Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept ...Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.展开更多
Harvesting solar energy to drive the semiconductor photocatalysis offers a promising tactic to address ever-growing challenges of both energy shortage and environmental pollution.Design and synthesis of nano-heterostr...Harvesting solar energy to drive the semiconductor photocatalysis offers a promising tactic to address ever-growing challenges of both energy shortage and environmental pollution.Design and synthesis of nano-heterostructure photocatalysts with controllable components and morphologies are the key factors for achieving highly efficient photocatalytic processes.Onedimensional(1D)semiconductor nanofibers produced by electrospinning possess a large ratio of length to diameter,high ratio of surface to volume,small grain sizes,and high porosity,which are ideally suited for photocatalytic reactions from the viewpoint of structure advantage.After the secondary treatment of these nanofibers through the solvothermal,gas reduction,in situ doping,or assembly methods,the multi-component nanofibers with hierarchical nano-heterostructures can be obtained to further enhance their light absorption and charge carrier separation during the photocatalytic processes.In recent years,the electrospun semiconductorbased nano-heterostructures have become a“hot topic”in the fields of photocatalytic energy conversion and environmental remediation.This review article summarizes the recent progress in electrospinning synthesis of various kinds of high-performance semiconductor-based nano-heterostructure photocatalysts for H2 production,CO_(2) reduction,and decomposition of pollutants.The future perspectives of these materials are also discussed.展开更多
Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests ...Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.展开更多
Continual learning(CL)studies the problem of learning to accumulate knowledge over time from a stream of data.A crucial challenge is that neural networks suffer from performance degradation on previously seen data,kno...Continual learning(CL)studies the problem of learning to accumulate knowledge over time from a stream of data.A crucial challenge is that neural networks suffer from performance degradation on previously seen data,known as catastrophic forgetting,due to allowing parameter sharing.In this work,we consider a more practical online class-incremental CL setting,where the model learns new samples in an online manner and may continuously experience new classes.Moreover,prior knowledge is unavailable during training and evaluation.Existing works usually explore sample usages from a single dimension,which ignores a lot of valuable supervisory information.To better tackle the setting,we propose a novel replay-based CL method,which leverages multi-level representations produced by the intermediate process of training samples for replay and strengthens supervision to consolidate previous knowledge.Specifically,besides the previous raw samples,we store the corresponding logits and features in the memory.Furthermore,to imitate the prediction of the past model,we construct extra constraints by leveraging multi-level information stored in the memory.With the same number of samples for replay,our method can use more past knowledge to prevent interference.We conduct extensive evaluations on several popular CL datasets,and experiments show that our method consistently outperforms state-of-the-art methods with various sizes of episodic memory.We further provide a detailed analysis of these results and demonstrate that our method is more viable in practical scenarios.展开更多
Hexaploid triticale(×Triticosecale,AABBRR)is an important forage crop and a promising energy plant.Transferring D-genome chromosomes or segments from common wheat(Triticum aestivum)into hexaploid triticale is att...Hexaploid triticale(×Triticosecale,AABBRR)is an important forage crop and a promising energy plant.Transferring D-genome chromosomes or segments from common wheat(Triticum aestivum)into hexaploid triticale is attractive in improving its economically important traits.Here,a hexaploid triticale 6D(6A)substitution line Lin 456 derived from the cross between the octoploid triticale line H400 and the hexaploid wheat Lin 56 was identified and analyzed by genomic in situ hybridization(GISH),fluorescence in situ hybridization(FISH),and molecular markers.The GISH analysis showed that Lin 456 is a hexaploid triticalewith 14 rye(Secale cereale)chromosomes and 28 wheat chromosomes,whereas non-denaturing fluorescence in situ hybridization(ND-FISH)and molecular marker analysis revealed that it is a 6D(6A)substitution line.In contrast to previous studies,the signal of Oligo-pSc119.2 was observed at the distal end of 6DL in Lin 456.The wheat chromosome 6D was associatedwith increased grain weight and decreased spikelet number using the genotypic data combined with the phenotypes of the F2 population in the three environments.The thousand-grain weight and grain width in the substitution individuals were significantly higher than those in the non-substitution individuals in the F2 population across the three environments.We propose that the hexaploid triticale 6D(6A)substitution line Lin 456 can be a valuable and promising donor stock for genetic improvement during triticale breeding.展开更多
1.Introduction Carbon materials have been widely investigated as the anode materials for Na+storage due to their moderate capacity,good stability,and low cost.The Na+storage mechanisms of carbon are generally classifi...1.Introduction Carbon materials have been widely investigated as the anode materials for Na+storage due to their moderate capacity,good stability,and low cost.The Na+storage mechanisms of carbon are generally classified into diffusion-controlled interlayer insertion/desertion and capacitive-controlled surface adsorption/desorption[1].展开更多
Taking advantage of heat absorbing and releasing capability of phase change material(PCM),Paraffin wax-based concrete was prepared to assess its automatic temperature control performance.The mechanical properties of P...Taking advantage of heat absorbing and releasing capability of phase change material(PCM),Paraffin wax-based concrete was prepared to assess its automatic temperature control performance.The mechanical properties of PCM concrete with eight different Paraffin wax contents were tested by the cube compression test and four-point bending test.The more Paraffin wax incorporated,the greater loss of the compressive strength and bending strength.Based on the mechanical results,four contents of Paraffin wax were chosen for studying PCM concrete's thermal properties,including thermal conductivity,thermal diffusivity,specific heat capacity,thermal expansion coefficient and adiabatic temperature rise.When the Paraffin wax content increases from 10%to 20%,the thermal conductivity and the thermal diffusivity decrease from 7.31 kJ/(m·h·°C)to 7.10 kJ/(m·h·°C)and from 3.03×10−3 m2/h to 2.44×10−3 m2/h,respectively.Meanwhile the specific heat capacity and thermal expansion coefficient rise from 5.38×10−1 kJ/(kg·°C)to 5.76×10−1 kJ/(kg·°C)and from 9.63×10−6/°C to 14.02×10−6/°C,respectively.The adiabatic temperature rise is found to decrease with an increasing Paraffin wax content.Considering both the mechanical and thermal properties,15%of Paraffin wax was elected for the mass concrete model test,and the model test results confirm the effect of Paraffin wax in automatic mass concrete temperature control.展开更多
Objective: To investigate the expression of vascular endothelial growth factor D (VEGF-D) in gastric cancer and its relationship with lymph node metastasis. Methods: 100 cases of gastric carcinoma tissues (50 cases wi...Objective: To investigate the expression of vascular endothelial growth factor D (VEGF-D) in gastric cancer and its relationship with lymph node metastasis. Methods: 100 cases of gastric carcinoma tissues (50 cases with lymph node metastasis, 50 cases negative) and 30 cases of normal gastric tissues were gathered to detect the expressions of VEGF-C and D proteins by immunohistochemistry. Results: VEGF-C and D were revealed in cytoplasm of gastric carcinoma tissues and normal gastric tissues. The positive rates of VEGF-C and D expressions were significantly higher in gastric cancer tissues than those in the normal ones (51%, 60% vs 10%, 20% respectively; both P < 0.05). There were significant correlations be- tween the positive expression of VEGF-D and lymph node metastasis, lymphatic invasion, positive expression of VEGF-C, but not with tumour size, tissue differentiation, and venous invasion. Conclusion: The expression of VEGF-D is closely related to lymph node metastasis in gastric carcinoma.展开更多
Based on the Simplified Bishop Method, the minimum safety factor of ice slope both with and without tension cracks is calculated in combination with triaxial compression tests. It is found that there exists a critical...Based on the Simplified Bishop Method, the minimum safety factor of ice slope both with and without tension cracks is calculated in combination with triaxial compression tests. It is found that there exists a critical depth for each crack. Then, factors influencing ice slope stability such as slope ratio, slope height, ice cohesion, internal friction angle, unit weight and temperature were analyzed. Meanwhile, a regression equation between the aforementioned factors and safety factor is obtained, with which sensitivity analysis is carried out. The performance function is built in combination with random distribution of physical and mechanical parameters to analyze the reliability index. The Advanced First Order Second Moment Method is employed on the solution to the perfor- mance function. The one-way coupling system of ice slope stability is therefore formed based on safety factor and reliability index. Finally, an illustrated example of ice slope is provided, which shows that failure probability is relatively high, up to 6.18%, alt- hough safety factor is 2.77. Thus, it is objective and reasonable to apply the coupled system method to the slope stability rating.展开更多
Red phosphor is an important component of the phosphor-converted white light-emitting diodes(pcWLEDs).The development of the novel red phosphor with excellent luminescence properties is of great significance for high ...Red phosphor is an important component of the phosphor-converted white light-emitting diodes(pcWLEDs).The development of the novel red phosphor with excellent luminescence properties is of great significance for high performance WLEDs.In this study,NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)red phosphors with excellent luminescence properties were successfully synthesized and systematically investigated.Our results show that the Zn^(2+)-doping concentration has significant effect on the microstructures and luminescence properties of the NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)phosphors.The NaGd_(0.4)Eu_(0.6)Mg_(1-x)ZnxWO_(6)(0≤x≤0.7)samples are well crystallized pure solid solution sub-microcrystals,whereas the phase purity gradually decreases at 0.7<x≤1.0.The NaGd_(0.4)Eu_(0.6)Mg_(1-x)ZnxWO_(6)(0<x≤0.5)phosphors have stronger emissions than NaGd_(0.4)Eu_(0.6)MgWO_(6),and the optimized NaGd_(0.4)Eu_(0.6)Mg_(0.9)Zn_(0.1)WO_(6)phosphor possesses the best luminescence properties including thermal stability,CIE chromaticity coordinate,life time and quantum yield.The packaged WLED using NaGd_(0.4)Eu_(0.6)Mg_(0.9)Zn_(0.1)WO_(6)phosphor emits bright white light with higher CRI,lower CCT,and chromaticity coordinate close to the pure white light.The developed NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)phosphors have potential application in lighting and display.This work can offer an effective strategy for boosting luminescence properties of tungstate phosphors with the double perovskite structure.展开更多
Pd-based metallic nanosheets with advanced physicochemical properties have been widely prepared and employed in various electrocatalytic reactions.However,few concerns were focused on their multiple performances in di...Pd-based metallic nanosheets with advanced physicochemical properties have been widely prepared and employed in various electrocatalytic reactions.However,few concerns were focused on their multiple performances in different electrocatalysis.Here,highly curved and ultrathin PdNiRu nanosheets(NSs)are developed by facile wet-chemistry strategy and exhibit excellent electrocatalytic performance toward both oxygen reduction reaction(ORR)and ethylene glycol oxidation reaction(EGOR).Owing to the synergistically structural(e.g.,ultrathin,curved,defects/steps-rich)and compositional(ternary alloy)advantages,PdNiRu NSs exhibited enhanced ORR and EGOR specific/mass activities and better stability/durability than control electrocatalysts.The specific activity(5.52 mA·cm^(−2))and mass activity(1.13 A·mg_(Pd)^(−1))of the PdNiRu NSs in ORR are 4.8 and 3.4 times as the ones of commercial Pt/C,respectively.The mass activity of PdNiRu NSs(3.86 A·mg_(Pd)^(−1))in EGOR is 2.6 times as commercial Pd/C(1.51 A·mg_(Pd)^(−1)).This study is helpful for the development of desired electrocatalysts with multi-functional application in practical fuel cells.展开更多
S-scheme heterojunction engineering is an effective strategy to attain distinctive photocatalysts.Herein,a carbon dots modulated S-scheme hetero-structured photocatalyst of Cd_(0.5)Zn_(0.5)S nanoparticles/Bi_(2)MoO_(6...S-scheme heterojunction engineering is an effective strategy to attain distinctive photocatalysts.Herein,a carbon dots modulated S-scheme hetero-structured photocatalyst of Cd_(0.5)Zn_(0.5)S nanoparticles/Bi_(2)MoO_(6) microspheres/carbon dots (CZCBM),aiming to conquer the photo-corrosion and strengthen the photocatalytic property of Cd_(0.5)Zn_(0.5)S,was developed via a facile solvothermal route.Under visible light,the optimal CZCBM-2 affords a 1.8-,1.5-,or 0.6-time reinforcement in the oxytetracycline degradation rate constant compared to Bi_(2)MoO_(6),Cd_(0.5)Zn_(0.5)S or Cd_(0.5)Zn_(0.5)S/Bi_(2)MoO_(6),which is credited to the strengthened visible-light response,increased reactive sites,and efficient dissolution of photo-carriers with optimal redox capacity because of the co-effect of carbon dots and S-scheme heterostructure.Significantly,the photo-corrosion of Cd_(0.5)Zn_(0.5)S is significantly suppressed and CZCBM-2 affords superior stability and reusability during cycling tests.Besides,CZCBM-2 can be well adapted to various environments.The toxicology appraisement unravels the decreased eco-toxicity of most intermediates compared to oxytetracycline.Lastly,an S-scheme charge transfer mechanism with carbon dots as electron reservoir in CZCBM is deduced,which uncloses that •O_(2)− and h+ dominantly account for oxytetracycline eradication and detoxification.This study demonstrates the design of unique carbon dots favored S-scheme heterostructures as an effective “Two Birds with One Stone” strategy to achieve high anti-photo-corrosion performance and reinforced photocatalytic performance of sulfides.展开更多
Oil leakages cause environmental pollution,economic losses,and even engineering safety accidents.In cold regions,researchers urgently investigate the movement of oil spill in soils exposed to freeze-thaw cycles.In th...Oil leakages cause environmental pollution,economic losses,and even engineering safety accidents.In cold regions,researchers urgently investigate the movement of oil spill in soils exposed to freeze-thaw cycles.In this study,a series of laboratory model experiments were carried out on the migration of oil leakage under freeze-thaw action,and the distributions of the soil temperature,unfrozen water content,and displacement were analyzed.The results showed that under freeze-thaw action,liquid water in soils migrated to the freezing front and accumulated.After the pipe cracked,oil pollutants first gathered at one side of the leak hole,and then moved around.The pipe wall temperature affected the soil temperature field,and the thermal influence range below and transverse the pipe wall(35–40 cm)was larger than that above the pipe wall(8 cm)owing to the soil surface temperature.The leaked oil's temperature would make the temperature of the surrounding soil rise.Oil would inhibit the cooling of the soils.Besides,oil migration was significantly affected by the gravity and water flow patterns.The freeze-thaw action would affect the migration of the oil,which was mainly manifested as inhibiting the diffusion and movement of oil when soils were frozen.Unfrozen water transport caused by freeze-thaw cycles would also inhibit oil migration.The research results would provide a scientific reference for understanding the relationship between the movement of oil pollutants,water,and soil temperature,and for establishing a waterheat-mass transport model in frozen soils.展开更多
To address the insufficient electrocatalytic activity and stability of formic acid oxidation reaction （FAOR） electrocatalysts, as well as their high cost, we herein demonstrate the facile hydrothermal synthesis of u...To address the insufficient electrocatalytic activity and stability of formic acid oxidation reaction （FAOR） electrocatalysts, as well as their high cost, we herein demonstrate the facile hydrothermal synthesis of ultrathin AgPt alloy nanowires using amine-terminated poly（N-isopropylacrylamide） （PNIPAM-NH2） as a structure-directing agent. The initial generation of AgC1 precipitates, subsequent formation of AgPt nanoparticles, and their oriented attachment account for the formation of ultrathin AgPt alloy nanowires. Benefiting from their unique one-dimensional （1D） anisotropy and alloyed composition, the prepared ultrathin AgPt nanowires exhibit a superior electrocatalytic activity and better CO tolerance for the FAOR, reaching a 1.6-fold and 3.7-fold higher specific current density than AgPt nanoparticles and a commercial Pt black catalyst, respectively. Additionally, the ultrathin AgPt alloy nanowires manifest a superior electrochemical stability and structural robustness during electrocatalysis, making them a promising FAOR electrocatalyst. This work not only provides a reliable strategy for the synthesis of noble metal-based ultrathin nanowires, but also opens an avenue towards the rational des ign of efficient electrocatalysts for fuel cell systems.展开更多
基金financially supported by the National Natural Science Foundation of China(21972068,22072067,22232004)the High-level Talents Project of Jinling Institute of Technology(jit-b-202164)。
文摘Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.12074055 and 62005036)Liaoning BaiQianWan Talents Program,Dalian Science Foundation for Distinguished Young Scholars(2018RJ05)+1 种基金the Natural Science Foundation of Liaoning Province(Grant No.2020-MZLH-15)the Program for Dalian Excellent Talents(Grant No.2020RQ131).
文摘Harvesting solar energy to drive the semiconductor photocatalysis offers a promising tactic to address ever-growing challenges of both energy shortage and environmental pollution.Design and synthesis of nano-heterostructure photocatalysts with controllable components and morphologies are the key factors for achieving highly efficient photocatalytic processes.Onedimensional(1D)semiconductor nanofibers produced by electrospinning possess a large ratio of length to diameter,high ratio of surface to volume,small grain sizes,and high porosity,which are ideally suited for photocatalytic reactions from the viewpoint of structure advantage.After the secondary treatment of these nanofibers through the solvothermal,gas reduction,in situ doping,or assembly methods,the multi-component nanofibers with hierarchical nano-heterostructures can be obtained to further enhance their light absorption and charge carrier separation during the photocatalytic processes.In recent years,the electrospun semiconductorbased nano-heterostructures have become a“hot topic”in the fields of photocatalytic energy conversion and environmental remediation.This review article summarizes the recent progress in electrospinning synthesis of various kinds of high-performance semiconductor-based nano-heterostructure photocatalysts for H2 production,CO_(2) reduction,and decomposition of pollutants.The future perspectives of these materials are also discussed.
基金the National Natural Science Foundation of China(No.31901300)Natural Science Foundation of Guizhou Province+2 种基金China(No.(2019)1165)Science and Technology Foundation of Guizhou ProvinceChina(No.[2018]137,No.[2018]133)。
文摘Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.
基金supported in part by the National Natura Science Foundation of China(U2013602,61876181,51521003)the Nationa Key R&D Program of China(2020YFB13134)+2 种基金Shenzhen Science and Technology Research and Development Foundation(JCYJ20190813171009236)Beijing Nova Program of Science and Technology(Z191100001119043)the Youth Innovation Promotion Association,Chinese Academy of Sciences。
文摘Continual learning(CL)studies the problem of learning to accumulate knowledge over time from a stream of data.A crucial challenge is that neural networks suffer from performance degradation on previously seen data,known as catastrophic forgetting,due to allowing parameter sharing.In this work,we consider a more practical online class-incremental CL setting,where the model learns new samples in an online manner and may continuously experience new classes.Moreover,prior knowledge is unavailable during training and evaluation.Existing works usually explore sample usages from a single dimension,which ignores a lot of valuable supervisory information.To better tackle the setting,we propose a novel replay-based CL method,which leverages multi-level representations produced by the intermediate process of training samples for replay and strengthens supervision to consolidate previous knowledge.Specifically,besides the previous raw samples,we store the corresponding logits and features in the memory.Furthermore,to imitate the prediction of the past model,we construct extra constraints by leveraging multi-level information stored in the memory.With the same number of samples for replay,our method can use more past knowledge to prevent interference.We conduct extensive evaluations on several popular CL datasets,and experiments show that our method consistently outperforms state-of-the-art methods with various sizes of episodic memory.We further provide a detailed analysis of these results and demonstrate that our method is more viable in practical scenarios.
基金supported by the National Key Research and Development Program of China (2017YFD0101004)the National Natural Science Foundation of China (91435204)the Science and Technology Independent Innovation Ability Upgrading Project of Shanxi Academy of Agricultural Sciences (2017ZZCX-23)
文摘Hexaploid triticale(×Triticosecale,AABBRR)is an important forage crop and a promising energy plant.Transferring D-genome chromosomes or segments from common wheat(Triticum aestivum)into hexaploid triticale is attractive in improving its economically important traits.Here,a hexaploid triticale 6D(6A)substitution line Lin 456 derived from the cross between the octoploid triticale line H400 and the hexaploid wheat Lin 56 was identified and analyzed by genomic in situ hybridization(GISH),fluorescence in situ hybridization(FISH),and molecular markers.The GISH analysis showed that Lin 456 is a hexaploid triticalewith 14 rye(Secale cereale)chromosomes and 28 wheat chromosomes,whereas non-denaturing fluorescence in situ hybridization(ND-FISH)and molecular marker analysis revealed that it is a 6D(6A)substitution line.In contrast to previous studies,the signal of Oligo-pSc119.2 was observed at the distal end of 6DL in Lin 456.The wheat chromosome 6D was associatedwith increased grain weight and decreased spikelet number using the genotypic data combined with the phenotypes of the F2 population in the three environments.The thousand-grain weight and grain width in the substitution individuals were significantly higher than those in the non-substitution individuals in the F2 population across the three environments.We propose that the hexaploid triticale 6D(6A)substitution line Lin 456 can be a valuable and promising donor stock for genetic improvement during triticale breeding.
基金supported by the National Natural Science Foundation of China(Nos.51972342,5187205652062046,and 51702275)the Taishan Scholar Project of Shandong Province(ts20190922)+3 种基金the Key Basic Research Projects of Natural Science Foundation of Shandong province(ZR2019ZD51)the CAS Key aboratory of Carbon Materials(KLCMKFJJ2012)the Science Foundation of Xinjiang Autonomous Region(2020D01C019)the Fundamental Research Funds for the Central Universities(20CX05010A)。
文摘1.Introduction Carbon materials have been widely investigated as the anode materials for Na+storage due to their moderate capacity,good stability,and low cost.The Na+storage mechanisms of carbon are generally classified into diffusion-controlled interlayer insertion/desertion and capacitive-controlled surface adsorption/desorption[1].
基金This work is jointly supported by the National Natural Science Foundation of China(Grant Nos.51909223,51902270)the National Science Fund for Distinguished Young Scholars(Grant No.41825015)+2 种基金the Natural Science Basic Research Program of Shaanxi(Grant No.2019JQ-921)the Special research project of the Education Department of Shaanxi Provincial Government(Grant No.19JK0913)the Special Fund for the Launch of Scientific Research in Xijing University(Grant No.XJ18T02).
文摘Taking advantage of heat absorbing and releasing capability of phase change material(PCM),Paraffin wax-based concrete was prepared to assess its automatic temperature control performance.The mechanical properties of PCM concrete with eight different Paraffin wax contents were tested by the cube compression test and four-point bending test.The more Paraffin wax incorporated,the greater loss of the compressive strength and bending strength.Based on the mechanical results,four contents of Paraffin wax were chosen for studying PCM concrete's thermal properties,including thermal conductivity,thermal diffusivity,specific heat capacity,thermal expansion coefficient and adiabatic temperature rise.When the Paraffin wax content increases from 10%to 20%,the thermal conductivity and the thermal diffusivity decrease from 7.31 kJ/(m·h·°C)to 7.10 kJ/(m·h·°C)and from 3.03×10−3 m2/h to 2.44×10−3 m2/h,respectively.Meanwhile the specific heat capacity and thermal expansion coefficient rise from 5.38×10−1 kJ/(kg·°C)to 5.76×10−1 kJ/(kg·°C)and from 9.63×10−6/°C to 14.02×10−6/°C,respectively.The adiabatic temperature rise is found to decrease with an increasing Paraffin wax content.Considering both the mechanical and thermal properties,15%of Paraffin wax was elected for the mass concrete model test,and the model test results confirm the effect of Paraffin wax in automatic mass concrete temperature control.
基金Supported by a grant from Importance Introduction Person with Ability Startup Fund of Jiangsu University Affiliated Hospital (Number: p-67).
文摘Objective: To investigate the expression of vascular endothelial growth factor D (VEGF-D) in gastric cancer and its relationship with lymph node metastasis. Methods: 100 cases of gastric carcinoma tissues (50 cases with lymph node metastasis, 50 cases negative) and 30 cases of normal gastric tissues were gathered to detect the expressions of VEGF-C and D proteins by immunohistochemistry. Results: VEGF-C and D were revealed in cytoplasm of gastric carcinoma tissues and normal gastric tissues. The positive rates of VEGF-C and D expressions were significantly higher in gastric cancer tissues than those in the normal ones (51%, 60% vs 10%, 20% respectively; both P < 0.05). There were significant correlations be- tween the positive expression of VEGF-D and lymph node metastasis, lymphatic invasion, positive expression of VEGF-C, but not with tumour size, tissue differentiation, and venous invasion. Conclusion: The expression of VEGF-D is closely related to lymph node metastasis in gastric carcinoma.
基金supported by the Western Project Program of the Chinese Academy of Sciences (KZCX2-XB3-19)the National key Basic Research Program of China (973 Program:No.2012CB026102)+4 种基金the Program for Innovative Research Group of Natural Science Foundation of China (No. 41121061)the Foundation of State Key Laboratory of Frozen Soil Engineering(SKLFSE-ZY-03)the foundation of State Key Laboratory of Frozen Soil Engineering (SKLFSE-ZY-03)the National Natural Science Foundation of China (40971045,41171060)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-QN301)
文摘Based on the Simplified Bishop Method, the minimum safety factor of ice slope both with and without tension cracks is calculated in combination with triaxial compression tests. It is found that there exists a critical depth for each crack. Then, factors influencing ice slope stability such as slope ratio, slope height, ice cohesion, internal friction angle, unit weight and temperature were analyzed. Meanwhile, a regression equation between the aforementioned factors and safety factor is obtained, with which sensitivity analysis is carried out. The performance function is built in combination with random distribution of physical and mechanical parameters to analyze the reliability index. The Advanced First Order Second Moment Method is employed on the solution to the perfor- mance function. The one-way coupling system of ice slope stability is therefore formed based on safety factor and reliability index. Finally, an illustrated example of ice slope is provided, which shows that failure probability is relatively high, up to 6.18%, alt- hough safety factor is 2.77. Thus, it is objective and reasonable to apply the coupled system method to the slope stability rating.
基金Project supported by the National Natural Science Foundation of China(62104164)Natural Science Foundation of Sichuan Province(2022NSFSC2001,2022NSFSC1212)。
文摘Red phosphor is an important component of the phosphor-converted white light-emitting diodes(pcWLEDs).The development of the novel red phosphor with excellent luminescence properties is of great significance for high performance WLEDs.In this study,NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)red phosphors with excellent luminescence properties were successfully synthesized and systematically investigated.Our results show that the Zn^(2+)-doping concentration has significant effect on the microstructures and luminescence properties of the NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)phosphors.The NaGd_(0.4)Eu_(0.6)Mg_(1-x)ZnxWO_(6)(0≤x≤0.7)samples are well crystallized pure solid solution sub-microcrystals,whereas the phase purity gradually decreases at 0.7<x≤1.0.The NaGd_(0.4)Eu_(0.6)Mg_(1-x)ZnxWO_(6)(0<x≤0.5)phosphors have stronger emissions than NaGd_(0.4)Eu_(0.6)MgWO_(6),and the optimized NaGd_(0.4)Eu_(0.6)Mg_(0.9)Zn_(0.1)WO_(6)phosphor possesses the best luminescence properties including thermal stability,CIE chromaticity coordinate,life time and quantum yield.The packaged WLED using NaGd_(0.4)Eu_(0.6)Mg_(0.9)Zn_(0.1)WO_(6)phosphor emits bright white light with higher CRI,lower CCT,and chromaticity coordinate close to the pure white light.The developed NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)phosphors have potential application in lighting and display.This work can offer an effective strategy for boosting luminescence properties of tungstate phosphors with the double perovskite structure.
基金supported by the National Natural Science Foundation of China(Nos.21972068,22272179).
文摘Pd-based metallic nanosheets with advanced physicochemical properties have been widely prepared and employed in various electrocatalytic reactions.However,few concerns were focused on their multiple performances in different electrocatalysis.Here,highly curved and ultrathin PdNiRu nanosheets(NSs)are developed by facile wet-chemistry strategy and exhibit excellent electrocatalytic performance toward both oxygen reduction reaction(ORR)and ethylene glycol oxidation reaction(EGOR).Owing to the synergistically structural(e.g.,ultrathin,curved,defects/steps-rich)and compositional(ternary alloy)advantages,PdNiRu NSs exhibited enhanced ORR and EGOR specific/mass activities and better stability/durability than control electrocatalysts.The specific activity(5.52 mA·cm^(−2))and mass activity(1.13 A·mg_(Pd)^(−1))of the PdNiRu NSs in ORR are 4.8 and 3.4 times as the ones of commercial Pt/C,respectively.The mass activity of PdNiRu NSs(3.86 A·mg_(Pd)^(−1))in EGOR is 2.6 times as commercial Pd/C(1.51 A·mg_(Pd)^(−1)).This study is helpful for the development of desired electrocatalysts with multi-functional application in practical fuel cells.
基金financially supported by the National Natural Science Foundation of China (Nos.U1809214 and 51708504)the Natural Science Foundation of Zhejiang Province (Nos.LY20E080014 and LTGN23E080001)+1 种基金the Zhejiang Province Industrial Innovation Service Complex "Opening list and Hanging" Project (No.YY-2021C1006)and the Science and Technology Project of Zhoushan (No.2022C41011).
文摘S-scheme heterojunction engineering is an effective strategy to attain distinctive photocatalysts.Herein,a carbon dots modulated S-scheme hetero-structured photocatalyst of Cd_(0.5)Zn_(0.5)S nanoparticles/Bi_(2)MoO_(6) microspheres/carbon dots (CZCBM),aiming to conquer the photo-corrosion and strengthen the photocatalytic property of Cd_(0.5)Zn_(0.5)S,was developed via a facile solvothermal route.Under visible light,the optimal CZCBM-2 affords a 1.8-,1.5-,or 0.6-time reinforcement in the oxytetracycline degradation rate constant compared to Bi_(2)MoO_(6),Cd_(0.5)Zn_(0.5)S or Cd_(0.5)Zn_(0.5)S/Bi_(2)MoO_(6),which is credited to the strengthened visible-light response,increased reactive sites,and efficient dissolution of photo-carriers with optimal redox capacity because of the co-effect of carbon dots and S-scheme heterostructure.Significantly,the photo-corrosion of Cd_(0.5)Zn_(0.5)S is significantly suppressed and CZCBM-2 affords superior stability and reusability during cycling tests.Besides,CZCBM-2 can be well adapted to various environments.The toxicology appraisement unravels the decreased eco-toxicity of most intermediates compared to oxytetracycline.Lastly,an S-scheme charge transfer mechanism with carbon dots as electron reservoir in CZCBM is deduced,which uncloses that •O_(2)− and h+ dominantly account for oxytetracycline eradication and detoxification.This study demonstrates the design of unique carbon dots favored S-scheme heterostructures as an effective “Two Birds with One Stone” strategy to achieve high anti-photo-corrosion performance and reinforced photocatalytic performance of sulfides.
基金supported by the National Natural Science Foundation of China(31901300,31960636)Natural Science Foundation of Guizhou Province((2019)1165)and Science and Technology Foundation of Guizhou Province([2018]137).
基金the Science and Technology program of Gansu Province(Grant No.23ZDFA017)the National Natural Science Foundation of China(Grant Nos.U21A2012,42101136)the Program for Top Leading Talents of Gansu Province(Granted to Dr.MingYi Zhang).
文摘Oil leakages cause environmental pollution,economic losses,and even engineering safety accidents.In cold regions,researchers urgently investigate the movement of oil spill in soils exposed to freeze-thaw cycles.In this study,a series of laboratory model experiments were carried out on the migration of oil leakage under freeze-thaw action,and the distributions of the soil temperature,unfrozen water content,and displacement were analyzed.The results showed that under freeze-thaw action,liquid water in soils migrated to the freezing front and accumulated.After the pipe cracked,oil pollutants first gathered at one side of the leak hole,and then moved around.The pipe wall temperature affected the soil temperature field,and the thermal influence range below and transverse the pipe wall(35–40 cm)was larger than that above the pipe wall(8 cm)owing to the soil surface temperature.The leaked oil's temperature would make the temperature of the surrounding soil rise.Oil would inhibit the cooling of the soils.Besides,oil migration was significantly affected by the gravity and water flow patterns.The freeze-thaw action would affect the migration of the oil,which was mainly manifested as inhibiting the diffusion and movement of oil when soils were frozen.Unfrozen water transport caused by freeze-thaw cycles would also inhibit oil migration.The research results would provide a scientific reference for understanding the relationship between the movement of oil pollutants,water,and soil temperature,and for establishing a waterheat-mass transport model in frozen soils.
文摘To address the insufficient electrocatalytic activity and stability of formic acid oxidation reaction （FAOR） electrocatalysts, as well as their high cost, we herein demonstrate the facile hydrothermal synthesis of ultrathin AgPt alloy nanowires using amine-terminated poly（N-isopropylacrylamide） （PNIPAM-NH2） as a structure-directing agent. The initial generation of AgC1 precipitates, subsequent formation of AgPt nanoparticles, and their oriented attachment account for the formation of ultrathin AgPt alloy nanowires. Benefiting from their unique one-dimensional （1D） anisotropy and alloyed composition, the prepared ultrathin AgPt nanowires exhibit a superior electrocatalytic activity and better CO tolerance for the FAOR, reaching a 1.6-fold and 3.7-fold higher specific current density than AgPt nanoparticles and a commercial Pt black catalyst, respectively. Additionally, the ultrathin AgPt alloy nanowires manifest a superior electrochemical stability and structural robustness during electrocatalysis, making them a promising FAOR electrocatalyst. This work not only provides a reliable strategy for the synthesis of noble metal-based ultrathin nanowires, but also opens an avenue towards the rational des ign of efficient electrocatalysts for fuel cell systems.
