Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transiti...Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transition in a Hubbard model by using the dynamical mean-field theory and introduce the local quantum state fidelity to depict the Mott metal–insulator transition. The local quantum state fidelity provides a convenient approach to determining the critical point of the Mott transition. Additionally, it presents a consistent description of the two distinct forms of the Mott transition points.展开更多
This research delves into the often-underappreciated role of middle leaders in educational organizations,highlighting their significance as the linchpins between senior leadership and classroom teachers.Utilizing qual...This research delves into the often-underappreciated role of middle leaders in educational organizations,highlighting their significance as the linchpins between senior leadership and classroom teachers.Utilizing qualitative research methods,the study investigates the multifaceted responsibilities,challenges,and contributions of middle leaders in schools.Findings indicate that middle leaders foster a culture of trust within the institution by providing mentorship and guidance to new teachers.They undertake substantial tasks,such as team coordination,grade direction,and student supervision,in addition to their teaching duties.Despite their pivotal role,middle leaders often face mounting pressures and heavy workloads.This research underscores the need to recognize and support middle leaders in educational settings,acknowledging their vital role in fostering cohesion and facilitating the implementation of educational reforms.展开更多
Aqueous rechargeable zinc ion batteries are regarded as a competitive alternative to lithium-ion batteries because of their distinct advantages of high security,high energy density,low cost,and environmental friendlin...Aqueous rechargeable zinc ion batteries are regarded as a competitive alternative to lithium-ion batteries because of their distinct advantages of high security,high energy density,low cost,and environmental friendliness.However,deep-seated problems including Zn dendrite and adverse side reactions severely impede the practical application.In this work,we proposed a freestanding Zn-electrolyte interfacial layer composed of multicapsular carbon fibers(MCFs)to regulate the plating/stripping behavior of Zn anodes.The versatile MCFs protective layer can uniformize the electric field and Zn^(2+)flux,meanwhile,reduce the deposition overpotentials,leading to high-quality and rapid Zn deposition kinetics.Furthermore,the bottom-up and uniform deposition of Zn on the Zn-MCFs interface endows long-term and high-capacity plating.Accordingly,the Zn@MCFs symmetric batteries can keep working up to 1500 h with 5 mAh cm^(−2).The feasibility of the MCFs interfacial layer is also convinced in Zn@MCFs||MnO_(2) batteries.Remarkably,the Zn@MCFs||α-MnO_(2)batteries deliver a high specific capacity of 236.1 mAh g^(−1)at 1 A g^(−1)with excellent stability,and maintain an exhilarating energy density of 154.3 Wh kg^(−1) at 33%depth of discharge in pouch batteries.展开更多
Herein,N-Ti3C2@CNT microspheres are successfully synthesized by the simple spray drying method.In the preparation process,HCl-treated melamine(HTM)is selected as the sources of carbon and nitrogen.It not only realizes...Herein,N-Ti3C2@CNT microspheres are successfully synthesized by the simple spray drying method.In the preparation process,HCl-treated melamine(HTM)is selected as the sources of carbon and nitrogen.It not only realizes in situ growth of CNTs on the surface of MXene nanosheets with the catalysis of Ni,but also introduces efficient N-doping in both MXene and CNTs.Within the microsphere,MXene nanosheets interconnect with CNTs to form porous and conductive network.In addition,N-doped MXene and CNTs can provide strong chemical immobilization for polysulfides and effectively entrap them within the porous microspheres.Above-mentioned merits enable N-Ti3C2@CNT microspheres to be ideal sulfur host.When used in lithium–sulfur(Li–S)battery,the N-Ti3C2@CNT microspheres/S cathode delivers initial specific capacity of 927 mAh g−1 at 1 C and retains high capacity of 775 mAh g−1 after 1000 cycles with extremely low fading rate(FR)of 0.016%per cycle.Furthermore,the cathode still shows high cycling stability at high C-rate of 4 C(capacity of 647 mAh g−1 after 650 cycles,FR 0.027%)and high sulfur loading of 3 and 6 mg cm−2 for Li–S batteries.展开更多
The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor...The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.展开更多
The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK...The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK（α,β）（x,y）：=∑∞k=0 Ck（α,β）（x）Qk（α,β）（y）,where Qk（α,β） （x） are the Jacobi polynomials of order k on （0, 1 ）, Ck（α,β） 〉 0 are real numbers, and from which give the lower and upper bounds of the covering number for some particular reproducing kernel Hilbert space reproduced by Kα,β （x, y）.展开更多
With the development of adaptive optics and post restore processing techniques,large aperture ground-based telescopes can obtain high-resolution images(HRIs)of targets.The pose of the space target can be estimated fro...With the development of adaptive optics and post restore processing techniques,large aperture ground-based telescopes can obtain high-resolution images(HRIs)of targets.The pose of the space target can be estimated from HRIs by several methods.As the target features obtained from the image are unstable,it is difficult to use existing methods for pose estimation.In this paper a method based on real-time target model matching to estimate the pose of space targets is proposed.First,the physicallyconstrained iterative deconvolution algorithm is used to obtain HRIs of the space target.Second,according to the 3D model,the ephemeris data,the observation time of the target,and the optical parameters of the telescope,the simulated observation image of the target in orbit is rendered by a scene simulation program.Finally,the target model searches through yaw,pitch,and roll until the correlation between the simulated observation image and the actual observation image shows an optimal match.The simulation results show that the proposed pose estimation method can converge to the local optimal value with an estimation error of about 1.6349°.展开更多
This paper considers online classification learning algorithms for regularized classification schemes with generalized gradient. A novel capacity independent approach is presented. It verifies the strong convergence o...This paper considers online classification learning algorithms for regularized classification schemes with generalized gradient. A novel capacity independent approach is presented. It verifies the strong convergence of sizes and yields satisfactory convergence rates for polynomially decaying step sizes. Compared with the gradient schemes, this al- gorithm needs only less additional assumptions on the loss function and derives a stronger result with respect to the choice of step sizes and the regularization parameters.展开更多
The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
The inducible CRISPR activation(CRISPR-a)system offers unparalleled precision and versatility for regu-lating endogenous genes,making it highly sought after in plant research.In this study,we developed a chem-ically i...The inducible CRISPR activation(CRISPR-a)system offers unparalleled precision and versatility for regu-lating endogenous genes,making it highly sought after in plant research.In this study,we developed a chem-ically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system.We systematically compared different induction strategies and achieved high efficiency in target gene activation.We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration.Further experiments showed that induced activation of these morphogenic genes can accelerate regenera-tion and improve regeneration efficiency in both eudicot and monocot plants,including alfalfa,woodland strawberry,and sheepgrass.Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.展开更多
To the Editor:Breast cancer is a prevalent malignant tumor and ranks as the second leading cause of cancer-related deaths globally.^([1])The breast is the target organ of some endocrine hormones,which regulate its gro...To the Editor:Breast cancer is a prevalent malignant tumor and ranks as the second leading cause of cancer-related deaths globally.^([1])The breast is the target organ of some endocrine hormones,which regulate its growth and development.Aside from estrogen and progesterone,the relationship among prolactin,androgen,and breast cancer has recently garnered increasing attention.展开更多
Rational microbial chassis design and engineering for improving production of amino acids have attracted a considerable attention.l-glutamate,l-lysine,l-threonine and l-tryptophan are the main amino acids demanded in ...Rational microbial chassis design and engineering for improving production of amino acids have attracted a considerable attention.l-glutamate,l-lysine,l-threonine and l-tryptophan are the main amino acids demanded in the food industry.Systems metabolic engineering and synthetic biology engineering generally are believed as the comprehensive engineering approaches to obtain rationally designed strains and construct high-performance platforms for amino acids.The strate-gies focus on microbial chassis characterization optimization,precise metabolic engineering such as promoter engineer-ing,modular pathway engineering,transporter engineering,and dynamic switch systems application,and global genome streamline engineering to reduce cell burden.In this review,we summarized the efficient engineering strategies to optimize Corynebacterium glutamicum and Escherichia coli cell factories for improving the production of l-glutamate,l-lysine,l-threonine,and l-tryptophan.展开更多
Ceria-zirconia based(CZ) materials are still a crucial component of three-way catalysts(TWCs) now.Compared with traditional cubic or tetragonal phase,CZ material with pyrochlore-type κ-Ce_(2)Zr_(2)O_(8) phase shows a...Ceria-zirconia based(CZ) materials are still a crucial component of three-way catalysts(TWCs) now.Compared with traditional cubic or tetragonal phase,CZ material with pyrochlore-type κ-Ce_(2)Zr_(2)O_(8) phase shows an excellent oxygen storage capacity,and thus is examined as a promising material for developing TWCs.Considering the remarkable surface Ce/Zr ratio change during the κ-Ce_(2)Zr_(2)O_(8) formation,we investigated the effects of surface Ce/Zr ratio on the formation of κ-Ce_(2)Zr_(2)O_(8) and on the supported Pdonly three-way catalysts.Raman and transmission electron microscopy(TEM) results demonstrate that partial κ-Ce_(2)Zr_(2)O_(8) structure is formed in the three oxides,and the content of κ-Ce_(2)Zr_(2)O_(8) structure increases with increasing surface Ce/Zr ratio,but its stability declines.After thermal aging,the proportions of Ce^(3+) and oxidized palladium(Pd^(δ+)+Pd^(2+)) in the catalysts,which are shown to be positively correlated with catalytic activity,follow the same sequence as the stability of κ-Ce_(2)Zr_(2)O_(8),namely Pd/M0.33 ROa> Pd/M0.4 ROa> Pd/CeM0.33 ROa.In particular,Pd/M0.33 RO,which possesses 100%((Pd^(δ+)+Pd^(2+))/Pd) even after thermal aging at 900℃ for 4 h,owing to the strengthened metal-support interaction by the presence of stable κ-Ce_(2)Zr_(2)O_(8),shows the best catalytic performance.This work is instructive to the application of κ-Ce_(2)Zr_(2)O_(8) in three-way catalysis.展开更多
The lack of genome editing platforms has hampered efforts to study and improve forage crops that can be grown on lands not suited to other crops.Here,we established efficient Agrobacterium-mediated clustered regularly...The lack of genome editing platforms has hampered efforts to study and improve forage crops that can be grown on lands not suited to other crops.Here,we established efficient Agrobacterium-mediated clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)genome editing in a perennial,stress-tolerant forage grass,sheepgrass(Leymus chinensis).By screening for active single-guide RNAs(sg RNAs),accessions that regenerate well,suitable Agrobacterium strains,and optimal culture media,and co-expressing the morphogenic factor Ta WOX5,we achieved 11%transformation and 5.83%editing efficiency in sheepgrass.Knocking out Teosinte Branched1(TB1)significantly increased tiller number and biomass.This study opens avenues for studying gene function and breeding in sheepgrass.展开更多
The nanostructures and redox properties of CeO_(2)-ZrO_(2)materials can be tuned via optimized thermal treatments.In this study,the CeO_(2)-ZrO_(2)-Y_(2)O_(3)-La_(2)O_(3)(CZ) materials were prepared by co-precipitatio...The nanostructures and redox properties of CeO_(2)-ZrO_(2)materials can be tuned via optimized thermal treatments.In this study,the CeO_(2)-ZrO_(2)-Y_(2)O_(3)-La_(2)O_(3)(CZ) materials were prepared by co-precipitation method and submitted to different thermal treatment conditions(atmosphere:nitrogen(N) and air(A);temperature(x):700,800 and 900℃).Due to the protective effects of the "in-situ-formed" carbon powder,treating the surfactants assisted-CZ precursors under N2atmosphere can keep the pore structures and then the CZ-N700 and CZ-N800 can achieve larger surface area than CZ-A700 and CZ-A800,respectively.In comparison,with high treatment temperature(900℃),the effects of thermal atmosphere on surface area can be ignored.However,the redox properties of CZ materials correlate closely with thermal treatment atmosphere and temperature simultaneously.As demonstrated by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) characterizations,the N_(2)atmosphere facilitates the formation of Ce^(3+)without disturbing the mixing degree of Ce and Zr.Thereby the CZ-Nx materials exhibit superior reducibility than corresponding CZ-Ax materials.In additio n,the XRD and XPS results also demonstrate the formation of a more homogeneous CZ solid solution by Zr atoms rearrangement with temperature ignoring the atmosphere.As a result,the reducibility of CZ materials increases with the treatment temperature increasing and is not affected by the worsening of the textural properties.Specially,due to the synergistic effects of N_(2)atmosphere and high treatment temperature,the CZ-N900 shows the best reducibility.This improvement also emphasizes the important role of structural properties of CZ in explaining the temperature-dependent reducibility.展开更多
Inflammatory bowel disease(IBD)is caused by an uncontrolled immune response in the intestinal lumen,leading to inflammation in genetically predisposed individuals.Immunotherapy may be a promising approach to the treat...Inflammatory bowel disease(IBD)is caused by an uncontrolled immune response in the intestinal lumen,leading to inflammation in genetically predisposed individuals.Immunotherapy may be a promising approach to the treatment of IBD.Here,we show that transforming growth factor-β1(TGF-β1)gene-modified immature dendritic cells(imDCs)could enhance the inhibitory function of imDCs and delay the progress of IBD induced by dextran sodium sulfate in mice.The results of fluorescence-activated cell sorter(FACS)demonstrated that this protective effect is mediated partially by inducing CD4^(+)Foxp3^(+)regulatory T cells(Tregs)in mesentery lymph nodes to control inflammation.In vitro experiments also supported this hypothesis.In conclusion,we provide evidence that TGF-b1-modified bone marrow-derived imDCs may have a therapeutic effect to IBD.展开更多
At present, there is little commercial sale of biochar, since farmers find they can not gain a return on their investment in this amendment in the first few years after its application, because of the high cost associ...At present, there is little commercial sale of biochar, since farmers find they can not gain a return on their investment in this amendment in the first few years after its application, because of the high cost associated with large application rates. To overcome this constraint, development of artificially aged enriched biochar-mineral complexes(BMCs), having a higher mineral content, surface functionality, exchangeable cations, high concentration of magnetic iron(Fe) nanoparticles, and higher water-extractable organic compounds has been undertaken by a combined team of researchers and a commercial company. Two biochars produced under different pyrolysis conditions were activated with a phosphoric acid treatment. A mixture of clay, chicken litter, and minerals were added to the biochar, and then this composite was torrefied at either 180 or 220?C. In this study a pot experiment was carried out in glasshouse conditions to determine the effects of four different BMCs, with different formulations applied at rates of 100 and 200 kg ha-1, on the mycorrhizal colonisation, wheat growth and nutrient uptake, and soil quality improvement. It was found that the phosphorus(P) and nitrogen uptake in wheat shoots were significantly greater for a low application rate of BMCs(100 kg ha-1). The present formulation of BMC was effective in enhancing growth of wheat at low application rate(100 kg ha-1). The increase in growth appeared due to an increase in P uptake in the plants that could be partly attributed to an increase in mycorrhizal colonisation and partly due to the properties of the BMC.展开更多
基金Project supported by the Scientific Research Foundation for Youth Academic Talent of Inner Mongolia University (Grant No.1000023112101/010)the Fundamental Research Funds for the Central Universities of China (Grant No.JN200208)+2 种基金supported by the National Natural Science Foundation of China (Grant No.11474023)supported by the National Key Research and Development Program of China (Grant No.2021YFA1401803)the National Natural Science Foundation of China (Grant Nos.11974051 and 11734002)。
文摘Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transition in a Hubbard model by using the dynamical mean-field theory and introduce the local quantum state fidelity to depict the Mott metal–insulator transition. The local quantum state fidelity provides a convenient approach to determining the critical point of the Mott transition. Additionally, it presents a consistent description of the two distinct forms of the Mott transition points.
文摘This research delves into the often-underappreciated role of middle leaders in educational organizations,highlighting their significance as the linchpins between senior leadership and classroom teachers.Utilizing qualitative research methods,the study investigates the multifaceted responsibilities,challenges,and contributions of middle leaders in schools.Findings indicate that middle leaders foster a culture of trust within the institution by providing mentorship and guidance to new teachers.They undertake substantial tasks,such as team coordination,grade direction,and student supervision,in addition to their teaching duties.Despite their pivotal role,middle leaders often face mounting pressures and heavy workloads.This research underscores the need to recognize and support middle leaders in educational settings,acknowledging their vital role in fostering cohesion and facilitating the implementation of educational reforms.
基金supported by the National Natural Science Foundation of China(51901206)“the Fundamental Research Funds for the Central Universities”(2021QNA4003).
文摘Aqueous rechargeable zinc ion batteries are regarded as a competitive alternative to lithium-ion batteries because of their distinct advantages of high security,high energy density,low cost,and environmental friendliness.However,deep-seated problems including Zn dendrite and adverse side reactions severely impede the practical application.In this work,we proposed a freestanding Zn-electrolyte interfacial layer composed of multicapsular carbon fibers(MCFs)to regulate the plating/stripping behavior of Zn anodes.The versatile MCFs protective layer can uniformize the electric field and Zn^(2+)flux,meanwhile,reduce the deposition overpotentials,leading to high-quality and rapid Zn deposition kinetics.Furthermore,the bottom-up and uniform deposition of Zn on the Zn-MCFs interface endows long-term and high-capacity plating.Accordingly,the Zn@MCFs symmetric batteries can keep working up to 1500 h with 5 mAh cm^(−2).The feasibility of the MCFs interfacial layer is also convinced in Zn@MCFs||MnO_(2) batteries.Remarkably,the Zn@MCFs||α-MnO_(2)batteries deliver a high specific capacity of 236.1 mAh g^(−1)at 1 A g^(−1)with excellent stability,and maintain an exhilarating energy density of 154.3 Wh kg^(−1) at 33%depth of discharge in pouch batteries.
文摘Herein,N-Ti3C2@CNT microspheres are successfully synthesized by the simple spray drying method.In the preparation process,HCl-treated melamine(HTM)is selected as the sources of carbon and nitrogen.It not only realizes in situ growth of CNTs on the surface of MXene nanosheets with the catalysis of Ni,but also introduces efficient N-doping in both MXene and CNTs.Within the microsphere,MXene nanosheets interconnect with CNTs to form porous and conductive network.In addition,N-doped MXene and CNTs can provide strong chemical immobilization for polysulfides and effectively entrap them within the porous microspheres.Above-mentioned merits enable N-Ti3C2@CNT microspheres to be ideal sulfur host.When used in lithium–sulfur(Li–S)battery,the N-Ti3C2@CNT microspheres/S cathode delivers initial specific capacity of 927 mAh g−1 at 1 C and retains high capacity of 775 mAh g−1 after 1000 cycles with extremely low fading rate(FR)of 0.016%per cycle.Furthermore,the cathode still shows high cycling stability at high C-rate of 4 C(capacity of 647 mAh g−1 after 650 cycles,FR 0.027%)and high sulfur loading of 3 and 6 mg cm−2 for Li–S batteries.
基金funded by the Natural Science Foundation of Shanghai(22ZR1428200)the National Natural Science Foundation of China(51950410581)+1 种基金the Shanghai Government(20JC141500)and CATL-SJTU joint funding.
文摘The complete elimination of methylammonium(MA)cations in Sn-Pb composites can extend their light and thermal stabilities.Unfortunately,MA-free Sn-Pb alloyed perovskite thin films suffer from wrinkled surfaces and poor crystallization,due to the coexistence of mixed intermediate phases.Here,we report an additive strategy for finely regulating the impurities in the intermediate phase of Cs_(0.25)FA_(0.75)Pb_(0.6)Sn_(0.4)I_(3)and,thereby,obtaining high-performance solar cells.We introduced d-homoserine lactone hydrochloride(D-HLH)to form hydrogen bonds and strong Pb-O/Sn-O bonds with perovskite precursors,thereby weakening the incomplete complexation effect between polar aprotic solvents(e.g.,DMSO)and organic(FAI)or inorganic(CsI,PbI_(2),and SnI_(2))components,and balancing their nucleation processes.This treatment completely transformed mixed intermediate phases into pure preformed perovskite nuclei prior to thermal anneal-ing.Besides,this D-HLH substantially inhibited the oxidation of Sn^(2+) species.This strategy generated a record efficiency of 21.61%,with a Voc of 0.88 V for an MA-free Sn-Pb device,and an efficiency of 23.82%for its tandem device.The unencapsulated devices displayed impressive thermal stability at 85℃ for 300 h and much improved continuous operation stability at MPP for 120 h.
基金Supported by the National Natural Science Foundation of China (Grant No. 10871226)
文摘The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK（α,β）（x,y）：=∑∞k=0 Ck（α,β）（x）Qk（α,β）（y）,where Qk（α,β） （x） are the Jacobi polynomials of order k on （0, 1 ）, Ck（α,β） 〉 0 are real numbers, and from which give the lower and upper bounds of the covering number for some particular reproducing kernel Hilbert space reproduced by Kα,β （x, y）.
文摘With the development of adaptive optics and post restore processing techniques,large aperture ground-based telescopes can obtain high-resolution images(HRIs)of targets.The pose of the space target can be estimated from HRIs by several methods.As the target features obtained from the image are unstable,it is difficult to use existing methods for pose estimation.In this paper a method based on real-time target model matching to estimate the pose of space targets is proposed.First,the physicallyconstrained iterative deconvolution algorithm is used to obtain HRIs of the space target.Second,according to the 3D model,the ephemeris data,the observation time of the target,and the optical parameters of the telescope,the simulated observation image of the target in orbit is rendered by a scene simulation program.Finally,the target model searches through yaw,pitch,and roll until the correlation between the simulated observation image and the actual observation image shows an optimal match.The simulation results show that the proposed pose estimation method can converge to the local optimal value with an estimation error of about 1.6349°.
文摘This paper considers online classification learning algorithms for regularized classification schemes with generalized gradient. A novel capacity independent approach is presented. It verifies the strong convergence of sizes and yields satisfactory convergence rates for polynomially decaying step sizes. Compared with the gradient schemes, this al- gorithm needs only less additional assumptions on the loss function and derives a stronger result with respect to the choice of step sizes and the regularization parameters.
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
基金supported by the National Key R&D Program of China (2022YFD1500503 to X.S.)the Key Projects in Science and Technology of Inner Mongolia (2021ZD0031 to X.C.and S.Z.)+6 种基金the National Key Research and Development Program (2022YFF1002802 to X.D.)the Youth Innovation Promotion Association,CAS (Y2022039 to X.D.)the Youth Innovation Promotion Association,CAS (2022096 to S.Z.)the National Science Foundation of China (NSFC32272692 to J.Z.)Project ZR2022QC054 of the Shandong Provincial Natural Science Foundation (to Y.T.)funding from the State Key Laboratory of Protein and Plant Gene Research (to Q.L.).
文摘The inducible CRISPR activation(CRISPR-a)system offers unparalleled precision and versatility for regu-lating endogenous genes,making it highly sought after in plant research.In this study,we developed a chem-ically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system.We systematically compared different induction strategies and achieved high efficiency in target gene activation.We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration.Further experiments showed that induced activation of these morphogenic genes can accelerate regenera-tion and improve regeneration efficiency in both eudicot and monocot plants,including alfalfa,woodland strawberry,and sheepgrass.Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.
基金supported by Shandong Provincial Natural Science Foundation,China(No.ZR2022MH248)
文摘To the Editor:Breast cancer is a prevalent malignant tumor and ranks as the second leading cause of cancer-related deaths globally.^([1])The breast is the target organ of some endocrine hormones,which regulate its growth and development.Aside from estrogen and progesterone,the relationship among prolactin,androgen,and breast cancer has recently garnered increasing attention.
基金supported by the National Natural Science Foundation of China(32100023)the Provincial Natural Science Foundation of Jiangsu Province(BK20210466)+2 种基金the National Natural Science Foundation of China(32000020)the Provincial Natural Science Foundation of Jiangsu Province(BK20200615)and the Youth Fund for Basic Research Program of Jiangnan University(JUSRP122009).
文摘Rational microbial chassis design and engineering for improving production of amino acids have attracted a considerable attention.l-glutamate,l-lysine,l-threonine and l-tryptophan are the main amino acids demanded in the food industry.Systems metabolic engineering and synthetic biology engineering generally are believed as the comprehensive engineering approaches to obtain rationally designed strains and construct high-performance platforms for amino acids.The strate-gies focus on microbial chassis characterization optimization,precise metabolic engineering such as promoter engineer-ing,modular pathway engineering,transporter engineering,and dynamic switch systems application,and global genome streamline engineering to reduce cell burden.In this review,we summarized the efficient engineering strategies to optimize Corynebacterium glutamicum and Escherichia coli cell factories for improving the production of l-glutamate,l-lysine,l-threonine,and l-tryptophan.
基金Project supported by the National Natural Science Foundation of China (21972097,21773189)。
文摘Ceria-zirconia based(CZ) materials are still a crucial component of three-way catalysts(TWCs) now.Compared with traditional cubic or tetragonal phase,CZ material with pyrochlore-type κ-Ce_(2)Zr_(2)O_(8) phase shows an excellent oxygen storage capacity,and thus is examined as a promising material for developing TWCs.Considering the remarkable surface Ce/Zr ratio change during the κ-Ce_(2)Zr_(2)O_(8) formation,we investigated the effects of surface Ce/Zr ratio on the formation of κ-Ce_(2)Zr_(2)O_(8) and on the supported Pdonly three-way catalysts.Raman and transmission electron microscopy(TEM) results demonstrate that partial κ-Ce_(2)Zr_(2)O_(8) structure is formed in the three oxides,and the content of κ-Ce_(2)Zr_(2)O_(8) structure increases with increasing surface Ce/Zr ratio,but its stability declines.After thermal aging,the proportions of Ce^(3+) and oxidized palladium(Pd^(δ+)+Pd^(2+)) in the catalysts,which are shown to be positively correlated with catalytic activity,follow the same sequence as the stability of κ-Ce_(2)Zr_(2)O_(8),namely Pd/M0.33 ROa> Pd/M0.4 ROa> Pd/CeM0.33 ROa.In particular,Pd/M0.33 RO,which possesses 100%((Pd^(δ+)+Pd^(2+))/Pd) even after thermal aging at 900℃ for 4 h,owing to the strengthened metal-support interaction by the presence of stable κ-Ce_(2)Zr_(2)O_(8),shows the best catalytic performance.This work is instructive to the application of κ-Ce_(2)Zr_(2)O_(8) in three-way catalysis.
基金supported by Key Projects in Science and Technology of Inner Mongolia (2021ZD0031)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA26030202)the Youth Innovation Promotion Association,CAS (2022096)。
文摘The lack of genome editing platforms has hampered efforts to study and improve forage crops that can be grown on lands not suited to other crops.Here,we established efficient Agrobacterium-mediated clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)genome editing in a perennial,stress-tolerant forage grass,sheepgrass(Leymus chinensis).By screening for active single-guide RNAs(sg RNAs),accessions that regenerate well,suitable Agrobacterium strains,and optimal culture media,and co-expressing the morphogenic factor Ta WOX5,we achieved 11%transformation and 5.83%editing efficiency in sheepgrass.Knocking out Teosinte Branched1(TB1)significantly increased tiller number and biomass.This study opens avenues for studying gene function and breeding in sheepgrass.
基金Project supported by the National Natural Science Foundation of China (21972097)the National Engineering Laboratory for Mobile Source Emission Control Technology (NELMS2020A04)。
文摘The nanostructures and redox properties of CeO_(2)-ZrO_(2)materials can be tuned via optimized thermal treatments.In this study,the CeO_(2)-ZrO_(2)-Y_(2)O_(3)-La_(2)O_(3)(CZ) materials were prepared by co-precipitation method and submitted to different thermal treatment conditions(atmosphere:nitrogen(N) and air(A);temperature(x):700,800 and 900℃).Due to the protective effects of the "in-situ-formed" carbon powder,treating the surfactants assisted-CZ precursors under N2atmosphere can keep the pore structures and then the CZ-N700 and CZ-N800 can achieve larger surface area than CZ-A700 and CZ-A800,respectively.In comparison,with high treatment temperature(900℃),the effects of thermal atmosphere on surface area can be ignored.However,the redox properties of CZ materials correlate closely with thermal treatment atmosphere and temperature simultaneously.As demonstrated by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) characterizations,the N_(2)atmosphere facilitates the formation of Ce^(3+)without disturbing the mixing degree of Ce and Zr.Thereby the CZ-Nx materials exhibit superior reducibility than corresponding CZ-Ax materials.In additio n,the XRD and XPS results also demonstrate the formation of a more homogeneous CZ solid solution by Zr atoms rearrangement with temperature ignoring the atmosphere.As a result,the reducibility of CZ materials increases with the treatment temperature increasing and is not affected by the worsening of the textural properties.Specially,due to the synergistic effects of N_(2)atmosphere and high treatment temperature,the CZ-N900 shows the best reducibility.This improvement also emphasizes the important role of structural properties of CZ in explaining the temperature-dependent reducibility.
基金We thank Professor Lin-Rong Lu for his critical review of the manuscript.This work was supported by the National Key Basic Research Program of China(Grant 2007CB512400)the National High Technology Research and Development Program of China(Grants2006AA02A239 and 2007AA021102)+1 种基金the National Natural Science Foundation of China(Grant 30671909 and 30972725)Natural Science Foundation of Zhejiang Province(Z2090042).
文摘Inflammatory bowel disease(IBD)is caused by an uncontrolled immune response in the intestinal lumen,leading to inflammation in genetically predisposed individuals.Immunotherapy may be a promising approach to the treatment of IBD.Here,we show that transforming growth factor-β1(TGF-β1)gene-modified immature dendritic cells(imDCs)could enhance the inhibitory function of imDCs and delay the progress of IBD induced by dextran sodium sulfate in mice.The results of fluorescence-activated cell sorter(FACS)demonstrated that this protective effect is mediated partially by inducing CD4^(+)Foxp3^(+)regulatory T cells(Tregs)in mesentery lymph nodes to control inflammation.In vitro experiments also supported this hypothesis.In conclusion,we provide evidence that TGF-b1-modified bone marrow-derived imDCs may have a therapeutic effect to IBD.
基金supported by Ven Earth LLC,San Francisco,CA,USA and the Australian Research Council
文摘At present, there is little commercial sale of biochar, since farmers find they can not gain a return on their investment in this amendment in the first few years after its application, because of the high cost associated with large application rates. To overcome this constraint, development of artificially aged enriched biochar-mineral complexes(BMCs), having a higher mineral content, surface functionality, exchangeable cations, high concentration of magnetic iron(Fe) nanoparticles, and higher water-extractable organic compounds has been undertaken by a combined team of researchers and a commercial company. Two biochars produced under different pyrolysis conditions were activated with a phosphoric acid treatment. A mixture of clay, chicken litter, and minerals were added to the biochar, and then this composite was torrefied at either 180 or 220?C. In this study a pot experiment was carried out in glasshouse conditions to determine the effects of four different BMCs, with different formulations applied at rates of 100 and 200 kg ha-1, on the mycorrhizal colonisation, wheat growth and nutrient uptake, and soil quality improvement. It was found that the phosphorus(P) and nitrogen uptake in wheat shoots were significantly greater for a low application rate of BMCs(100 kg ha-1). The present formulation of BMC was effective in enhancing growth of wheat at low application rate(100 kg ha-1). The increase in growth appeared due to an increase in P uptake in the plants that could be partly attributed to an increase in mycorrhizal colonisation and partly due to the properties of the BMC.
