Combined Use of Differential Scanning Calorimetry and Cross-Sectional Transmission Electron Microscopy for Characterization of Thin-Film Reactions

We demonstrate that the combined use of differential scanning calorimetry(DSC)and cross-sectional transmission electron microscopy(XTEM)is a powerful technique in the quantitative investigation of the nucleation and growth of metastable and equilibrium phases during thin-film interdiffusion reactions.The Various approaches and advantages of the DSC/XTEM technique in obtaining a variety of kinetic and thermodynamic data are discussed.Explosive reactions,as opposed to conventionally controlled reactions,may occur in thin films where the multilayer geometry is used.

Managing Variable Transmittance Windowpanes byModel-Based Autonomous Control

The use of digitally activated, variable transmittance materials and artificial intelligence methods to building control will enhance the performance of buildings, and programmable components will change the traditional modes of architectural design, manufacturing and construction. In the presented key study, the architectural form and functionality of windows are revisited with a view to integrate current advances in material science, control systems engineering and human-computer interaction. The features of a building facade, involving a matrix of programmable windows that enables precise control of daylight, view and privacy in the interior of a house are discussed. Managing the variable transmittance materials of the facade by an autonomous high-level control system allows the optimization of the house performance based on real time data and the schedule of the inhabitants. Using constraint violations as a measure of success, the autonomous control of the house outperforms any existing deterministic control models.

Deformation of Rigid Conjugate Self-dual Galois Representations

In this article,we study deformations of conjugate self-dual Galois representations.The study is twofold.First,we prove an R=T type theorem for a conjugate self-dual Galois representation with coefficients in a finite field,satisfying a certain property called rigid.Second,we study the rigidity property for the family of residue Galois representations attached to a symmetric power of an elliptic curve,as well as to a regular algebraic conjugate self-dual cuspidal representation.

四川泸定昔格达组的堰塞湖成因及其意义

文章通过对泸定大渡河上松林-大板厂地段T6阶地基座古堰塞坝崩塌-块体流堆积的识别,以及与其上游邻近地段甘海子T6阶地基座昔格达组崩塌、块体流堆积至湖相沉积序列的对比和成因联系分析,阐明了泸定昔格达组的堰塞湖成因。该区在晚新生代时,由于古大渡河岸坡的不稳定性,发生大型崩塌-块体流,堵塞河道,形成古堰塞坝和古堰塞湖,并在湖盆中充填了以海子坪昔格达组上部为代表的湖相沉积和少量的低能河流相沉积;同时,指出在对昔格达组大区域对比和综合研究中,特别是在分析它的地质意义时,必须考虑这种复杂性和非等时性。古堰塞坝和古堰塞湖应对地质灾害监测和水利工程建设有很好的启示。

藏北羌塘盆地中部莫霍面形态及其动力学成因

本文通过对羌塘盆地内49个临时宽频带地震观测台阵数据的接收函数分析,采用H_(-κ)叠加和CCP叠加成像两种方法,获得到了藏北羌塘中部莫霍面深度以及泊松比分布.作为羌塘盆地构造单元的南缘边界,班公湖一怒江缝合带下的Moho存在一个南深北浅、断距约10km的台阶;把羌塘盆地分为两部分的羌塘中央隆起带下存在一个3 km的Moho台阶;北羌塘盆地下的Moho平均深度约为60km,而南羌塘约为63km.羌塘高原下的近水平Moho结构可能是受到印度大陆北向俯冲作用下的青藏高原隆升过程中Moho再均衡所致或者与其构造演化有关.泊松比值具有明显的构造分区特征,如南羌塘下的泊松比平均为0.31,双湖缝合带下的泊松比接近正常值,为0.265,而北羌塘的泊松比平均为0.285.

超临界CO_(2)驱提高致密油藏采收率实验研究

针对玛湖地区致密油藏衰竭式开发后期采油速度快速递减的问题,提出利用超临界CO_(2)驱替开发致密油藏的研究思路,通过开展超临界CO_(2)萃取致密油实验、最小混相压力实验及长岩心驱替实验,探究了超临界CO_(2)驱替提高致密油采收率的作用机理、开发特征及影响因素,优选了注气速度、CO_(2)转注时机等重要操作参数。实验结果表明:CO_(2)萃取轻质组分能力随萃取次数的增加而减弱;注气速度对最终采收率影响较大,最优注气速度为0.10 cm 3/min;原油与超临界CO_(2)最小混相压力为34.18 MPa;当前油藏压力条件为最佳CO_(2)转注时机。该研究成果对致密油藏高效开发具有一定指导意义。

Nanoparticle cancer vaccines:Design considerations and recent advances

Vaccines therapeutics manipulate host’s immune system and have broad potential for cancer prevention and treatment.However,due to poor immunogenicity and limited safety,fewer cancer vaccines have been successful in clinical trials.Over the past decades,nanotechnology has been exploited to deliver cancer vaccines,eliciting longlasting and effective immune responses.Compared to traditional vaccines,cancer vaccines delivered by nanomaterials can be tuned towards desired immune profiles by(1)optimizing the physicochemical properties of the nanomaterial carriers,(2)modifying the nanomaterials with targeting molecules,or(3)co-encapsulating with immunostimulators.In order to develop vaccines with desired immunogenicity,a thorough understanding of parameters that affect immune responses is required.Herein,we discussed the effects of physicochemical properties on antigen presentation and immune response,including but not limited to size,particle rigidity,intrinsic immunogenicity.Furthermore,we provided a detailed overview of recent preclinical and clinical advances in nanotechnology for cancer vaccines,and considerations for future directions in advancing the vaccine platform to widespread anti-cancer applications.

WHAT I LEARNED FROM BRITTON CHANCE

In this personal and reflective article,I honor the memory of Britton Chance and explain how his mentorship during my tenure at the Johnson Research Foundation greatly impacted my scientific career.I emphasize the critical role of mentors on the development of scientists and present some wonderful and remarkable attributes that characterized Britton Chance's scientific and personal style.

Micro and nanolattice fabrication using projection micro litho stereo exposure additive manufacturing techniques and synchrotron X-ray 3D imaging-based defect characterization

Synchrotron radiation X-ray micro-computed tomography(SR-μCT)is a 3D imaging technique that is widely employed for the characterization of defects in advanced materials and structures.In this study,we characterize several typical defects in octettruss and re-entrant 3D lattice structures by using SR-μCT.The 3D micro-lattice structures are manufactured using projection micro litho stereo exposure(PμLSE)additive manufacturing technology.The as-fabricated 3D lattice samples are characterized using optical microscopy,and subsequently,by SR-μCT.Further more,a statistical analysis is performed to characterize the surface roughness and internal defects qualitatively,whereby the statistical geometrical parameters of struts along different directions and strut joints are analyzed and classified.Consequently,several typical defects are identified:(1)holes at the joints of the strut and irregular diameter deviations of the strut in the octet-truss lattice structure;(2)irregular diameter variations,bulges,dislocations,grooves,accumulations,and torsion in the re-entrant lattice structure.All of these defects are related to the building direction,the weight of the structure,bubbles,dust,and impurities during the PμLSE additive manufacturing process.

Principles to Support Modular Software Construction

The construction of large software systems is always achieved through assembly of independently written components -- program modules. For these software components to work together, they must share a common set of data types and principles for representing structured data such as arrays of values and files. This common set of tools for creating and operating on data objects is provided by the infrastructure of the computer system： the hardware, operating system and runtime code. Because the nature and properties of these tools are crucial for correct operation of software components and their inter-operation, it is essential to have a precise specification that may be used for verifying correctness of application software on one hand, and to verify correctness of system behavior on the other. We call such a specification a program execution model （PXM）. It is evident that the properties of the PXM implemented by a computer system can have serious impact on the ability of application programmers to practice modular software construction. This paper discusses the concept of program execution models and presents a set of principles that a PXM must satisfy to provide a sound basis for modular software construction. Because parallel program execution on computer systems with many processing units is an essential part of contemporary computing environments, the expression of parallelism and modular software construction using components involving parallel operations is included in this treatment. The conclusion is that it is possible to build computer systems that implement a PXM within which any parallel program may be used, unmodified, as a component for building more substantial parallel programs.

A study of the hydrogen bonds effect on the water density and the liquid-liquid transition

We study the hydrogen bonds effect on the water density as a function of temperature and pressure from the supercritical region to the metastable supercooled and amorphous phases. We identify two important thermodynamic thresholds, that is P~*■2 kbar and T~*■315 K, that separate two different water behaviors in terms of hydrogen bonding capability. For T < T~* and P < P~* the formation and stability of hydrogen bonded local structures are enhanced. The additional analyses of the proton NMR chemical shift and of the relaxation time confirm this evidence and highlight the structure breaking effects of the pressure. The investigation of both structural and dynamical quantities allow us to draw a complete picture of the water properties in terms of the temperaturepressure dependence of hydrogen bonding.

Evidence for niche differentiation of nitrifying communities in grassland soils after 44 years of different field fertilization scenarios

Long-term nitrogen(N)fertilization imposes strong selection on nitrifying communities in agricultural soil,but how a progressively changing niche affects potentially active nitrifiers in the field remains poorly understood.Using a 44-year grassland fertilization experiment,we investigated community shifts of active nitrifiers by DNA-based stable isotope probing(SIP)of field soils that received no fertilization(CK),high levels of organic cattle manure(HC),and chemical N fertilization(CF).Incubation of DNA-SIP microcosms showed significant nitrification activities in CF and HC soils,whereas no activity occurred in CK soils.The 44 years of inorganic N fertilization selected only 13C-ammonia-oxidizing bacteria(AOB),whereas cattle slurry applications created a niche in which both ammonia-oxidizing archaea(AOA)and AOB could be actively13C-labeled.Phylogenetic analysis indicated that Nitrosospira sp.62-like AOB dominated inorganically fertilized CF soils,while Nitrosospira sp.41-like AOB were abundant in organically fertilized HC soils.The 13C-AOA in HC soils were affiliated with the 29i4 lineage.The 13C-nitrite-oxidizing bacteria(NOB)were dominated by both Nitrospira-and Nitrobacter-like communities in CF soils,and the latter was overwhelmingly abundant in HC soils.The 13C-labeled nitrifying communities in SIP microcosms of CF and HC soils were largely similar to those predominant under field conditions.These results provide direct evidence for a strong selection of distinctly active nitrifiers after 44 years of different fertilization regimes in the field.Our findings imply that niche differentiation of nitrifying communities could be assessed as a net result of microbial adaption over 44 years to inorganic and organic N fertilization in the field,where distinct nitrifiers have been shaped by intensified anthropogenic N input.

Texture Repairing by Unified Low Rank Optimization

In this paper, we show how to harness both low-rank and sparse structures in regular or near-regular textures for image completion. Our method is based on a unified formulation for both random and contiguous corruption. In addition to the low rank property of texture, the algorithm also uses the sparse assumption of the natural image： because the natural image is pieeewise smooth, it is sparse in certain transformed domain （such as Fourier or wavelet transform）. We combine low-rank and sparsity properties of the texture image together in the proposed algorithm. Our algorithm based on convex optimization can automatically and correctly repair the global structure of a corrupted texture, even without precise information about the regions to be completed. This algorithm integrates texture rectification and repairing into one optimization problem. Through extensive simulations, we show our method can complete and repair textures corrupted by errors with both random and contiguous supports better than existing low-rank matrix recovery methods. Our method demonstrates significant advantage over local patch based texture synthesis techniques in dealing with large corruption, non-uniform texture, and large perspective deformation.

潘吉亚超大陆时期的哈德雷环流

潘吉亚超大陆时期,是地球历史上的一个独特阶段.在约2.5亿年前,全球大陆汇聚成一块从南极延伸至北极的超级大陆,其面积约占地球表面积的35%,与现代大陆面积(约30%)相比要大得多.此时地球处于温室气候,全球平均地面温度约为26℃,二氧化碳浓度远高于现代.本文通过气候模拟研究了这一地质时期的哈德雷环流.结果表明,潘吉亚的哈德雷环流强度较弱,边界纬度较宽.一个最为显著的特征是,北半球和南半球冬季的哈德雷环流上升支分别位于23°S和18°N,比现代的上升支远离赤道得多.这是副热带较大的陆地面积以及与之相关的极高温度造成的.

The Boson peak interpretation and evolution in confined amorphous water

We study the evolution of the Boson peak for water confined in cement paste obtained by means of Inelastic Neutron Scattering from room temperature to the deep supercooled regime.We analyze the data in terms of a universal-like model,developed for glass forming liquids in the frame of the energy landscape.In such a way it is possible to discriminate between the fragile and strong glass forming character of supercooled liquids and the dynamical crossover,fragile to strong,between them.Hence,we confirm the link between the Boson peak and the water polymorphism.In particular,the main result is represented by a crossover from a local energetic minima configuration to that characteristic of saddle points on going towards the deep supercooled regime up to the dynamical arrest.

Scarcity events analysis in adequacy studies using CN2 rule mining

Dealing with scarcity events is nowadays gaining relevance in electricity market studies, as traditionally predictable generation and consumption patterns are fading. Policymakers and system planners use therefore adequacy studies to a) understand if the current market design will attract sufficient generation capacity to meet electricity demand in the future and b) to comprehend what drives system inadequacy or resource scarcity when future scenarios lack adequate capacity. This work addressed the latter and showcases a first in-its-kind rulebased methodology that filters scarcity events from a large set of electricity market simulations. In this proof-of-concept, a rule-mining algorithm is applied to outputs from ENTSO-E’s Pan-European electricity market model, which is run for 700 model scenarios, each covering 8760 time steps. The developed methodology shows how to unveil potential reasons behind scarcity events in an automated, interpretable, and scalable manner.

Hydrophilic and hydrophobic competition in water-methanol solutions

We study the thermal behavior of the longitudinal spin-lattice, T1, and the transverse spin-spin, T2, relaxation times of the macroscopic magnetization in water/methanol solutions. Our aim is to investigate the reciprocal influence of hydrophobic effects on water properties and of hydrophilicity（via hydrogen bond, HB, interactions） on the solute. Using classical Nuclear Magnetic Resonance spectroscopy, we find a single characteristic correlation time τcthat reflects all local structural configurations and characterizes the thermal motion effects of the magnetic nuclei on the spin-spin interaction. We find that in the supercooled regime the correlations are stronger, with respect to ambient temperature, because the HB interactions have a lifetime long enough to sustain a stable water network. However, increasing the temperature, progressively decreases the HB interaction lifetime and destroys the water clusters with a consequent decoupling in the dynamic modes of the system. In addition, at temperatures higher than about 265 K, the hydrophobicity becomes gradually stronger and governs the physical properties of the solutions.

A novel convolutional neural network for electronic component classification with diverse backgrounds

The rapid development of computer vision techniques has brought new opportunities for manufacturing industries,accelerating the intelligence of manufacturing systems in terms of product quality assurance,automatic assembly,and industrial robot control.In the electronics manufacturing industry,intensive variability in component shapes and colors,background brightness,and visual contrast between components and back-ground results in difficulties in printed circuit board image classification.In this paper,we apply computer vision techniques to detect diverse electronic components from their background images,which is a challenging problem in electronics manufacturing indus-tries because there are multiple types of components mounted on the same printed circuit board.Specifically,a 13-layer convolutional neural network(ECON)is proposed to detect electronic components either of a single category or of diverse categories.The proposed network consists of five Convolution-MaxPooling blocks,followed by a flat-tened layer and two fully connected layers.An electronic component image dataset from a real manufacturing company is applied to compare the performance between ECON,Xception,VGG16,and VGG19.In this dataset,there are 11 categories of components as well as their background images.Results show that ECON has higher accuracy in both single-category and diverse component classification than the other networks.

Experimental tests for a liquid-liquid critical point in water

Water is a fascinating material.Its composition is simple—one oxygen and two hydrogen atoms—but its chemistry and physics are extremely complex and exhibit 75 documented anomalies.Although these anomalies and their molecular origin are not completely understood,we know that hydrogen bonds play key roles in all of the phases of water.Moreover,there is experimental evidence that the polymorphism of the ice structure extends into the liquid phase and is associated with a liquid-liquid coexistence line.This is currently a topic of great interest in water research because there are indications that the end point of the coexistence line corresponds to a second critical point inside the supercooled liquid regime.We examine the recent progress in understanding water anomalies and the liquid-liquid phase transition hypothesis,including the results of recent experimental work and molecular simulations of both bulk and confined water.We examine experimental results that test whether the behavior of liquid water is consistent with the"liquid polymorphism"hypothesis that liquid water can exist in two distinct phases of differing densities.We also examine recent research on the anomalies of nanoconfined water and,in particular,on water in biological environments.We find that the concept of liquid polymorphism can also describe the properties of other liquids that have two characteristic length scales.