基于双核咪唑盐阴离子交换膜的制备与表征

采用两步法合成了双核溴化1-乙烯基-3-(6-(1-丁基咪唑))己基咪唑盐[VBIm HIm][Br]2,并通过1H-NMR对[VBIm HIm][Br]2的化学结构进行了表征;然后将[VBIm HIm][Br]2与苯乙烯、丙烯腈混合均匀后,通过紫外光引发聚合,得到碱性阴离子交换膜。通过傅里叶变换红外光谱对阴离子交换膜的结构进行了表征,并系统对膜的吸水率、溶胀度、热稳定性、力学性能及电导率等进行了研究。研究结果表明,该类阴离子交换膜降解温度达到300℃,[VBIm HIm][Br]2含量为10%的阴离子交换膜25℃时的吸水率为96%,溶胀度只有44%,拉伸强度为38. 32 MPa,最大断裂伸长率可达26. 37%;在80℃时,其离子的电导率可达22 m S/cm,该类阴离子交换膜有望应用于碱性阴离子交换膜燃料电池领域。

Anti-solvent engineering for efficient semitransparent CH3NH3PbBr3 perovskite solar cells for greenhouse applications

With ideal combination of benefits that selectively converts high photon energy spectrum into electricity while transmitting low energy photo ns for photos yn thesis,the CH3NH3PbBr3 perovskite solar cell(BPSC)is a promising candidate for efficient greenhouse based building integrated photovoltaic(BIPV)applications.However,the efficiency of BPSCs is still much lower than their theoretical efficiency.In general,interface band alignment is regarded as the vital factor of the BPSCs whereas only few reports on enhancing perovskite film quality.In this work,highly efficient BPSCs were fabricated by improving the crystallization process of CH3NH3PbBr3 with the assistance of anti-solvents.A new anti-solvent of diphenyl ether(DPE)was developed for its strong interaction with the solvents in the perovskite precursor solution.By using the anti-solvent of DPE,trap-state density of the CH3NH3PbBr3 film is reduced and the electron lifetime is enhanced along with the large-grain crystals compared with the samples from conventional anti-solvent of chlorobenzene.Upon preliminary optimization,the efficiencies of typical and semitransparent BPSCs are improved to as high as 9.54%and 7.51%,respectively.Optical absorption measurement demonstrates that the cell without metal electrode shows 80%transparency in the wavelength range of 550-1000 nm that is perfect for greenhouse vegetation.Considering that the cell absorbs light in the blue spectrum before 550 nm,it offers very high solar cell efficiency with only 17.8%of total photons,while over 60%of total photons can transm让through for photosynthesis if a transparent electrode can be obtained such as indium doped SnO2.

Post-treatment by an ionic tetrabutylammonium hexafluorophosphate for improved efficiency and stability of perovskite solar cells

Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surface defects of the perovskite film.It is found that TP6 effectively reduced the surface defects,especially at the grain boundaries where the defects are abundant.Meanwhile,the exposed long alkyl chains and fluorine atoms in the TP6 enhanced the moisture stability of the perovskite film due to its strong hydrophobicity.In addition,the driving force of charge carrier separation and transport is increased by enlarged built-in potential.Consequently,the power conversion efficiency(PCE)of PSCs is significantly improved from 20.59% to 22.41%by increased open-circuit voltage(V_(oc))and fill factor(FF).The unencapsulated device with TP6 treatment exhibits better stability than the control device,and the PCE retains-80%of its initial PCE after 30 days under 15%-25%relative humidity in storage,while the PCE of the control device declines by more than 50%.

Energy storage for black start services:A review

With the increasing deployment of renewable energy-based power generation plants,the power system is becoming increasingly vulnerable due to the intermittent nature of renewable energy,and a blackout can be the worst scenario.The current auxiliary generators must be upgraded to energy sources with substantially high power and storage capacity,a short response time,good profitability,and minimal environmental concern.Difficulties in the power restoration of renewable energy generators should also be addressed.The different energy storage methods can store and release electrical/thermal/mechanical energy and provide flexibility and stability to the power system.Herein,a review of the use of energy storage methods for black start services is provided,for which little has been discussed in the literature.First,the challenges that impede a stable,environmentally friendly,and cost-effective energy storage-based black start are identified.The energy storagebased black start service may lack supply resilience.Second,the typical energy storage-based black start service,including explanations on its steps and configurations,is introduced.Black start services with different energy storage technologies,including electrochemical,thermal,and electromechanical resources,are compared.Results suggest that hybridization of energy storage technologies should be developed,which mitigates the disadvantages of individual energy storage methods,considering the deployment of energy storage-based black start services.

Self-assembled CoOOH on TiO_(2) for enhanced photoelectrochemical water oxidation

Providing efficient charge transfer through the interface between the semiconductor and co-catalyst is greatly desired in photoelectrocatalytic (PEC) energy conversion.Herein,we excogitate a novel and facile means,via electrochemical activation,to successfully load the amorphous CoOOH layer architecture onto the surface of TiO_(2).Intriguingly,the as-obtained 6%CoOOH-TiO_(2)photoelectrode manifests optimal PEC performance with a high photocurrent density of 1.3 mA/cm~2,3.5 times higher than that of pristine TiO_(2).Electrochemical impedance spectroscopy (EIS),Tafel analysis and cyclic voltammetry (CV) methods show that the carrier transfer barrier within the electrode and the transition of Co^(3+)OOH to Co^(4+)OOH have the dominating effects on the PEC performance.Theoretical calculation reveals that the interface between the CoOOH and TiO_(2)improves the homogeneity of effective d-orbital electronic-transfer ability among Co sites.This research sheds light on the water oxidation reaction and the design of more favorable PEC cocatalysts.

In-situ photoisomerization of azobenzene to inhibit ion-migration for stable high-efficiency perovskite solar cells

Ion migration is a notorious problem in perovskite solar cells(PSCs)that severely mutilates device performance.Herein,a strategy to inhibit ion migration in situ is developed by using photoisomerization of azobenzene(AZO)to immobilize cations in the lattice.During the nucleation process,the photoisomerized cis-AZO reacts with FA^(+),MA^(+)and Pb2+cations in the perovskite precursor by synergistic cation-πinteraction and Lewis base coordination,leading to heterogeneous nucleation to produce uniform perovskite film.Meanwhile,it accelerates conversion of intermediate yellowδ-phase to desired black aphase of FAPb I3for improved crystallinity with well-passivated grain surface.Consequently,defect density is effectively reduced for the perovskite film to demonstrate suppressed carrier recombination and enhanced carrier extraction.Subsequently,the solar cell efficiency is elevated from 21.29%to 23.58%with negligible J-V hysteresis.Long-term stability is also improved,with the bare device without any encapsulation retaining 84%of its initial efficiency after aging 744 hours in ambient.

Crystallization tailoring of cesium/formamidinium double-cation perovskite for efficient and highly stable solar cells

Achieving high-quality perovskite crystal films is a critical prerequisite in boosting solar cell efficiency and improving the device stability,but the delicate control of nucleation and growth of the perovskite film remains limited success.Herein,a facile but effective strategy has been developed to finely tailor the crystallization of thermally stable cesium/formamidinium(Cs/FA)based perovskite via partially replacing PbI2 with PbCl2 in the precursor solution.The incorporation of chlorine into the perovskite crystal lattice derived from PbCl2 changes the crystallization process and improves the crystal quality,which further results in the formation of larger crystal grains compared to the control sample.The larger crystal grains with high crystallinity lead to reduced grain boundaries,suppressed non-radiative recombination,and enhanced photoluminescence lifetime.Under the optimized conditions,the methylammonium free perovskite solar cells(PSCs)delivers a champion power conversion efficiency(PCE)of 21.30%with an open-circuit voltage as high as 1.18 V,which is one of the highest efficiencies for Cs/FA based PSCs up to now.Importantly,the unencapsulated PSC devices retain more than 95%and 81%of their original PCEs even after long-term(over one year)storage under ambient conditions or 2000 h’s thermal aging at 850C in a nitrogen atmosphere,respectively.

Experiment on the Fattening Effects of Mixed Silage of Wolfberry Branches on Hybrid

[Objectives] This study was conducted to use the feeding value of wolfberry branches and to provide a basis for the rational use of its active ingredients and nutrients and the development of new feed resources. [Methods] Wolfberry branches and whole-plant corn were used to make mixed silage of wolfberry branches, which replaced different proportions of whole-plant corn silage for feeding hybrid mutton sheep, and the feeding effect of the mixed silage of wolfberry branches on hybrid mutton sheep was analyzed, which provides a technical basis for rational utilization of mulberry resources to ruminants. A single factor feeding comparison experiment was carried out. 32 hybrid mutton sheep of 8 months old with conform gender, age, body weight, physiological state and feeding management level were selected and divided into two groups, 16 in each group. [Results] The gross output value of weight gain of the experimental group was 18.06 yuan, which was higher than the CK(12.97 yuan) by 5.09 yuan. [Conclusions] The addition of the mixed silage of wolfberry branches to the diet had a positive effect on the increase of the weight gain of the hybrid mutton sheep and the reduction of the feed conversion ratio compared with the single whole-plant corn silage.

Photovoltaic molecules based on vinylene-bridged oligothiophene applied for bulk-heterojunction organic solar cells

We have synthesized two photovoltaic molecules（HEX-3TVT-ID and EH-3TVT-ID） based on vinylenebridged oligothiophene applied as donor for the solution-processable bulk-heterojunction organic solar cells（OSCs）. Vinylene unit was introduced as π-bridge in the oligothiophenes with 1,3-indenedione as end group and 4,4’-dihexyl-2,2’：5’,2’-terthiophene or 3’,4’-di（octan-3-yl）-2,2’：5’,2’-terthiophene as core,respectively. Due to the different substituent positions of the alkyl group relative to the vinylene unit in the terthiophene, HEX-3TVT-ID and EH-3TVT-ID show different optical and electrochemical properties, corresponding to the photovoltaic performance of the OSCs devices. The power conversion efficiency（PCE） of the OSCs based on a blend of HEX-3TVT-ID and PC71BM（1：0.8, weight ratio, 0.5% CN） reached 2.3%. In comparison, the OSCs based on the blend of EH-3TVT-ID and PC71BM in the weight ratio of 1：1 without the additive show a higher PCE of 2.7%, with a typically high VOC of 0.93 V, under the illumination of AM 1.5, 100 mW cm-2.

Study on Addition Amount of Lactic Acid Bacteria and Cellulase in Mixed Silage of Potato Plants

[Objectives]This study was conducted to investigate the appropriate addition amounts of lactic acid bacteria and cellulase in the mixed silage of potato plants,so as to provide a basis for the rational use of potato plants.[Methods]Fresh potato(Solanum tuberosum)seedling plants,watermelon(Citrullus lanatus)plants,and melon(Cucumis melo)plants were selected as raw materials for silage,each of which was added at a ratio of 32%,and 4%of brown flour was added additionally.On this basis,an L 9(32)orthogonal experiment was designed to investigate the effects of the amount of lactic acid bacteria(10,20,30 g/kg)and the amount of cellulase(5,10,15 g/kg)on the experimental results with sensory evaluation score as an investigation index.[Results]With the increase of the amount of lactic acid bacteria and the amount of cellulase,the sensory evaluation score of silage increased,and it was the highest when the amount of lactic acid bacteria added was 20 g/kg and the amount of cellulose was 10 g/kg.With the increase of the amounts of lactic acid bacteria and cellulase added,ammonia nitrogen showed a decreasing trend,and the pH and ammonia nitrogen were the lowest when the amount of lactic acid bacteria added was 20 g/kg and the amount of cellulose was 10 g/kg.[Conclusions]This study provides a theoretical basis for the rational use of effective ingredients and nutrients in potato plants and the development of new feed resources.

Development of Microbial Fermented Feed and Its Effect on the Production Performance of Holstein Cows

[Objectives]This study was conducted to investigate the development method of microbial fermented feed and its effect on the production performance of Holstein cows.[Methods]Thirty Holstein cows were selected and randomly divided into 2 groups,15 cows in each group.The diet composition of the experimental group was:concentrate supplement added with 30% microbial fermented feed+silage+alfalfa hay,and the diet composition of the control group was:concentrate supplement added with 30% flax cake+silage+alfalfa hay.The experimental period was 60 d.[Results]Compared with the control group,the experimental group increased the average daily milk yield per cow by 2.25%(P>0.05)and the total increase in average milk yield per cow in the experimental period by 43.51%(P<0.01),and reduced the average feed-to-milk ratio by 9.20%(P<0.05).The average gross profit per cow of the experimental group was 40.34 yuan higher than that of the control group,showing an increase of 3.53% in the economic benefit.[Conclusions]Feeding a diet supplemented with the microbial fermented feed could improve the efficiency of Holstein cow farming and is recommended to be promoted.

Effect of Wolfberry Polysaccharide Additive Premixed Feed on Fattening Effect of Tan Sheep

[Objectives]This study was conducted to explore and rationally use the effective value and nutritional components of wolfberry polysaccharide to provide a basis for the use of new feed resources.[Methods]The premixed feed prepared with the wolfberry polysaccharide additive was applied to fattening Tan sheep in Ningxia,and the effect of the wolfberry polysaccharide additive on the fattening Tan sheep was analyzed,so as to provide technical support for the rational utilization of the wolfberry polysaccharide resources.The study adopted a single-factor comparison method,selecting 84 tan sheep in the fattening period with conform gender,feeding management,weight,age,and physiological status,which were divided into 2 test groups and 1 control group,28 in each group.[Results]Within 90 d,the weight gain of the group with 0.1%wolfberry polysaccharide additive increased by 6.98%,showing a significant difference(P<0.05),and the feed conversion ratio decreased by 9.66%,which was significant as well(P<0.05).The gross profit of this group was 125.76 yuan,which was higher than the control group by 57.52 yuan.The group with 0.2%wolfberry polysaccharide additive increased the weight gain by 8.63%,which was significant(P<0.05),and the feed conversion ratio decreased by 10.80%,which was significant as well(P<0.05).The gross profit of group 2 was 125.76 yuan,which was higher than the control group by 63.41 yuan.There were no significant differences in weight gain,feed conversion ratio and gross profit between the groups with 0.1%and 0.2%of wolfberry polysaccharide additive.The results showed that the use of wolfberry polysaccharide additive premixed feed has a positive effect on increasing the weight gain of fattening Tan sheep,reducing the feed conversion ratio,and improving the feed conversion efficiency.The addition of 0.1%and 0.2%of the wolfberry polysaccharide additive premixed feed had no significant differences.[Conclusions]The wolfberry polysaccharide additive has a positive effect on increasing the weight gain of fattening Tan sheep,reducing the feed conversion ratio,and improving the feed conversion efficiency.

Experiment on the Fattening Effects of Mixed Silage of Mulberry Branches and Leaves on Hybrid Mutton Sheep

[Objectives] This study was conducted to investigate the effect of mixed silage of mulberry branches and leaves on the production performance of Tan Han hybrid mutton sheep and explore the feasibility in production. [Methods] Twenty-six Tan Han hybrid mutton sheep were selected and divided into two groups, 13 in each group. The experimental group was fed with the mixed silage and the control group(CK) was fed with whole-plant corn silage. [Results] The average daily weight gain per sheep of the experimental group was 9.2% higher than that of the CK(P<0.05), and the feed conversion ratio was decreased by 6.98%(P<0.05). The average daily weight gain per sheep in the 30 d improved the gross profit by 7.75 yuan, which meant an increase of 16.32%. [Conclusions] The mulberry mixed silage is feasible in the production, and it could significantly improve the production performance of the hybrid mutton sheep.

Temperature-responsive peristome-structured smart surface for the unidirectional controllable motion of large droplets

The manipulation of fast,unidirectional motion for large droplets shows important applications in the fields of fog collection and biochemical reactions.However,driving large droplets(>5μL)to move directionally and quickly remains challenging due to the nonnegligible volume force.Herein,we fabricated a scalable,bionic peristome substrate with a microcavity width of 180μm using a 3D printing method,which could unidirectionally drive a large water droplet(~8μL)at a speed reaching 12.5 mm/s by temperature-responsive wettability.The substrate surface was grafted with PNIPAAm,which could reversibly change its wettability in response to temperature,thereby enabling a temperature-responsive smart surface that could regulate droplet movement in real-time by changing the temperature.A series of temperature-responsive smart patterns were designed to induce water transport along specific paths to further realize controllable droplet motion with the antibacterial treatment of predesignated areas.The ability to achieve temperature-responsive unidirectional motion and dynamic control of droplet movement could allow programmable fluidic biosensors and precision medical devices.

Multifunctional indaceno[1,2-b:5,6-b']dithiophene chloride molecule for stable high-efficiency perovskite solar cells

The additive strategy has emerged as an effective approach to improving the performance of perovskite solar cells(PSCs).Herein,a small acceptor-donor-acceptor type molecule indaceno[1,2-b:5,6-b’]dithiophene chloride(IDT-Cl)is designed and synthesized to advance both the efficiency and stability of FA_(0.85)MA_(0.15)PbI_(3)PSCs.Within the IDT-Cl molecule,the S-group with high electron density promotes chemical bonding with the lead cations in the perovskite,resulting in enlarged grain size and smoother surface topography of the perovskite absorber.In addition,the undercoordinated lead ions in the perovskite layer may be passivated by the carbonyl group in the 5-chloroindolin-2-one unit,thereby reducing the number of nonradiative recombination centers.Meanwhile,the IDT-Cl adjusts the energy level mismatch between the perovskite and two adjacent carrier transport layers,leading to easy charge collection.By the multifunctional effect of the IDT-Cl molecule,the modified device yields a high power conversion efficiency(PCE)of 24.46%,8.8%higher than that of the control PSC(22.48%).More importantly,the hydrophobic alkyl side-chain of the IDT-Cl molecule further ensures enhanced humidity stability of the perovskite film and environmental,thermal,and light stabilities of the PSC devices.

High Performance Soft Electrochemical Actuators Based on Hierarchical Conductive Polymer Ionogels

Electrochemical actuators based on conductive polymers are emerging as a strong competitive in the field of soft actuators because of their intrinsically conformable/elastic nature,low cost,low operating voltage and air-working ability.Recent development has shown that adding electroactive materials,such as CNT and graphene,can improve their actuation performance.Despite the complex material systems used,their output strains(one of the key factors)are generally lower than 1%,which limited further applications of them in multiple scenarios.Here,we report soft electrochemical actuators based on conductive polymer ionogels by embedding polyaniline particles between the PEDOT:PSS nanosheets.Results show that such a hierarchical structure not only leads to a high conductivity(1250 S/cm)but also improved electrochemical activities.At a low operating voltage of 1 V,the maximum strain of these soft actuators reaches an exceptional value of 1.5%,with a high blocking force of 1.3 mN.Using these high-performance electrochemical actuators,we demonstrate soft grippers for manipulating object and a bionic flower stimulated by an electrical signal.This work sets an important step towards enabling the enhanced performance of electrochemical actuators based on conductive polymers with designed microstructures.

Coiled Polymer Artificial Muscles Having Dual-Mode Actuation with Large Stress Generation

Coiled polymer artificial muscles with both large tensile stroke and giant force generation are needed for practical applications in robotics,soft exosuits,and prosthesis.However,most polymer yarn artificial muscles cannot generate a large force or stress.Here,we report an inexpensive Twisted and Coiled Polymer artificial muscle(TCP)that performs both large isobaric and isometric contractions.This TCP can generate a tensile stroke of 20.1%and a specific work capacity of up to 1.3 kJ kg^(−1) during temperature changes from 20 to 180℃.Moreover,the nylon yarn artificial muscle produced a reversible output stress of 28.4 MPa,which is 100 times larger than human skeletal muscle.A robot arm and a simple gripper were made to demonstrate the isobaric actuation and isometric actuation of our TCP muscle,repectivley.Thus,the polymer artificial muscles with dual-mode actuation show potential applications in the field of robotics,grippers,and exoskeletons and so on.

Fabrication and tribological properties of superhydrophobic nickel films with positive and negative biomimetic microtextures

Nickel(Ni)films with positive and negative textured surfaces of lotus and rice leaf patterns were fabricated through an inexpensive and effective method.The as-prepared Ni films were superhydrophobic and exhibited excellent tribological properties after chemical treatment.Experimental results indicated that the water contact angles(WCAs)on the surfaces of biomimetic textured Ni films(approximately 120°)were far greater than those on smooth films(65°).The biomimetic textured surfaces became superhydrophobic(WCA of approximately 150°)after perfluoropolyether(PFPE)treatment,which could be due to the combined effects of the special texture and the PFPE.The as-prepared biomimetic-textured Ni films modified with PFPE were improved with a low friction coefficient and excellent antiwear properties,which were due to the combination of the effective lubrication of PFPE and the special textures that served as a good lubricant and a debris reservoir.Moreover,the antiwear properties of the as-prepared Ni films with negative biomimetic microtextures modified with PFPE were much better than those of films with positive biomimetic microtextures modified with PFPE.

Effect of Nd2O3 doping on the electrical properties of Ba0.96Ca0.04Ti0.90Sn0.10O3 ceramics

The Ba（0.96）Ca（0.04）Ti（0.90）Sn（0.10）O3-xNd2 O3（x = 0-0.08%） ceramics were prepared via traditional solid-state sintering method. The influences of Nd3＋ substitution on the phase structure, dielectric properties,piezoelectric and ferroelectric properties of the ceramics were investigated. All the samples possess pure BaTiO3-type perovskite structure. MPB with orthorhombic and tetragonal phase coexist at around x = 0.03-0.04. Nd^（3＋） doping decreases both Tc and T（O-T） to lower temperature. All the samples exhibit an intermediate state with the coexistence of ferroelectric and diffuse relaxor ferroelectric behavior with the addition of Nd^（3＋）. The electric properties of the ceramics were optimized at x = 0.03 with d33, Kp, εr and Pr values of 545 pC/N, 51.9%, 24,412 and 10.74 μC/cm^2.