Palynological assemblage in the late Early Cretaceous from Sikouzi Section, Liupanshan Group, Central China and its implication to paleoenvironment change

The Cretaceous(ca.145 Ma^65 Ma)was characterized by remarkable greenhouse conditions which was more server than present greenhouse gas emissions.However,this special climate condition is mainly documented from marine records.The information derived from continental sediments including terrestrial vegetation is relatively scarce.Here,we report on a palynological study of 17 samples from the Lower Cretaceous Liupanshan Group of the Sikouzi Section(spanning116 Ma^103 Ma),Liupanshan Basin and analyzed for paleoclimate implications.The palynoflora is diverse,dominated by Classopollis(Cheirolepidiaceae),with abundant ferns and rare angiosperms.The dominant ferns are from Lygodiaceae and Schizaeaceae.The palynological data shows that the Early Cretaceous floras are derived from various settings,i.e.,the Coniferales on high elevation mountains,Cheirolepidiaceae along low hills near lakes,ferns in marsh wetlands,and algae in fresh water lakes.The palynoflora indicates that the climate in the Liupanshan area is hot and dry,and the palaeogeography is characterized by complex and various outlook during the Early Cretaceous,furthermore,climate evolution revealed by the vegetation can be divided into two stages during this period.From 116 Ma to 112 Ma,the concentration of thermophilic and xerophilous species such as Cheirolepidiaceae and Schizaeaceae were relatively low,conifers increased significantly,and fern concentration remained steady.This ecosystem suggests a humid and cold climate during this period.From 112 Ma to 103 Ma,the concentration of Cheirolepidiaceae and Schizaeaceae was relatively high,and conifers decreased significantly.Compared to the upper stage,the total percentage of Lygodiaceae spores were relatively low.Vegetation change during this period may indicate an increased trend of a dry and hot environment in this region.The trend of climate change recorded by the pollen assemblages during this period coincide with global sea surface temperature fluctuation.Thus,climate change recorded by the palynological assemblage in the Sikouzi section correlates well with global climate change during the Early Cretaceous.

PIMS:An Efficient Process Integrity Monitoring System Based on Blockchain and Trusted Computing in Cloud-Native Context

With the advantages of lightweight and high resource utilization,cloud-native technology with containers as the core is gradually becoming themainstreamtechnical architecture for information infrastructure.However,malware attacks such as Doki and Symbiote threaten the container runtime’s security.Malware initiates various types of runtime anomalies based on process form(e.g.,modifying the process of a container,and opening the external ports).Fortunately,dynamic monitoring mechanisms have proven to be a feasible solution for verifying the trusted state of containers at runtime.Nevertheless,the current routine dynamic monitoring mechanisms for baseline data protection are still based on strong security assumptions.As a result,the existing dynamicmonitoringmechanismis still not practical enough.To ensure the trustworthiness of the baseline value data and,simultaneously,to achieve the integrity verification of the monitored process,we combine blockchain and trusted computing to propose a process integrity monitoring system named IPMS.Firstly,the hardware TPM 2.0 module is applied to construct a trusted security foundation for the integrity of the process code segment due to its tamper-proof feature.Then,design a new format for storing measurement logs,easily distinguishing files with the same name in different containers from log information.Meanwhile,the baseline value data is stored on the blockchain to avoidmalicious damage.Finally,trusted computing technology is used to perform fine-grained integrity measurement and remote attestation of processes in a container,detect abnormal containers in time and control them.We have implemented a prototype system and performed extensive simulation experiments to test and analyze the functionality and performance of the PIMS.Experimental results show that PIMS can accurately and efficiently detect tampered processes with only 3.57% performance loss to the container.

一流本科专业建设背景下突出应用特色的多元化实践课程体系建设

在新时期教育部推动一流本科专业建设项目的背景下,作为一所地方性应用型高校,郑州轻工业大学应用化学专业在国家一流专业建设过程中,依托综合实验课程、国家级实践教学基地、产学研合作以及大学生学科竞赛等单元,建设起独具应用特色的多元化创新创业实践平台和人才培养体系,为一流专业建设中强化学科分层次发展和重点建设,提升应用化学专业人才教育质量提供了一种可供借鉴的模式。

Analog Optical Computing for Artificial Intelligence

The rapid development of artificial intelligence(AI)facilitates various applications from all areas but also poses great challenges in its hardware implementation in terms of speed and energy because of the explosive growth of data.Optical computing provides a distinctive perspective to address this bottleneck by harnessing the unique properties of photons including broad bandwidth,low latency,and high energy efficiency.In this review,we introduce the latest developments of optical computing for different AI models,including feedforward neural networks,reservoir computing,and spiking neural networks(SNNs).Recent progress in integrated photonic devices,combined with the rise of AI,provides a great opportunity for the renaissance of optical computing in practical applications.This effort requires multidisciplinary efforts from a broad community.This review provides an overview of the state-of-the-art accomplishments in recent years,discusses the availability of current technologies,and points out various remaining challenges in different aspects to push the frontier.We anticipate that the era of large-scale integrated photonics processors will soon arrive for practical AI applications in the form of hybrid optoelectronic frameworks.

Tunable Weyl fermions and Fermi arcs in magnetized topological crystalline insulators

Based on k · p analysis and realistic tight-binding calculations, we find that time-reversal-breaking Weyl semimetals can be realized in magnetically-doped(Mn, Eu, Cr, etc.) Sn_(1-x)Pb_x(Te, Se) class of topological crystalline insulators. All the Weyl points are well separated in momentum space and possess nearly the same energy due to high crystalline symmetry.Moreover, both the Weyl points and Fermi arcs are highly tunable by varying Pb/Sn composition, pressure, magnetization,temperature, surface potential, etc., opening up the possibility of manipulating Weyl points and rewiring the Fermi arcs.

All-optical logic gate computing for high-speed parallel information processing

Optical computing and optical neural network have gained increasing attention in recent years because of their potential advantages of parallel processing at the speed of light and low power consumption by comparison with electronic computing.The optical implementation of the fundamental building blocks of a digital computer,i.e.logic gates,has been investigated extensively in the past few decades.Optical logic gate computing is an alternative approach to various analogue optical computing architectures.In this paper,the latest development of optical logic gate computing with different kinds of implementations is reviewed.Firstly,the basic concepts of analogue and digital computing with logic gates in the electronic and optical domains are introduced.And then a comprehensive summary of various optical logic gate schemes including spatial encoding of light field,semiconductor optical amplifiers(SOA),highly nonlinear fiber(HNLF),microscale and nanoscale waveguides,and photonic crystal structures is presented.To conclude,the formidable challenges in developing practical all-optical logic gates are analyzed and the prospects of the future are discussed.

Towards a bright future:The versatile applications of organic solar cells

Due to the mechanical flexibility,light weight,aesthetics,absorption tunability and environmental friendliness,organic solar cells(OSCs)have superior application potential over their inorganic counterparts including silicon and perovskite solar cells(PSCs).Thanks to these benefits,the past decade have witnessed the rapid growth of flexible OSCs,semitransparent OSCs and indoor OSCs.In this progress report,we firstly overview the recent advance of the applications of the three promising OSCs.Subsequently,we sketch the critical points for the three classes of OSCs and highlight the efforts paid by the research community to address these issues.Besides,we discuss some popular strategies to afford great performance of each kind of OSC,respectively,and underline the corresponding breakthrough directions.Last but not least,we present the remaining challenges for advancing the commercial applications of these three classes of OSCs.

机械力诱导MHC-Ⅰ构象变化增强TCR抗原识别及T细胞活化

CD8+T细胞主要通过T细胞表面受体(T cell recep tor,TCR)识别并与Ⅰ型主要组织性复合物提呈的抗原(pMHC-Ⅰ)相互作用[1]。TCR对刺激型抗原的识别在CD8+T细胞毒性和适应性免疫中发挥着关键作用。许多证据表明机械力可以延长TCR与刺激性pMHC作用的键合时间(bond lifetime)形成抗原特异性逆锁键(catch bond)[2],并且这种逆锁键对抗原识别非常重要。然而,机械力调控TCR抗原识别的具体结构机制仍不清楚。通过分子动力学模拟、单分子生物膜力学探针、磁镊、T细胞活化实验和动物模型对此问题展开了系统的研究[4]。发现作用在TCR-pMHC-Ⅰ复合体上的拉力可以作用在TCR-pMHC-Ⅰ复合体上的拉力可以打破MHC-I分子内部α1-α2和β2结构域间的相互作用,导致α1-α2结构域旋转并发生构象变化。力诱导的MHC-I构象变化可以进一步别构地调节TCR与刺激性抗原肽及α1-α2结构域的构象及相互作用,诱导产生新的氢键,增强TCR-pMHC-Ⅰ之间的键合时间,但并不能增强TCR与抑制性pMHC-Ⅰ之间的作用。当用点突变阻断这些新形成的氢键,或者α1-α2和β2结构域被二硫键锁住时,最佳力诱导的TCR-pMHC-Ⅰ作用的键合时间明显缩短并且T细胞的活化受到抑制。另外,在人TCR和HLA-A2相互作用中发现了类似机制,并且与肿瘤相关的HLA-A2点突变[3]可以通过限制HLA-A2α1--α2和β2结构域之间的构象打开减弱TCR对肿瘤抗原的识别及T细胞的功能。研究结果表明,机械力诱导的MHC-I构象变化对TCR抗原识别和T细胞活化非常重要,进一步地阐明了机械力调控TCR抗原识别机制,为临床肿瘤的免疫治疗和药物设计提供了新思路和新靶点。

Pt-H2SO4/Zr-montmorillonite： An efficient catalyst for the polymerization of octamethylcy-clotetrasiloxane, polymethylhydrosiloxane and hexamethyldisiloxane to low-hydro silicone oil

The liquid phase ring-opening of octamethylcy-clotetrasiloxane(D_4) was investigated over Pt-H_2SO_4/Zrmontmorillonite catalyst. Montmorillonite(Mt), Zr-Mt, H_2SO_4/Mt, H_2SO_4/Zr-Mt and Pt-H_2SO_4/Zr-Mt were also detected for evaluation. The catalysts were characterized by X-ray fluorescence, X-ray diffraction, nitrogen adsorption–desorption, NH_3-TPD and pyridine-FTIR measurements. In comparison to activate clay which is used in the industry of catalyst, Zr-Mt catalyst displayed stronger acidity and more excellent catalytic activity in the polymerization of D_4, polymethylhydrosiloxane(D_4 H) and hexamethyldisiloxane(MM) to low-hydro silicone oil. Relative to Zr-Mt, the acidity of H_2SO_4/Zr-Mt was noticeably improved and the catalyst exhibited a higher capability of ring-opening of D_4 conversion and yield of low-hydro silicone oil. To enhance the stability of H_2SO_4/Zr-Mt catalyst, a small amount of metals(Pt) was doped. The nitrogen adsorption–desorption results indicated that pore textural parameters of the Pt-H_2SO_4/Zr-Mt had not changed with larger specific surface area. Compared with H_2SO_4/Zr-Mt, the total acidity of Pt-H_2SO_4-Zr/Mt catalyst retained, but the content of the Br?nsted acid increased and the content of the Lewis acid decreased. The Pt-H_2SO_4-Zr/Mt catalyst displayed higher catalyst reproducibility. After 40 h reaction of polymerization, the yield of low-hydro silicone oil decreased from 93% to 42% over H_2SO_4/Zr-Mt catalyst, while the yield of low-hydro silicone oil reduced from 93% to 78%over Pt-H_2SO_4/Zr-Mt catalyst. A sharp decrease in catalytic activity after 35 h of Pt-H_2SO_4/Zr-Mt catalyst was detected. Furthermore, Pt-H_2SO_4/Zr-Mt was completely regenerated under appropriate condition and appeared good repeatability in the D_4, D_4 Hand MM to low-hydro silicone oil.

尿道内钬激光切开术对尿道狭窄的临床价值分析

目的探讨尿道内钬激光切开术对尿道狭窄的临床价值分析。方法收集我院2015~2018年收治的各类尿道狭窄患者均行钬激光切开术共计27例均行钬激光切开术,对治疗效果进行统计分析。结果共27例1次手术成功率为100%,术后无复发。结论钬激光切开术对尿道狭窄是一种安全、微创、有效的治疗方法。

Optimization of inter-helix spacing for helical piles in sand

The optimization of the inter-helix spacing is a key issue of the axial bearing capacity of helical piles.In this paper,based on the cavity expansion,an analytical approach considering the small-strain stiffness,strength,compressibility and stress level of sand around the helical pile was proposed to analyze the influence zone of the helices to determine the optimal inter-helix spacing in sand.The calculation results of the proposed method were verified using the centrifuge test data and finite element analysis for helical pile in Congleton HST95 sand.They were also compared with those using the Meyerhof pile foundation theory.The results show that the optimal inter-helix spacing based on Meyerhof pile foundation theory differs significantly from the measurement.The range of the influence zone for the helices in sand calculated by the cavity expansion theory matches with the data from literature.The calculation results with the proposed method are consistent with the range of the optimal spacing ratio inferred in the centrifuge tests.The results based on the two-dimensional(2D)finite element model(FEM)are also basically consistent with the calculated analytical solution.

Magnus Hall Effect in Two-Dimensional Materials

The Magnus Hall effect(MHE) is a new type of linear-response Hall effect, recently proposed to appear in two-dimensional(2D) nonmagnetic systems at zero magnetic field in the ballistic limit. The MHE arises from a self-rotating Bloch electron moving under a gradient-electrostatic potential, analogous to the Magnus effect in the macrocosm. Unfortunately, the MHE is usually accompanied by a trivial transverse signal, which hinders its experimental observation. We systematically investigate the material realization and experimental measurement of the MHE, based on symmetry analysis and first-principles calculations. It is found that both the out-ofplane mirror and in-plane two-fold symmetries can neutralize the trivial transverse signal to generate clean MHE signals. We choose two representative 2D materials, monolayer MoS_(2), and bilayer WTe_(2), to study the quantitative dependency of MHE signals on the direction of the electric field. The results are qualitatively consistent with the symmetry analysis, and suggest that an observable MHE signal requires giant Berry curvatures. Our results provide detailed guidance for the future experimental exploration of MHE.

Simultaneous Optimization of Efficiency,Stretchability,and Stability in All-Polymer Solar Cells via Aggregation Control

With the emergence of Y-series small molecule acceptors,polymerizing the small molecule acceptors with aromatic linker units has attracted significant research attention,which has greatly advanced the photovoltaic performance of all-polymer solar cells.Despite the rapid increase in efficiency,the unique characteristics(e.g.,mechanical stretchability and flexibility)of all-polymer systems were still not thoroughly explored.In this work,we demonstrate an effective approach to simultaneously improve device performance,stability,and mechanical robustness of all-polymer solar cells by properly suppressing the aggregation and crystallization behaviors of polymerized Y-series acceptors.Strikingly,when introducing 50 wt%PYF-IT(a fluorinated version of PY-IT)into the well-known PM6:PY-IT system,the all-polymer devices delivered an impressive photovoltaic efficiency of 16.6%,significantly higher than that of the control binary cell(15.0%).Compared with the two binary systems,the optimal ternary blend exhibits more efficient charge separation and balanced charge transport accompanying with less recombination.Moreover,a high-performance 1.0 cm^(2)large-area device of 15%efficiency was demonstrated for the optimized ternary all-polymer blend,which offered a desirable PCE of 14.5%on flexible substrates and improved mechanical flexibility after bending 1000 cycles.Notably,these are among the best results for 1.0 cm^(2)all-polymer OPVs thus far.This work also heralds a bright future of all-polymer systems for flexible wearable energy-harvesting applications.

Chemo-drugs in cell microparticles reset antitumor activity of macrophages by activating lysosomal P450 and nuclear hnRNPA2B1

Macrophages in tumors(tumor-associated macrophages,TAMs),a major population within most tumors,play key homeostatic functions by stimulating angiogenesis,enhancing tumor cell growth,and suppressing antitumor immunity.Resetting TAMs by simple,efficacious and safe approach(s)is highly desirable to enhance antitumor immunity and attenuate tumor cell malignancy.Previously,we used tumor cell-derived microparticles to package chemotherapeutic drugs(drug-MPs),which resulted in a significant treatment outcome in human malignant pleural effusions via neutrophil recruitments,implicating that drug-MPs might reset TAMs,considering the inhibitory effects of M2 macrophages on neutrophil recruitment and activation.Here,we show that drug-MPs can function as an antitumor immunomodulator by resetting TAMs with M1 phenotype and IFN-βrelease.Mechanistically,drug molecules in tumor MPs activate macrophage lysosomal P450 monooxygenases,resulting in superoxide anion formation,which further amplifies lysosomal ROS production and pH value by activating lysosomal NOX2.Consequently,lysosomal Ca^(2+)signaling is activated,thus polarizing macrophages towards M1.Meanwhile,the drug molecules are delivered from lysosomes into the nucleus where they activate DNA sensor hnRNPA2B1 for IFN-βproduction.This lysosomal-nuclear machinery fully arouses the antitumor activity of macrophages by targeting both lysosomal pH and the nuclear innate immunity.These findings highlight that drug-MPs can act as a new immunotherapeutic approach by revitalizing antitumor activity of macrophages.This mechanistic elucidation can be translated to treat malignant ascites by drug-MPs combined with PD-1 blockade.

椭圆截面弹体贯穿有限厚金属靶特性研究

本文结合弹性衰减-塑性衰减-开裂三阶段贯穿模型及椭圆截面弹体形状函数,建立了椭圆截面弹体贯穿有限厚金属靶侵彻模型.随后,开展了两种椭圆截面弹体及一种圆截面弹体以230~570 m/s的撞击速度对铝合金靶板的贯穿试验,且试验覆盖了弹道极限速度.在此基础上,采用本文及文献中的试验数据对模型进行了验证,模型的计算结果与试验结果吻合较好.此外,对比分析了椭圆截面弹体与圆截面弹体对有限厚金属靶的贯穿特性.结果表明,当椭圆截面弹体与圆截面弹体的质量、弹体头部长度、任意弹体截面面积及弹体长度相等时,二者可视为等效弹体.其次,确定了无量纲靶体临界厚度与弹体撞击因子间的关系.计算结果表明,无量纲靶体临界厚度与弹体撞击因子呈线性关系,同时,进一步分析了椭圆截面弹体头部形状因子对其贯穿特性的影响规律.

Refining acceptor aggregation in nonfullerene organic solar cells to achieve high efficiency and superior thermal stability

With the rapid increase in photoelectric conversion efficiency of organic photovoltaics(OPVs),prolonging the operational lifetime of devices becomes one of the critical prerequisites for commercial applications.Guided by the theoretical calculations of molecular stacking and miscibility,we proposed an effective approach to simultaneously improve device performance and thermal stability of high-efficiency OPVs by refining the aggregation of Y-series acceptors.The key to this approach is deliberately designing an asymmetric Y-series acceptor,named Y6-CNO,which acts as a third component regulator to finely tune the degree of acceptor aggregation and crystallization in the benchmark PM6:Y6-BO system.Strikingly,a champion photovoltaic efficiency of 18.0%was achieved by introducing 15 wt%Y6-CNO into the PM6:Y6-BO system,significantly higher than the control binary cell(16.7%).Moreover,annealing at 100°C for over 1,200 h does not markedly affect the photovoltaic performance of the optimal ternary devices,maintaining above 95%of the initial performance and exhibiting an exceptionally high T_(80)lifetime of 9,000 h under continuous thermal annealing.By contrast,binary devices suffer from excessive crystallization of acceptors with long-term annealing.Additionally,mixing thermodynamics combined with morphological characterizations were employed to elucidate the microstructure-thermal stability relationships.The ternary OPVs consisting of symmetric and asymmetric homologous acceptors form better charge transport channels and can effectively suppress excessive aggregation of acceptors under long-term annealing.This work demonstrates the effectiveness of refining acceptor aggregation via molecular design for highly efficient and stable nonfullerene-based OPVs.

Rise of ecofriendly AgBiS_(2) nanocrystal solar cells

During the past decade,nanocrystal solar cells have attracted worldwide research attention due to their high absorption coefficient,broad and tunable absorption range,and promising multiple exciton generation.With joint efforts,great performance breakthroughs have been achieved in the field of nanocrystal solar cell technology,with a certified efficiency of 18.1%for perovskite nanocrystal solar cells(https://www.nrel.gov/pv/cell-efficiency.html)and a record efficiency of 15.4%for PbS nanocrystal solar cells[1].Despite the striking advances,the high toxicity of Pbbased nanocrystal materials raises great concerns when introduced into consumer electronics.Environmental concerns have opened an opportunity for the exploration of ecofriendly alternatives.

Unconventional ferroelectricity in half-filling states of antiparallel stacking of twisted WSe_(2)

We report on emergence of an abnormal electronic polarization in twisted double bilayer WSe_(2) in antiparallel interface stacking geometry,where local centrosymmetry of atomic registries at the twist interface does not favor the spontaneous electronic polarizations as recently observed in the parallel interface stacking geometry.The unconventional ferroelectric behaviors probed by electronic transport measurement occur at half filling insulating states at 1.5 K and gradually disappear at about 40 K.Single band Hubbard model based on the triangular moirélattice and the interlayer charge transfer controlled by insulating phase transition are proposed to interpret the formation of electronic polarization states near half filling in twisted WSe_(2) devices.Our work highlights the prominent role of many-body electronic interaction in fostering novel quantum states in moiré-structured systems.

Boosting daytime radiative cooling performance with nanoporous polyethylene film

Radiative cooling without energy consumption and environmental pollution holds great promise as the next-generation cooling technology.To date,daytime radiative cooling performance is still slightly low,especially in humid areas.In this work,we demonstrated that nanoporous polyethylene(Nano PE)film can improve solar reflectivity from 96%to 99%,thus boosting radiative cooling performance.Moreover,the experimental results in humid areas indicate that Nano PE films can improve radiative cooling performance by∼76%in a clear day and 120%in a day with few clouds.Additionally,compared with ordinary PE films,thin Nano PE films have significantly higher weather fastness and mechanical strength.More importantly,nano PE films can scatter part of visible light,thus suppressing the generation of light pollution in practical applications.Lastly,the modeling results reveal that with Nano PE films,more than 95%of China’s areas can achieve daytime cooling performance.Our work can boost the development of radiative cooling technology with a very low cost.

腹腔镜和开腹胆囊癌根治性切除术近期疗效及远期预后的比较

目的比较腹腔镜和开腹胆囊癌根治术的近期临床疗效及远期预后。方法回顾性分析2010年1月至2020年12月于浙江省人民医院肝胆胰外科接受胆囊癌根治术的133例胆囊癌患者的临床及术后随访资料。其中80例完成腹腔镜胆囊癌根治术(腹腔镜组),男性23例,女性57例,年龄[M(IQR)]66.0(12.8)岁(范围:28.0~82.0岁);53例完成开腹胆囊癌根治术(开腹组),男性8例,女性45例,年龄63.0(6.0)岁(范围:45.0~80.0岁)。腹腔镜组与开腹组在年龄、性别、体重指数、术前白蛋白、术前总胆红素、N分期、脉管侵犯、神经侵犯及肿瘤分化的差异均无统计学意义(P值均>0.05),而术前CA19-9(Z=-2.955,P=0.003)、术前ALT水平(Z=-2.801,P=0.031)、T分期分布(χ^(2)=19.110,P=0.007)的差异均有统计学意义。定量资料的比较采用非参数检验,分类资料的比较采用χ^(2)检验或Fisher确切概率法。结果两组患者在手术时间、淋巴结清扫数目、阳性淋巴结数目、术中胆囊破裂,术后胆瘘、腹腔出血、腹腔感染发生率,术后30 d和90 d病死率、切口种植及术后腹腔转移方面的差异均无统计学意义(P值均>0.05);腹腔镜组术中出血量[100.0(200.0)ml比400.0(250.0)ml](Z=-5.260,P<0.01)、引流管留置时间[6.0(3.8)d比7.0(4.0)d](Z=-3.351,P=0.001)及术后住院时间[8.0(5.0)d比14.0(7.5)d](Z=-6.079,P<0.01)优于开腹组。腹腔镜组1、3年总体生存率分别为63.6%、49.6%,开腹组1、3年总体生存率分别为37.7%、12.9%,差异有统计学意义(P<0.01);腹腔镜组1、3年无进展生存率分别为79.4%、54.1%,开腹组1、3年无进展生存率分别为55.7%、37.6%,差异有统计学意义(P<0.01)。对T1b~T2期及T3期胆囊癌进行亚组分析,结果显示,两组术后总体生存率及无进展生存率的差异均无统计学意义(P值均>0.05)。结论腹腔镜胆囊癌根治术可取得与开腹手术类似的近期临床结局和长期预后,且具有手术创伤小及术后恢复快的优势。