冬小麦开花期光合源构成及其对穗粒重的贡献

采用剪摘叶片、包穗方法研究了4个冬小麦品种开花期不同光合源构成及其对穗粒重的影响。结果表明，开花期不同光合器官占总绿色面积的比例为：叶片49．82％～55．27％，茎鞘24．76％～30．83％，穗部19．11％～21．68％；4个品种非叶器官绿色面积与叶片面积的比例依次为1．00：1，1．01：1，0．81：1和0．96：1，且随着时间的推移逐渐增大。不同光合器官对穗粒重的贡献率分别为：叶片37．62％～55．49％、茎鞘23．78％～31．72％、穗部20．73％～30．65％，不同穗型品种比较，大穗型品种的茎鞘和穗部贡献率均大于多穗型品种，而叶片的贡献率则相反；不同叶位叶片的贡献率为：旗叶〉倒二叶〉倒三叶〉倒四叶，4个品种一致。当某一叶片损失后，剩余邻近叶片的光合速率有明显的补偿效应。

Photosynthetic Characteristic Variation of Different Provenances of Liriodendron chinense Sarg. at Seedling Stage

[Objective]The aim was to study photosynthetic characteristic variation of different provenances of Liriodendron chinense Sarg. at seedling stage and provide the theoretical basis for work of provenance selection,parent selection of hybridizing breeding,genetic resource conservation of L.chinense Sarg.. [Method]With 13 provenances 1-year-old L.chinense Sarg. seedlings as tested materials,the photosynthetic characteristic variation of different provenances were studied. [Result]The L.chinense Sarg. seedlings of different provenances had the significant difference on net photosynthetic rate （Pn）,stomata conductivity （Gs） and water use efficiency （WUE）. The Pn of the highest provenance was 2.36 times the lowest. Majority seed sources light saturation point （LSP） were in 800-1 200 μmol photons/（m2·s）. Gs,transpiration rate （Tr） and Pn were significantly positively correlated,and the three had a significant positive correlation with the light compensation point （LCP）. Pn,LSP and WUE were negatively correlated. [Conclusion]The photosynthetic characteristics of L.chinense Sarg. had significant variation among provenances. Maybe Gs is the important factor leading to difference in Pn of L.chinense Sarg. seedlings. L.chinense Sarg. seedlings still need higher light intensity and more water.

Peak shaving operation optimization of high proportion new energypower generation considering wind-solar complementationand source-load coupling

To optimize peaking operation when high proportion new energy accesses to power grid,evaluation indexes are proposed which simultaneously consider wind-solar complementation and source-load coupling.A typical wind-solar power output scene model based on peaking demand is established which has anti-peaking characteristic.This model uses balancing scenes and key scenes with probability distribution based on improved Latin hypercube sampling(LHS)algorithm and scene reduction technology to illustrate the influence of wind-solar on peaking demand.Based on this,a peak shaving operation optimization model of high proportion new energy power generation is established.The various operating indexes after optimization in multi-scene peaking are calculated,and the ability of power grid peaking operation is compared whth that considering wind-solar complementation and source-load coupling.Finally,a case of high proportion new energy verifies the feasibility and validity of the proposed operation strategy.

Structural change of molybdenum sulfide facilitates the electrocatalytic hydrogen evolution reaction at neutral pH as revealed by in situ Raman spectroscopy

Molybdenum sulfides are promising electrocatalysts for the hydrogen evolution reaction(HER).Sand Mo‐related species have been proposed as the active site for forming adsorbed hydrogen to initiate the HER;however,the nature of the interaction between Mo centers and S ligands is unclear.Further,the development of cost‐effective water‐splitting systems using neutral water as a proton source for H2evolution is highly desirable,whereas the mechanism of the HER at neutral pH is rarely discussed.Here,the structural change in the Mo?Mo and S?S species in a synthesized molybdenum sulfide was monitored at neutral pH using in situ electrochemical Raman spectroscopy.Analysis of the potential dependent Raman spectra revealed that the band assigned to a terminal S?S species emerged along with synchronized changes in the frequency of the Mo?Mo,Mo3?μ3S,and Mo?S vibrational bands.This indicates that Mo?Mo bonds and terminal S?S ligands play synergistic roles in facilitating hydrogen evolution,likely via the internal reorganization of trinuclear Mo3?thio species.The nature and role of metal‐ligand interactions in the HER revealed in this study demonstrated a mechanism that is distinct from those reported previously in which the S or Mo sites function independently.

Numerical simulation and experimental study of hybrid laser-electric arc welding between dissimilar Mg alloys

This work aims to establish a suitable numerical simulation model for hybrid laser-electric arc heat source welding of dissimilar Mg alloys between AZ31 and AZ80. Based on the energy conservation law and Fourier’s law of heat conduction, the differential equations of the three-dimensional temperature field for nonlinear transient heat conduction are built. According to the analysis of nonlinear transient heat transfer, the equations representing initial conditions and boundary conditions are obtained. The “double ellipsoidal heat source + 3D Gaussian heat source”combination was chosen to construct the laser-electric arc hybrid heat source. The weld bead morphologies and the distribution of temperature, stress, displacement and plastic strains are numerically simulated. The actual welding experiments were performed by a hybrid laser-electric arc welding machine. The interaction mechanism between laser and electric arc in the hybrid welding of Mg alloys is discussed in detail. The hybrid heat source can promote the absorption of laser energy and electric arc in the molten pool, resulting in more uniform energy distribution in the molten pool and the corresponding improvement of welding parameters. This work can provide theoretical guidance and data supports for the optimization of the hybrid laser-electric arc welding processes for Mg alloys.

能量之源——光与光合作用(第三课时)教学设计和案例

1教学目标的确定 课程标准的具体内容标准中，与本节有关的表述是“说明光合作用，研究影响光合作用速率的环境因素。”其中属于了解的是：化能合成作用；属于理解并达到应用层次的是：光合作用的过程以及相关的反应场所、反应条件、物质变化、能量变化等基本知识，影响光合作用强度的环境因素。依据新课标、教科书和学生实际将本节课的三维教学目标确定为：

Design and application of integrated automation system platform of mine based on PON

This article analyzes the design and integrates application of a mine integrated automation system platform based on PON. At the beginning, the paper analyzes the basic principle and structure of PON. The set of integrated automation network platform according to the information transmission characteristics of mine based on access network and Ethernet of PON is designed. The paper descripes the platform in detail from aspacts of designs of system hardware, software and others. The results show that the system platform can improve the efficiency and reduce the cost.

Advanced yolk-shell nanoparticles as nanoreactors for energy conversion

Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.

Transmission Mechanism Based on Burst Filling in Hybrid Optical Burst/Circuit Switching Networks

Hybrid optical switching networks make full use of the advantages of Optical Circuit Switching(OCS)and Optical Burst Switching(OBS).In parallel hybrid optical switching networks,edge nodes choose a switching mode for traffic and no longer change.The inflexible decision making of the traffic transfer mode leads to low resource utilization when the arrival rate of the OCS traffic is lower than the capacity of the light path.In this paper,a new transmission scheme is proposed to improve resource utilization for hybrid optical switching networks.When the traffic arrival rate of the light path is lower than the transmission rate of the light path,the OCS traffic flow is reshaped at the edge nodes to generate a series of voids.Then,several message packets are sent along the light path to inform the core nodes of the voids of the light paths that represent the unused bandwidth resources.To improve the resource utilization,the voids can be filled with data bursts by core nodes.The simulation results show that the new scheme can effectively reduce the burst loss rate and improve the link utilization of the hybrid optical switching network on the premise of a providing service quality guarantee for OCS traffic.

Integration of the Energy and Building Technologies

The performance of each type of building must meet all the needs and requests of new real estate markets. In fact, in the excellent architectures, the user can manage, with autonomy and flexibility, each system and product, according to the new energy and building technologies too. The main objective is the social and environmental sustainability with the reduction of fossil fuels and the greenhouse gas effect, pushing the use of renewable energies, in a new trend of land regeneration with sustainable buildings and settlement recovery. The energy crisis, mainly generated by the climate change, the air pollution, with consequent extinction of the species, reduction of the land and the work, the degradation and the environmental and seismic risk, focuses on the security and quality of construction systems, integrated use of clean resources. The methodologies aimed at integrating of energy-efficient and innovative building technologies in architecture, from design to management, to produce electric and thermal energy with active and passive properties, for a high-performance habitat. Therefore, the use of solar photovoltaic in the buildings, BIPV （Building Integrated Photovoltaic） with high-performance glass vision, efficient systems, intelligent materials, is integrated in architectures with the use of innovative construction systems, finally, technology of OPV （Organic Photovoltaic）, multi-junction cells, the dye sensitized solar cells in the solid state, etc., and adoption of storage systems.

西北绿洲灌区玉米叶片衰老特征对不同地膜覆盖利用方式的响应

西北绿洲灌区玉米传统生产模式中大量使用地膜伴随着生态环境污染严重,且在极端高温下玉米出现叶片早衰。针对该现象,通过免耕一膜2年覆盖利用技术探讨延缓玉米叶片衰老并增加玉米产量的可行性,以期为构建西北绿洲灌区地膜减量玉米高效生产技术提供理论支撑。2013年在西北绿洲灌区设置免耕一膜2年覆盖利用(NTP)、秋免耕春覆膜(RTP)和传统每年覆新膜(对照, CTP) 3种处理(本文采用2021-2023数据),探究玉米叶片光合源、持绿特性、细胞抗氧化酶活性和渗透调节物质含量对不同地膜覆盖利用方式的响应。结果表明,NTP和RTP可有效调节玉米生育期内光合源和叶片持绿性能的动态关系,维持生育后期较大的叶面积指数(LAI)、光合势(LAD)、叶片持绿性(SG)和叶绿素相对含量(SPAD),有利于延缓叶片衰老。与CTP相比, NTP玉米出苗后75~120 d的LAI、LAD、SG和SPAD分别提高15.1%~16.1%、14.8%~15.5%、7.2%~9.2%和11.3%~11.7%,RTP分别提高12.4%~13.0%、11.5%~12.4%、10.0%~17.6%和6.0%~6.7%。同时,通过单株绿色叶面积的拟合,发现NTP和RTP较CTP叶片衰老时间平均推迟了5.8~7.0d和6.2~7.7d,这可能是由于NTP和RTP有助于增强玉米大喇叭口期-灌浆期叶片的抗氧化能力和细胞渗透调节作用。玉米出苗后60~105 d, NTP较CTP叶片抗氧化酶(SOD、POD、CAT和APX)活性分别提高17.6%~20.0%、28.4%~34.4%、6.7%~8.4%和8.3%~10.9%, RTP较CTP分别提高11.3%~11.7%、16.9%~18.2%、4.4%~6.1%和5.8%~7.7%。此外,与CTP相比,NTP与RTP可溶性蛋白和脯氨酸含量分别提高35.9%~43.9%和29.5%~31.8%,20.7%~31.7%和17.4%~20.4%,丙二醛含量分别降低26.0%~27.8%和17.5%~25.9%。NTP对抗氧化酶和渗透调节物质的影响更大,NTP较CTP增产5.2%~6.0%。免耕一膜2年覆盖利用技术是西北灌区在实现资源减投条件下,有效延缓玉米叶片衰老且增加产量的适宜措施。

Decoherence-and Dimerization-assisted Energy Transport in Protomer of Light-Harvesting Complexes

We have investigated the dynamics of a protomer coupled to two different decoherent environments,each in a configuration called the spin star configuration.Using the quantum mechanics method,in different situations,we obtain the analytical expressions for the transition probability in the protomer system.In thermal equilibrium,there exist well-defined ranges of parameters for which decoherent interaction between the protomer and the environment assists energy transfer in the protomer system,while in pure quantum mechanics states,the decoherent interaction assists energy transfer for an eigenstate but against energy transfer for quantum mechanics averages.In particular,we also find that the dimerization of two bacteriochlorophylls in protomer can always assist energy transfer in certain parameter range,and in the appropriate spin bath energy,the efficiency of energy transport is sensitively depended on the temperature of environments.

Tunable time delay in active fiber Bragg grating coupler

Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In this paper,the transmission spectrum and reflective spectrum of active fiber Bragg grating(FBG)couplers are studied,and the analytic expressions of dispersion and time delay are obtained.By changing the detuning and gain coefficient,different dispersions and time delays in active fiber Bragg grating coupler are obtained.The results show that different detunings and gain coefficients can result in various time delays,and thus tunable time delay could be achieved by changing signal frequency or gain coefficient.

Sharp scattering spectra induced brilliant and directional structural colors

Structural color materials,which generate colors through the interaction between light and nano-microstructures,have always been research hotspots in the fields of display,anticounterfeiting and stimuli-responsive materials.Structural colors based on scattering have received increasing attention due to their wider viewing angles than that originating from the specular reflection of photonic crystals.However,the wide scattering spectrum of an amorphous structure leads to lower purity and brightness of the appeared colors.Few researchers have focused on the scattering of ordered structures due to their strong reflection and diffraction in the visible regions.In this work,by building ordered films(OFs)using SiO2 spheres(refractive index n=1.46)with a diameter of 300–500 nm,for the first time,sharp scattering spectra with narrow full width at half-maximum(FWHM,24 nm)were generated.Importantly,under ambient light,brilliant colors covering the entire visible region can be observed,and a formula was proposed to calculate the scattering spectra of OFs.Moreover,rainbow structural color was realized under irradiation of the nonparallel light,and full-spectrum structural color patterns were fabricated using building blocks with a single particle size by a spraying method.Finally,a composite structure was constructed to explore possibilities in the field of flexible transparent displays.

Photocatalysis with visible-light-active uranyl complexes

Atomic energy is an important part of current energy resources.Production of nuclear weapons and applications of nuclear fuels in nuclear power plants have accumulated numerous spent fuels containing238U compounds,which are critical nuclear materials.How to reduce the nuclear wastes and to make use of the spent uranium are key scientific issues of environmental and nuclear science.We have reviewed here the physiochemical properties and photocatalytic mechanisms of homogeneous and heterogeneous uranium-containing materials.The current research efforts demonstrate that spent fuels can become promising new photocatalytic materials.

Facile preparation of self-assembled MXene@Au@CdS nanocomposite with enhanced photocatalytic hydrogen production activity

Photocatalytic hydrogen production is considered a promising approach to generating clean sustainable energy.However,the conventional co-catalyst(e.g.,Pt)used in photocatalytic hydrogen production is high-cost and difficult to obtain.Here,we designed and prepared a ternary nanocomposite MXene@Au@Cd S,which can be used in the field of efficient and excellent photocatalytic hydrogen production.The MXene@Au@Cd S has a hydrogen production rate of 17,070.43μmol g^-1h^-1(tested for 2 h),which is 1.85 times that of pure Cd S nanomaterials.The improved hydrogen production performance of the MXene@Au@Cd S is attributed to:(i)MXene provides more active adsorption sites and reaction centers for Au and Cd S nanoparticles;(ii)the synergistic effect of Au’s strong surface plasmon resonance expands the optical response range of Cd S.Therefore,this work solves the problem of the solid connection between the surface functional groups of photocatalyst,and achieves rapid interface charge transfer and long-term stability during the hydrogen production.