Deterministic Synthesis Research Articles

Deterministic Synthesis of a Two-Dimensional MAPbI3 Nanosheet and Twisted Structure with Moiré Superlattice.

The synthesis of extremely thin 2D halide perovskites and the exploration of their interlayer interactions have garnered significant attention in current research. A recent advancement we have made involves the development of a successful technique for generating ultrathin MAPbI3 nanosheets with controlled thickness and an exposed intrinsic surface. This innovative method relies on utilizing the Ruddlesden-Popper (RP) phase perovskite (BA2MAn-1PbnI3n+1) as a template. However, the precise reaction mechanism remains incompletely understood. In this work, we systematically examined the dynamic evolution of the phase conversion process, with a specific focus on the influence of inorganic slab (composed of [PbI6]4- octahedrons) numbers on regulating the thickness and quality of the resulting MAPbI3 nanosheets. Additionally, the atomic structure is directly visualized using the transmission electron microscopy (TEM) method, confirming its exceptional quality. To illustrate interfacial interactions in ultrathin structures, artificial moiré superlattices are constructed through a physical transfer approach, revealing multiple localized high-symmetry stacks within a distinctive square moiré pattern. These findings establish a novel framework for investigating the physics of interfacial interactions in ionic semiconducting crystals.

Formation Mechanism and Morphology Evolution of β-NaYF4 Single Microcrystals in Hydrothermal Process

Lanthanide-doped upconversion (Ln-doped UC) materials with predicable phase and geometry are attractive for their promising application in optics and biological. Herein, we report a facile strategy for deterministic synthesis of β-NaYF4 microcrystals by an ethylenediaminetetraacetic acid (EDTA) assisted hydrothermal process. The nucleation and growth process of the β-NaYF4 microcrystals have been experimentally revealed with different hydrothermal times. The phase and geometry of as-obtained crystals can be well manipulated by the experimental parameters such as pH values, precursors’ ratio, and reactant concentrations. The formation and morphology evolution mechanism of β-NaYF4 single microcrystals can be qualitatively analyzed using energy minimization principles under the thermodynamic and kinetic control. In addition, we presented the colour-changing up-conversion of Tm3+ and Yb3+ doped single β-NaYF4 microrod. Our work could help the understanding on crystal growth and design of rare earth fluoride mateirals at micro and nanoscale.

Probabilistic state synthesis based on optimal convex approximation

When preparing a pure state with a quantum circuit, there is an unavoidable approximation error due to the compilation error in fault-tolerant implementation. A recently proposed approach called probabilistic state synthesis, where the circuit is probabilistically sampled, is able to reduce the approximation error compared to conventional deterministic synthesis. In this paper, we demonstrate that the optimal probabilistic synthesis quadratically reduces the approximation error. Moreover, we show that a deterministic synthesis algorithm can be efficiently converted into a probabilistic one that achieves this quadratic error reduction. We also numerically demonstrate how this conversion reduces the T-count and analytically prove that this conversion halves an information-theoretic lower bound on the circuit size. In order to derive these results, we prove general theorems about the optimal convex approximation of a quantum state. Furthermore, we demonstrate that this theorem can be used to analyze an entanglement measure.

Constrained Deterministic Synthesis of Conformal Supershaped Antenna Arrays

Constrained Deterministic Synthesis of Conformal Supershaped Antenna Arrays

Deterministic Synthesis of Pd Nanocrystals Enclosed by High-Index Facets and Their Enhanced Activity toward Formic Acid Oxidation.

Noble-metal nanocrystals enclosed by high-index facets are of growing interest due to their enhanced catalytic performance in a variety of reactions. Herein, we report the deterministic synthesis of Pd nanocrystals encased by high-index facets by controlling the rate of deposition (Vdeposition) relative to that of surface diffusion (Vdiffusion). For octahedral seeds with truncated corners, a reduction rate (and thus deposition rate) faster than that of surface diffusion (i.e., Vdeposition/Vdiffusion > 1) led to the formation of concave trisoctahedra (TOH) with high-index facets. When the reduction was slowed down, in contrast, surface diffusion dominated the growth pathway. In the case of Vdeposition/Vdiffusion ≈ 1, truncated octahedra with enlarged sizes were produced. When the reduction rate was between these two extremes, we obtained concave tetrahexahedra (THH) without or with truncation. Similar growth patterns were also observed for the cuboctahedral seeds. When the Pd octahedra, concave TOH, and concave THH were tested for electrocatalyzing the formic acid oxidation (FAO) reaction, those with high-index facets were advantageous over the conventional Pd octahedra enclosed by {111} facets. This work not only contributes to the understanding of surface diffusion and its role in nanocrystal growth but also offers a general protocol for the synthesis of nanocrystals enclosed by high-index facets.

Deterministic nanoscale quantum spin-defect implantation and diffraction strain imaging

Local crystallographic features negatively affect quantum spin defects by changing the local electrostatic environment, often resulting in degraded or varied qubit optical and coherence properties. Few tools exist that enable the deterministic synthesis and study of such intricate systems on the nano-scale, making defect-to-defect strain environment quantification difficult. In this paper, we highlight state-of-the-art capabilities from the U.S. Department of Energy’s Nanoscale Science Research Centers that directly address these shortcomings. Specifically, we demonstrate how complementary capabilities of nano-implantation and nano-diffraction can be used to demonstrate the quantum relevant, spatially deterministic creation of neutral divacancy centers in 4H silicon carbide, while investigating and characterizing these systems on the scale with strain sensitivities on the order of relevant to defect formation dynamics. This work lays the foundation for ongoing studies into the dynamics and deterministic formation of low strain homogeneous quantum relevant spin defects in the solid state.

Optimal Deterministic Controller Synthesis from Steady-State Distributions

Optimal Deterministic Controller Synthesis from Steady-State Distributions

Strain‐Induced Structure Evolution of Multimetallic Nanoplates

AbstractThe surface structure and lattice strain necessary to optimize oxygen reduction reaction (ORR) in a cost‐effective electrocatalyst still requires systematic exploration. Here, by means of oxidative etching of surface confinement stacking faults, a comparative study of the influence of defects on the growth and lattice strain of PtAgPb core‐shell nanoplates for ORR is conducted. Stacking faults are key to forming the core–shell structure and induce tensile and compressive strains to improve catalytic performance of nanoplates. In particular, the compressive strain arising from the optimal composition of nanoplates enhances the ORR activity. The findings show how compressive strain in core–shell nanoplates shift the electronic band structure of platinum (Pt) and weakens chemisorption of oxygenated species. As a result, the obtained PtAgPb‐IV/C nanoplates display superior specific and mass activities (5.06 mA cm−2 and 2.24 A mgPt−1) for ORR that are ≈18 and ≈13 times higher than that of commercial Pt/C, placing it among the best reported Pt based ORR electrocatalysts. Furthermore, the PtAgPb‐IV/C catalyst exhibits substantially improved durability relative to commercial Pt/C catalysts. This work represents a major step toward the deterministic synthesis of Pt‐based multimetallic nanocrystals with specific structure and surface strain for efficient ORR performance.

Performance Comparison of Quantized Control Synthesis Methods of Antenna Arrays

There is a great potential in small satellite technology for testing new sensors, processes, and technologies for space applications. Antennas need careful design when developing a small satellite to establish stable communication between the ground station and the satellite. This work is motivated by the design of an antenna array for a future rotatorless base station for the VZLUSAT group of Czech nano-satellites. The realized antenna array must cover a relatively broad range of elevation and azimuth angles, and the control must be fast enough to track the satellite in low Earth orbits. The paper deals with possibilities of synthesis of quantized control of the antenna array. It compares quantization influence for well-known deterministic synthesis methods. It shows the method for decreasing computational cost of synthesis using optimization approach and presents the multi-criteria optimization as a tool for reaching required radiation pattern shape and low sensitivity to quantization at the same time.

Synthesis of layered vs planar Mo2C: role of Mo diffusion

Chemical vapor deposition growth of metal carbides is of great interest as this method provides large area growth of MXenes. This growth is mainly done using a melted diffusion based process; however, different morphologies in growth process is not well understood. In this work, we report deterministic synthesis of layered (non-uniform c-axis growth) and planar (uniform c-axis growth) of molybdenum carbide (Mo2C) using a diffusion-mediated growth. Mo-diffusion limited growth mechanism is proposed where the competition between Mo and C adatoms determines the morphology of grown crystals. Difference in thickness of catalyst at the edge and center lead to enhanced Mo diffusion which plays a vital role in determining the structure of Mo2C. The layered structures exhibit an expansion in the lattice confirmed by the presence of strain. Density functional theory shows consistent presence of strain which is dependent upon Mo diffusion during growth. This work demonstrates the importance of precise control of diffusion through the catalyst in determining the structure of Mo2C and contributes to broader understanding of metal diffusion in growth of MXenes.

Synthesized soliton crystals

Dissipative Kerr soliton (DKS) featuring broadband coherent frequency comb with compact size and low power consumption, provides an unparalleled tool for nonlinear physics investigation and precise measurement applications. However, the complex nonlinear dynamics generally leads to stochastic soliton formation process and makes it highly challenging to manipulate soliton number and temporal distribution in the microcavity. Here, synthesized and reconfigurable soliton crystals (SCs) are demonstrated by constructing a periodic intra-cavity potential field, which allows deterministic SCs synthesis with soliton numbers from 1 to 32 in a monolithic integrated microcavity. The ordered temporal distribution coherently enhanced the soliton crystal comb lines power up to 3 orders of magnitude in comparison to the single-soliton state. The interaction between the traveling potential field and the soliton crystals creates periodic forces on soliton and results in forced soliton oscillation. Our work paves the way to effectively manipulate cavity solitons. The demonstrated synthesized SCs offer reconfigurable temporal and spectral profiles, which provide compelling advantages for practical applications such as photonic radar, satellite communication and radio-frequency filter.

Conceptual Model of Enterprise Financial Management System with the Application of Modern Information Technologies

In modern conditions of information technology development, the business management regime has changed. The sphere of management has expanded from internal to external. The innovation model of corporate Finance management must also adapt to this change. In an era of the global implementation of information systems and management tools, the innovation of the corporate financial management regime is not only in the rational planning and use of the company’s own resources but also in the inclusion of various categories of social resources necessary for the company’s operations in the category of corporate financial management and delivery to the enterprise. The purpose of the article is to consider the conceptual model of the financial management system of enterprises using modern information technologies. In the study, the author used a systematic approach to the enterprise’s financial management and methods of economic and deterministic factor analysis, synthesis, and grouping as well.

Deterministic synthesis of Cu9S5 flakes assisted by single-layer graphene arrays.

The employment of two-dimensional materials, as growth substrates or buffer layers, enables the epitaxial growth of layered materials with different crystalline symmetries with a preferential crystalline orientation and the synthesis of heterostructures with a large lattice constant mismatch. In this work, we employ single crystalline graphene to modify the sulfurization dynamics of copper foil for the deterministic synthesis of large-area Cu9S5 crystals. Molecular dynamics simulations using the Reax force-field are used to mimic the sulfurization process of a series of different atomistic systems specifically built to understand the role of graphene during the sulphur atom attack over the Cu(111) surface. Cu9S5 flakes show a flat morphology with an average lateral size of hundreds of micrometers. Cu9S5 presents a direct band-gap of 2.5 eV evaluated with light absorption and light emission spectroscopies. Electrical characterization shows that the Cu9S5 crystals present high p-type doping with a hole mobility of 2 cm2 V−1 s−1.

State of the Art on Neural Rendering

AbstractEfficient rendering of photo‐realistic virtual worlds is a long standing effort of computer graphics. Modern graphics techniques have succeeded in synthesizing photo‐realistic images from hand‐crafted scene representations. However, the automatic generation of shape, materials, lighting, and other aspects of scenes remains a challenging problem that, if solved, would make photo‐realistic computer graphics more widely accessible. Concurrently, progress in computer vision and machine learning have given rise to a new approach to image synthesis and editing, namely deep generative models. Neural rendering is a new and rapidly emerging field that combines generative machine learning techniques with physical knowledge from computer graphics, e.g., by the integration of differentiable rendering into network training. With a plethora of applications in computer graphics and vision, neural rendering is poised to become a new area in the graphics community, yet no survey of this emerging field exists. This state‐of‐the‐art report summarizes the recent trends and applications of neural rendering. We focus on approaches that combine classic computer graphics techniques with deep generative models to obtain controllable and photorealistic outputs. Starting with an overview of the underlying computer graphics and machine learning concepts, we discuss critical aspects of neural rendering approaches. Specifically, our emphasis is on the type of control, i.e., how the control is provided, which parts of the pipeline are learned, explicit vs. implicit control, generalization, and stochastic vs. deterministic synthesis. The second half of this state‐of‐the‐art report is focused on the many important use cases for the described algorithms such as novel view synthesis, semantic photo manipulation, facial and body reenactment, relighting, free‐viewpoint video, and the creation of photo‐realistic avatars for virtual and augmented reality telepresence. Finally, we conclude with a discussion of the social implications of such technology and investigate open research problems.

Anticancer evaluation of a manganese complex on HeLa and MCF-7 cancer cells: design, deterministic solvothermal synthesis approach, Hirshfeld analysis, DNA binding, intracellular reactive oxygen species production, electrochemical characterization and density functional theory

Herein, a deterministic solvothermal strategy was employed to synthesize an efficient anticancer agent ‘cis-dichlorobis(1,10-phenanthroline)manganese(II)’ (Mn(phen)2Cl2). A single-crystal X-ray diffraction analysis revealed that Mn(phen)2Cl2 crystallizes in a triclinic system with the space group P-1. Cyclic voltammetric studies of Mn(phen)2Cl2 indicated that the electrode process occurs only due to complex formation and has a diffusion-controlled mechanism. Density functional theory estimations showed that the Mn(phen)2Cl2 is quite stable and exists in sextet spin state (five unpaired electrons) as the most stable form and hence, Mn(phen)2Cl2 is a high spin complex. Mn(phen)2Cl2 demonstrated significant anticancer potential against HeLa and MCF-7 cancer cells and less toxic behaviour towards normal BHK-21 cells. Fluorescence imaging confirmed that the production of reactive oxygen species (ROS) in HeLa cells by Mn(phen)2Cl2 induces oxidized fluorescence of dichlorofluorescein which emitted fluorescence at 530 nm after excitation at 488 nm. The microscopic investigation of apoptotic effect of Mn(phen)2Cl2 using propidium iodide and 4′,6-diamidino-2-phenylindole staining indicated that nuclear condensation, cell detachment and shrinkage occur after treatment with IC50 values of Mn(phen)2Cl2. Furthermore, an assessment of caspase-9 and caspase-3 activity after exposure to Mn(phen)2Cl2 in HeLa cells indicated that at IC50 values of Mn(phen)2Cl2, 1.5 fold and 4.8 fold increase in caspase-9 and caspase-3 activity, respectively, occurs. The measurement of mitochondrial membrane potential of a cationic dye (JC-1) showed a decrease in mitochondrial membrane potential in both HeLa and MCF-7 cells depicting that compound might have adopted intrinsic pathway of apoptosis. Ability of Mn(phen)2Cl2 to interact with HS-DNA demonstrates hyperchromicity with slight blue shift from 269 nm to 265 nm showing a non-covalent interaction with Gibbs free energy of ΔG = −14.62 kJ/mol. Communicated by Ramaswamy H. Sarma

Tolerance Design of Path Generating Four Bar Mechanism

Mechanisms are used for different path generation tasks, where a point on the coupler traces the required path. The link dimensions of a mechanism are determined using deterministic synthesis, where, the dimensional tolerances and the joint clearances are not considered. The performance of such mechanisms deviates due to internal and external uncertainties. It is necessary to allocate optimum tolerances and clearances to these mechanisms. Tolerance design is a technique to allocate optimum tolerances to such mechanisms. In this paper, two approaches of tolerance design have been discussed, common tolerance level approach and combined tolerance level approach. The first one has been iterative, where tolerance design begins with maximum tolerance allocation to all control factors. The tolerances of most influencing control factors have been tightened iteratively in order to improve robustness. Combined tolerance level approach has been direct, where the tolerance design has been done by analyzing all control factors at all tolerance levels simultaneously. A vertical line has been specified as the path generation task. The design parameter values have been synthesized deterministically. Both the approaches have been applied for tolerance design of the best deterministically synthesized mechanism. It has been observed that both the approaches have resulted in distinct tolerance allocation and robustness.

Deterministic Constrained Synthesis Technique for Conformal Aperiodic Linear Antenna Arrays—Part II: Applications

The aim of this paper is to illustrate the application of the antenna placement methodology introduced in Part I for the deterministic synthesis of general conformal aperiodic arrays subject to multiple concurrent design constraints on the relevant layout and excitation tapering, as it is typically the case in satellite communications and radar applications. Antenna mutual coupling is not considered in the developed methodology; hence, to assess the sensitivity of the design procedure to such nonideality, a dedicated investigation has been conducted using rigorous full-wave electromagnetic modeling and experimental measurements collected on physical prototypes. The obtained results demonstrate the effectiveness and versatility of the proposed array synthesis approach, even in operative scenarios in which a significant deviation from the desired antenna operation is observed.

One-pot synthesis of Pt−Cu bimetallic nanocrystals with different structures and their enhanced electrocatalytic properties

Shape-controlled synthesis of Pt−Cu alloy nanocrystals (NCs) with unique geometries is of great importance in the rational design and deterministic synthesis of highly active electrocatalysts. Herein, Pt−Cu alloy NCs with concave octahedron (COH), porous octahedron (POH), yolk–shell (YSH), and nanoflower (NOF) structures were fabricated by altering the sequential reduction kinetics in a one-pot aqueous phase. The effect of the reaction kinetics on the formation of Pt−Cu bimetallic NCs with different morphologies was analyzed quantitatively. The concentrations of glycine and metal cation are demonstrated to play a key role in the reduction of Pt(IV) and Cu(II) ions; these significantly affected the morphology of Pt−Cu NCs. These Pt−Cu alloy NCs exhibit substantially enhanced catalytic activity and durability for methanol and formic acid oxidation compared to the commercial Pt/C catalyst. Specifically, the COH and NOF Pt−Cu NCs with more step atoms, intragranular dislocations, and protrusions showed superior electrochemical properties than those of POH and YSH Pt−Cu NCs. The structure–property relationship between the Pt−Cu NCs and their electrochemical performances was also investigated in depth.

Multiple-ring Circular Array for Ground-Penetrating Radar Applications: Basic Ideas and Preliminary Results

In this paper, the possibility of using a multiple-ring circular array as an antenna array for Ground-Pene-trating Radar systems is investigated. The theory behind theproposed idea is presented. The preliminary numerical re-sults that are obtained suggest that the proposed congura-tion is promising. It allows achieving a wide frequency bandand low dynamic range ratio of excitations, thus simplifyingthe feeding network. Further interesting requirements maybe satised by exploiting a combination of deterministic andstochastic synthesis techniques to design the array.

Reduction rate as a quantitative knob for achieving deterministic synthesis of colloidal metal nanocrystals.

Despite the incredible developments made to the synthesis of colloidal metal nanocrystals, it is still challenging to produce them in a reproducible and predictable manner. This drawback can be attributed to the fact that the protocols continue to be built upon qualitative observations and empirical laws. Because of the vast number of intricately entangled experimental parameters in a synthesis, it is almost impossible to predict and control the outcome by knowingly alternating these parameters. In this Perspective article, we discuss the recent efforts in pushing nanocrystal synthesis towards a deterministic process based upon quantitative measurements. In particular, we focus on how the reduction rate of a salt precursor can be used as a quantitative knob for predicting and controlling the outcomes of both nucleation and growth. We begin with a brief introduction to the techniques that have been used to extract the kinetic information of a synthesis and then discuss how the reduction rate is correlated with the defect structure, shape/morphology, and elemental distribution of the resultant nanocrystals. We conclude by highlighting some of the recent advances related to in situ probing of nanocrystal synthesis, with an emphasis on the real-time, quantitative aspects with regard to both nucleation and growth.