Petrology and organic geochemistry of the Baishaping and Damaidi Devonian cutinitic liptobioliths,west of the Kangdian Uplift,China

Devonian cutinitic liptobiolith is a special type of coal formed during the early evolutionary stage of land plants.The Baishaping and Damaidi Devonian coals are notable for their distinct papery,sheet-like texture,and unusually high cutinite content(>50%),belonging to typical cutinitic liptobiolith.They are bituminous coals and have a suppressed vitrinite reflectance.Compared with typical typeⅢkerogen,these liptobioliths are characterized by extremely high yields of volatile matter and high hydrogen contents owing to their enhanced cutinite contents.As indicated by pyrolysis and elemental analysis results,the Devonian cutinitic liptobioliths are dominated by typeⅠ-Ⅱkerogens and have an excellent potential to generate liquid hydrocarbons.The Baishaping cutinitic liptobioliths are mainly composed of ribbon-like thick-walled cutinites,with small amounts of thin-walled type.Vitrinite is only present in trace amounts and is dominated by telinite.Meanwhile,the Damaidi Devonian coals are primarily composed of ribbon-like thin-walled cutinites,followed by collotelinites which are usually sandwiched by cutinites.The different petrological characteristics of the Baishaping and Damaidi liptobioliths might indicate a structural variation in the coal-forming plant cuticles and two distinct coal-forming conditions.The molecular bio markers in the Devonian coals are mainly composed of C_(18)-C_(20)tetracyclic diterpenoids,which are assumed to be the dominant soluble constituent of the Devonian land-plant cuticles and might have played an important role in early land plant radiation.Other molecules include aromatic tetracyclic diterpenoids,3-5 ring polycyclic aromatic hydrocarbons and their methylated counterparts,and C_(16)-and C_(18)-monocarboxylic acids.n-Alkanes are present only in small amounts.The molecular composition of the cutinite-rich coals is unexpected,because cuticular waxes are one of the most important sources of n-alkanes.In general,the petrology and geochemistry of the Devonian cutinitic liptobiolith indicate a distinct structure and composition for the early land-plant cuticles,which is significantly different from that of the plant cuticles since Carboniferous.Devonian cutinitic liptobioliths are of great interest because of their unique petrography,geochemistry,coal-forming plants,and oil-prone potential.Studies on this unique coal type provide a better understanding of coal-forming plants,paleoenvironment,paleoclimate,and early land-plant evolution in the Devonian.

Abiotic-Biological Hybrid Systems for CO2 Conversion to Value-Added Chemicals and Fuels

Abiotic-biological hybrid systems that combine the advantages of abiotic catalysis and biotransformation for the conversion of carbon dioxide(CO2)to value-added chemicals and fuels have emerged as an appealing way to address the global energy and environmental crisis caused by increased CO2 emission.We illustrate the recent progress in this field.Here,we first review the natural CO2 fixation pathways for an in-depth understanding of the biological CO2 transformation strategy and why a sustainable feed of reducing power is important.Second,we review the recent progress in the construction of abiotic-biological hybrid systems for CO2 transformation from two aspects:(i)microbial electrosynthesis systems that utilize electricity to support whole-cell biological CO2 conversion to products of interest and(ii)photosynthetic semiconductor biohybrid systems that integrate semiconductor nanomaterials with CO2-fixing microorganisms to harness solar energy for biological CO2 transformation.Lastly,we discuss potential approaches for further improvement of abiotic-biological hybrid systems.

Thiophene-Conjugated Porous C_(3)N_(4) Nanosheets for Boosted Photocatalytic Nicotinamide Cofactor Regeneration to Facilitate Solar-to-Chemical Enzymatic Reactions

The low catalytic efficiency of redox-active cofactor photoregeneration severely limits the performance of photoenzymatic hybrid systems. Herein, we synthesized thiophene-conjugated porous C3N4 nanosheets(CN-ATCN) exhibiting boosted photoregeneration activity of nicotinamide cofactors(NADH and NADPH), which are the most common redox cofactors of oxidoreductases, with regeneration rates of 59.00 μM/min for NADH and 40.99 μM/min for NADPH, ~ 84.3 and 24.7 times higher than those of bulk g-C3N4, respectively. The thin nanosheet structure of CN-ATCN facilitates the exposure of active sites to reactants and favors the diff usion of reactants and products. Upon conjugation of a thiophene moiety into the carbon nitride framework, the optical and photoelectric properties of CN-ATCN were considerably enhanced by an extended π-conjugation system in the frameworks and molecular type II heterojunctions formed between the incorporated and nonincorporated portions of CN-ATCN. Upon coupling NAD(P)H photoregeneration reaction by CN-ATCN with NAD(P)H-dependent enzymatic systems, sustainable synthesis of L-tert-leucine and styrene oxide was achieved with rates of 964 and 14.9 μM/h, respectively.

Research on V2G Control Strategy for EV Charge and Discharge Equipmen

In this paper, the fundamental structure of charge and discharge device of V2G is analyzed. As for three phase voltage source PWM converter’s control, this paper presents that the control strategy of direct power control PWM rectifier is adopted under charging operation and constant power control strategy is used under discharging operation. For bidirectional DC/DC converter control strategy, dual closed-loop control of external voltage loop and internal current loop is put into use. The whole system of charge and discharge device of V2G is modeled and simulated by using the toolbox of PSCAD/EMTDC. Two-way power energy and information interaction of electric vehicle and power grid has been realized, current harmonic on grid side is decreased, power factor and power quality are improved.

Ringing spectroscopy in the magnomechanical system

The ringing phenomenon has been studied in optical whispering gallery mode(WGM)resonators and can be used to sense the ultrafast process in spectroscopy.Here we observe the ringing phenomenon in a magnomechanical system for the first time,which is induced by the interference between the microwave photons converted from the damped phonons and the probing microwave photons.This interference eventually appears as a transparency window even along with the ringing phenomenon in the measured microwave reflection spectrum,which is influenced by the scanning speed and the input power.Then,the ringing spectroscopy is used to measure the coupling strength between the magnon and phonon modes,and outline the displacement profile of𝑆1,2,2 mechanical mode in a YIG microsphere,demonstrating the theoretical analysis.In addition,the ring-up spectroscopy is developed in our magnomechanical system,laying the foundation for fast sensing based on mechanical motion.

生物光电化学电池复合系统:光电驱动生物转化

生物催化以活性高、选择性高、条件温和及底物范围广泛等优势著称,其催化目标氧化还原反应时需消耗氧化还原力.光电化学电池可利用清洁、可持续的光能和电能从水中提取电子并转化为生物催化剂可用的还原力.生物光电化学电池复合系统将生物催化和光电化学电池的优势进行结合,利用光电化学电池为生物催化提供还原力,可实现光电驱动的绿色、可持续的生物催化转化过程.本文基于构成复合系统的功能组件,首先介绍复合系统中光电极的选择策略,随后从酶、微生物两类生物催化剂出发,分别综述了近年来的研究进展,最后展望了该研究领域的未来发展.

基于辅因子的光驱动酶催化复合体系

氧化还原酶因其优越的区域、立体和对映体选择性,并具有反应条件温和、低能耗等优点,在医药、食品添加剂和燃料等合成中有重大应用.然而氧化还原酶催化反应需要依赖昂贵的辅因子来提供或接受电子.最近的研究表明可以利用有机(或无机)光敏剂诱导电子转移实现光驱动下的辅因子再生,并通过将光催化和生物催化相结合的方法构成一个基于辅因子的光驱动酶催化体系,实现清洁、高效的化学品合成.本文综述了近年来基于不同辅因子的光驱动酶催化复合体系的研究进展,并概述了光直接激发辅因子驱动酶催化的反应体系,在此基础上对未来的发展进行展望.

Low-Cycle Fatigue and Creep-Fatigue Behaviors of a Second-Generation Nickel-Based Single-Crystal Superalloy at 760℃

Low-cycle fatigue(LCF)behaviors of a second-generation nickel-based single-crystal superalloys with[001]orientation at 760℃ have been investigated.Different strain amplitudes were introduced to investigate the creep-fatigue effects.The LCF life of none tensile holding(NTH)was higher than that of the 60-s tensile hold(TH)at any strain amplitude.As the strain amplitude was 0.7%,the stacking and cross-slip dislocations appeared together at the γ/γ’coherent microstructure in both TH and NTH specimens.At the strain amplitude of 0.9%,plenty of the cross-slip dislocations appeared inγchannel and other dislocations were stacking at γ/γ’interfaces.However,the SFs still appeared in γ’phase with 60-s TH which caused cyclic softening.As the strain amplitude increased up to 1.2%,the dislocations are piling up at the γ/γ’interfaces and cutting through the γ’phase in both TH and NTH tests,which caused cyclic hardening.The influences of strain amplitude and holding time were complicated.Different stress response behaviors occurred in different loading conditions.The surface characteristic and fracture mechanism were observed by scanning electron microscopy.This result is helpful for building the relationship of various blade fatigue failure modes,cyclic stress response and microstructure deformation under different strain amplitudes.