Decoupled water electrolysis:Flexible strategy for pure hydrogen production with small voltage inputs

Hydrogen gas is widely regarded as an ideal green energy carrier and a potential alternative to fossil fuels for coping with the aggravating energy crisis and environmental pollution.Currently,the vast majority of the world's hydrogen is produced by reforming fossil fuels;however,this hydrogen-making technology is not sustainable or environmentally friendly because ofits high energy consumption and large carbon emissions.Renewables-driven water splitting(2H_(2)0-2H_(2)+0_(2))becomes an extensively studied scheme for sustain-able hydrogen production.Conventional water electrolysis requires an input voltage higher than 1.23 V and forms a gas mixture of H_(2)/O_(2),which results in high electricity consumption,potential safety hazards,and harmful reactive oxygen species.By virtue of the auxiliary redox mediators(RMs)as the robust H^(+)/e^(-)reservoir,decoupled electrolysis splits water at a much lower potential and evolves O_(2)(H_(2)O+RMS_(ox)-O_(2)+H-RMS_(red))and H_(2)(H-RMS_(red)-H_(2)+RMS_(ox))at separate times,rates,and spaces,thus pro-ducing the puretarget hydrogen gas safely.Decoupled electrolysis has accelerated the development ofwater electrolysis technology for H_(2) production.However,itis still lack of a comprehensive and in-depth review in this field based on different types of RMs.This review highlights the basic principles and critical progress of this emerging water electrolysis mode over the past decade.Several representative examples are then dis-played in detail according to the differences in the RMs.The rational choice and design of RMs have also been emphasized.Subsequently,novel applications of decoupled water splitting are briefly discussed,including the manufacture of valuable chemicals,Cl_(2) production,pollutant degradation,and other half-reactions in artificial photosynthesis.Finally,thekey characteristics and disadvantages of each type of mediator are sum-marized in depth.In addition,we present an outlook for future directions in decoupled water splitting.Thus,the flexibility in the design of mediators provides huge space for improving this electrochemical technology.@2024 Science Press and Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by ELSEVIER B.V.and Science Press.All rights reserved.

Facet-dependent anchoring of gold nanoparticles on TiO2 for CO oxidation

The interfacial perimeter of gold nanocatalysts is popularly viewed as the active sites for a number of chemical reactions,while the geometrical structure of the interface at atomic scale is less known.Here,TiO2-nanosheets and nanospindles were adapted to accommodate Au particles(~2.2 nm),forming Au-TiO2{001}and Au-TiO2{101}interfaces.Upon calcination at 623 K in air,HAADF-STEM images evidenced that the Au particles on TiO2{101}enlarged to 3.1 nm and these on TiO2{001}remained unchanged,suggesting the stronger metal-support interaction on TiO2{001}.Au/TiO2{001}was more active for CO oxidation than Au/TiO2{101}system.

Controlled Assembly of Luminescent Lanthanide‑Organic Frameworks via Post‑Treatment of 3D‑Printed Objects

Complex multiscale assemblies of metal-organic frameworks are essential in the construction of largescale optical platforms but often restricted by their bulk nature and conventional techniques.The integration of nanomaterials and 3D printing technologies allows the fabrication of multiscale functional architectures.Our study reports a unique method of controlled 3D assembly purely relying on the post-printing treatment of printed constructs.By immersing a 3D-printed patterned construct consisting of organic ligand in a solution of lanthanide ions,in situ growth of lanthanide metal-organic frameworks(LnMOFs)can rapidly occur,resulting in macroscopic assemblies and tunable fluorescence properties.This phenomenon,caused by coordination and chelation of lanthanide ions,also renders a sub-millimeter resolution and high shape fidelity.As a proof of concept,a type of 3D assembled LnMOFsbased optical sensing platform has demonstrated the feasibility in response to small molecules such as acetone.It is anticipated that the facile printing and design approach developed in this work can be applied to fabricate bespoke multiscale architectures of functional materials with controlled assembly,bringing a realistic and economic prospect.

Strong metal‐support interaction boosting the catalytic activity of Au/TiO_(2) in chemoselective hydrogenation

Gold catalysts have been reported as highly effective catalysts in various oxidation reactions.However,for chemoselective hydrogenation reactions,gold‐based catalysts normally show much lowercatalytic activity than platinum group metals,even though their selectivities are excellent.Here,wereport that the chemoselective hydrogenation activity of 3‐nitrostyrene to 3‐vinylaniline overAu/TiO_(2)can be enhanced up to 3.3 times through the hydrogen reduction strategy.It is revealedthat strong metal‐support interaction,between gold nanoparticles(NPs)and TiO_(2)support,is introducedthrough hydrogen reduction,resulting in partial dispersion of reduced TiOx on the Au surface.The partially covered Au not only increases the perimeter of the interface between the gold NPs andthe support,but also benefits H_(2)activation.Reaction kinetic analysis and H_(2)‐D2 exchange reactionshow that H_(2)activation is the critical step in the hydrogenation of 3‐nitrostyrene to 3‐vinylaniline.Density functional theory calculations verify that hydrogen dissociation and hydrogen transfer arefavored at the interface of gold NPs and TiO_(2)over the hydrogen‐reduced Au/TiO_(2).This study providesinsights for fabricating highly active gold‐based catalysts for chemoselective hydrogenationreactions.

Targeted Ptpn11 deletion in mice reveals the essential role of SHP2 in osteoblast differentiation and skeletal homeostasis

The maturation and function of osteoblasts(OBs)rely heavily on the reversible phosphorylation of signaling proteins.To date,most of the work in OBs has focused on phosphorylation by tyrosyl kinases,but little has been revealed about dephosphorylation by protein tyrosine phosphatases(PTPases).SHP2(encoded by PTPN11)is a ubiquitously expressed PTPase.PTPN11 mutations are associated with both bone and cartilage manifestations in patients with Noonan syndrome(NS)and metachondromatosis(MC),although the underlying mechanisms remain elusive.Here,we report that SHP2 deletion in bone gamma-carboxyglutamate protein-expressing(Bglap+)bone cells leads to massive osteopenia in both trabecular and cortical bones due to the failure of bone cell maturation and enhanced osteoclast activity,and its deletion in Bglap+chondrocytes results in the onset of enchondroma and osteochondroma in aged mice with increased tubular bone length.Mechanistically,SHP2 was found to be required for osteoblastic differentiation by promoting RUNX2/OSTERIX signaling and for the suppression of osteoclastogenesis by inhibiting STAT3-mediated RANKL production by osteoblasts and osteocytes.These findings are likely to explain the compromised skeletal system in NS and MC patients and to inform the development of novel therapeutics to combat skeletal disorders.

Highly efficient base-free aerobic oxidation of alcohols over gold nanoparticles supported on ZnO-CuO mixed oxides

The design and preparation of suitable supports are of great importance for gold catalysts to attain excellent catalytic performance for alcohol oxidation.In this work,we found that ZnO-CuO mixed oxides supported gold catalysts showed much better catalytic activity for base-free aerobic oxidation of benzyl alcohol than Au/ZnO and Au/CuO catalysts,and among them Au/Zn0.7Cu0.3O displayed the best catalytic performance.In addition,the Au/Zn0.7Cu0.3O catalyst could selectively catalyze the aerobic oxidation of a wide range of alcohols to produce the corresponding carbonyl compounds with high yields under mild conditions without base.Further characterizations indicated that the outstanding catalytic performance of Au/Zn0.7Cu0.3O was correlated with the small size of Au nanoparticles(NPs),good low-temperature reducibility,high concentration of surface oxygen species,and collaborative interaction between Au NPs and mixed oxide.

Variability of Prorocentrum donghaiense response to allelopathic action from Alexandrium pacificum in laboratory culture

The dinoflagellates Alexandrium pacificum and Prorocentrum donghaiense are two well-known harmful algal blooms(HABs)-forming species,both were usually found in the same sea areas in form of HABs in China.To date,there is no mechanistic model that can fully explain the occurrence of P.donghaiense blooms with A.pacificum.We found that different strains of P.donghaiense had different intrinsic growth rates of 0.107-0.215/d,and these strains exhibited different responses to the allelopathic action from A.pacificum.Some strains of P.donghaiense could grow well despite some degrees of inhibition in a short period,suggesting the two algal species P.donghaiense and A.pacificum could coexist,even if A.pacificum was allelopathic.Our findings may advance the understanding of phenotypes in P.donghaiense and provide a potential mechanism involved in the coexistence of P.donghaiense and A.pacificum in the same area.

Discrimination of background events in the PolarLight X-ray polarimeter

PolarLight is a space-borne X-ray polarimeter that measures the X-ray polarization via electron tracking in an ionization chamber.It is a collimated instrument and thus suffers from the background on the whole detector plane.The majority of background events are induced by high energy charged particles and show ionization morphologies distinct from those produced by X-rays of interest.Comparing on-source and off-source observations,we find that the two datasets display different distributions on image properties.The boundaries between the source and background distributions are obtained and can be used for background discrimination.Such a means can remove over 70%of the background events measured with PolarLight.This approaches the theoretical upper limit of the background fraction that is removable and justifies its effectiveness.For observations with the Crab nebula,the background contamination decreases from 25%to 8%after discrimination,indicative of a polarimetric sensitivity of around 0.2 Crab for PolarLight.This work also provides insights into future X-ray polarimetric telescopes.

水稻突变体pe-1对弱光胁迫的响应机制

以γ射线诱变籼稻双科早(Oryza sativa subsp.indica cv.‘Shuangkezao’)获得的早熟鲜绿突变体pe-1为实验材料,在三叶期和分蘖期进行弱光胁迫,探讨pe-1与野生型在形态特征、非生物胁迫相关酶活性及其调控基因表达量、叶绿素含量、叶绿体合成与降解及光形态建成相关基因表达对弱光响应的差异。结果表明,与野生型相比,弱光胁迫后,pe-1叶片黄化程度显著降低,株高和叶面积显著增加;三叶期和分蘖期的叶片中不同叶绿素含量变化不同。此外,pe-1叶绿素含量增加,且其抗氧化应激反应相关酶过氧化氢酶(CAT)和过氧化物酶(POD)的活性及相关基因的表达量均高于野生型,表明在弱光胁迫下pe-1活性氧清除能力增强,适应能力更强。pe-1的光形态建成相关基因表达量高于野生型,表明弱光处理下pe-1的光接收能力更强。综上,pe-1突变体具有抵御弱光胁迫的潜力,该结果有助于耐弱光水稻品种的选育。

Readily prepared and processed multifunctional MXene nanocomposite hydrogels for smart electronics

Booming sophisticated robotics and prosthetics put forward high requirements on soft conductive materials that can bridge electronics and biology,those soft conductive materials should imitate the mechanical properties of biological tissues and build information transmission networks.Until now,it remains a great challenge to handle the trade-off among ease of preparation,high conductivity,processability,mechanical adaptability,and external stimuli responsiveness.Herein,a kind of readily prepared and processed multifunctional MXene nanocomposite hydrogel is reported,which is prepared via the fast gelation of cationic monomer initiated by delaminated MXene sheets.The gelation time can be adjusted(several seconds to minutes)based on the MXene loadings.By adjusting the MXene ratio,the resulting nanocomposites are ultrastretchable(>5000%),three-dimensional(3D)printable,and show outstanding mechanical and electrical self-healing.As expected,the integration of multifunctional systems onto various substrates(e.g.,gloves and masks)is further demonstrated via 3D printing and could achieve diverse sensory capabilities toward strain,pressure,and temperature,showing great prospects as smart flexible electronics.

Decitabine induces IRF7-mediated immune responses in p53-mutated triple-negative breast cancer:a clinical and translational study

p53 is mutated in half of cancer cases.However,no p53-targeting drugs have been approved.Here,we reposition decitabine for triple-negative breast cancer(TNBC),a subtype with frequent p53 mutations and extremely poor prognosis.In a retrospective study on tissue microarrays with 132 TNBC cases,DNMT1 overexpression was associated with p53 mutations(P=0.037)and poor overall survival(OS)(P=0.010).In a prospective DEciTabinE and Carboplatin in TNBC(DETECT)trial(NCT03295552),decitabine with carboplatin produced an objective response rate(ORR)of 42%in 12 patients with stage IV TNBC.Among the 9 trialed patients with available TP53 sequencing results,the 6 patients with p53 mutations had higher ORR(3/6 vs.0/3)and better OS(16.0 vs.4.0 months)than the patients with wild-type p53.In a mechanistic study,isogenic TNBC cell lines harboring DETECT-derived p53 mutations exhibited higher DNMT1 expression and decitabine sensitivity than the cell line with wild-type p53.In the DETECT trial,decitabine induced strong immune responses featuring the striking upregulation of the innate immune player IRF7 in the p53-mutated TNBC cell line(upregulation by 16-fold)and the most responsive patient with TNBC.Our integrative studies reveal the potential of repurposing decitabine for the treatment of p53-mutated TNBC and suggest IRF7 as a potential biomarker for decitabine-based treatments.

Selective and stable Au-Cu bimetallic catalyst for CO-PROX

Gold-based catalysts are promising in CO preferential oxidation(CO-PROX)reaction in H_(2)-rich stream on account of their high intrinsic activity for CO elimination even at ambient temperature.However,the decrease of CO conversion at elevated temperature due to the competition of H_(2)oxidation,together with the low stability of gold nanoparticles,has posed a dear challenge.Herein,we report that Au-Cu bimetallic catalyst prepared by galvanic replacement method shows a wide temperature window for CO total conversion(30-100℃)and very good catalyst stability without deactivation in a 200-h test.Detailed characterizations combined with density functional theory(DFT)calculation reveal that the synergistic effect of Au-Cu,the electron transfer from Au to Cu,leads to not only strengthened chemisorption of CO but also weakened dissociation of H_(2),both of which are helpful in inhibiting the competition of H_(2)oxidation thus widening the temperature window for CO total conversion.

Structural isomer and high-yield of Pt1Ag28 nanoduster via one-pot chemical wet method

In order to understand the structure-property correlation and explore the application of metal nanoclusters, it is important and intriguing to determine their crystal structure and obtain high-yield. At the same time, this is also a challenge in nanoscience and technology. Here, we report the highly efficient synthesis of Pt1Ag28 nanocluster via one-pot chemical wet method. The crystal structure of Pt1Ag28 nanocluster was determined by X-ray crystallography to be a face centered cubic (FCC) kernel. This novel structure is the structural isomerization of Pt1Ag28 nanocluster reported before. This phenomenon is first discovered in the synthesis of alloy nanoclusters. In addition, Pt1Ag28 nanocluster has high yield and exhibits potential optics in the near infrared (NIR) fluorescent imaging. The time-dependent density functional theory (TD-DFT) calculation implied that the optical property of Pt1Ag28 was sensitive to its structure. This work provides a simple method to synthesize alloy nanoclusters with structural isomerization.

ClusterSLAM:A SLAM backend for simultaneous rigid body clustering and motion estimation

We present a practical backend for stereo visual SLAM which can simultaneously discover individual rigid bodies and compute their motions in dynamic environments.While recent factor graph based state optimization algorithms have shown their ability to robustly solve SLAM problems by treating dynamic objects as outliers,their dynamic motions are rarely considered.In this paper,we exploit the consensus of 3 D motions for landmarks extracted from the same rigid body for clustering,and to identify static and dynamic objects in a unified manner.Specifically,our algorithm builds a noise-aware motion affinity matrix from landmarks,and uses agglomerative clustering to distinguish rigid bodies.Using decoupled factor graph optimization to revise their shapes and trajectories,we obtain an iterative scheme to update both cluster assignments and motion estimation reciprocally.Evaluations on both synthetic scenes and KITTI demonstrate the capability of our approach,and further experiments considering online efficiency also show the effectiveness of our method for simultaneously tracking ego-motion and multiple objects.

Interactive modeling of lofted shapes from a single image

Modeling the complete geometry of general shapes from a single image is an ill-posed problem.User hints are often incorporated to resolve ambiguities and provide guidance during the modeling process. In this work, we present a novel interactive approach for extracting high-quality freeform shapes from a single image. This is inspired by the popular lofting technique in many CAD systems, and only requires minimal user input. Given an input image, the user only needs to sketch several projected cross sections, provide a"main axis", and specify some geometric relations. Our algorithm then automatically optimizes the common normal to the sections with respect to these constraints,and interpolates between the sections, resulting in a high-quality 3 D model that conforms to both the original image and the user input. The entire modeling session is efficient and intuitive. We demonstrate the effectiveness of our approach based on qualitative tests on a variety of images, and quantitative comparisons with the ground truth using synthetic images.

One-step rapid synthesis,crystal structure and 3.3 microseconds long excited-state lifetime of Pd1Ag28 nanocluster

Doping foreign atom(s)in metal nanoclusters is an effective strategy to engineer the properties and functionalities of metal nanoclusters.However,until now,to dope Pd atom into Ag nanoclusters remains a huge challenge.Here we develop a one-step rapid method to synthesize the Pd-doped Ag nanocluster with high yield.The prepared Pd1Ag28 nanocluster was characterized by mass spectroscopy,X-ray photoelectron spectroscopy,X-ray crystallography,fluorescence spectroscopy,ultraviolet-visible absorption spectroscopy and transient absorption spectroscopy.The nanocluster exhibits a perfect face-centered cubic(FCC)kernel structure with a tetrahedron-like shell.Of note,Pd1Ag28 nanocluster had an unexpectedly long excited-state lifetime of 3.3 microseconds,which is the longest excited-state lifetime for Ag-based nanoclusters S0 far.Meanwhile,the excellent near-infrared luminescence indicated the nanocluster has the potential in fluorescent bio-imaging.Besides,it was revealed that Pd1Ag28 nanocluster could be transformed into Au1Ag28 nanocluster via ion exchange reaction of AuPPhzCl with Pd1Ag28 nanocluster.This work provides an efficient synthetic protocol of alloy nanoclusters and wil contribute to study the effect of foreign atom on the properties of metal nanoclusters.

Synthesis and structure of Au_(19)Ag_4(S-Adm)_(15) nanocluster:Polymorphs and optical properties

Polymorphism is a common phenomenon in nature.Here,we report one-pot wet chemical method to synthesize two polymorphs of Au_(19)Ag_(4)(S-Adm)_(15) nanocluster protected by 1-adamantanethiol(HSAdm),which adopt P-1 and P2_(1)/c space group respectively.The crystal structures of two polymorphs were determined by X-ray crystallography.Compared to the previously reported Au_(19)Ag_(4)(S-Adm)_(15)nanocluster adopting P2_(1)/n space group,polymorphs of Au_(19)Ag_(4)(S-Adm)_(15) with P-1 and P2_(1)/c space group show the different optical properties.Moreove r,Au_(19)Ag_(4)(S-Adm)_(15) with P-1 space group exhibits good thermal stability.Meanwhile,we investigated the effect of solvent and molar ratio of metal precursors on the polymorphs.This work provides an insight to polymorphs of metal nanoclusters.

HDR-Net-Fusion:Real-time 3D dynamic scene reconstruction with a hierarchical deep reinforcement network

Reconstructing dynamic scenes with commodity depth cameras has many applications in computer graphics,computer vision,and robotics.However,due to the presence of noise and erroneous observations from data capturing devices and the inherently ill-posed nature of non-rigid registration with insufficient information,traditional approaches often produce low-quality geometry with holes,bumps,and misalignments.We propose a novel 3D dynamic reconstruction system,named HDR-Net-Fusion,which learns to simultaneously reconstruct and refine the geometry on the fly with a sparse embedded deformation graph of surfels,using a hierarchical deep reinforcement(HDR)network.The latter comprises two parts:a global HDR-Net which rapidly detects local regions with large geometric errors,and a local HDR-Net serving as a local patch refinement operator to promptly complete and enhance such regions.Training the global HDR-Net is formulated as a novel reinforcement learning problem to implicitly learn the region selection strategy with the goal of improving the overall reconstruction quality.The applicability and efficiency of our approach are demonstrated using a large-scale dynamic reconstruction dataset.Our method can reconstruct geometry with higher quality than traditional methods.

NIR-to-NIR UCL/T_1-weighted MR/CT multimodal imaging by NaYbF_4:Tm@NaGdF_4:Yb-PVP upconversion nanoparticles

Multimodal imaging nanoprobes are urgently sought because they can integrate different imaging func- tion into individual nanoplatform and provide more comprehensive and accurate information for the diagnosis of early-stage tumor. Lanthanide-based upconversion nanoparticles （UCNPs） are regarded as promising nanoplatforms to fabricate these probes. Herein, we firstly developed the active core-active shell structured NaYbF4：Tm@NaGdF4：Yb-PVP UCNPs with the average diameter of 13.23 ＋ 0.96 nm as multimodal imaging probes. These water-dispersible nanoprobes presented excellent near-infrared to near-infrared （NIR-to-NIR） upconversion luminescence （UCL） performance, which is favorable for optical bioimaging due to deeper tissue penetration and autofluorescence reduction. After coated with the NaGdF4：Yb active shell, the UCL emission intensity at 800 nm increased by 7.2 times. These nanoprobes exhibited a desirable longitudinal relaxivity （rl = 3.58 L/（mmol s）） and strong X-ray attenuation property （58.84 HU L/g）. The cytotoxicity assessment, histology analysis and biodistribution study revealed that NaYbF4：Tm@NaGdF4：Yb-PVP UCNPs had relatively low cytotoxicity and negligible organ toxicity. These UCNPs were applied for NIR-to-NIR UCL imaging in vivo. More importantly, the detection of small tumor was successfully achieved under Trweighted MRI and CT imaging modalities after intravenous injection of these UCNPs. These results revealed that NaYbF4：Tm@NaGdF4：Yb-PVP UCNPs could serve as promising NIR-to-NIR UCL/MRI/CT trimodal imaging probes.

DeepPrimitive: Image decomposition by layered primitive detection

The perception of the visual world through basic building blocks, such as cubes, spheres, and cones gives human beings a parsimonious understanding of the visual world. Thus, efforts to find primitive-based geometric interpretations of visual data date back to 1970 s studies of visual media. However, due to the difficulty of primitive fitting in the pre-deep learning age, this research approach faded from the main stage and the vision community turned primarily to semantic image understanding. In this paper, we revisit the classical problem of building geometric interpretations of images, using supervised deep learning tools. We build a framework to detect primitives from images in a layered manner by modifying the YOLO network an RNN with a novel loss function is then used to equip this network with the capability to predict primitives with a variable number of parameters. We compare our pipeline to traditional and other baseline learning methods, demonstrating that our layered detection model has higher accuracy and performs better reconstruction.