads in a conical fluidized bed, micro-vortices resulting from the fluidization promoted the collision and aggregation of suspended fine kaolin powders. The abatement efficiencies of the suspended fine solids under several hydrodynamic conditions were studied, and a suitable control strategy for operating the conical fluidized bed flocculators was identified. The suspended solids abatement efficiency was found to increase with increasing Camp Number and flocculation time （T）, but decreased with the increase of velocity gradient （G） within the range studied in this research （165.1-189.6s-1）. The abatement efficiencies were all more than 60% at the range of G = 165-180 s 1 and T = 15-33 s at an initial kaolin solid concentration of 150mg·L-1, polymer aluminum chloride dosage of 60 mg· L -1 and sedimentation time of 20 min. However, the formation of flocs was influenced by the liquid back- mixing. Excessive backmixing caused the breakup of ftocs and resulted in difficulty for the fine powders to aggregate and sediment to the reactor bottom. The results of the calculated fractal dimension and measured free sedimenta- tion velocity of flocs obtained at different runs showed similar flocs properties, and indicated an easy control strategy for sedimentation of the flocs.展开更多
Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequen...Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequency modulation to amplitude modulation(FM-to-AM)conversion in high power laser facility is demonstrated.The Jones matrix is applied to analyze the relationship between optical characteristics of the filter and physical parameters(including amplitude ratio,phase delay,and susceptibility of the birefringence to temperature)of the polarization optical field.Both the transmission peak wavelength and extinction ratio of the spectral transmission are able to be changed simultaneously,hence,it shows more efficient FM-to-AM compensation ability.Besides,the transmission peak shift is about 18pm/°C with the PM-PCF configuration,which is about two orders of magnitude less than the normal polarization maintaining fiber(PMF)configuration.The demonstrated filter presents a practical application potential in large scale laser driven facility.展开更多
Flocculation time is conventionally believed to be proportional to the flocculation efficiency of a cylindrical fluidized bed flocculator.However,in a single-stage velocity gradient situation,the flocculation efficien...Flocculation time is conventionally believed to be proportional to the flocculation efficiency of a cylindrical fluidized bed flocculator.However,in a single-stage velocity gradient situation,the flocculation efficiency decreases when the optimal flocculation time is exceeded.A multi-stage velocity gradient was established in a cylindrical fluidized bed flocculator,based on the hydraulic classification theory.This multi-stage velocity gradient fluidized bed flocculator(MGF) created a more suitable environment for floc growth and protection,which was confirmed by the size distribution of flocs along the bed height.Correspondingly,the abatement efficiencies for Kaolin slurry and dyed wastewater treatment in the MGF were enhanced by5-10%,and by 7-20%,respectively,compared with those in the single-stage velocity gradient fluidized bed flocculators(SGFs).The initial bed height distribution ratio along the velocity gradients was an important factor for MGF optimization.展开更多
The virtual anatomy laboratory was jointly established by the Jilin Province Department of Public Security,Public Security Bureau of Changchun,Jilin University and Neusoft Medical Systems Co.,Ltd.on December 30,2019.D...The virtual anatomy laboratory was jointly established by the Jilin Province Department of Public Security,Public Security Bureau of Changchun,Jilin University and Neusoft Medical Systems Co.,Ltd.on December 30,2019.Details of the laboratory construction,virtual autopsy process,case analysis,research and development,establishment of standards,application in teaching,and other aspects of the center are summarized in this paper.In addition,we expound the prospective and practical significance of the virtual anatomy laboratory.Based on computed tomography and magnetic resonance detection methods,the prospective applications of virtual anatomy in forensic identification are explored through the analyses of two real-life cases.Using information from traditional anatomy as the gold standard,this study expanded on and explored the application technology and scenarios of virtual anatomy in imaging,clinical diagnosis,and equipment manufacturing,among other fields.The four cooperating units have their strengths and will yield valuable scientific research results and social benefits.展开更多
文摘The third paragraph in Sec.IV REGENERATIVE AMPLIFICATION erroneously states“In other words,the distribution of spectral components is time-dependent,and the spectral distortion in the amplification process will not change the time-domain shape.”
基金support of the National Natural Science Foundation of China(Grant Nos.62075030,62075201,and 11904339)the Sichuan Provincial Project for Outstanding Young Scholars in Science and Technology(Grant No.2020JDJQ0024)。
文摘Broadband low-coherence light is considered to be an effective way to suppress laser plasma instability.Recent studies have demonstrated the ability of low-coherence laser facilities to reduce back-scattering during beam–target coupling.However,to ensure simultaneous low coherence and high energy,complex spectral modulation methods and amplification routes have to be adopted.In this work,we propose the use of a random fiber laser(RFL)as the seed source.The spectral features of this RFL can be carefully tailored to provide a good match with the gain characteristics of the laser amplification medium,thus enabling efficient amplification while maintaining low coherence.First,a theoretical model is constructed to give a comprehensive description of the output characteristics of the spectrum-tailored RFL,after which the designed RFL is experimentally realized as a seed source.Through precise pulse shaping and efficient regenerative amplification,a shaped random laser pulse output of 28 mJ is obtained,which is the first random laser system with megawatt-class peak power that is able to achieve low coherence and efficient spectrum-conformal regenerative amplification.
基金the National Natural Science Foundation of China (Nos. 52070036, U20A20322)the Fundamental Research Funds for the Central Universities (No. 2412018ZD042) for their financial support。
文摘The coevolution and coexistence of bacterial–fungal consortium have been widely reported in various natural ecosystems. The transboundary communication mediated by bacterial acyl–homoserine lactone signals probably is the driving force of fungal spore germination. This study aimed to report a functional bacterial signal molecule, C10-acyl homoserine lactone, which could be sensed by Galactomyces geotrichum. The spore germination rates of G. geotrichum increased by 22%. Meanwhile, carbohydrate production improved by 1.0-to 2.5-fold. G. geotrichum signaled to C10-HSL through receptor gene Rho1and made a response in cell wall assembly and carbohydrate biosynthesis by the upregulated expression(above 1-fold) of functional genes, such as Smi1, Utr2, and Chs2. It contributed to spore germination and morphology transformation together. This study provides a novel perspective for understating the transboundary cooperation between fungi and bacteria by cell-to-cell communication.
基金This work was supported by the National Natural Science Foundation of China(Nos.52100025,U20A20322,and 52070036)Department of Science and Technology of Jilin Province(China)(No.YDZJ202201ZYTS481)Postdoctoral Fund of Jilin Province(China)(No.JCSZ2021-1242).
文摘Climate affects the natural landscape,the economic productivity of societies,and the lifestyles of its inhabitants.It also influences municipal wastewater treatment.Biological processes are widely employed in municipal wastewater treatment plants(WWTPs),and the prolonged cold conditions brought by the winter months each year pose obstacles to meeting the national standards in relatively cold regions.Therefore,both a systematic analysis of existing technical bottlenecks as well as promising novel technologies are urgently needed for these cold regions.Taking North-east China as a case,this review studied and analyzed the main challenges affecting 20 municipal WWTPs.Moreover,we outlined the currently employed strategies and research issues pertaining to low temperature conditions.Low temperatures have been found to reduce the metabolism of microbes by 58%or more,thereby leading to chemical oxygen demand(COD)and NH_(4)^(-)-N levels that have frequently exceeded the national standard during the winter months.Furthermore,the extracellular matrix tends to lead to activated sludge bulking issues.Widely employed strategies to combat these issues include increasing the aeration intensity,reflux volume,and flocculant addition;however,these strategies increase electricity consumption by>42%in the winter months.Internationally,the processes of anaerobic ammonium oxidation(anammox),granular sludge,and aerobic denitrification have become the focus of research for overcoming low temperature.These have inspired us to review and propose directions for the further development of novel technologies suitable for cold regions,thereby overcoming the issues inherent in traditional processes that have failed to meet the presently reformed WWTP requirements.
基金the Natural Sciences and Engineering Council of Canada (NSERC) for the financial support in the form ofa discovery grant
文摘The isotherms of original AC (activated carbon) and photocatalysts (TiO2-AC) calcined at 500℃ for phenol were measured. The results showed a reversible adsorption of phenol onto both kinds of particles at 25℃, and could be fitted well to the Freundlich adsorption equation for the dilute solution. Five oxidation processes, namely O3 , O3 /UV, O3 /UV/AC, O2 /UV/TiO2 and O3 /UV/TiO2 , for phenol degradation in fluidized bed were evaluated and compared, and the photocatalytic ozonation was found to give the highest phenol conversion because of the combined actions of homogenous ozonation in the liquid phase, heterogeneous ozonation on the surface of the catalyst support, i.e. activated carbon, and heterogeneous photocatalytic oxidation on the TiO2 catalyst surface. With the simplified kinetic model, photolytic ozonation was confirmed to predominantly take place on the particle surface in comparison with the heterogeneous and homogeneous photolytic ozonation. Additionally, the heterogeneous photocatalytic oxidation constant was found to be enhanced by 3.73 times in photocatlaytic ozonation process with ozone as the scavenger compared to the photocatalytic oxidation process with oxygen as the scavenger.
基金the financial support from the Natural Sciences Foundation of China (50908096, 50908097)the Research Fund for the Doctoral Program of Higher Education of China (20090061120035)Fundamental Research Fund of Jilin University (200903155)
文摘The efficiency of a fluidized-bed flocculator with 800- m particles of 1360 kg/m3 in density was studied, and the anti-shock capability of the unit was estimated for three kinds of industrial wastewater: heavy turbidity wastewater, dispersed dyeing wastewater and starch wastewater. Steady removal efficiency was contributed by the following characteristics of the flocculator: (1) the dynamic conditions, flocculation time and velocity gradient, which were stabilized at a steady level as the loading rate changed; (2) hydrodynamic characteristics, especially the considerable rise of expanded bed height with increasing superficial velocity when small and light particles were employed as the solid phase; (3) flocs growth characteristics in the fluidized bed, which caused the density and size of the flocs being maintained at a compensational relationship, resulted the stabilized settling velocity of the flocs.
文摘With the random movement of silica gel beads in a conical fluidized bed, micro-vortices resulting from the fluidization promoted the collision and aggregation of suspended fine kaolin powders. The abatement efficiencies of the suspended fine solids under several hydrodynamic conditions were studied, and a suitable control strategy for operating the conical fluidized bed flocculators was identified. The suspended solids abatement efficiency was found to increase with increasing Camp Number and flocculation time （T）, but decreased with the increase of velocity gradient （G） within the range studied in this research （165.1-189.6s-1）. The abatement efficiencies were all more than 60% at the range of G = 165-180 s 1 and T = 15-33 s at an initial kaolin solid concentration of 150mg·L-1, polymer aluminum chloride dosage of 60 mg· L -1 and sedimentation time of 20 min. However, the formation of flocs was influenced by the liquid back- mixing. Excessive backmixing caused the breakup of ftocs and resulted in difficulty for the fine powders to aggregate and sediment to the reactor bottom. The results of the calculated fractal dimension and measured free sedimenta- tion velocity of flocs obtained at different runs showed similar flocs properties, and indicated an easy control strategy for sedimentation of the flocs.
基金This work was supported by the Science and Technology Major Project of Guangxi(Grant No.AA18118032)Laser Fusion Research Center Funds for Young Talents(Grant No.RCFCZ3-2019-7).
文摘Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequency modulation to amplitude modulation(FM-to-AM)conversion in high power laser facility is demonstrated.The Jones matrix is applied to analyze the relationship between optical characteristics of the filter and physical parameters(including amplitude ratio,phase delay,and susceptibility of the birefringence to temperature)of the polarization optical field.Both the transmission peak wavelength and extinction ratio of the spectral transmission are able to be changed simultaneously,hence,it shows more efficient FM-to-AM compensation ability.Besides,the transmission peak shift is about 18pm/°C with the PM-PCF configuration,which is about two orders of magnitude less than the normal polarization maintaining fiber(PMF)configuration.The demonstrated filter presents a practical application potential in large scale laser driven facility.
基金the financial support from the Natural Sciences Foundation of China(50908096,50908097)
文摘Flocculation time is conventionally believed to be proportional to the flocculation efficiency of a cylindrical fluidized bed flocculator.However,in a single-stage velocity gradient situation,the flocculation efficiency decreases when the optimal flocculation time is exceeded.A multi-stage velocity gradient was established in a cylindrical fluidized bed flocculator,based on the hydraulic classification theory.This multi-stage velocity gradient fluidized bed flocculator(MGF) created a more suitable environment for floc growth and protection,which was confirmed by the size distribution of flocs along the bed height.Correspondingly,the abatement efficiencies for Kaolin slurry and dyed wastewater treatment in the MGF were enhanced by5-10%,and by 7-20%,respectively,compared with those in the single-stage velocity gradient fluidized bed flocculators(SGFs).The initial bed height distribution ratio along the velocity gradients was an important factor for MGF optimization.
基金The project was funded by the National Natural Science Foundation of China(U1708261).
文摘The virtual anatomy laboratory was jointly established by the Jilin Province Department of Public Security,Public Security Bureau of Changchun,Jilin University and Neusoft Medical Systems Co.,Ltd.on December 30,2019.Details of the laboratory construction,virtual autopsy process,case analysis,research and development,establishment of standards,application in teaching,and other aspects of the center are summarized in this paper.In addition,we expound the prospective and practical significance of the virtual anatomy laboratory.Based on computed tomography and magnetic resonance detection methods,the prospective applications of virtual anatomy in forensic identification are explored through the analyses of two real-life cases.Using information from traditional anatomy as the gold standard,this study expanded on and explored the application technology and scenarios of virtual anatomy in imaging,clinical diagnosis,and equipment manufacturing,among other fields.The four cooperating units have their strengths and will yield valuable scientific research results and social benefits.
