[Objectives]The paper was to investigate the effects of different application rates of pesticides and fertilizers on wheat stripe rust and wheat yield.[Methods]Two-factor split block design was adopted.[Results]Differ...[Objectives]The paper was to investigate the effects of different application rates of pesticides and fertilizers on wheat stripe rust and wheat yield.[Methods]Two-factor split block design was adopted.[Results]Different application rates of pesticides and chemical fertilizers would affect the incidence of wheat stripe rust,and further affect the yield of wheat.Triadimefon had no significant effect on wheat yield,and potassium sulfate compound fertilizer had significant effect on wheat yield,while their interaction had no significant effect on wheat yield.There were significant differences in wheat yield among the 15 treatment combinations,which may be due to the fact that the application rate of potassium sulfate compound fertilizer had extremely significant effect on wheat yield.[Conclusions]Under the wheat/green manure/maize zonal rotation system in Bijie,the sowing width of wheat is guaranteed to be 0.5 m under the 1.65 m zonal cropping system,and the sowing rate of wheat is arranged according to the basic seedling of 1.2 million plants/hm^(2).In the early stage of wheat stripe rust,15%triadimefon WP can be sprayed evenly at the dose of 1050 g/hm^(2)by a high-power sprayer in a sunny day.展开更多
Treatment of potassium bromodifluoroacetate(1)with alkyl halides in the presence of copper,iodide and potassium fluoride in DMF at 85—90℃ for 3—5h gavethe trifluoromethylated derivatives in moderate to high yields.
With the outbreak of COVID-19,disinfection protection has become a necessary measure to prevent infection.As a new type of disinfectant,potassium peroxymonosulfate compound salt(PMS)has the advantages of good bacteric...With the outbreak of COVID-19,disinfection protection has become a necessary measure to prevent infection.As a new type of disinfectant,potassium peroxymonosulfate compound salt(PMS)has the advantages of good bactericidal effect,non-toxicity,high safety and stability.However,the current PMS products with irregular particle shapes lead to poor flowability,high hygroscopicity,poor stability of reactive oxygen species(ROS)and serious caking problems.In this work,an agglomeration-dissolution mechanism was designed to prepare spherical PMS particles with large size(>300μm)and high sphericity(up to 90%),effectively addressing the above problems.Shaping(dissolution and abrasion)is the key to improving sphericity,which is mainly controlled by the design of the heating mode,residence time and stirring rate.Compared with the irregular PMS particles,the large spherical particles present better flowability(angle of repose decreased by 35.80%,Carr's index decreased by 64.29%,Hausner's ratio decreased by 19.14%),lower hygroscopicity(decreased by 38.0%),lower caking ratio(decreased by 84.50%),and higher stability(the monthly loss of ROS was reduced by 61.68%).The agglomeration-dissolution mechanism demonstrates the crystallization,agglomeration,dissolution and abrasion process of inorganic salt crystals,providing an opportunity to prepare high-end inorganic crystal materials with high-quality morphologies.展开更多
A novel 3-dimensional potassium supermolecular compound [K（HDNR）（H2DNR）（H20）], （H2DNR 2,4-dinitro resorcinol） was synthesized and characterized by elemental analysis and FT-IR spectroscopy. The crystal structu...A novel 3-dimensional potassium supermolecular compound [K（HDNR）（H2DNR）（H20）], （H2DNR 2,4-dinitro resorcinol） was synthesized and characterized by elemental analysis and FT-IR spectroscopy. The crystal structure investigated by X-ray single crystal diffraction shows that [K（HDNR）（HzDNR）（H20）],, crystallizes with a monoclinic unit cell in the space group P2（1）/c with unit cell dimensions of a= 17.648（5） A, b= 12.527（3） A, c= 7.735（2） A, β=94.33（2）°, V= 1705.00（73） A3, Z=4. The structure was refined to the final R=0.0670 and wR= 0.0722 for 2022 observed reflections with 1〉2σ（/）. In the compound, potassium cation is assembled into one-dimensional chains along c-axis through oxygen atoms from water molecules, and the chains were connected by the bridged HDNR- anions to form a two-dimensional net structure. The two-dimensional nets constructed a three-dimensional supramolecular architecture via intermolecular hydrogen bonds and N--O…π interaction. Density functional theory （DFT） B3LYP was employed to optimize the structure and calculate energies for three tautomers of HDNR univalent anion. Three stable tautomers were located. It was found that the structure （I） with O（1） losing hydrogen atom is more stable than the structure （II） also with O（1） losing hydrogen atom and the structure （III） with O（4） losing hydrogen atom.展开更多
In this Letter, a gray-tracking-resistant--potassium titanyl phosphate （GTR-KTP） crystal is used for intracav- ity frequency doubling red laser generation for the first time. Under the 808 nm LD pump power of 180 W,...In this Letter, a gray-tracking-resistant--potassium titanyl phosphate （GTR-KTP） crystal is used for intracav- ity frequency doubling red laser generation for the first time. Under the 808 nm LD pump power of 180 W, as high as 12.5 W of red laser output is obtained with the optimum repetition rate of 7 kHz. Within the red laser power variation range between the maximum to 70%, a temperature tolerance is measured to be 35℃. The results prove that GTR-KTP should be a potential nonlinear crystal for red laser generation.展开更多
Electron-phonon interactions and electron-electron correlations represent two crucial facets of condensed matter physics.For instance,in a half-filled spin-1/2 anti-ferromagnetic chain,the lattice dimerization induced...Electron-phonon interactions and electron-electron correlations represent two crucial facets of condensed matter physics.For instance,in a half-filled spin-1/2 anti-ferromagnetic chain,the lattice dimerization induced by electron-nucleus interaction can be intensified by onsite Coulomb repulsion,resulting in a spin-Peierls state.Through first-principles calculations and crystal structure prediction methods,we have identified that under mild pressures,potassium and ammonia can form stable compounds:R3m K(NH_(3))_(2),Pm3 m K(NH_(3))_(2),and Cm K_(2)(NH_(3))_(3).Our predictions suggest that the R3 m K(NH_(3))_(2)exhibits electride characteristics,marked by the formation of interstitial anionic electrons(IAEs)in the interlayer space.These IAEs are arranged in quasi-two-dimensional triangular arrays.With increasing pressure,the electronic van-Hove singularity shifts toward the Fermi level,resulting in an augmented density of states and the onset of both Peierls and magnetic instabilities.Analyzing these instabilities,we determine that the ground state of the R3 m K(NH_(3))_(2)is the dimerized P2_(1)/m phase with zigzag-type anti-ferromagnetic IAEs.This state can be described by the triangular-lattice antiferromagnetic Heisenberg model with modulated magnetic interactions.Furthermore,we unveil the coexistence and positive interplay between magnetic and Peierls instability,constituting a scenario of spin-Peierls instability unprecedented in realistic 2D materials,particularly involving IAEs.This work provides valuable insights into the coupling of IAEs with the adjacent lattice and their spin correlations in quantum materials.展开更多
文摘[Objectives]The paper was to investigate the effects of different application rates of pesticides and fertilizers on wheat stripe rust and wheat yield.[Methods]Two-factor split block design was adopted.[Results]Different application rates of pesticides and chemical fertilizers would affect the incidence of wheat stripe rust,and further affect the yield of wheat.Triadimefon had no significant effect on wheat yield,and potassium sulfate compound fertilizer had significant effect on wheat yield,while their interaction had no significant effect on wheat yield.There were significant differences in wheat yield among the 15 treatment combinations,which may be due to the fact that the application rate of potassium sulfate compound fertilizer had extremely significant effect on wheat yield.[Conclusions]Under the wheat/green manure/maize zonal rotation system in Bijie,the sowing width of wheat is guaranteed to be 0.5 m under the 1.65 m zonal cropping system,and the sowing rate of wheat is arranged according to the basic seedling of 1.2 million plants/hm^(2).In the early stage of wheat stripe rust,15%triadimefon WP can be sprayed evenly at the dose of 1050 g/hm^(2)by a high-power sprayer in a sunny day.
基金Project supported by the National Natural Science Foundation of China.
文摘Treatment of potassium bromodifluoroacetate(1)with alkyl halides in the presence of copper,iodide and potassium fluoride in DMF at 85—90℃ for 3—5h gavethe trifluoromethylated derivatives in moderate to high yields.
基金The authors are grateful to the financial support of the National Natural Science Foundation of China(grant No.22108195)Nature Science Foundation of Tianjin(grant No.21JCQNJC00580)+1 种基金Key R&D Program of Zhejiang(grant No.2022c01208)Haihe Laboratory of Sustainable Chemical Transformations,and the key project of State Key Laboratory of Chemical Engineering(grant No.SKL-ChE-20Z03).
文摘With the outbreak of COVID-19,disinfection protection has become a necessary measure to prevent infection.As a new type of disinfectant,potassium peroxymonosulfate compound salt(PMS)has the advantages of good bactericidal effect,non-toxicity,high safety and stability.However,the current PMS products with irregular particle shapes lead to poor flowability,high hygroscopicity,poor stability of reactive oxygen species(ROS)and serious caking problems.In this work,an agglomeration-dissolution mechanism was designed to prepare spherical PMS particles with large size(>300μm)and high sphericity(up to 90%),effectively addressing the above problems.Shaping(dissolution and abrasion)is the key to improving sphericity,which is mainly controlled by the design of the heating mode,residence time and stirring rate.Compared with the irregular PMS particles,the large spherical particles present better flowability(angle of repose decreased by 35.80%,Carr's index decreased by 64.29%,Hausner's ratio decreased by 19.14%),lower hygroscopicity(decreased by 38.0%),lower caking ratio(decreased by 84.50%),and higher stability(the monthly loss of ROS was reduced by 61.68%).The agglomeration-dissolution mechanism demonstrates the crystallization,agglomeration,dissolution and abrasion process of inorganic salt crystals,providing an opportunity to prepare high-end inorganic crystal materials with high-quality morphologies.
基金Project supported by the National Natural Science Foundation of China （No. 20471008）, the Project of State Key Laboratory of Science and Technology （No. YBKT10-03） and the Program for New Century Excellent Talents in University （No. NCET-09-0051）.
文摘A novel 3-dimensional potassium supermolecular compound [K（HDNR）（H2DNR）（H20）], （H2DNR 2,4-dinitro resorcinol） was synthesized and characterized by elemental analysis and FT-IR spectroscopy. The crystal structure investigated by X-ray single crystal diffraction shows that [K（HDNR）（HzDNR）（H20）],, crystallizes with a monoclinic unit cell in the space group P2（1）/c with unit cell dimensions of a= 17.648（5） A, b= 12.527（3） A, c= 7.735（2） A, β=94.33（2）°, V= 1705.00（73） A3, Z=4. The structure was refined to the final R=0.0670 and wR= 0.0722 for 2022 observed reflections with 1〉2σ（/）. In the compound, potassium cation is assembled into one-dimensional chains along c-axis through oxygen atoms from water molecules, and the chains were connected by the bridged HDNR- anions to form a two-dimensional net structure. The two-dimensional nets constructed a three-dimensional supramolecular architecture via intermolecular hydrogen bonds and N--O…π interaction. Density functional theory （DFT） B3LYP was employed to optimize the structure and calculate energies for three tautomers of HDNR univalent anion. Three stable tautomers were located. It was found that the structure （I） with O（1） losing hydrogen atom is more stable than the structure （II） also with O（1） losing hydrogen atom and the structure （III） with O（4） losing hydrogen atom.
基金supported by the National Natural Science Foundation of China(Grant Nos.61308042 and 61275142)the China Postdoctoral Science Foundation(Grant Nos.2013M531594 and 2014T70633)
文摘In this Letter, a gray-tracking-resistant--potassium titanyl phosphate （GTR-KTP） crystal is used for intracav- ity frequency doubling red laser generation for the first time. Under the 808 nm LD pump power of 180 W, as high as 12.5 W of red laser output is obtained with the optimum repetition rate of 7 kHz. Within the red laser power variation range between the maximum to 70%, a temperature tolerance is measured to be 35℃. The results prove that GTR-KTP should be a potential nonlinear crystal for red laser generation.
基金financial support from the National Key R&D Program of China(2022YFA1403201)the National Natural Science Foundation of China(12125404,11974162,and 11834006)the Fundamental Research Funds for the Central Universities。
文摘Electron-phonon interactions and electron-electron correlations represent two crucial facets of condensed matter physics.For instance,in a half-filled spin-1/2 anti-ferromagnetic chain,the lattice dimerization induced by electron-nucleus interaction can be intensified by onsite Coulomb repulsion,resulting in a spin-Peierls state.Through first-principles calculations and crystal structure prediction methods,we have identified that under mild pressures,potassium and ammonia can form stable compounds:R3m K(NH_(3))_(2),Pm3 m K(NH_(3))_(2),and Cm K_(2)(NH_(3))_(3).Our predictions suggest that the R3 m K(NH_(3))_(2)exhibits electride characteristics,marked by the formation of interstitial anionic electrons(IAEs)in the interlayer space.These IAEs are arranged in quasi-two-dimensional triangular arrays.With increasing pressure,the electronic van-Hove singularity shifts toward the Fermi level,resulting in an augmented density of states and the onset of both Peierls and magnetic instabilities.Analyzing these instabilities,we determine that the ground state of the R3 m K(NH_(3))_(2)is the dimerized P2_(1)/m phase with zigzag-type anti-ferromagnetic IAEs.This state can be described by the triangular-lattice antiferromagnetic Heisenberg model with modulated magnetic interactions.Furthermore,we unveil the coexistence and positive interplay between magnetic and Peierls instability,constituting a scenario of spin-Peierls instability unprecedented in realistic 2D materials,particularly involving IAEs.This work provides valuable insights into the coupling of IAEs with the adjacent lattice and their spin correlations in quantum materials.
