Hydrodynamic resistance of pore–throat structures and its effect on shale oil apparent permeability

Oil transport is greatly affected by heterogeneous pore–throat structures present in shale.It is therefore very important to accurately characterize pore–throat structures.Additionally,it remains unclear how pore–throat structures affect oil transport capacity.In this paper,using finite element(FE)simulation and mathematical modeling,we calculated the hydrodynamic resistance for four pore–throat structure.In addition,the influence of pore throat structure on shale oil permeability is analyzed.According to the results,the hydrodynamic resistance of different pore throat structures can vary by 300%.The contribution of additional resistance caused by streamline bending is also in excess of 40%,even without slip length.Fur-thermore,Pore–throat structures can affect apparent permeability by more than 60%on the REV scale,and this influence increases with heterogeneity of pore size distribution,organic matter content,and organic matter number.Clearly,modeling shale oil flow requires consideration of porous–throat structure and additional resistance,otherwise oil recovery and flow capacity may be overestimated.

Optimization of Gas-Flooding Fracturing Development in Ultra-Low Permeability Reservoirs

Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which areat the root of well-known problems related to injection and production. In this study, a gas injection floodingapproach is analyzed in the framework of numerical simulations. In particular, the sequence and timing of fracturechanneling and the related impact on production are considered for horizontal wells with different fracturemorphologies. Useful data and information are provided about the regulation of gas channeling and possible strategiesto delay gas channeling and optimize the gas injection volume and fracture parameters. It is shown that inorder to mitigate gas channeling and ensure high production, fracture length on the sides can be controlled andlonger fractures can be created in the middle by which full gas flooding is obtained at the fracture location in themiddle of the horizontal well. A Differential Evolution (DE) algorithm is provided by which the gas injectionvolume and the fracture parameters of gas injection flooding can be optimized. It is shown that an improvedoil recovery factor as high as 6% can be obtained.

QTL mapping and QTL × environment interaction analysis of multi-seed pod in cultivated peanut(Arachis hypogaea L.)

To dissect the genetic mechanism of multi-seed pod in peanut, we explored the QTL/gene controlling multi-seed pod and analyzed the interaction effect of QTL and environment. Two hundred and forty eight recombinant inbred lines(RIL) from cross Silihong × Jinonghei 3 were used as experimental materials planted in 8 environments from 2012 to 2017. Three methods of analysis were performed. These included individual environment analysis, joint analysis in multiple environments, and epistatic interaction analysis for multi-seed pod QTL. Phenotypic data and best linear unbiased prediction(BLUP) value of the ratio of multi-seed pods per plant(RMSP) were used for QTL mapping. Seven QTL detected by the individual environmental mapping analysis and were distributed on linkage groups 1, 6, 9, 14, 19(2), and 21. Each QTL explained 4.42%–11.51% of the phenotypic variation in multi-seed pod, and synergistic alleles of5 QTL were from the Silihong parent. One QTL, explaining 4.93% of the phenotypic variation was detected using BLUP data, and this QTL mapped in the same interval as q RMSP19.1 detected in the individual environment analysis. Seventeen additive QTL were identified by joint analysis across multiple environments. A total of 43 epistatic QTL were detected by ICIM-EPI mapping in the multiple environment trials(MET) module, and involved 57 loci. Two main-effect QTL related to multi-seed pod in peanut were filtered. We also found that RMSP had a highly significant positive correlation with pod yield per plant(PY), and epistatic effects were much more important than additive effects. These results provide theoretical guidance for the genetic improvement of germplasm resources and further fine mapping of related genes in peanut.

Stable overall water splitting in an asymmetric acid/ alkaline electrolyzer comprising a bipolar membrane sandwiched by bifunctional cobalt-nickel phosphide nanowire electrodes

Water splitting has been proposed to be a promising approach to producing clean hydrogen fuel.The two half-reactions of water splitting,that is,the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),take place kinetically fast in solutions with completely different pH values.Enabling HER and OER to simultaneously occur under kinetically favorable conditions while using exclusively low-cost,earth-abundant electrocatalysts is highly desirable but remains a challenge.Herein,we demonstrate that using a bipolar membrane(BPM)we can accomplish HER in a strongly acidic solution and OER in a strongly basic solution,with bifunctional self-supported cobaltnickel phosphide nanowire electrodes to catalyze both reactions.Such asymmetric acid/alkaline water electrolysis can be achieved at 1.567 V to deliver a current density of 10 mA/cm2 with ca.100%Faradaic efficiency.Moreover,using an“irregular”BPM with unintentional crossover the voltage needed to afford 10 mA/cm2 can be reduced to 0.847 V,due to the assistance of electrochemical neutralization between acid and alkaline.Furthermore,we show that BPM-based asymmetric water electrolysis can be accomplished in a circulated single-cell electrolyzer delivering 10 mA/cm2 at 1.550 V and splitting water very stably for at least 25 hours,and that water electrolysis is enabled by a solar panel operating at 0.908 V(@13 mA/cm2),using an“irregular”BPM.BPMbased asymmetric water electrolysis is a promising alternative to conventional proton and anion exchange membrane water electrolysis.

Improved C_(3-4) transfer for treatment of root avulsion of the brachial plexus upper trunk Animal experiments and clinical application

Experimental rats with root avulsion of the brachial plexus upper trunk were treated with the improved C34 transfer for neurotization of 05-6. Results showed that Terzis grooming test scores were significantly increased at 6 months after treatment, the latency of C5-6 motor evoked potential was gradually shortened, and the amplitude was gradually increased. The rate of C3 instead of C5 and the C4 ＋ phrenic nerve instead of C6 myelinated nerve fibers crossing through the anastomotic stoma was approximately 80%. Myelinated nerve fibers were arranged loosely but the thickness of the myelin sheath was similar to that of the healthy side. In clinical applications, 39 patients with root avulsion of the brachial plexus upper trunk were followed for 6 months to 4.5 years after treatment using the improved C3 instead of C5 nerve root transfer and C4 nerve root and phrenic nerve instead of C6 nerve root transfer. Results showed that the strength of the brachial biceps and deltoid muscles recovered to level IIHV, scapular muscle to level Ill-W, latissimus dorsi and pectoralis major muscles to above level Ⅲ, and the brachial triceps muscle to level 0 Ill. Results showed that the improved 03-4 transfer for root avulsion of the brachial plexus upper trunk in animal models is similar to clinical findings and that C3-4 and the phrenic nerve transfer for neurotization of C5-6 can innervate the avulsed brachial plexus upper trunk and promote the recovery of nerve function in the upper extremity.

Effects of glucocorticoid dexamethasone on serum nitric oxide synthase activity and nitric oxide levels in a rat model of lung disease-induced brain injury

In this study, we investigated the effects of dexamethasone, pertussis toxin （a Gi protein inhibitor） and actinomycin （a transcription inhibitor） on serum nitric oxide synthase activity and nitric oxide content in a rat model of lung disease-induced brain injury. High-dose dexamethasone （13 mg/kg） and dexamethasone ＋ actinomycin reduced lung water content, increased serum nitric oxide synthase activity and nitric oxide content, diminished inflammatory cell infiltration in pulmonary alveolar interstitium, attenuated meningeal vascular hyperemia, reduced glial cell infiltration, and decreased cerebral edema. These results demonstrate that high-dose glucocorticoid treatment can reduce the severity of lung disease-induced brain injury by increasing nitric oxide synthase activity and nitric oxide levels.

Neuroprotective effects of ClC-3 chloride channel in glutamate-induced retinal ganglion cell RGC-5 apoptosis

Transforming growth factor β plays a role in regulation of apoptosis in CIC-3 and the Smads signaling pathway, although the underlying mechanisms remain unclear. The present study determined possible signal transduction mechanisms based on CIC-3 expression, which accordingly affected apoptosis of retinal ganglion cells in a glutamate-induced retinal ganglion cell RGC-5 apoptosis model. Results revealed significantly increased cell survival rate and significantly decreased apoptosis rate following apoptosis of CIC-3 cDNA-transfected glutamate-induced retinal ganglion cells. Following inhibition of the CIC-3 chloride channel using RNAi technology, cell survival and apoptosis rates were reversed. In addition, expression of transforming growth factor β2 Smads2, Smads3, Smads4, and Smads7 increased to varying degrees. These results suggest that CIC-3 chloride channel plays a protective role in glutamate-induced apoptosis of retinal ganglion cells, and transforming growth factor β/Smads signal transduction pathways are involved in this process.

PARK1 gene mutation of autosomal dominant Parkinson's disease family

Studies have shown that PARK1 gene is associated with the autosomal dominant inheritance of Parkinson＇s disease. PARK1 gene contains two mutation sites, namely Ala30Pro and Ala53Thr, which are located on exons 3 and 4, respectively. However, the genetic loci of the pathogenic genes remain unclear. In this study, blood samples were collected from 11 members of a family with high prevalence of Parkinson＇s disease, including four affected cases, five suspected cases and two non-affected cases. Point mutation screening of common mutation sites on PARK1 gene exon 4 was conducted using PCR, to determine the genetic loci of the causative gene for Parkinson＇s disease. Gene identification and sequencing results showed that a T base deletion mutation was observed in the PARK1 gene exon 4 of all 11 collected samples. It was confirmed that the PARK1 gene exon 4 gene mutation is an important pathogenic mutation for Parkinson＇s disease.

Easy preparation of multifunctional ternary PdNiP/C catalysts toward enhanced small organic molecule electro-oxidation and hydrogen evolution reactions

The small organic molecule electro-oxidation(OMEO) and the hydrogen evolution(HER) are two important half-reactions in direct liquid fuel cells(DLFCs) and water electrolyzers,respectively,whose performance is largely hindered by the low activity and poor stability of electrocatalysts.Herein,we demonstrate that a simple phosphorization treatment of commercially available palladium-nickel(PdNi) catalysts results in multifunctional ternary palladium nickel phosphide(PdNiP) catalysts,which exhibit substantially enhanced electrocatalytic activity and stability for HER and OMEO of a number of molecules including formic acid,methanol,ethanol,and ethylene glycol,in acidic and/or alkaline media.The improved performance results from the modification of electronic structure of palladium and nickel by the introduced phosphorus and the enhanced corrosion resistance of PdNiP.The simple phosphorization approach reported here allows for mass production of highly-active OMEO and HER electrocatalysts,holding substantial promise for their large-scale application in direct liquid fuel cells and water electrolyzers.

Development of a droplet digital polymerase chain reaction assay for the sensitive detection of total and integrated HIV-1 DNA

Background:Total human immunodeficiency virus(HIV)DNA and integrated HIV DNA are widely used markers of HIV persistence.Droplet digital polymerase chain reaction(ddPCR)can be used for absolute quantification without needing a standard curve.Here,we developed duplex ddPCR assays to detect and quantify total HIV DNA and integrated HIV DNA.Methods:The limit of detection,dynamic ranges,sensitivity,and reproducibility were evaluated by plasmid constructs containing both the HIV long terminal repeat(LTR)and human CD3 gene(for total HIV DNA)and ACH-2 cells(for integrated HIV DNA).Forty-two cases on stable suppressive antiretroviral therapy(ART)were assayed in total HIV DNA and integrated HIV DNA.Correlation coefficient analysis was performed on the data related to DNA copies and cluster of differentiation 4 positive(CD4^(+))T-cell counts,CD8^(+)T-cell counts and CD4/CD8 T-cell ratio,respectively.The assay linear dynamic range and lower limit of detection(LLOD)were also assessed.Results:The assay could detect the presence of HIV-1 copies 100%at concentrations of 6.3 copies/reaction,and the estimated LLOD of the ddPCR assay was 4.4 HIV DNA copies/reaction(95%confidence intervals[CI]:3.6-6.5 copies/reaction)with linearity over a 5-log_(10)-unit range in total HIV DNA assay.For the integrated HIV DNA assay,the LLOD was 8.0 copies/reaction(95%CI:5.8-16.6 copies/reaction)with linearity over a 3-log 10-unit range.Total HIV DNA in CD4^(+)T cells was positively associated with integrated HIV DNA(r=0.76,P<0.0001).Meanwhile,both total HIV DNA and integrated HIV DNA in CD4^(+)T cells were inversely correlated with the ratio of CD4/CD8 but positively correlated with the CD8^(+)T-cell counts.Conclusions:This ddPCR assay can quantify total HIV DNA and integrated HIV DNA efficiently with robustness and sensitivity.It can be readily adapted for measuring HIV DNA with non-B clades,and it could be beneficial for testing in clinical trials.

Human mpox co-infection with advanced HIV-1 and XDR-TB in a MSM patient previously vaccinated against smallpox:A case report

Mpox is a zoonotic infectious disease caused by the mpox virus(MPXV).Historically,the majority of mpox cases have been documented in Central Africa.However,since May 2022,there has been a notable rise in reported cases from regions beyond Africa.Currently,over 110 countries spanning Europe,North America,South America,Asia,and other territories have reported mpox infections.This report details a case involving a patient who identifies as a man who has sex with men(MSM)and is concurrently infected with MPXV,human immunodeficiency virus type 1(HIV-1),Pneumocystis jiroveci,as well as extensively drug-resistant tuberculosis(XDR-TB).This patient had also received a vaccination for smallpox in the past.Additionally,we provide photographic documentation charting the progression of dermatological manifestations associated with mpox.This case highlights the significance of sexual intercourse as a crucial mode of transmission for mpox.The rapid and widespread dissemination of the MPXV across various regions,especially among MSM communities,underscores the importance of enhancing preventive education efforts targeted at high-risk populations.

Mixed iridium-nickel oxides supported on antimony-doped tin oxide as highly efficient and stable acidic oxygen evolution catalysts

Proton exchange membrane(PEM)water electrolysis represents a promising technology for green hydrogen production,but its widespread deployment is greatly hindered by the indispensable usage of platinum group metal catalysts,especially iridium(Ir)based materials for the energy-demanding oxygen evolution reaction(OER).Herein,we report a new sequential precipitation approach to the synthesis of mixed Ir-nickel(Ni)oxy-hydroxide supported on antimony-doped tin oxide(ATO)nanoparticles(IrNiyO_(x)/ATO,20 wt.%(Ir+Ni),y=0,1,2,and 3),aiming to reduce the utilisation of scarce and precious Ir while maintaining its good acidic OER performance.When tested in strongly acidic electrolyte(0.1 M HClO_(4)),the optimised IrNi1Ox/ATO shows a mass activity of 1.0 mAµgIr^(−1) and a large turnover frequency of 123 s^(−1) at an overpotential of 350 mV,as well as a comparatively small Tafel slope of 50 mV dec^(−1),better than the IrOx/ATO control,particularly with a markedly reduced Ir loading of only 19.7µgIr cm^(−2).Importantly,IrNi1O_(x)/ATO also exhibits substantially better catalytic stability than other reference catalysts,able to continuously catalyse acidic OER at 10 mA cm^(−2) for 15 h without obvious degradation.Our in-situ synchrotron-based x-ray absorption spectroscopy confirmed that the Ir^(3+)/Ir^(4+)species are the active sites for the acidic OER.Furthermore,the performance of IrNi1Ox/ATO was also preliminarily evaluated in a membrane electrode assembly,which shows better activity and stability than other reference catalysts.The IrNi1Ox/ATO reported in this work is a promising alternative to commercial IrO_(2) based catalysts for PEM electrolysis.

High entropy materials as emerging electrocatalysts for hydrogen production through low-temperature water electrolysis

The production of hydrogen through water electrolysis(WE)from renewable electricity is set to revolutionise the energy sector that is at present heavily dependent on fossil fuels.However,there is still a pressing need to develop advanced electrocatalysts able to show high activity and withstand industrially-relevant operating conditions for a prolonged period of time.In this regard,high entropy materials(HEMs),including high entropy alloys and high entropy oxides,comprising five or more homogeneously distributed metal components,have emerged as a new class of electrocatalysts owing to their unique properties such as low atomic diffusion,structural stability,a wide variety of adsorption energies and multi-component synergy,making them promising catalysts for challenging electrochemical reactions,including those involved in WE.This review begins with a brief overview about WE technologies and a short introduction to HEMs including their synthesis and general physicochemical properties,followed by a nearly exhaustive summary of HEMs catalysts reported so far for the hydrogen evolution reaction,the oxygen evolution reaction and the overall water splitting in both alkaline and acidic conditions.The review concludes with a brief summary and an outlook about the future development of HEM-based catalysts and further research to be done to understand the catalytic mechanism and eventually deploy HEMs in practical water electrolysers.

A lightweight distillation CNN-transformer architecture for remote sensing image super-resolution

Remote sensing images exhibit rich texture features and strong autocorrelation.Although the super-resolution(SR)method of remote sensing images based on convolutional neural networks(CNN)can capture rich local information,the limited perceptual field prevents it from establishing long-distance dependence on global information,leading to the low accuracy of remote sensing image reconstruction.Furthermore,it is difficult for existing SR methods to be deployed in mobile devices due to their large network parameters and high computational demand.In this study,we propose a lightweight distillation CNN-Transformer SR architecture,named DCTA,for remote sensing SR,addressing the aforementioned issues.Specifically,the proposed DCTA first extracts the coarse features through the coarse feature extraction layer and then learns the deep features of remote sensing at different scales by fusing the feature distillation extraction module of CNN and Transformer.In addition,we introduce the feature fusion module at the end of the feature distillation extraction module to control the information propagation,aiming to select the informative components for better feature fusion.The extracted low-resolution(LR)feature maps are reorganized through the up-sampling module to obtain high-resolution(HR)feature maps with high accuracy to generate highquality HR remote sensing images.The experiments comparing different methods demonstrate that the proposed approach performs well on multiple datasets,including NWPU-RESISC45,Draper,and UC Merced.This is achieved by balancing reconstruction performance and network complexity,resulting in both competitive subjective and objective results.

Glut1 expression on CD8^(dim)T cells is associated with immune recovery in HIV-1-infected individuals

To the Editor:Immune non-responders(INRs),who account for approximately 10-40%of human immunodeficiency virus(HIV)-infected individuals,have received effective treatment and exhibit persistent suppression of viral replication,but their CD4^(+)T-cell counts are not restored.They are likely to have an increased risk of non-acquired immunodeficiency syndrome(AIDS)-related morbidity and mortality compared with immune responders(IRs).[1]CD8^(+)T cells play an important role in viral infection,and the functional properties of circulating CD8^(+)T cells have been associated with immune control of HIV.High CD8^(+)T-cell counts are beneficial for persistent viral decay and CD4 T-cell recovery in immune-restored patients during long-term antiretroviral therapy(ART).[2]Two subsets of CD8^(+)T cells have been identified according to their intensity of CD8 expression:CD8^(bri)and CD8^(dim)T lymphocytes.It was demonstrated that CD3^(+)CD8^(dim)T cells,with weaker function than CD3^(+)CD8^(bri)T cells,were associated with disease progression during HIV infection.[3]However,dynamic changes in the numbers of CD8^(bri)and CD8^(dim)T cells in INRs and IRs before and after ART have not yet been reported.

Mechanically reprogrammable Pancharatnam-Berry metasurface for microwaves

Metasurfaces have enabled the realization of several optical functionalities over an ultrathin platform,fostering the exciting field of flat optics.Traditional metasurfaces are achieved by arranging a layout of static meta-atoms to imprint a desired operation on the impinging wavefront,but their functionality cannot be altered.Reconfigurability and programmability of metasurfaces are the next important step to broaden their impact,adding customized on-demand functionality in which each meta-atom can be individually reprogrammed.We demonstrate a mechanical metasurface platform with controllable rotation at the meta-atom level,which can implement continuous Pancharatnam–Berry phase control of circularly polarized microwaves.As the proof-of-concept experiments,we demonstrate metalensing,focused vortex beam generation,and holographic imaging in the same metasurface template,exhibiting versatility and superior performance.Such dynamic control of electromagnetic waves using a single,low-cost metasurface paves an avenue towards practical applications,driving the field of reprogrammable intelligent metasurfaces for a variety of applications.

Development of upland rice introgression lines and identification of QTLs for basal root thickness under different water regimes

Introgression lines （ILs） are valuable materials for identifying quantitative trait loci （QTLs）, evaluating genetic interactions, and marker assisted breeding. A set of 430 ILs （BC5F3） containing segments from upland tropical japonica cultivar IRAT109 in a lowland temperate japonica cultivar Yuefu background were developed. One hundred and seventy-six polymorphic markers were used to identify introgressed segments. No segment from IRAT109 was found in 160 lines. Introgressed segments of the other 270 lines covered 99.1% of the donor genome. The mean number of introgressed donor segments per individual was 3.3 with an average length of 14.4 cM. QTL analysis was conducted on basal root thickness （BRT） of the 270 ILs grown under irrigated lowland, upland and hydroponic conditions. A total of 22 QTLs affecting BRT were identified, six QTLs （qBRT3.1, qBRT3.2, qBRT6.1, qBRTS.2, qBRT9.1, and qBRT9.2） were consistently expressed under at least two environments （location and water regime）, and qBRT7.2 was a new BRT QTL identified under lowland conditions. IL255 containing qBRT9.1 showed an increase of 10.09% and 7.07% BRT over cultivar Yuefu when grown under upland and lowland conditions, respectively. Using a population of 304 F2：3 lines derived from the cross IL255 Yuefu, qBRT9.1 was validated and mapped to a 1.2 cM interval between RM24271 and RM566. The presence of qBRT9.1 explained 12% of BRT variation. The results provide upland rice ILs and BRT QTLs for analyzing the genetic basis of drought resistance, detecting favorable genes from upland rice, and rice drought resistance breeding.

Conformal and continuous deposition of bifunctional cobalt phosphide layers on p-silicon nanowire arrays for improved solar hydrogen evolution

Vertically aligned p-silicon nanowire （SiNW） arrays have been extensively investigated in recent years as promising photocathodes for solar-driven hydrogen evolution. However, the fabrication of SiNW photocathodes with both high photoelectrocatalytic activity and long-term operational stability using a simple and affordable approach is a challenging task. Herein, we report conformal and continuous deposition of a di-cobalt phosphide （C02P） layer on lithography- patterned highly ordered SiNW arrays via a cost-effective drop-casting method followed by a low-temperature phosphorization treatment. The as-deposited C02P layer consists of crystalline nanoparticles and has an intimate contact with SiNWs, forming a well-defined SiNW@Co2P core/shell nanostructure. The conformal and continuous Co2P layer functions as a highly efficient catalyst capable of substantially improving the photoelectrocatalytic activity for the hydrogen evolution reaction （HER） and effectively passivates the SiNWs to protect them from photo-oxidation, thus prolonging the lifetime of the electrode. As a consequence, the SiNW@Co2P photocathode with an optimized C02P layer thickness exhibits a high photocurrent density of -21.9 mA·cm^-2 at 0 V versus reversible hydrogen electrode and excellent operational stability up to 20 h for solar-driven hydrogen evolution, outperforming many nanostructured silicon photocathodes reported in the literature. The combination of passivation and catalytic functions in a single continuous layer represents a promising strategy for designing high-performance semiconductor photoelectrodes for use in solar-driven water splitting, which may simplify fabrication procedures and potentially reduce production costs.

Boosting acidic water oxidation performance by constructing arrays-like nanoporous Ir_(x)Ru_(1−x)O_(2) with abundant atomic steps

The fabrication of electrocatalysts with high activity and acid stability for acidic oxygen evolution reaction(OER)is an urgent need,yet extremely challenging.Here,we report the design and successful fabrication of a high performance self-supported cogwheel arrays-like nanoporous Ir_(x)Ru_(1−x)O_(2) catalyst with abundant atomic steps for acidic OER using a facile alloy-spinningelectrochemical activation method that allows large-scale fabrication.The obtained Ir_(x)Ru_(1−x)O_(2) catalysts merely need overpotentials of 211 and 295 mV to deliver catalytic current densities of 10 and 300 mA·cm^(−2) in 0.5 M H_(2)SO_(4),respectively,and can sustain constant OER electrolysis for at least 140 h at a high current density of 300 mA·cm^(−2).Further density functional theory(DFT)calculations uncover that such high intrinsic activities mainly originate from the largely exposed high-index atomic step planes,which markedly lower the limiting potential of the rate-determining step(RDS)of OER.These findings provide an insight into the exploration of high performance electrocatalysts,and open up an avenue for further developing the state-of-theart Ir and/or Ru-based catalysts for large-scale practical applications.

Plasma tailoring in WTe_(2)nanosheets for efficiently boosting hydrogen evolution reaction

2D transition metal dichalcogenides(TMDs)have been considered as promising non-precious electrocatalysts for the hydrogen evolution reaction(HER).However,their limited active sites and poor electric conductivity pose a significant hurdle to their HER performance,resulting in a large overpotential.Here,we report the defect engineering in ultrathin tungsten telluride(WTe_(2))nanosheets with semimetal nature to improve hydrogen evolution effectively.We find that the oxygen plasma etching imposes a cutting effect on WTe_(2)nanosheets,resulting in a large number of tungsten vacancies.Particularly,the sample after plasma treatment for 10 min shows a feather-like structure with an overpotential of 251m V at 10 m A/cm~2and a Tafel slope of 94 m V/dec,which is 4 times lower than the Tafel slope of pristine nanosheets.Further first-principles calculations shed light on the evolution of defect-rich WTe_(2)nanosheets and offer rational explanation to their superiority in efficient hydrogen evolution.