高强度耐低温离子水凝胶的制备及在摩擦纳米发电机中的应用

摩擦纳米发电机(TENG)作为一种新型可持续的能量收集设备,具有自供电、高输出、低成本、灵活性和轻量化等优点。然而,传统TENG的电极材料为金属薄膜、碳片和液态金属等,存在可拉伸性差、导电性差且在低温无法工作等缺点。文中将氯化锌(ZnCl_(2))、磺基甜菜碱(SBMA)、纳米纤维素(CNC)和柠檬酸(CA)引入聚丙烯酸(AA)基体中,制备了具有优异力学性能(拉伸强度2.16 MPa、断裂伸长率382%)、抗疲劳性、导电性能(9.3 mS/cm)、抗冻性能(-75℃)和保水性能的离子水凝胶材料。基于该离子水凝胶所制备的TENG具有良好的可拉伸性、抗冻性(-50℃)和稳定的输出电压(60 V),能够将人体运动产生的机械能转化为电能,并成功点亮了39个LED灯。因此该水凝胶基TENG在能量收集领域展示出巨大的发展潜力,具有广阔的应用前景。

Targeting the chromatin structural changes of antitumor immunity

Epigenomic imbalance drives abnormal transcriptional processes,promoting the onset and progression of cancer.Although defective gene regulation generally affects carcinogenesis and tumor suppression networks,tumor immunogenicity and immune cells involved in antitumor responses may also be affected by epigenomic changes,which may have significant implications for the development and application of epigenetic therapy,cancer immunotherapy,and their combinations.Herein,we focus on the impact of epigenetic regulation on tumor immune cell function and the role of key abnormal epigenetic processes,DNA methylation,histone post-translational modification,and chromatin structure in tumor immunogenicity,and introduce these epigenetic research methods.We emphasize the value of small-molecule inhibitors of epigenetic modulators in enhancing antitumor immune responses and discuss the challenges of developing treatment plans that combine epigenetic therapy and immuno-therapy through the complex interaction between cancer epigenetics and cancer immunology.

Automation in road distress detection,diagnosis and treatment

Road transportation plays a crucial role in society and daily life,as the functioning and durability of roads can significantly impact a nation's economic development.In the whole life cycle of the road,the emergence of disease is unavoidable,so it is necessary to adopt relevant technical means to deal with the disease.This study comprehensively reviews the advancements in computer vision,artificial intelligence,and mobile robotics in the road domain and examines their progress and applications in road detection,diagnosis,and treatment,especially asphalt roads.Specifically,it analyzes the research progress in detecting and diagnosing surface and internal road distress and related techniques and algorithms are compared.In addition,also introduces various road gover-nance technologies,including automated repairs,intelligent construction,and path planning for crack sealing.Despite their proven effectiveness in detecting road distress,analyzing diagnoses,and planning maintenance,these technologies still confront challenges in data collection,parameter optimization,model portability,system accuracy,robustness,and real-time performance.Consequently,the integration of multidisciplinary technologies is imperative to enable the development of an integrated approach that includes road detection,diagnosis,and treatment.This paper addresses the challenges of precise defect detection,condition assessment,and unmanned construction.At the same time,the efficiency of labor liberation and road maintenance is achieved,and the automation level of the road engineering industry is improved.

A nonlinear creep model for surrounding rocks of tunnels based on kinetic energy theorem

The initiating condition for the accelerated creep of rocks has caused difficulty in analyzing the whole creep process.Moreover,the existing Nishihara model has evident shortcomings in describing the accelerated creep characteristics of the viscoplastic stage from the perspective of internal energy to analyze the mechanism of rock creep failure and determine the threshold of accelerated creep initiation.Based on the kinetic energy theorem,Perzyna viscoplastic theory,and the Nishihara model,a unified creep constitutive model that can describe the whole process of decaying creep,stable creep,and accelerated creep is established.Results reveal that the energy consumption and creep damage in the process of creep loading mainly come from the internal energy changes of geotechnical materials.The established creep model can not only describe the viscoelasticeplastic creep characteristics of rock,but also reflect the relationship between rock energy and creep deformation change.In addition,the research results provide a new method for determining the critical point of creep deformation and a new idea for studying the creep model and creep mechanical properties.

金属有机框架衍生的阳离子调控金属硫化物增强析氧反应活性

析氧反应(OER)在电化学能源存储与转化技术(例如,电解水与金属-空气电池)中扮演着至关重要的角色.OER涉及四个电子的连续转移,动力学较为缓慢,因此需要较高的过电位来驱动反应进行,这严重限制了其在电化学储能和转换系统中的应用.IrO_(2)和RuO_(2)等贵金属基催化剂资源稀缺、价格高昂,因此,开发高活性、高稳定性及低成本的OER电催化剂显得尤为重要,并且极具挑战.杂原子掺杂是一种有效提升过渡金属化合物OER电催化剂活性的策略,但是当前对其本征活性位点的识别及活性提升机制的研究仍然不足.本文提出了一种阳离子掺杂策略,通过引入金属阳离子调控多金属组分的电子结构,优化OER中间体吸附能,进而提升OER活性.通过简单的一步热解硫化钴镍双金属有机框架材料前驱体,成功制备了Ni掺杂CoS/氮掺杂介孔碳(Ni-CoS/NC)复合结构电催化剂;并采用循环伏安法研究了其电化学行为与OER性能,结合谱学研究结果与密度泛函理论(DFT)计算,从原子层面揭示了OER条件下真实活性位点及掺杂型电催化剂的活性提升机制.电化学研究结果表明,所制备Ni-CoS/NC催化剂在1.0 mol L^(-1)KOH溶液中表现出较好的OER反应活性,其在10 mA cm^(-2)电流密度下的过电位为270mV,Tafel斜率为37 mV dec^(-1).采用X射线光电子能谱、高角度环形暗场扫描透射电子显微镜与电子能量损失谱等表征方法分析了OER前后催化剂的结构变化;结果表明,在OER电位下Ni-CoS/NC催化剂由金属硫化物转变为羟基氧化物Co_(x)Ni_(1–x)OOH,Co_(x)Ni_(1-x)OOH才是OER反应的活性位点.理论结算结果表明,在Co_(x)Ni_(1–x)OOH材料中,Ni部分取代Co位点,使两种金属之间产生强烈的电子相互作用,导致Co位点带有更多的负电荷,Ni位点带有更多的正电荷,从而增强了对中间物种OOH*的吸附,提升OER活性.综上,金属阳离子掺杂调变金属活性中心的电子结构,是提高电催化剂OER活性的有效策略.过渡金属硫化物电催化剂在OER电位下发生了重构,由晶态的金属硫化物转变为非晶态的金属羟基氧化物,作为OER催化剂的活性位点.本文为低成本、高性能电催化剂设计提供了一种可行的阳离子调控策略,并且加深了对本征活性位点及活性提升机制的认识,可为电化学能源存储与转化材料的开发提供借鉴.

Enhancing performance of inverted quantum-dot light-emitting diodes based on a solution-processed hole transport layer via ligand treatment

The performance of inverted quantum-dot light-emitting diodes(QLEDs)based on solution-processed hole transport layers(HTLs)has been limited by the solvent-induced damage to the quantum dot(QD)layer during the spin-coating of the HTL.The lack of compatibility between the HTL’s solvent and the QD layer results in an uneven surface,which negatively impacts the overall device performance.In this work,we develop a novel method to solve this problem by modifying the QD film with 1,8-diaminooctane to improve the resistance of the QD layer for the HTL’s solvent.The uniform QD layer leads the inverted red QLED device to achieve a low turn-on voltage of 1.8 V,a high maximum luminance of 105500 cd/m2,and a remarkable maximum external quantum efficiency of 13.34%.This approach releases the considerable potential of HTL materials selection and offers a promising avenue for the development of high-performance inverted QLEDs.

A novel cerebrovascular drug-coated balloon catheter for treating symptomatic intracranial atherosclerotic stenosis lesions:Study protocol for a prospective,multicenter,single-arm,target-value clinical trial

Background:Previous single-center studies have demonstrated that drug-coated balloons(DCBs)may reduce restenosis rates,which is an important factor affecting the prognosis for intracranial interventional therapy.However,currently available cardiac DCBs are not always suitable for the treatment of intracranial atherosclerotic stenosis(ICAS).This study aimed to evaluate the safety and efficacy of a novel DCB catheter designed for patients with severely symptomatic ICAS.Methods:This prospective,multicenter,single-arm,target-value clinical trial was conducted in 9 Chinese stroke centers to evaluate the safety and efficacy of a novel DCB catheter for treating symptomatic severe ICAS.Primary metrics and other indicators were collected and analyzed using SAS version 9.4(SAS Institute,Cary,NC,USA).Results:A total of 155 patients were enrolled in this study.The preliminary collection of follow-up data has been completed,while data quality control is ongoing.Conclusion:Results of this study demonstrated the patency rate,safety,and effectiveness of a novel on-label paclitaxel DCB designed for the treatment of ICAS.Ethics and dissemination:This study,involving human participants,was reviewed and approved by the Ethics Committee of Drugs(Devices)Clinical Experiment at Henan Provincial People’s Hospital(reference number:2020-145-03)and other research centers participating in the clinical trial.The results of this study will be presented at international conferences and sent to peer-reviewed journals for publication.Standard protocol items:The Recommendations for Interventional Trials checklist was used when drafting the study protocol.Trial registration number:Registered with the Chinese Clinical Trial Registry on June 11,2021(Chi CTR2100047223).

Rice DENSE AND ERECT PANICLE 2 is essential for determining panicle outgrowth and elongation

The architecture of the panicle, including grain size and panicle morphology, directly determines grain yield. Panicle erectness, which is selected for achieving ideal plant arehitecture in the northern part of China, has drawn increasing attention of rice breeders. Here, dense and erect panicle 2 （dep2） mutant, which shows a dense and erect panicle phenotype, was identified. DEP2 encodes a plant-specific protein without any known functional domain. Expression profiling of DEP2 revealed that it is highly expressed in young tissues, with most abundance in young panicles. Morphological and expression analysis indicated that mutation in DEP2 mainly affects the rapid elongation of rachis and primary and secondary branches, but does not impair the initiation or formation of panicle primordia. Further analysis suggests that decrease of panicle length in dep2 is caused by a defect in cell proliferation during the exponential elongation of panicle. Despite a more compact plant type in the dep2 mutant, no significant alteration in grain production was found between wild type and dep2 mutant. Therefore, the study of DEP2 not only strengthens our understanding of the molecular genetic basis of panicle architecture but also has important implications for rice breeding.

Angle estimation for bistatic MIMO radar with unknown mutual coupling based on three-way compressive sensing

The problem of angle estimation for bistatic multiple-input multiple-output radar in the present of unknown mutual coupling (MC) is investigated, and a three-way compressive sensing (TWCS) estimation algorithm is developed. To exploit the inherent multi-dimensional structure of received data, a trilinear tensor model is firstly formulated. Then the de-coupling operation is followed. Thereafter, the high-order singular value decomposition is applied to compress the high dimensional tensor to a much smaller one. The estimation of the compressed direction matrices are linked to the compressed trilinear model, and finally two over-complete dictionaries are constructed for angle estimation. Also, Cramer-Rao bounds for angle and MC estimation are derived. The proposed TWCS algorithm is effective from the perspective of estimation accuracy as well as the computational complexity, and it can achieve automatically paired angle estimation. Simulation results show that the proposed method has much better estimation accuracy than the existing algorithms in the low signal-to-noise ratio scenario, and its estimation performance is very close to the parallel factor analysis (PARAFAC) algorithm at the high SNR regions. © 2017 Beijing Institute of Aerospace Information.

Na_(2)SO_(4)-NaCl binary eutectic salt roasting to enhance extraction of lithium from pyrometallurgical slag of spent lithium-ion batteries

Effectively extracting lithium at a relatively low temperature from the slag produced by the pyrometallurgical treatment of spent lithium-ion batteries remains a great challenge,which limits the acquirement of lithium.Herein,we proposed a eutectic system to roast slag at a lower temperature based on sodium sulfate-sodium chloride(Na_(2)SO_(4)-NaCl)binary eutectic salts.The optimal roasting conditions are as follows:the slag was roasted at 750℃with a(SO_(4)^(2-)+Cl^(-))/Li+molar ratio of 5:1 for 120 min.Followed by aqueous leaching 5 min at room temperature with a water/roasted samples mass ratio of 30:1,it can get 97.07%lithium extraction efficiency.

Theoretical Analysis and Experimental Research of Surface Texture Hydrodynamic Lubrication

The research on surface texture is developing from single macro-texture to composite micro-nano texture.The current research on the anti-friction mechanism and theoretical models of textures is relatively weak.Studying the characteristics of different types of surface textures and determining the applicable working conditions of each texture is the focus of current research.In this paper,a mathematical model of hydrodynamic lubrication is established based on Navier-Stokes equations.The FLUENT software is used to simulate and analyze the four texture models,explore the dynamic pressure lubrication characteristics of different texture types,and provide data support for texture optimization.The key variable values required by the mathematical model are obtained through the simulation data.The friction coefficient of the texture under different working conditions was measured through friction and wear experiments,and the mathematical model was verified by the experimental results.The research results show that circular texture is suitable for low to medium speed and high load conditions,chevron texture is suitable for medium to high speed and medium to high load conditions,groove texture is suitable for high speed and low load conditions,and composite texture is suitable for high speed and medium to high load conditions.Comparing the experimental results with the results obtained by the mathematical model,it is found that the two are basically the same in the ranking of the anti-friction performance of different textures,and there is an error of 10%−40%in the friction coefficient value.In this study,a mathematical model of hydrodynamic lubrication was proposed,and the solution method of the optimal surface texture model was determined.

Effects of ZnCl2/H2O/C2H5OH Treatment on the Filter Paper Performance

Bleached softwood kraft pulp (BSKP) fibers were pretreated in a 5 mol/L NaOH aqueous solution at 35℃ for 90 min. The ZnCl2/H2O/ C2H5OH was used to treat the pretreated BSKP fibers, filter papers were then prepared. In the course of processing, the effects of various molar ratios of ZnCl2/H2O/C2H5OH on the filter paper performance were evaluated. SEMEDX was conducted to analyze the physical configuration of the filter papers. Moreover, FT-IR and XPS were performed to further characterize the BSKP, the pretreated BSKP and the filter paper fibers. The results indicated that the fibers treated by ZnCl2/H2O/C2H5OH were swollen and exhibited slight fibrillation, leading to a looser fiber structure and therefore, enhanced filter paper performance. Air permeability increased from 161.7 L/(m2·s) to 1450.4 L/(m2·s) for the filter papers when the molar ratio of ZnCl2/H2O/C2H5OH was 1:14:1. The optimum molar ratio of ZnCl2/H2O/C2H5OH was found to be 1:14:1, and no significant effect of ZnCl2/H2O/C2H5OH on fibers’ functional groups was detected. These results showed that filtration performance of filter papers was improved when treated with the ZnCl2/H2O/C2H5OH solution.

Flexible Nanopaper Composed of Wood-Derived Nanofibrillated Cellulose and Graphene Building Blocks

Nanopaper has attracted considerable interest in the fields of films and paper research.However,the challenge of integrating the many advantages of nanopaper still remains.Herein,we developed a facile strategy to fabricate multifunctional nanocomposite paper(NGCP)composed of wood-derived nanofibrillated cellulose(NFC)and graphene as building blocks.NFC suspension was consisted of long and entangled NFCs(10–30 nm in width)and their aggregates.Before NGCP formation,NFC was chemically modified with a silane coupling agent to ensure that it could interact strongly with graphene in NGCP.The resulting NGCP samples were flexible and could be bent repeatedly without any structural damage.Within the NGCP samples,the high aspect ratio of NFC made a major contribution to its high mechanical strength,whereas the sheet-like graphene endowed the NGCP with electrical resistance and electrochemical activity.The mechanical strength of the NGCP samples decreased as their graphene content increased.However,the electrical resistance and electrochemical activity of the NGCP samples both rose with increasing content of graphene.The NGCPs still kept advantageous mechanical properties even at high temperatures around 300℃ because of the high thermal stability of NFCs and their strong entangled web-like structures.In view of its sustainable building blocks and multifunctional characteristics,the NGCP developed in this work is promising as low-cost and high-performance nanopaper.

Tissue Engineering and Regulatory Science

Tissue engineering has successfully evolved from its original concept[1]into medical products with a rapid pace of develop-ment and a multi-billion dollar market[2].Compared with tradi-tional medical products,tissue-engineered medical products(TEMPs)have distinct characteristics that provide unique benefits for the repair and regeneration of damaged or diseased tissues or organs[1,2].

Current state and prospect on the development of advanced nuclear fuel system materials:A review

The intricate balance between reactor economics and safety necessitates the emergence of new and advanced nuclear systems and,very importantly,advanced materials,which can overcome current shortcomings and bring about more economic nuclear systems with designed-in inherent safety features.These advances will achieve greater safety and better nuclear reactor economics by reaching longer reactor lives with higher levels neutron irradiation,and by providing higher operation temperatures and resistance to more aggressive corrosive environments.This paper provides a review of the current state of research and development on innovative nuclear fuel materials design and development which have the potential of benefiting simultaneously reactor economics and safety.Our discussion focuses on three areas of research:Accident-tolerant Fuels(ATFs),Oxidation Dispersion Strengthened(ODS)steels and High Entropy Alloys(HEAs).The paper also gives a prospective description of future research activities on these materials.

Understanding Surface Water-Groundwater Conversion Relationship and Associated Hydrogeochemistry Evolution in the Upper Reaches of Luan River Basin, North China

Luan River is the main water source in Beijing-Tianjin-Hebei region,northern China,where the groundwater system is vulnerable and pollution issue is serious.It is significant for regional groundwater resources protection to identify the hydrogeochemistry evolution and affecting factors along flow direction occurred in the upper reaches,especially the surface water-groundwater(SWGW)conversion relationship.In this study,recharge,conversion and geochemistry evolution of SW and GW were elucidated based on physical-hydrochemical indicators and stable isotopes in 36 GW samples and 20 SW samples,which were collected in July 2019 and July 2020.The factor analysis was further utilized to determine the main factors responsible for regional hydrogeochemical evolution.Results indicate that GW recharged SW in plateau area,and SW and GW recharged each other in typical Alpine valley area.The hydrochemical types are HCO3-Ca·Mg and HCO3-Ca,and the hydrochemical evolution is dominated by weathering of silicate and carbonate minerals.The cation exchange adsorption has minor impact on groundwater hydrochemistry.The rise of SO42-and NO3-contents in groundwater is related to industrial and agricultural activities.The main controlling factors of SW hydrochemical components included recharge from groundwater,industrial and mining activities,explaining 90.04%of data variance.However,water-rock interaction,agricultural and domestic sewage are responsible for GW quality,accounting for 83.38%.

对再生型疝修补补片动物试验设计的考量

再生型疝修补补片作为一种理想的疝和腹壁缺损修复医疗器械,对再生修复功效的评价是该类补片安全性和有效性的核心关键,与患者的疝复发直接相关。动物试验是疝修补补片再生功效评价的重要方法之一。结合多项已上市再生型疝补片动物研究及相关文献报道,本文对该类器械动物试验设计的各个要素进行了初步探讨并给出相关建议,供再生型疝修复生物材料的研发人员、动物试验研究人员、普通外科临床医生参考。

A Critical Review of Single-Crystal LiNi_(x)Mn_(y)Co_(1-x-y)O_(2) Cathode Materials

To meet the range requirements of electric vehicles,the lithium nickel-rich manganese cobalt oxides(nickel-rich LiNi_(x)Mn_(y)Co_(1-x-y)O_(2);x≥0.5 or NMC)material is a promising contender due to its superior energy and power density.Commercial polycrystalline nickel-rich NMC(PC-NMC)materials typically exhibit layered structures in which primary particles aggregate to form secondary particles to increase the contact area density.Thereby increasing the cathode energy density.However,PC-NMC materials present a number of challenges in terms of cycle life and thermal stability,many of which stem from their extensive surface area,including severe surface phase transitions,intergranular microcracks,oxygen evolution,and transition metal dissolution.To address these challenges,single-crystal NMC(SCNMC)materials were introduced,which exhibited higher capacity retention and thermal robustness owing to their unique structures,characterized by lower active surface area and heightened mechanical strength.Nevertheless,SC-NMC materials also had their own problems,including sluggish Li+bulk diffusion kinetics and nonuniform distribution of lattice strain,as well as their complex high-temperature calcination process.This review concentrates on discussing the merits and demerits of SC-NMC over PC-NMC materials and introduces the current research efforts aimed at improving the electrochemical performance of SC-NMC.

局麻下利用软性膀胱镜联合铥激光治疗麻醉高风险膀胱肿瘤患者的经验

目的探讨高龄、麻醉高风险患者在局麻(尿道黏膜麻醉)或无麻醉下利用膀胱软镜行铥激光膀胱肿瘤切除术(ThuLRBT)治疗的可行性。方法天津医科大学第二医院2020年6月至2022年1月共12例经评估一般状态较差、麻醉手术风险较大的高龄膀胱癌患者,利用膀胱软镜行局麻下铥激光膀胱肿瘤切除治疗。术前利用麻醉分级、Essen卒中风险评分量表、运动耐量、改良心脏危险指数评分及心脏并发症发生率综合评估患者全麻术中及术后风险,利用Karnofsky功能状态评分标准、年龄校正察尔森合并症指数及衰弱筛查量表评分数粗略预测术后恢复情况及手术价值。术中即刻利用疼痛数字评分法评估患者耐受情况,同时收集术后尿管留置时间、术后住院时间、并发症发生情况等。术后随访至2023年1月或患者复发。结果所有患者术中均未出现闭孔神经反射及膀胱穿孔等并发症,术后未出现持续膀胱出血及膀胱填塞。即刻疼痛评分(NRS)0~7分,中位评分2分。所有患者均可耐受手术过程,且痛苦较小。术后中位尿管留置时间2 d。术后中位住院时间2 d。术后12例患者定期随访,随访时间3~19个月,其中1例失访,1例患者术后5个月复发,1例患者术后13个月复发。结论ThuLRBT治疗麻醉高风险的高龄膀胱肿瘤患者是一种相对安全有效的治疗方式,其并发症少,患者耐受良好,近期疗效满意。

Microstructure and Mechanical Properties of FeCoNiCrAl x High-entropy Alloys by Selective Laser Melting

In this study,the thermal analysis theory of selective laser melting(SLM)was introduced,and different high-entropy alloy(HEA)specimens were prepared using the SLM technology.The effects of different powder sizes,elemental contents,and process parameters on the microstructure and mechanical properties of FeCoNiCrAl x HEA specimens fabricated using SLM were analyzed.Moreover,hardness and tensile tests of these high-entropy alloys were performed.The results showed that with increasing laser power and hatch spacing,the hardness of the specimens initially increased and subsequently decreased;it also increased with increasing scanning speed.The FeCoNiCrAl 0.5 HEA specimens prepared using fine powder exhibited better tensile properties,followed by FeCoNiCrAl 0.8 HEA.However,the FeCoNiCrAl 0.5 HEA prepared using coarse powder exhibited the poorest tensile properties.A comparison of the tensile properties of the specimens at different heights revealed that the specimens formed at the middle height exhibited improved tensile properties.