Plant photosynthesis assimilates CO_(2)from the atmosphere,and CO_(2)diffusion efficiency is mainly constrained by stomatal and mesophyll resistance.The stomatal and mesophyll conductance of plants are sensitive to ab...Plant photosynthesis assimilates CO_(2)from the atmosphere,and CO_(2)diffusion efficiency is mainly constrained by stomatal and mesophyll resistance.The stomatal and mesophyll conductance of plants are sensitive to abiotic stress factors,which affect the CO_(2)concentrations at carboxylation sites to control photosynthetic rates.Early studies conducted relevant reviews on the responses of stomatal conductance to the environment and the limitations of mesophyll conductance by internal structure and biochemical factors.However,reviews on the abiotic stress factors that systematically regulate plant CO_(2)diffusion are rare.Therefore,in this review,the rapid and long-term responses of stomatal and mesophyll conductance to abiotic stress factors(such as light intensity,drought,CO_(2)concentration and temperature)and their physiological mechanisms are summarized.Finally,future research trends are also investigated.展开更多
Resistive switching characteristics of hafnium oxide are studied for possible nonvolatile memory device applications.The HfOx films with different oxygen contents are deposited by rf magnetron sputtering under differe...Resistive switching characteristics of hafnium oxide are studied for possible nonvolatile memory device applications.The HfOx films with different oxygen contents are deposited by rf magnetron sputtering under different O_(2) flow rates.The films are amorphous,and the stoichiometric of the film is improved by increasing the O_(2) flow rate.Current-voltage characteristics of the TiN/HfOx/ITO device are investigated with 1 mA compliance.The bipolar resistive switching behavior is observed for the TiN/HfOx/ITO structure,and the resistive switching mechanism of the TiN/HfOx/ITO structure is explained by trap-controlled space charge limit current conduction.展开更多
Hafnium oxide films are deposited on Si(100)substrates by means of rf magnetron sputtering.The interfacial structure is studied using high-resolution transmission electron microscopy(HRTEM)and x-ray photoelectron spec...Hafnium oxide films are deposited on Si(100)substrates by means of rf magnetron sputtering.The interfacial structure is studied using high-resolution transmission electron microscopy(HRTEM)and x-ray photoelectron spectroscopy(XPS),and the electrical properties of the Au/HfO_(2)/Si stack are analyzed by frequency−dependent capacitance-voltage(C–V–f)measurements.The amorphous interfacial layer between HfO_(2) and the Si substrate is observed by the HRTEM method.From the results of XPS,the interfacial layer comprises hafnium silicate and silicon oxide.For C–V–f measurements,the C–V plots show a peak at a low frequency and the change in frequency has effects on the intensity of the peak.As expected,rapid thermal annealing can passivate the interface states of the HfO_(2)/Si stack.展开更多
The structural,electronic and mechanical properties of cubic SrHfO_(3) under hydrostatic pressure up to 70 GPa are investigated using the first-principles density functional theory(DFT).The calculated lattice paramete...The structural,electronic and mechanical properties of cubic SrHfO_(3) under hydrostatic pressure up to 70 GPa are investigated using the first-principles density functional theory(DFT).The calculated lattice parameter,elastic constants and mechanical properties of cubic SrHfO_(3) at zero pressure are in good agreement with the available experimental data and other calculational values.As pressure increases,cubic SrHfO_(3) will change from an indirect band gap(Γ-R)compound to a direct band gap(Γ-Γ)compound.Charge densities reveal the coexistence of covalent bonding and ionic bonding in cubic SrHfO_(3).With the increase of pressure,both the covalent bonding(HfO)and ionic bonding(SrO)are strengthened.Cubic SrHfO_(3) is mechanically stable when pressure is lower than 55.1 GPa,whereas that is instable when pressure is higher than 55.1 GPa.With the increasing pressure,enthalpy,bulk modulus,shear modulus and Young's modulus increase,whereas the lattice parameter decreases.Moreover,cubic SrHfO_(3) under pressure has higher hardness and better ductility than that at zero pressure.展开更多
Sweden has transformed into a considerable gender equality and family-friendly society over the past half-century. Meanwhile, Swedish involved fathers have been not only regarded as the role model in many countries, b...Sweden has transformed into a considerable gender equality and family-friendly society over the past half-century. Meanwhile, Swedish involved fathers have been not only regarded as the role model in many countries, but also been the focus of extensive research. However, the trajectory trends of shifting practices on fatherhood in postmodem Sweden and the reasons underlying the whole gender equality reforms are still not clearly illustrated and explored. Therefore, this paper tries to answer these questions by reviewing related literature from 1960 to 2017. It is found that although dual-earner and dual-carer models were proposed together as early as the mid-1960s, it was the former that proved easier to achieve. Since 1990s substantial shifts in the practices on fatherhood have occurred in Sweden. Nowadays, it becomes quite nature and common for Swedish fathers to take parental leave and share housework and childcare with their partners. The findings also highlight that in the transition towards a father-friendly state, the following causes and factors have interplayed with each other in Sweden： （a） Comprehensive and thorough grassroots feminist cultures and strategists have laid the foundations of gender equality in education, politics, economics and religion; （b） New images of fatherhood in the literature and medium programs have further shaped the values of respecting nurturing and soft fathers; （c） Father-friendly social policies have significantly constructed the dual-earner and dual-carer models; and （d） Organizational culture on balancing work and life has strongly supported the practices on involved and active fathering. Last, this paper concludes with a discussion on the importance of oral history and comparative studies on shifting fatherhood.展开更多
基金supported by National Natural Science Foundation of China(32071963)the Chengdu Science and Technology Project,China(2020-YF09-00033-SN)+1 种基金a grant from the International S&T Cooperation Projects of Sichuan Province,China(2020YFH0126)the China Agriculture Research System of MOF and MARA(CARS04-PS19)。
文摘Plant photosynthesis assimilates CO_(2)from the atmosphere,and CO_(2)diffusion efficiency is mainly constrained by stomatal and mesophyll resistance.The stomatal and mesophyll conductance of plants are sensitive to abiotic stress factors,which affect the CO_(2)concentrations at carboxylation sites to control photosynthetic rates.Early studies conducted relevant reviews on the responses of stomatal conductance to the environment and the limitations of mesophyll conductance by internal structure and biochemical factors.However,reviews on the abiotic stress factors that systematically regulate plant CO_(2)diffusion are rare.Therefore,in this review,the rapid and long-term responses of stomatal and mesophyll conductance to abiotic stress factors(such as light intensity,drought,CO_(2)concentration and temperature)and their physiological mechanisms are summarized.Finally,future research trends are also investigated.
基金Supported by the National Natural Science Foundation of China under Grant No 51202196the Northwestern Polytechnical University(NPU)Foundation for Fundamental Research(No JC201111)+1 种基金the Research Fund of the State Key Laboratory of Solidification Processing(NWPU)(No 58-TZ-2011)the 111 Project(No B08040).
文摘Resistive switching characteristics of hafnium oxide are studied for possible nonvolatile memory device applications.The HfOx films with different oxygen contents are deposited by rf magnetron sputtering under different O_(2) flow rates.The films are amorphous,and the stoichiometric of the film is improved by increasing the O_(2) flow rate.Current-voltage characteristics of the TiN/HfOx/ITO device are investigated with 1 mA compliance.The bipolar resistive switching behavior is observed for the TiN/HfOx/ITO structure,and the resistive switching mechanism of the TiN/HfOx/ITO structure is explained by trap-controlled space charge limit current conduction.
基金by the Northwestern Polytechnical University(NPU)Foundation for Fundamental Research under Grant No JC201111the Research Fund of the State Key Laboratory of Solidification Processing(NWPU)under Grant No 58-TZ-2011,and the 111 Project under Grant No B08040.
文摘Hafnium oxide films are deposited on Si(100)substrates by means of rf magnetron sputtering.The interfacial structure is studied using high-resolution transmission electron microscopy(HRTEM)and x-ray photoelectron spectroscopy(XPS),and the electrical properties of the Au/HfO_(2)/Si stack are analyzed by frequency−dependent capacitance-voltage(C–V–f)measurements.The amorphous interfacial layer between HfO_(2) and the Si substrate is observed by the HRTEM method.From the results of XPS,the interfacial layer comprises hafnium silicate and silicon oxide.For C–V–f measurements,the C–V plots show a peak at a low frequency and the change in frequency has effects on the intensity of the peak.As expected,rapid thermal annealing can passivate the interface states of the HfO_(2)/Si stack.
基金Supported by the Natural Science Foundation of China under Grant No 50902110the Natural Science Foundation of Shaannxi Province under Grant No 2012JM6012+1 种基金the 111 Project under Grant No B07040the Northwestern Polytechnical University Foundation for Fundamental Research under Grant No JC20110245.
文摘The structural,electronic and mechanical properties of cubic SrHfO_(3) under hydrostatic pressure up to 70 GPa are investigated using the first-principles density functional theory(DFT).The calculated lattice parameter,elastic constants and mechanical properties of cubic SrHfO_(3) at zero pressure are in good agreement with the available experimental data and other calculational values.As pressure increases,cubic SrHfO_(3) will change from an indirect band gap(Γ-R)compound to a direct band gap(Γ-Γ)compound.Charge densities reveal the coexistence of covalent bonding and ionic bonding in cubic SrHfO_(3).With the increase of pressure,both the covalent bonding(HfO)and ionic bonding(SrO)are strengthened.Cubic SrHfO_(3) is mechanically stable when pressure is lower than 55.1 GPa,whereas that is instable when pressure is higher than 55.1 GPa.With the increasing pressure,enthalpy,bulk modulus,shear modulus and Young's modulus increase,whereas the lattice parameter decreases.Moreover,cubic SrHfO_(3) under pressure has higher hardness and better ductility than that at zero pressure.
文摘Sweden has transformed into a considerable gender equality and family-friendly society over the past half-century. Meanwhile, Swedish involved fathers have been not only regarded as the role model in many countries, but also been the focus of extensive research. However, the trajectory trends of shifting practices on fatherhood in postmodem Sweden and the reasons underlying the whole gender equality reforms are still not clearly illustrated and explored. Therefore, this paper tries to answer these questions by reviewing related literature from 1960 to 2017. It is found that although dual-earner and dual-carer models were proposed together as early as the mid-1960s, it was the former that proved easier to achieve. Since 1990s substantial shifts in the practices on fatherhood have occurred in Sweden. Nowadays, it becomes quite nature and common for Swedish fathers to take parental leave and share housework and childcare with their partners. The findings also highlight that in the transition towards a father-friendly state, the following causes and factors have interplayed with each other in Sweden： （a） Comprehensive and thorough grassroots feminist cultures and strategists have laid the foundations of gender equality in education, politics, economics and religion; （b） New images of fatherhood in the literature and medium programs have further shaped the values of respecting nurturing and soft fathers; （c） Father-friendly social policies have significantly constructed the dual-earner and dual-carer models; and （d） Organizational culture on balancing work and life has strongly supported the practices on involved and active fathering. Last, this paper concludes with a discussion on the importance of oral history and comparative studies on shifting fatherhood.
