Decade Milestone Advancement of Defect-Engineered g-C_(3)N_(4) for Solar Catalytic Applications

Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is still confronted with a general fatal issue of insufficient supply of thermodynamically active photocarriers due to its inferior solar harvesting ability and sluggish charge transfer dynamics. Fortunately, this could be significantly alleviated by the “all-in-one” defect engineering strategy, which enables a simultaneous amelioration of both textural uniqueness and intrinsic electronic band structures. To this end, we have summarized an unprecedently comprehensive discussion on defect controls including the vacancy/non-metallic dopant creation with optimized electronic band structure and electronic density, metallic doping with ultraactive coordinated environment(M–N_(x), M–C_(2)N_(2), M–O bonding), functional group grafting with optimized band structure, and promoted crystallinity with extended conjugation π system with weakened interlayered van der Waals interaction. Among them, the defect states induced by various defect types such as N vacancy, P/S/halogen dopants, and cyano group in boosting solar harvesting and accelerating photocarrier transfer have also been emphasized. More importantly, the shallow defect traps identified by femtosecond transient absorption spectra(fs-TAS) have also been highlighted. It is believed that this review would pave the way for future readers with a unique insight into a more precise defective g-C_(3)N_(4) “customization”, motivating more profound thinking and flourishing research outputs on g-C_(3)N_(4)-based photocatalysis.

Dual‑Doped Nickel Sulfide for Electro‑Upgrading Polyethylene Terephthalate into Valuable Chemicals and Hydrogen Fuel

Electro-upcycling of plastic waste into value-added chemicals/fuels is an attractive and sustainable way for plastic waste management.Recently,electrocatalytically converting polyethylene terephthalate(PET)into formate and hydrogen has aroused great interest,while developing low-cost catalysts with high efficiency and selectivity for the central ethylene glycol(PET monomer)oxidation reaction(EGOR)remains a challenge.Herein,a high-performance nickel sulfide catalyst for plastic waste electro-upcycling is designed by a cobalt and chloride co-doping strategy.Benefiting from the interconnected ultrathin nanosheet architecture,dual dopants induced upshifting d band centre and facilitated in situ structural reconstruction,the Co and Cl co-doped Ni_(3)S_(2)(Co,Cl-NiS)outperforms the singledoped and undoped analogues for EGOR.The self-evolved sulfide@oxyhydroxide heterostructure catalyzes EG-to-formate conversion with high Faradic efficiency(>92%)and selectivity(>91%)at high current densities(>400 mA cm^(−2)).Besides producing formate,the bifunctional Co,Cl-NiS-assisted PET hydrolysate electrolyzer can achieve a high hydrogen production rate of 50.26 mmol h^(−1)in 2 M KOH,at 1.7 V.This study not only demonstrates a dual-doping strategy to engineer cost-effective bifunctional catalysts for electrochemical conversion processes,but also provides a green and sustainable way for plastic waste upcycling and simultaneous energy-saving hydrogen production.

Smart mid-infrared metasurface microspectrometer gas sensing system

Smart,low-cost and portable gas sensors are highly desired due to the importance of air quality monitoring for environmental and defense-related applications.Traditionally,electrochemical and nondispersive infrared(IR)gas sensors are designed to detect a single specific analyte.Although IR spectroscopy-based sensors provide superior performance,their deployment is limited due to their large size and high cost.In this study,a smart,low-cost,multigas sensing system is demonstrated consisting of a mid-infrared microspectrometer and a machine learning algorithm.The microspectrometer is a metasurface filter array integrated with a commercial IR camera that is consumable-free,compact(~1 cm^(3))and lightweight(~1 g).The machine learning algorithm is trained to analyze the data from the microspectrometer and predict the gases present.The system detects the greenhouse gases carbon dioxide and methane at concentrations ranging from 10 to 100%with 100%accuracy.It also detects hazardous gases at low concentrations with an accuracy of 98.4%.Ammonia can be detected at a concentration of 100 ppm.Additionally,methyl-ethyl-ketone can be detected at its permissible exposure limit(200 ppm);this concentration is considered low and nonhazardous.This study demonstrates the viability of using machine learning with IR spectroscopy to provide a smart and low-cost multigas sensing platform.

A Survey on Model Predictive Control of DFIGs in Wind Energy Conversion Systems

This paper presents a comprehensive study on the model predictive control(MPC)of doubly fed induction generators(DFIG)in wind energy conversion systems(WECS);in particular the MPC of the rotor side converter.The general principle of prevalent MPC strategies is discussed to introduce the theoretical framework in the first place.Furthermore,mainstream and high-performance MPC methods of DFIGs have been identified as model predictive current control(MPCC),model predictive torque control(MPTC),and model predictive power control(MPPC).Starting from analyzing dynamic models,these MPC strategies are investigated in terms of operating principles and technical developments.The paper further investigates implementation of MPC strategies in unbalanced grids.Based on the quantitative and qualitative analysis of several case studies,performance of various MPC schemes is compared and their special features are identified.Guidelines for designing MPC strategies of DFIGs in WECS are provided.

Realization of flexible in-memory computing in a van der Waals ferroelectric heterostructure tri-gate transistor

Combining logical function and memory characteristics of transistors is an ideal strategy for enhancing computational efficiency of transistor devices.Here,we rationally design a tri-gate two-dimensional(2D)ferroelectric van der Waals heterostructures device based on copper indium thiophosphate(CuInP_(2)S_(6))and few layers tungsten disulfide(WS_(2)),and demonstrate its multi-functional applications in multi-valued state of data,non-volatile storage,and logic operation.By co-regulating the input signals across the tri-gate,we show that the device can switch functions flexibly at a low supply voltage of 6 V,giving rise to an ultra-high current switching ratio of 107 and a low subthreshold swing of 53.9 mV/dec.These findings offer perspectives in designing smart 2D devices with excellent functions based on ferroelectric van der Waals heterostructures.

Immunoregulatory and Anti-cancer Activities of Combination Treatment of Novel Four-Herb Formula and Doxorubicin in 4T1-Breast Cancer Bearing Mice

Objective To investigate the in vivo immunomodulatory and anti-tumor mechanisms of the combined treatment of novel Four-Herb formula(4HF)and doxorubicin in triple-negative breast cancer(TNBC).Methods Murine-derived triple-negative mammary carcinoma cell line,4T1 cells,was cultured and inoculated into mouse mammary glands.Sixty-six mice were randomly assigned into 6 groups(n=11 in ench):naive,control,LD 4HF(low dose 4HF),HD 4HF(high dose 4HF),LD 4HF+D(low dose and doxorubicin),and D(doxorubicin).Apart from the naive group,each mouse received subcutaneous inoculation with 5×10^(5)4T1 cells resuspended in 100µL of normal saline in the mammary fat pads.Starting from the day of tumor cell inoculation,tumors were grown for 6 days.The LD and HD groups received daily oral gavage of 658 and 2,630 mg/kg 4HF,respectively.The LD 4HF+D group received daily oral gavage of 658 mg/kg 4HF and weekly intraperitoneal injection of doxorubicin(5 mg/kg).The D group received weekly intraperitoneal injections of doxorubicin(5 mg/kg).The treatment naive mice received daily oral gavage of 0.2 mL double distilled water and 0.1 mL normal saline via intraperitoneal injection once a week.The control group received daily oral gavage of 0.2 mL double-distilled water.The treatment period was 30 days.At the end of treatment,mice organs were harvested to analyze immunological activities via immunophenotyping,gene and multiplex analysis,histological staining,and gut microbiota analysis.Results Mice treated with the combination of 4HF and doxorubicin resulted in significantly reduced tumor and spleen burdens(P<0.05),altered the hypoxia and overall immune lymphocyte landscape,and manipulated gut microbiota to favor the anti-tumor immunological activities.Moreover,immunosuppressive genes,cytokines,and chemokines such as C-C motif chemokine 2 and interleukin-10 of tumors were significantly downregulated(P<0.05).4HF-doxorubicin combination treatment demonstrated synergetic activities and was most effective in activating the anti-tumor immune response(P<0.05).Conclusion The above results provide evidence for evaluating the immune regulating mechanisms of 4HF in breast cancer and support its clinical significance in its potential as an adjunctive therapeutic agent or immune supplement.

EZH2 inhibitors promote β-like cell regeneration in young and adult type 1 diabetes donors

β-cells are a type of endocrine cell found in pancreatic islets that synthesize,store and release insulin.In type 1 diabetes(T1D),T-cells of the immune system selectively destroy the insulin-producingβ-cells.Destruction of these cells leads to a lifelong dependence on exogenous insulin administration for survival.Consequently,there is an urgent need to identify novel therapies that stimulateβ-cell growth and induceβ-cell function.We and others have shown that pancreatic ductal progenitor cells are a promising source for regeneratingβ-cells for T1D owing to their inherent differentiation capacity.Default transcriptional suppression is refractory to exocrine reaction and tightly controls the regenerative potential by the EZH2 methyltransferase.In the present study,we show that transient stimulation of exocrine cells,derived from juvenile and adult T1D donors to the FDAapproved EZH2 inhibitors GSK126 and Tazemetostat(Taz)influence a phenotypic shift towards aβ-like cell identity.The transition from repressed to permissive chromatin states are dependent on bivalent H3K27me3 and H3K4me3 chromatin modification.Targeting EZH2 is fundamental toβ-cell regenerative potential.Reprogrammed pancreatic ductal cells exhibit insulin production and secretion in response to a physiological glucose challenge ex vivo.These pre-clinical studies underscore the potential of small molecule inhibitors as novel modulators of ductal progenitor differentiation and a promising new approach for the restoration ofβ-like cell function.

Dynamic investigation of oxygen defects on transition metal-based electrocatalysts:formation,characterization,and mechanism during alkaline oxygen evolution reaction

Oxygen defects play a critical role in the electrocatalytic oxygen evolution reaction(OER).Therefore,in-depth understanding the structure-activity-mechanism relationship of these defects is the key to design efficient OER electrocatalysts.This relationship needs to be understood dynamically due to the potential for irreversible phase transitions during OER.Consequently,significant efforts have been devoted to study the dynamic evolution of oxygen defects to shed light on the OER mechanism.This review critically examines and analyzes the dynamic processes occurring at oxygen defect sites during OER,including defect formation and defect evolution mechanisms,along with the advanced characterization techniques needed to understand these processes.This review aims to provide a comprehensive understanding of high-efficiency electrocatalysts,with a particular emphasis on the importance of in situ monitoring the dynamic evolution of oxygen defects,providing a new perspective towards efficient OER electrocatalyst design.

Recent advances of SiO_(x)-based anodes for sustainable lithium-ion batteries

The world is facing an ever-growing global energy crisis with unprecedented depth and complexity.The sustainable development of high energy density lithium-ion batteries for electric vehicles and portable electric devices has become a feasible way to deal with this problem.Silicon suboxides(SiO_(x))have been deemed as one of the most promising anode materials because of their ultrahigh theoretical lithium storage capacity,proper working potential,natural abundance,and environmental friendliness.However,the mass utilization of SiO_(x)-based anodes is severely obstructed by their low electrical conductivity and inevitable volume expansion.While lithium silicate and lithium oxide formed in the first lithiation process act as buffer layers to some extent,it is urgent to address the accompanying low initial Coulombic efficiency and unsatisfactory cycling stability.In this review,we summarized recent advances in the synthesis methods of SiO_(x)-based materials.Besides,the benefits and shortcomings of the various methods are briefly concluded.Then,we discussed the effective combination of SiO_(x) with carbon materials and designs of porous structure,which could considerably enhance the electrochemical performance in detail.Furthermore,progresses on the modified strategies,advanced characteristics and industrial applications for SiO_(x)-based anodes are also mentioned.Finally,the remaining challenges encountered and future perspectives on SiO_(x)-based anodes are highlighted.

Tunable THz spectrum analyzer with hyperspectral resolution

We present a tunable terahertz(THz)spectrum analyzer with hyperspectral resolution formed from electrically tunable metamaterial and plasmonic structures.As few as eight encoders based on four detectors are needed to recover 396 spectral bands.The incident spectra in the range of 1–5 THz can be reconstructed with a localization precision of 0.3 GHz and a minimum average mean squared error(MSE)of 6.9×10−5.Our proposed analyzers are faster and more portable than those based on frequency combs and power meters,and more accurate than existing Fourier transform techniques,showing promising applications in pathology,biomedical imaging,and many other areas.