Analysis of Transient Cutting Forces in Cortical Bone During Ultrasonically Assisted Cutting.

Ultrasonically assisted cutting (UAC), a process characterized by high-performance material removal and enhanced surface finish, is widely employed in orthopedic surgery. However, variability in the mechanical properties of cortical bone may lead to unstable fractures and fluctuating cutting force during material removal, particularly under high-frequency vibration cutting. This study introduces a transient shear strength model that utilizes strain rate fluctuations to estimate cutting forces in the UAC process.

Toward Low Energetic Disorder in Organic Solar Cells: The Critical Role of Polymer Donors.

Compared with those of inorganic and perovskite solar cells, the power conversion efficiencies of organic solar cells (OSCs) are severely limited by a large energetic disorder. However, the origin of energetic disorder for OSCs remains poorly understood. Herein, we systematically investigate the energetic disorder in representative OSCs and the effect of both the acceptors and polymer donors by combining atomistic molecular dynamics simulations with density functional theory calculations.

Asymmetric small-molecule acceptor enables suppressed electron-vibration coupling and minimized driving force for organic solar cells.

Minimizing the energy loss, particularly the non-radiative energy loss (ΔE), without sacrificing the charge collection efficiency, is the key to further improve the photovoltaic performance of organic solar cells (OSCs). Herein, we proposed an asymmetric molecular design strategy, via developing alkyl/thienyl hybrid side chain based asymmetric small molecule acceptors (SMAs) BTP-C11-TBO and BTP-BO-TBO, to manipulate the intermolecular interactions to realize enhanced luminescence efficiency and reduced energy loss. Theoretical and experimental results indicate that compared to the three symmetric SMAs BTP-DC11, BTP-DTBO and BTP-DBO, the asymmetric SMAs BTP-C11-TBO and BTP-BO-TBO exhibit repressed electron-vibration coupling and reduced ΔE.

Parameter Optimization and Precision Control of Water-Soluble Support Cores for Hollow Composite Castings Fabricated by Slurry Microextrusion Direct Forming Method.

The optimization of slurry content and forming process parameters has a significant effect in slurry microextrusion direct forming method. In this article, magnesium sulfate monohydrate (MgSO) and polyvinylpyrrolidone (PVP) were used as raw materials to prepare the slurry, and the component ratios of the slurry and the optimization of its forming process were discussed. The optimum slurry content is 64 wt.

The Key Descriptors for Predicting the Exciton Binding Energy of Organic Photovoltaic Materials.

Exciton binding energy (E) is a key parameter to determine the mechanism and performance of organic optoelectronic devices. Small E benefits to reduce the interfacial energy offset and the energy loss of organic solar cells. However, quantum-chemical calculations of the E in solid state with considering electronic polarization effects are extremely time-consuming.

Efficient and Accurate Estimation of Electronic Polarization Energies for Organic Semiconductors: An Embedding Charge Quantum Mechanics/Continuum Dielectric Model.

Electronic polarization plays a pivotal role in determining the molecular energy levels of organic semiconductors (OSCs) in the condensed phase. However, accurate estimation of the electronic polarization energy is a challenging task due to the intricate imbalance between the precision and efficiency. In this work, we have developed an embedding charge quantum mechanics/continuum dielectric (EC-QM/CD) model, which enables quantitative evaluation of the ionization potential (IP), electron affinity (EA), and polarization energy in both crystalline and amorphous solids for OSCs.

Surface Roughness of Interior Fine Flow Channels in Selective Laser Melted Ti-6Al-4V Alloy Components.

A challenge remains in achieving adequate surface roughness of SLM fabricated interior channels, which is crucial for fuel delivery in the space industry. This study investigated the surface roughness of interior fine flow channels (1 mm diameter) embedded in SLM fabricated TC4 alloy space components. A machine learning approach identified layer thickness as a significant factor affecting interior channel surface roughness, with an importance score of 1.

The impact of molecular orientations on the energy levels of A-D-A acceptors: implications for the charge separation driving force of organic solar cells.

The energetic landscape of charge carriers, namely the ionization potential (IP) and electron affinity (EA), can play a crucial role in the charge separation and migration processes for organic solar cells (OSCs). However, the impact of molecular orientations on the energy levels remains elusive, especially in acceptor-donor-acceptor (A-D-A) type nonfullerene acceptors (NFAs) with intrinsic anisotropy. Using the self-consistent quantum mechanics/embedded charge (sc-QM/EC) approach, we have investigated the energy level shifts from the edge-on or face-on surfaces to the bulk phase for three typical NFA crystals, IDIC-4F, INIC-4F, and Y6.

The role of interfacial donor-acceptor percolation in efficient and stable all-polymer solar cells.

Polymerization of Y6-type acceptor molecules leads to bulk-heterojunction organic solar cells with both high power-conversion efficiency and device stability, but the underlying mechanism remains unclear. Here we show that the exciton recombination dynamics of polymerized Y6-type acceptors (Y6-PAs) strongly depends on the degree of aggregation. While the fast exciton recombination rate in aggregated Y6-PA competes with electron-hole separation at the donor-acceptor (D-A) interface, the much-suppressed exciton recombination rate in dispersed Y6-PA is sufficient to allow efficient free charge generation.

Precision Grinding Technology of Silicon Carbide (SiC) Ceramics by Longitudinal Torsional Ultrasonic Vibrations.

Silicon carbide (SiC) ceramic material has become the most promising third-generation semiconductor material for its excellent mechanical properties at room temperature and high temperature. However, SiC ceramic machining has serious tool wear, low machining efficiency, poor machining quality and other disadvantages due to its high hardness and high wear resistance, which limits the promotion and application of such materials. In this paper, comparison experiments of longitudinal torsional ultrasonic vibration grinding (LTUVG) and common grinding (CG) of SiC ceramics were conducted, and the longitudinal torsional ultrasonic vibration grinding SiC ceramics cutting force model was developed.

Diazulenorubicene as a Non-benzenoid Isomer of peri-Tetracene with Two Sets of 5/7/5 Membered Rings Showing Good Semiconducting Properties.

Non-benzenoid polycyclic aromatic hydrocarbons (PAHs) have received a lot of attention because of their unique optical, electronic, and magnetic properties, but their synthesis remains challenging. Herein, we report a non-benzenoid isomer of peri-tetracene, diazulenorubicene (DAR), with two sets of 5/7/5 membered rings synthesized by a (3+2) annulation reaction. Compared with the precursor containing only 5/7 membered rings, the newly formed five membered rings switch the aromaticity of the original heptagon/pentagon from antiaromatic/aromatic to non-aromatic/antiaromatic respectively, modify the intermolecular packing modes, and lower the LUMO levels.

Electron Transport in Organic Photovoltaic Acceptor Materials: Improving the Carrier Mobilities by Intramolecular and Intermolecular Modulations.

High carrier mobility is beneficial to increase the active-layer thickness while maintaining a high fill factor, which is crucial to further improve the light harvesting and organic photovoltaic efficiency. The aim of this Perspective is to elucidate the electron transport mechanisms in prototypical non-fullerene (NF) acceptors through our recent theoretical studies. The electron transport in A-D-A small-molecule acceptors (SMAs), e.

Molecular Design of A-D-A Electron Acceptors Towards Low Energy Loss for Organic Solar Cells.

Low energy loss is a prerequisite for organic solar cells to achieve high photovoltaic efficiency. Electron-vibration coupling (i. e.

Toward Quantifying the Relation between Exciton Binding Energies and Molecular Packing.

Reducing the exciton binding energy of organic photoactive materials is critical to minimize the energy loss and improve the photovoltaic efficiency of organic solar cells. However, the relation between the and molecular packing is not well understood. Herein, the in the crystals of a series of A-D-A type nonfullerene acceptors with different lengths of alkyl side chains has been examined by self-consistent quantum mechanics/embedded charge calculations.

Singlet-Triplet Energy Gap as a Critical Molecular Descriptor for Predicting Organic Photovoltaic Efficiency.

In contrast to the inorganic and perovskite solar cells, organic photovoltaics (OPV) depend on a series of charge generation and recombination processes, which complicates molecular design to improve the power conversion efficiencies (PCEs). Herein, we first propose the singlet-triplet energy gap (ΔE ) as a critical molecular descriptor for predicting the PCE considering that minimizing ΔE is beneficial to simultaneously reduce voltage loss and triplet recombination. Remarkably, the results from data-driven machine learning verify that the prediction accuracy of the ΔE (Pearson's correlation coefficient r=0.

The Intrinsic Role of the Fusion Mode and Electron-Deficient Core in Fused-Ring Electron Acceptors for Organic Photovoltaics.

The A-DA'D-A fused-ring electron acceptors with an angular fusion mode and electron-deficient core has significantly boosted organic photovoltaic efficiency. Here, the intrinsic role of the peculiar structure is revealed by comparing representative A-DA'D-A acceptor Y6 with its A-D-A counterparts having different fusion modes. Owing to the more delocalized HOMO and deeper LUMO level, Y6 exhibits stronger and red-shifted absorption relative to the linear and angular fused A-D-A acceptors, respectively.

Molecular Insight into Efficient Charge Generation in Low-Driving-Force Nonfullerene Organic Solar Cells.

ConspectusFor organic solar cells (OSCs), charge generation at the donor/acceptor interfaces is regarded as a two-step process: driven by the interfacial energy offsets, the excitons produced by light absorption are first dissociated into the charge-transfer (CT) states, and then the CT states are further separated into free charge carriers of holes and electrons by overcoming their Coulomb attraction. Meanwhile, the CT states can recombine through radiative and nonradiative decay. Owing to the emergence of narrow-band-gap A-D-A small-molecule acceptors, nonfullerene (NF) OSCs have developed rapidly in recent years and the power conversion efficiencies (PCEs) surpass 18% now.

Nucleotide-Oligomerizing Domain-1 Activation Exaggerates Cigarette Smoke-Induced Chronic Obstructive Pulmonary-Like Disease in Mice.

Introduction: Chronic obstructive pulmonary disease (COPD) is a progressive condition related to abnormal inflammatory responses. As an inflammatory driver, nucleotide-binding oligomerizing domain-1 (NOD1) is highly expressed in pulmonary inflammatory cells; however, the roles of NOD1 in COPD are unknown.

Methods: A COPD mouse model was established by lipopolysaccharides tracheal instillation plus cigarette smoke (CS) exposure.

Electrical Loss Management by Molecularly Manipulating Dopant-free Poly(3-hexylthiophene) towards 16.93 % CsPbI Br Solar Cells.

Inorganic cesium lead halide perovskites offer a pathway towards thermally stable photovoltaics. However, moisture-induced phase degradation restricts the application of hole transport layers (HTLs) with hygroscopic dopants. Dopant-free HTLs fail to realize efficient photovoltaics due to severe electrical loss.

Sub-5 nm single crystalline organic p-n heterojunctions.

The cornerstones of emerging high-performance organic photovoltaic devices are bulk heterojunctions, which usually contain both structure disorders and bicontinuous interpenetrating grain boundaries with interfacial defects. This feature complicates fundamental understanding of their working mechanism. Highly-ordered crystalline organic p-n heterojunctions with well-defined interface and tailored layer thickness, are highly desirable to understand the nature of organic heterojunctions.

Efficacy of oseltamivir compared with zanamivir in COPD patients with seasonal influenza virus infection: a randomized controlled trial.

Influenza viruses exacerbate chronic obstructive pulmonary disease (COPD) with considerable morbidity and mortality. Zanamivir and oseltamivir are effective in treating influenza. However, their efficacy in relieving influenza symptoms in COPD patients remains unknown, with the lack of controlled trials in this subject.

Unraveling the influence of non-fullerene acceptor molecular packing on photovoltaic performance of organic solar cells.

In non-fullerene organic solar cells, the long-range structure ordering induced by end-group π-π stacking of fused-ring non-fullerene acceptors is considered as the critical factor in realizing efficient charge transport and high power conversion efficiency. Here, we demonstrate that side-chain engineering of non-fullerene acceptors could drive the fused-ring backbone assembly from a π-π stacking mode to an intermixed packing mode, and to a non-stacking mode to refine its solid-state properties. Different from the above-mentioned understanding, we find that close atom contacts in a non-stacking mode can form efficient charge transport pathway through close side atom interactions.

Reducing the Singlet-Triplet Energy Gap by End-Group π-π Stacking Toward High-Efficiency Organic Photovoltaics.

To improve the power conversion efficiencies for organic solar cells, it is necessary to enhance light absorption and reduce energy loss simultaneously. Both the lowest singlet (S1) and triplet (T1) excited states need to energertically approach the charge-transfer state to reduce the energy loss in exciton dissociation and by triplet recombination. Meanwhile, the S1 energy needs to be decreased to broaden light absorption.

High-Performance Fluorinated Fused-Ring Electron Acceptor with 3D Stacking and Exciton/Charge Transport.

A new fluorinated electron acceptor (FINIC) based on 6,6,12,12-tetrakis(3-fluoro-4-hexylphenyl)-indacenobis(dithieno[3,2-b;2',3'-d]thiophene) as the electron-donating central core and 5,6-difluoro-3-(1,1-dicyanomethylene)-1-indanone as the electron-deficient end groups is rationally designed and synthesized. FINIC shows similar absorption profile in dilute solution to the nonfluorinated analogue INIC. However, compared with INIC, FINIC film shows red-shifted absorption, down-shifted frontier molecular orbital energy levels, enhanced crystallinity, and more ordered molecular packing.

Suppressing triplet decay in quinoidal singlet fission materials: the role of molecular planarity and rigidity.

Singlet fission, in which one singlet exciton is split into two triplet excitons, provides the potential to exceed the Shockley-Queisser limit for the power conversion efficiencies of organic solar cells. However, the charge transfer from the triplet state is found to be slow in singlet fission materials, so suppression of the triplet decay is crucial for effective utilization of singlet fission. Here, we first investigated triplet decay for the singlet fission molecular materials of ThBF and TThBF, which are characteristic of twisted and flexible quinoidal backbones.