摘要：During the operation of the rice combine harvester,the fuselage tilts due to the tilt and unevenness of the ground affect its maneuverability and operational *** at the problem of leveling due to the tilt of the field surface,this research developed an innovative dual-parallelogram chassis lifting mechanism for rice harvesters designed a hydraulic system to adjust the chassis height by extending the *** Adams simulation software,a detailed model of the lifting chassis was constructed to analyze its performance,revealing a direct correlation between the hydraulic cylinder extension and chassis ***,the mechanism could achieve leveling on slopes with inclination angles of up to 7.5°.Comprehensive evaluations of the liftable chassis system were conducted under both static and dynamic *** the static tests,the system exhibited the capacity for comprehensive or unilateral auto-leveling contingent upon the tilt,with leveling times and angular variations confined to 3.6 s and±0.4°,*** dynamic tests conducted on sloped fields and paddy soils,the system reduced post-leveling mean tilt angles and standard deviations remained below 1.2°and 0.6°,*** results demonstrated a substantial improvement in the stability and reliability of the chassis during *** research provides valuable insights into the design and optimization of automatic leveling mechanisms and structural innovations for harvester chassis.

摘要：The 1.55-μm quantum-dot (QD) micropillar cavities are strongly required as single photon sources (SPSs) for silica-fiber-based quantum information processing. Theoretical analysis shows that the adiabatic distributed Bragg reflector (DBR) structure may greatly improve the quality of a micropillar cavity. An InGaAsP/InP micropillar cavity is originally difficult, but it becomes more likely usable with inserted tapered (thickness decreased towards the center) distributed DBRs. Simulation turns out that, incorporating adiabatically tapered DBRs, a Si/SiO2- InP hybrid micropillar cavity, which enables weakly coupling InAs/InP quantum dots (QDs), can even well satisfy strong coupling at a smaller diameter. Certainly, not only the tapered structure, other adiabatic designs, e.g., both DBR layers getting thicker and one thicker one thinner, also improve the quality, reduce the diameter, and degrade the fabrication difficulty of Si/SiO2-InP hybrid micropillar cavities. Furthermore, the problem of the thin epitaxial semiconductor layer can also be greatly resolved by inserting adiabatic InGaAsP/InP DBRs. With tapered DBRs, the InGaAsP/InP-air-aperture micro-pillar cavity serves as an efficient, coherent, and monolithically producible 1.55-μm single-photon source (SPS). The adiabatic design is thus an effective way to obtain prospective candidates for 1.55-μm QD SPSs.

摘要：Electrochemical CO_(2) reduction reaction (CO_(2) RR) offers a practical solution to current global greenhouse effect by converting excessive CO_(2) into value-added chemicals or fuels. Noble metal-based nanomaterials have been considered as efficient catalysts for the CO_(2) RR owing to their high catalytic activity, long-term stability and superior selectivity to targeted products. On the other hand, they are usually loaded on different support materials in order to minimize their usage and maximize the utilization because of high price and limited reserve. The strong metal-support interaction (MSI) between the metal and substrate plays an important role in affecting the CO_(2) RR performance. In this review, we mainly focus on different types of support materials (e.g., oxides, carbons, ligands, alloys and metal carbides) interacting with noble metal as electrocatalysts for CO_(2) RR. Moreover, the positive effects about MSI for boosting the CO_(2) RR performance via regulating the adsorption strength, electronic structure, coordination environment and binding energy are presented. Lastly, emerging challenges and future opportunities on noble metal electrocatalysts with strong MSI are discussed.

摘要：As a famous hole transporting material, nickle oxide (NiOx) has drawn enormous attention due to its low cost and superior stability. However, the relatively low conductivity and high-density surface trap states of NiOx severely limit device performance in solar cell applications. Interfacial engineering is an efficient approach to achieve remarkable hole-transporting performance by surface passivation. Herein, the efficient NiOx hole transport layer was prepared by surface passivation engineering strategy via facile solution processes with cesium iodide (CsI). It is demonstrated that CsI plays a super-effective dual-function role in inverted solar cell device: On one hand, the presence of CsI hugely passivates the surface trap states at the NiOx/perovskite interface along with obviously improved conductivity by the incorporated Cs^(+);on the other hand, the ions immigration is significantly suppressed by the presence of I ion for high-quality perovskite films, resulting in a stable contact interface. The ameliorative interface leads to largely reduced carrier non-radiative recombination, attributing to boosted carrier extraction efficiency. As a result, decent power conversion efficiency (PCE) of 18.48% with a noticeable fill factor (FF) beyond 80% was achieved. This facile and efficient surface engineering approach with dual-function shows excellent potential for the design of high-performance functional interfacial modification layer to achieve high-performance solar cells.

摘要：研究了单道次皮尔格轧制过程中Ti-2Al-2.5Zr材料的变形行为和织构的演变规律。结果表明,在轧制过程中,■孪晶和柱面滑移是最容易被激活的2种变形模式,■孪晶的产生使得晶粒在轴向上的位向从■转向■。并且,在不同瞬时Q值和等效应变量下,滑移和孪生导致{0001}极图中最大极密度点在切向上发生变化。

摘要：With the development in photocatalysis field,photocatalysts have received increasing attention due to their important role in environmental pollution and energy *** a nonmetallic photocatalyst,graphitic carbon nitride(g-C3N4)has been widely recognized because of its excellent optical properties,low cost,and environment *** the g-C3N4 intrinsic frameworks,carbon atom tends to be the reducing active site,while nitrogen atom tends to be the oxidizing active site and reducing active site according to the difference of ***,the quantity and quality of these active sites are affected by many factors,including C N covalent bonds,surface properties,*** sites play an important role in photocatalysis;however,this role is not detailed in most *** this review,we proposed the following possible mechanisms of active sites in improving the photocatalytic activity of traditional g-C_(3)N_(4) based on its intrinsic:morphology regulation,carrier migration,surface active treatment,and substrate *** following factors affecting the active sites of g-C_(3)N_(4),including basal engineering and hybrid engineering,were also *** roles of these active sites in improving the photocatalytic activity of g-C_(3)N_(4)-based photocatalytic materials,including morphology regulation,surface treatment,heteroatom doping,and interfacial interaction,were also *** challenges and future development of g-C_(3)N_(4)-based photocatalysts that are rich in active surface sites were also *** review provides an in-depth understanding of g-C_(3)N_(4)-based photocatalysts.

摘要：Based on the precipitation data observed by stations and data simulated by 23 CMIP5 models,the features and future changes of summer(Jun-JulAug)extreme precipitation events in sichuan Province of China were *** found that the total precipitation(RSum),extreme precipitation threshold(Threshold90),extreme precipitation(TR90),extreme precipitation percentage(TR90 pct)and extreme precipitation intensity(TR90 str)decreased from the southeast to the northwest in sichuan Province,reflecting the differences between eastern sichuan(ESC,basins)and western sichuan(WSC,mountains).Compared with the observations,most of the CMIP5 models showed that there were wet biases in WSC and an unclear bias pattern in ESC for the RSum,Threshold90,TR90,and TR90 ***,the extreme precipitation days(ND90)and TR90 pct values simulated by the models were generally overestimated and underestimated,*** with the historical period,most models showed obvious increases in the TR90 and TR90 pct in the 21 century,while the characteristics of Rsum,ND90,and TR90 str were *** with the mid-21 st century,the extreme precipitation in the late-21 st century exhibited a certain degree of *** during the same period,the results of RCP8.5 were higher than those of RCP4.5,especially for the ND90,TR90,and TR90 pct.

摘要：During oil-gas well drilling and completion, downhole tools and apparatus should be conveyed to the destination to complete a series of downhole works. Downhole tractors have been used to convey tools in complex wellbores, however a very large tractive force is needed to carry more downhole tools to accomplish works with high efficiency. A novel serial active helical drive downhole tractor which has significantly improved performance compared with previous work is proposed. All previously reported helical drive downhole tractors need stators to balance the torque generated by the rotator. By contrast, the proposed serial downhole tractor does not need a stator; several rotator-driven units should only be connected to one another to achieve a tractive force multifold higher than that was previously reported. As a result, the length of a single unit is shortened, and the motion flexibility of the downhole tractor is increased. The major performance indicators, namely, gear ratio, velocity, and tractive force, are analyzed. Experimental results show that the maximum tractive force of a single-unit prototype with a length of 900 mm is 165.3 kg or 1620 N. The analysis and experimental results show that the proposed design has considerable potential for downhole works.

摘要：A dynamic geometry system,as an important application in the field of geometric constraint solving,is widely used in elementary mathematics education;moreover,the dynamic geometry system is also a fundamental environment for automated theorem proving in *** a geometric constraint solving process,a situation involving a critical point is often encountered,and geometric element degeneracy may occur at this ***,the degeneracy situation must be substantively focused on during the learning and exploration ***,many degeneracy situations cannot be completely presented even by the well-known dynamic geometry *** this paper,the mechanisms causing the degeneracy of a geometric element are analyzed,and relevant definitions and formalized descriptions for the problem are provided according to the relevant modern Euclidean geometry *** solve the problem,the data structure is optimized,and a domain model design for the geometric element and the constraint relationships thereof in the dynamic geometry system are formed;furthermore,an update algorithm for the element is proposed based on the novel domain *** addition,instances show that the proposed domain model and the update algorithm can effectively cope with the geometric element degeneracy situations in the geometric constraint solving process,thereby achieving unification of the dynamic geometry drawing and the geometric intuition of the user.

摘要：The combined use of guided tissue/bone regeneration(GTR/GBR)membranes and bone filling grafts represents a classical therapy for guiding the regeneration and functional reconstruction of oral soft and hard ***,due to its displacement and poor mechanical support,bone meal is not suitable for implantation in the case of insufficient cortical bone support and large dimensional *** combination of GTR/GBR membrane with a three-dimensional(3D)porous scaffold may offer a resolution for the repair and functional reconstruction of large soft and hard tissue *** this study,a novel integrated gradient biodegradable porous scaffold was prepared by bonding a poly(lactic-co-glycolic acid)(PLGA)/fish collagen(FC)electrospun membrane(PFC)to a 3D-printed PLGA/nano-hydroxyapatite(HA)(PHA)*** consistency of the composition(PLGA)ensured strong interfacial bonding between the upper fibrous membrane and the lower 3D *** vitro cell experiments showed that the PFC membrane(upper layer)effectively prevented the unwanted migration of L929 *** in vivo investigations with an oral soft and hard tissue defect model in beagles revealed that the integrated scaffold effectively guided the regeneration of defective oral *** results suggest that the designed integrated scaffold has great potential for guiding the regeneration and reconstruction of large oral soft and hard tissues.