Chemical modification of cellulose to prepare functional cellulose derivatives could enable the utilization of cellulose in various promising applications. However, the conventional methods for ...cellulose functionalization suffer from severe drawbacks, especially the environmental aspects, due to the use of toxic reagents and the generation of large amounts of waste. Herein, a more sustainable way, the novel hydroxyl-yne click reaction, is proposed to synthesize cellulose derivatives. The hydroxyl groups of ethyl cellulose (EC) were reacted with the alkyne groups of 1-phenyl-2-propargyl-1-ketone (PPK) at room temperature for preparing new kinds of ethyl cellulose phenyl propylene ketone ether derivatives (ECPPKs). More than 80% substitution was rapidly completed within the first 5 min and 82% of the residual hydroxyl groups (-OH
C3
) in EC could be substituted, demonstrating the high efficiency of the hydroxyl-yne click reaction for the modification of cellulosic materials. FTIR and NMR results proved the successful grafting of PPK
via
a vinyl ether linkage (-C-O-C&z.dbd;C-). The introduction of PPK moieties widened the temperature window for the melt processing of cellulose, which is beneficial for the thermo processing of cellulosic materials. Furthermore, owing to the existence of the newly formed vinyl ether linkage, ECPPKs showed almost 100% shielding ratio for UV light and visible light (420 nm) excited fluorescence properties. This facile and efficient method provides a more sustainable strategy for the functionalization of cellulosic materials, expanding its application in UV-blocking and fluorescent material fields.
A novel cellulose phenyl propylene ketone ether was efficiently prepared
via
a hydroxyl-yne click reaction at room temperature.
In this article, tube-based model predictive control (MPC) is investigated for a linear parameter-varying (LPV) system with external disturbances. The LPV system comes from an autonomous vehicle with ...external disturbances and scheduling parameters in trajectory tracking. An interval predictor is designed for state constraints under external disturbances and scheduling parameters. With a robust controller based on the nominal state obtained by solving MPC, antidisturbance ability and dynamic performance are improved for the LPV system with external disturbances. Both recursive feasibility and input-to-state stability are analyzed for the closed-loop system using the tube-based MPC with the interval predictor. The effectiveness of the tube-based MPC is shown by numerical simulation on trajectory tracking for the autonomous vehicle.
A neural network kinetic model is developed for oxidative coupling of methane (OCM). The model is designed in cognizance of the underlying chemistry and associated reactor balance equations and ...trained on publicly available high throughput experimental data spanning a large material space of supported mixed metal oxide catalysts. The resultant model is then used to evaluate one of the most popular catalysts for OCM, viz. MnNa2WO4/SiO2, to understand the reaction kinetics and sensitivity of the catalyst to changing different components of the catalyst. The predicted activation barrier for methane conversion is 251 kJ mol−1, and the rate r∼CH40.7O20.6. Furthermore, the reference catalyst is local optimal as small changes to its composition, for example, by changing the individual metals or the support, did not improve (or often substantially reduced) methane consumption or the C2 formation rate.
Two-dimensional (2D) Janus structure is promising for photocatalytic water splitting because its intrinsic built-in electric field can overpass the bandgap requirements of photocatalysts. However, ...how to achieve overall water splitting spontaneously in one structure is still difficult. Here, we present a novel family of 2D Janus perovskite oxynitrides, BaXNO
2
(X = Ta, Nb, V), with a large intrinsic built-in electric field based on first-principles calculations. Both 2D BaTaNO
2
and BaNbNO
2
exhibit remarkable activity for photocatalytic overall water splitting. For BaNbNO
2
, a lowest overpotential of 0.44 V for the oxygen evolution reaction (OER) is realized. The Gibbs free energy of hydrogen adsorption (Δ
G
H
) is near zero (0.02 eV) for BaTaNO
2
in the hydrogen evolution reaction (HER). Interestingly, 2D BaVNO
2
shows in-plane ferroelectricity due to the displacement of V ions accompanied by a ferroelastic distortion of the lattice, which modulates the band structures, resulting in optimized band alignment. The photocatalytic performance can be further improved by constructing a BaNbNO
2
/BaVNO
2
heterostructure, which has an overpotential of 0.47 V for the OER and Δ
G
H
of 0.16 eV for the HER. Our theoretical investigation provides not only a guidance to design Janus photocatalysts for full water splitting, but also strategies to modulate the photocatalytic performance through ferroelectricity.
In-plane ferroelectricity can control the band structures of 2D BaVNO
2
for optimized photocatalytic activity. Remarkable overall photocatalytic performance is achieved through effective ferroelectric modulation and heterostructure engineering.
Owing to a higher energy supply efficiency and operational flexibility, integrated energy system (IES), including the power, heating, and gas systems, will be the primary form of energy supply in the ...future. However, with the increase of large-scale stochastic wind power integration, the IES planning will face a significant challenge as the traditional power system. Therefore, a probability-interval-based IES planning considering wind power integration is proposed in this article. First, a conditional value-at-risk (CVaR) based probability-interval method is developed to describe the uncertain wind power. Second, beside traditional facilities, electricity storage system is introduced to improve the flexibility of IES. Then, an expansion planning model for IES is established to minimize the total cost including investment, operation, CVaR cost, and unserved energy cost. Moreover, the piecewise linearization method is used to deal with the nonlinear integral terms of the proposed model to improve the solution efficiency. Finally, IEEE14-NGS14 and IEEE118-NGS40 systems are constructed and the planning model is solved by GAMS/CPLEX. The numerical results illustrate the correctness and effectiveness of the proposed method.
Fully aromatic conjugated covalent organic frameworks (FAC‐COFs) with excellent physicochemical stability have been emerging as active semiconductors for diverse potential applications. Developing ...efficient synthesis methods for fabricating FAC‐COFs will significantly facilitate the exploration over their material and photonic/electronic functionalities. Herein, a facile solvent‐free strategy is developed for the synthesis of 2D phthalocyanine‐based FAC‐COFs (FAC‐Pc‐COFs). Cyclopolymerization of benzo1,2‐b:4,5‐b′bis1,4benzodioxin‐2,3,9,10‐tetracarbonitrile (BBTC) and quinoxalino2′,3′:9,10phenanthro4,5‐abcphenazine‐6,7,15,16‐tetracarbonitrile (QPPTC) in ZnCl2 leads to the fast formation and isolation of BB‐FAC‐Pc‐COF and QPP‐FAC‐Pc‐COF, respectively. Powder X‐ray diffraction and electron microscopy analysis reveal their crystalline nature with sql topology and AA stacking configuration. Thermogravimetric analysis and immersion experiment indicate their excellent stability. The conductivity test demonstrates their high conductivity of 0.93–1.94 × 10−4 S cm−1 owing to the fully π‐conjugated electronic structural nature. In particular, the as‐prepared FAC‐Pc‐COFs show high‐performance K+ storage in potassium‐ion batteries due to their excellent conductivity, highly ordered and robust structure, and N/O‐rich framework nature. Impressively, QPP‐FAC‐Pc‐COF shows a large reversible capacity of 424 mA h g−1 after 100 cycles at 50 mA g−1 and a capacity retention of nearly 100% at 2000 mA g−1 for over 10 000 cycles.
A facile solvent‐free strategy is developed for the fast synthesis of fully conjugated phthalocyanine‐based covalent organic frameworks (COFs). The as‐prepared COFs show high‐performance K+ storage in potassium‐ion batteries with the achievement of a high reversible capacity of 424 mA h g−1 at 50 mA g−1 due to their good conductivity, highly ordered and robust structure, and N/O‐rich framework nature.
A large number of distributed energy resources (DERs) integrate into the distribution network, which changes the power flow, increases the power fluctuations, and complicates the scheduling of the ...distribution network. To cope with that, a multitimescale scheduling method, which considers the demand response as well as user satisfaction, is proposed in this paper. First, in the day-ahead stage, both the generation-side and demand-side are combined to minimize the operating costs and reduce the impact of DERs. Second, in the real-time stage, the model predictive control method is introduced, smoothing the power fluctuations and maximizing the consumed renewable energy. Finally, the user comprehensive satisfaction is considered, ensuring the users' benefit and improving the flexibility of users to participate in scheduling while shifting electricity demands. By optimizing the generation-side and demand-side on both day-ahead and real-time timescales, the proposed method can improve the operation status for the distribution network effectively while ensuring the interests of users. Simulation on an improved IEEE-33 bus distribution system verifies the effectiveness of the proposed method.
We herein report an enantioselective palladium‐catalyzed cross‐coupling between α‐bromo carboxamides and aryl boronic acids, generating a series of chiral α‐aryl carboxamides in good yields and ...excellent enantioselectivities. The development of a chiral P,P=O ligand was critical in overcoming the second transmetalation issue and allows the first asymmetric palladium‐catalyzed coupling of α‐bromo carbonyl compounds.
A palladium catalyst loading as low as 0.5 mol % enables the cross‐coupling of α‐bromo carboxamides and aryl boronic acids, generating a series of chiral α‐aryl carboxamides in good yields and excellent enantioselectivities. The development of a chiral P,P=O ligand was critical in suppressing the formation of biaryl side products.
Brucellosis is a highly prevalent zoonotic disease characterized by abortion and reproductive dysfunction in pregnant animals. Although the mortality rate of Brucellosis is low, it is harmful to ...human health, and also seriously affects the development of animal husbandry, tourism and international trade. Brucellosis is caused by
, which is a facultative intracellular parasitic bacteria. It mainly forms
-containing vacuoles (BCV) in the host cell to avoid the combination with lysosome (Lys), so as to avoid the elimination of it by the host immune system.
not only has the ability to resist the phagocytic bactericidal effect, but also can make the host cells form a microenvironment which is conducive to its survival, reproduction and replication, and survive in the host cells for a long time, which eventually leads to the formation of chronic persistent infection.
can proliferate and replicate in cells, evade host immune response and induce persistent infection, which are difficult problems in the treatment and prevention of Brucellosis. Therefore, the paper provides a preliminary overview of the facultative intracellular parasitic and immune escape mechanisms of
, which provides a theoretical basis for the later study on the pathogenesis of
.
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