果胶酶产生菌的选育

本试验筛选到一株适于使苹果汁澄清的果胶酶产生黑曲菌No.07,应用物理因素及化学因素对No.07进行处理,从白色突变菌落中获得一高产株CL—8501,对CL—8501的培养基及发酵条件进行了优化,在优化的培养基及较适条件下,CL—8501产酶达631.6单位/毫升,产量此出发株No.07提高约105倍。     

Performance Improvement of Lead-Based Halide Perovskites through B-Site Ion-Doping Strategies

Owing to their excellent properties, lead halide perovskites have attracted extensive attention in the photoelectric field. Presently, the certified power conversion efficiency of perovskite solar cells has reached 25.7%, the specific detectivity of perovskite photodetectors has exceeded 10¹⁴ Jones, and the external quantum efficiency of perovskite-based light-emitting diode has exceeded 26%. However, their practical applications are limited by the inherent instability induced by the perovskite structure due to moisture, heat, and light. Therefore, one of the widely used strategies to address the issue is to replace partial ions of the perovskites with ions of smaller radii to shorten the bond length between halides and metal cations, improving the bond energy and enhancing the perovskite stability. Particularly, the B-site cation in the perovskite structure can affect the size of eight cubic octahedrons and their gap. However, the X-site can only affect four such voids. This review comprehensively summarizes the recent progress in B-site ion-doping strategies for lead halide perovskites and provides some perspectives for further performance improvements.     

A new model of gross primary productivity for North American ecosystems based solely on the enhanced vegetation index and land surface temperature from MODIS

Many current models of ecosystem carbon exchange based on remote sensing, such as the MODIS product termed MOD17, still require considerable input from ground based meteorological measurements and look up tables based on vegetation type. Since these data are often not available at the same spatial scale as the remote sensing imagery, they can introduce substantial errors into the carbon exchange estimates. Here we present further development of a gross primary production (GPP) model based entirely on remote sensing data. In contrast to an earlier model based only on the enhanced vegetation index (EVI), this model, termed the Temperature and Greenness (TG) model, also includes the land surface temperature (LST) product from MODIS. In addition to its obvious relationship to vegetation temperature, LST was correlated with vapor pressure deficit and photosynthetically active radiation. Combination of EVI and LST in the model substantially improved the correlation between predicted and measured GPP at 11 eddy correlation flux towers in a wide range of vegetation types across North America. In many cases, the TG model provided substantially better predictions of GPP than did the MODIS GPP product. However, both models resulted in poor predictions for sparse shrub habitats where solar angle effects on remote sensing indices were large. Although it may be possible to improve the MODIS GPP product through improved parameterization, our results suggest that simpler models based entirely on remote sensing can provide equally good predictions of GPP.     

Scalable and controllable synthesis of 2D high-proportion 1T-phase MoS2

Two-dimensional molybdenum disulfide (2D MoS₂) is considered as a promising candidate for many applications due to its unique structure and properties. However, the controllable synthesis of large-scale and high-quality 2D 1T-phase MoS₂ is still a challenge. Herein, we present the scalable and controllable synthesis of 2D MoS₂ from 2H to 1T@2H phase by using K₂SO₄ salt as a simultaneous high-temperature sulfur source and template. The as-synthesized 1T@2H-2D MoS₂ exhibits a high yield and can be easily assembled into freestanding electrode with high specific capacitance of 434 F/g at a scan rate of 1 mV/s in LiClO₄ ethylene carbonate/dimethyl carbonate (EC/DMC). Moreover, various single-crystal 2D transition metal sulfides (WS₂, PbS, MnS and Ni₉S₈) and 2D S-doped carbon can be synthesized using this method. We believe that this study may provide a new sight for scalable and controllable synthesis of other 2D materials beyond 2D MoS₂.

     

Microwave Combustion for Rapidly Synthesizing Pore‐Size‐Controllable Porous Graphene

Porous graphene has been widely applied in energy storage, electrocatalysis, photoelectron devices, etc. However, the producing process for porous graphene usually needs long time and is a tedious step. In this work, porous graphene is prepared with controllable pore size by using active metal nanoparticles to catalytically oxidize carbon under microwave combustion process within tens of seconds. The ion exchange membrane based on porous graphene with ≈5 nm pore diameter exhibits a great performance for salinity gradient power generation application with a power density output of ≈1.15 W m^?2. This work highlights a new strategy for the design and synthesis of pore‐size‐controllable porous graphene and provides new opportunities for 2D porous nanomaterials.     

A Solvent Molecule Driven Pure PEDOT:PSS Actuator

Actuators which mechanically respond to various external stimuli are promising for diverse applications including soft robots, energy generators, artificial muscles, and sensors. Herein, a PEDOT:PSS film based vapor‐driven soft actuator by using H₂SO₄ treated process is presented. This actuator exhibits rapid (0.24 s for one actuation) and robust (>1000 times without obvious fatigue) responses to stimuli of various organic solvents with reversible large‐shape deformations. By coating gold on the one side of the PEDOT:PSS film with subsequent generation of specific patterns, the designed bilayer‐structured actuator achieves controllable actuation including vertical and helical bending. Furthermore, a walking robot and a vapor‐driven generator are successfully constructed with remarkable performances upon vapor stimuli using the proposed PEDOT:PSS film based actuator. The achievement presented here opens a new avenue for a new generation of robots and smart sensors.