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Lithium metal–selenium (Li–Se) batteries offer high volumetric energy but are limited in their cycling life and fast charge characteristics. Here a facile approach is demonstrated to synthesize hierarchically porous hollow carbon spheres that host Se (Se@HHCS) and allow for state-of-the-art electrochemical performance in a standard carbonate electrolyte (1 M LiPF6 in 1 : 1 EC : DEC). The Se@HHCS electrodes display among the most favorable fast charge and cycling behavior reported. For example, they deliver specific capacities of 442 and 357 mA h g−1 after 1500 and 2000 cycles at 5C and 10C, respectively. At 2C, Se@HHCS delivers 558 mA h g−1 after 500 cycles, with cycling coulombic efficiency of 99.9%. Post-mortem microstructural analysis indicates that the structures remain intact during extended cycling. Per GITT analysis, Se@HHCS possesses significantly higher diffusion coefficients in both lithiation and delithiation processes as compared to the baseline. The superior performance of Se@HHCS is directly linked to its macroscopic and nanoscale pore structure: the hollow carbon sphere morphology as well as the remnant open nanoporosity accommodates the 69% volume expansion of the Li to Li2Se transformation, with the nanopores also providing a complementary fast ion diffusion path.

N-vacancy is an inevitable common point defect in GaN, but its behavior is still unclear during nano-grinding which is an indispensable process technique during some GaN devices manufacturing. In this study, we attempted to explore GaN with N-vacancy during nano-grinding from the perspective of molecular dynamics. The nano-grinding model of GaN with the N-vacancy concentrations from 0 at.% to 5 at.% was considered. The lattice disorder, phase transition, dislocation, grinding force, and temperature were analyzed. The results indicated that N-vacancy changed the behavior of lattice disorder, and created the potential well during the nano-grinding. By the analysis of the dislocation extraction algorithm (DXA), the inhibitory action on dislocation proliferation was observed, and the phase transition from the wurtzite to the zincblende reduced with the increase of the concentration of N-vacancy in GaN. Through the statistical analysis, it was found that N-vacancy also alleviated the grinding force fluctuation and increased the temperature during nano-grinding, which might imply that N-vacancy might improve the processing.

Monitoring the effects of mild hydrothermal conditions, in situ, on siliceous materials remains challenging using surface science techniques, which often require electrically conductive substrates....

Three-dimensional graphene network is a promising structure for improving both the mechanical properties and functional capabilities of reinforced polymer and ceramic matrix composites. However, direct application in a metal matrix remains difficult due to the reason that wetting is usually unfavorable in the carbon/metal system. Here we report a powder-metallurgy based strategy to construct a three-dimensional continuous graphene network architecture in a copper matrix through thermal-stress-induced welding between graphene-like nanosheets grown on the surface of copper powders. The interpenetrating structural feature of the as-obtained composites not only promotes the interfacial shear stress to a high level and thus results in significantly enhanced load transfer strengthening and crack-bridging toughening simultaneously, but also constructs additional three-dimensional hyperchannels for electrical and thermal conductivity. Our approach offers a general way for manufacturing metal matrix composites with high overall performance., Graphene networks have been used to reinforce polymer and ceramic composites, but connecting graphene into a three dimensional network in a metal matrix is challenging. Here the authors use a powder-metallurgy-based strategy to construct a three-dimensional graphene network reinforced copper matrix composite.

The morphology of a thin palladium film deposited on bilayer Al0.35Si0.65O2/Ru(0001), previously proposed as a two-dimensional zeolite model, is investigated using a set of complementary spectroscopy and microscopy tools. Pd single atoms are known to penetrate the bilayer silica, but when a thick Pd film is deposited on the aluminosilicate case some of the metal remains on top of the bilayer oxide. Annealing this surface results in a decrease in the Pd/Si ratio seen in X-ray photoelectron spectroscopy, indicating either further permeation of Pd, or dewetting of surface Pd to form nanoparticles and leave aluminosilicate exposed. An interesting observation is that two very distinct morphologies are obtained for the film. On small narrow terraces, flat wetting films are produced, while on larger terraces Pd particles leaving a partially exposed bilayer aluminosilicate framework are obtained.

Recently, the application of phosphorene structure analogues in gas sensors has been a hot research topic since the appearance of phosphorene. SnSe monolayer as one of them has been proved to be much more stable properties than phosphorene. Based on the density-functional theory, the interaction between gas molecules (CO, CO2, O2, NO, NH3, SO2 and NO2) and SnSe monolayer are theoretically investigated by first-principles calculation. Macroscopically, gas molecules selective adsorption of SnSe monolayer is analyzed by molecular dynamics. Compared to CO, CO2, O2, SnSe monolayer performs stronger affinity for SO2 and NO2, which possesses appropriate adsorption energies (−6.000 eV and −0.759 eV) and elevated charge transfers (−0.239 e and −0.328 e). SnSe monolayer chemical adsorption of NO2, while physically adsorbing SO2, is more suitable for the adsorption mode of SO2 sensors. Surprisingly, the adsorption amount of SO2 is 6 times that of NO2. Therefore, the adsorption of SO2 is more likely to occur compared to other gas molecules. For a mixed environment of SO2 and NO2, the adsorption quantity of SO2 is not significantly affected, while the adsorption of NO2 is inhibited. Therefore, the SnSe monolayer could be a promising candidate as SO2 sensors with high selectivity and sensitivity.

Transparent and easily fabricated films were obtained through the coupling of eugenol, a bio-sourced feedstock, and poly(methylhydrosiloxane), via the Piers–Rubinsztajn reaction and Pt-catalysed hydrosilylation. The precursor reagents are readily available and economical, and the reaction process used was mild and easily undertaken. Additionally, poly(methylhydrosiloxane), having an abundant source of pendant Si–H groups, can be cross-linked with eugenol at multiple juncture points, and thus the eugenol content in these films ranges from 13.12 to 45.42 wt%. It was found that as the eugenol content increased, the thermal stability of the films also improved, with T10% and Rw at 700 °C ranging from 350.1 to 584.3 °C and 46.41 to 86.63%, respectively, which is higher than other analogous biomass-derived polysiloxanes. Crucially, the prepared films also exhibited suitable optical properties, with a >90% transmittance within the 430–1100 nm region and near 100% absorbance in the UV region ( 1.5) LED encapsulants and also in stacked multi-layer reflectors. In addition, to protect the encapsulated chips from moisture erosion, these films exhibit good water vapour barrier properties and water repellence.

Due to the widespread use of electrical connectors while the lack of relevant in-depth theoretical models for contact states of them, this paper has investigated the electrical contact situations in contactor by establishing the theoretical model of a typical electrical connector-Subminiature version A (SMA), and used the finite element method (FEM) to analyze the actual contact state, including its contact potential distribution and the structural influence on resistance.

The charge stability of electret materials can directly affect the performance of electret-based devices such as electrostatic energy harvesters. In this paper, a spray-coating method is developed to deposit an electret layer with enhanced charge stability. The long-term stability of a spray-coated electret is investigated for 500 days and shows more stable performance than a spin-coated layer. A second-order linear model that includes both the surface charge and space charge is proposed to analyze the charge decay process of electrets in harsh environments at a high temperature (120 °C) and high humidity (99% RH); this model provides better accuracy than the traditional deep-trap model. To further verify the stability of the spray-coated electret, an electrostatic energy harvester is designed and fabricated with MEMS (micro-electromechanical systems) technology. The electret material can work as both the bonding interface and electret layer during fabrication. A maximum output power of 11.72 μW is harvested from a vibrating source at an acceleration of 28.5 m/s2. When the energy harvester with the spray-coated electret is exposed to a harsh environment (100 °C and 98% RH), an adequate amount of power can still be harvested even after 34 h and 48 h, respectively.

A method of predicting the thermal contact resistance (TCR) between indium and cap (copper) in semiconductor package by finite element simulation is presented in this paper. The effect of different interface pressures and surface roughness on the thermal contact resistance of the cap and indium interfaces contact was investigated. The deformation of the cap and indium under the interface pressure was analyzed by the finite element method. It was found that due to the low yield strength of indium, the small protrusions on the copper cap can be directly pressed into the indium, which increases the actual contact area and leads to the decrease in TCR. Moreover, larger surface roughness reduces the actual contact area and leads to the increase of TCR. Analysis shows that the reduction of TCR can be achieved by increasing the interfacial pressure or smoothing the contact surface.

A 1-decyl-2-methylimidazole (DMIm) functionalized poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) membrane is fabricated and employed to dope phosphoric acid (PA) for use as a high temperature proton exchange membrane. This kind of membrane displayed superior PA doping capability, but poor mechanical properties. In order to improve the dimensional and mechanical stabilities without sacrificing proton conductivities, a series of dual cross-linked membranes are prepared using the poly(styrene-vinylimidazole-divinylbenzene) (poly(St-VIm-DVB)) copolymer as a crosslinker. The reaction of vinylimidazole with benzyl bromide not only constructs a cross-linking network, but also endows the membranes with a PA doping capacity for proton conduction. The reticular polymer chain structure improves the mechanical properties of the membranes, especially at elevated temperatures. As an example, PPO-70%VIm-30%DMIm/180.1%PA achieves a high proton conductivity of 0.067 S cm−1 at 180 °C without humidification, while it displays suitable tensile strengths of 5.0 MPa and 2.1 MPa at room temperature and 120 °C, respectively. These membranes show great potential for use as an electrolyte in high temperature proton exchange membrane fuel cells.

Xenon (Xe) is a valuable and scarce noble gas used in various applications, including lighting, electronics, and anesthetics, among many others. It is also a volatile byproduct of the nuclear fission of uranium. A novel material architecture consisting of silicate nanocages in contact with a metal surface and an approach for trapping single Xe atoms in these cages is presented. The trapping is done at low Xe pressures and temperatures between 400 and 600 K, and the process is monitored in situ using synchrotron-based ambient pressure X-ray photoelectron spectroscopy. Release of the Xe from the cages occurs only when heating to temperatures above 750 K. A model that explains the experimental trapping kinetics is proposed and tested using Monte Carlo methods. Density functional theory calculations show activation energies for Xe exiting the cages consistent with experiments. This work can have significant implications in various fields, including Xe production, nuclear power, nuclear waste remediation, and nonproliferation of nuclear weapons. The results are also expected to apply to argon, krypton, and radon, opening an even more comprehensive range of applications.

Living organisms can sense extracellular forces via mechanosensitive ion channels, which change their channel conformations in response to external pressure and regulate ion transport through the cell membrane. Such pressure-regulated ion transport is critical for various biological processes, such as cellular turgor control and hearing in mammals, but has yet to be achieved in artificial systems using similar mechanisms. In this work, we construct a nanoconfinement by reversibly blocking a single nanopore with a nanoparticle and report anomalous and ultra-mechanosensitive ionic transport across the resulting nanoconfinement upon assorted mechanical and electrical stimuli. Our observation reveals a suppressed ion conduction through the system as the applied pressure increases, which imitates certain behaviors of stretch-inactivated ion channels in biological systems. Moreover, pressure-induced ionic current rectification is also observed despite the high ionic concentration of the solution. Using a combined experimental and simulation study, we correlate both phenomena to pressure-induced nanoparticle rotation and the resulting physical structure change in the blocked nanopore. This work presents a mechanosensitive nano-confinement requiring minimal fabrication techniques and provides new opportunities for bio-inspired nanofluidic applications.

In high-power white light emitting diode (LED) package, phosphor/silicone composite is generally used for luminosity and chromaticity conversion, but high-power white LED generates a lot of heat when working, and heat is dissipated into the environment through the LED light chip package. The material at the bottom of the chip is copper, which has good thermal conductivity. However, the top of the chip is wrapped by phosphor/silicone composite, so the thermal conductivity of the phosphor/silicone composite material has a great influence on the heat dissipation capability of the LED device. Phosphor/silicone composite with good thermal conductivity improve the overall heat dissipation capability of LEDs. Therefore, it is of great significance to study the thermal conductivity of phosphor/silica gel composites. In this paper, the thermal conductivity of phosphor/silicone composites was analyzed by finite element simulation, and the relationship between the mass fraction of phosphor and the thermal conductivity of composites was obtained. In addition, considering the existence of defects in the composite material, the pores are typical. The simulation results indicate that the thermal conductivity of the composites increases rapidly with the increase of phosphor mass fractions and decreases with the increase of porosity. The simulation results are consistent with the theoretical predictions.

The heat interface thermal resistance between the dielectric layer (Cu) and the barrier layer (Ti) in the Through-silicon via (TSV) are studied with molecular dynamics (MD) methods. The Cu/Ti interface thermal resistance is temperature dependent. Within the temperature from 293 K to 693 K, the resistance increases as the temperature rises. The increase in temperature causes an increase in atomic vacancy defects at the interface, and the interfacial voids degrade the heat transfer performance. However, when the temperature is higher than 693 K, the vacancies transfer from the interface to the second nearest or further neighbor on the adjacent atomic layers, which reduces the lattice mismatches at high temperatures. Besides, the single Ti atoms cross through the interface to match the Cu lattice vacancy when the temperature is higher than 693 K. As a result, interface thermal resistance decreases as temperature rises from 693 K to 1093 K.

Molecular Dynamics (MD) simulations are carried out to study the thinning mechanism of silicon wafer containing through silicon via (TSV) at different loading conditions. The nano-metric grinding process is explained by lattice slip and distortion induced by tool extrusion. When the grinding depth is relatively low, amorphous silicon will appear on the surface of the silicon. The nano-twin defects appear on the subsurface of the workpiece as the grinding depth reaches 1.5nm. We compared the depth of the defect at the Si-SiO2 interface and inside the silicon. The results show that the nano-twins extend to the interface leading to a deeper damage. Between 40 and 100m/s, increasing the grinding speed can slightly reduce the depth of interface damage, while the defects inside the silicon are mainly affected by the grinding depth. Moreover, both normal and tangential force decrease with the increase of speed from 40 to 100m/s. The friction coefficient calculation results show that the larger the grinding depth, the larger the friction coefficient. Higher speeds reduce the friction coefficient of the diamond abrasive particles and the workpiece surface over the speed range from 40 to 100m/s. At last, the surface contact stress is calculated based on the actual contact surface. With the depth of 1.0nm, the contact stress is the largest, i.e. 11.99GPa.

The molecular dynamics model of wurtzite crystal structure GaN in nano-grinding was established using the Tersoff multi-body potential. The complete structure defect-free GaN model and the defect-containing GaN model were set for comparison. The MD model used hemispherical diamond abrasive grains as the grinding tool, and the micro-regular ensemble (NVE) was used in the grinding process. Additionally, the GaN grinding simulation results under different loading conditions (changing grinding speed, depth) were analyzed to study the changes of internal crystal structure and the evolution of crystal defects. The results show that there is a transition from wurtzite to zinc-blende in GaN during the grinding. Moreover, defects and grinding force increase as the depth of grinding increases. The grinding speed has no obvious influence on the grinding force. When the grinding distance reaches 15 nm, the grinding force decreases slightly with the increase of the speed.

To deal with serious environmental damage resulting from plastic packaging materials, biodegradable films using natural products have gained considerable attention. Here, we provide a simple, fast, and environmentally-friendly route to construct a biodegradable film using chitosan (CS), bacterial cellulose (BC), and curcumin (Cur). Composite films (CSn-BC-Cur) using CS with different molecular weights were investigated, and their water moisture content (MC), water solubility (WS), contact angle (CA), mechanical properties, barrier properties, and antioxidant properties were compared. The obtained films were characterized by SEM, XRD, and TGA. The results showed that chitosan with a higher molecular weight presented higher contact angles and mechanical properties, along with a lower moisture content, water vapor transmission rate, and oxygen transmission rate. Furthermore, when the composite film was placed in 95 % ethanol, it released active substances. The results suggest that these composite films can be used as promising materials for food packaging.

We used some archival data from the Fourier transform spectrometer (FTS) at the US National Solar Observatory to study the hyperfine structure (HFS) patterns of Co I and Co II, and determined the HFS constants of Co I and Co II. In total, HFS constants A for 36 levels of Co I from 0.00 to 60,262.463 cm−1 and for 61 levels of Co II from 11,651.277 to 85,876.271 cm−1 were determined, of which 33 results for Co I and 58 results for Co II are reported for the first time, as far as we know. Our study increased the total number of HFS constants A to over 333 for Co I and over 86 for Co II.

The main goal of the surface machining of gallium nitride (GaN) is to obtain higher removal rate and good surface quality. Thus, we attempted to investigate the impact of the one-dimension sinusoidal assistant vibration on the nano-grinding of GaN by molecular dynamics simulations. By the comparison between the vibration-assisted nano-grinding and the conventional nano-grinding, it is found that the grinding force of the vibration-assisted nano-grinding fluctuated periodically, and the flow field of the vibration-assisted nano-grinding around the diamond abrasive was changed by the assisting vibration. Furthermore, the GaN fluidity of the vibration with period of 20 ps was better than the other condition and had a thinner sub-surface damaged layer than the conventional nano-grinding. Although the final surface quality of the vibration-assisted nano-grinding was worse than the conventional nano-grinding, it was proven that the vibration-assisted nano-grinding achieved higher removal rate and acceptable quality simultaneously by the vibration-assisted nano-grinding.

A spray-coating method for cyclic olefin copolymer (COC) electret material with polystyrene (PS) nanoparticles is developed here. Compared with the traditional polymer electret materials, the COC electrets with PS nanoparticles achieved better surface charge stability when exposed to harsh environment at high humidity or high temperature. With the spray coating technique, they can easily control the thickness of the electret layer. The surface charge stability of the electret has been detailed studied with various concentrations of the nanoparticles. They have also applied the spray coated electret to electrostatic energy harvesting devices. The experiments confirmed that the energy harvesting devices can generate more stable power output using the spray coated electret with nanoparticles.

Low cost poly(epichlorohydrin) (PECH) was modified with imidazolium groups to prepare high temperature proton exchange membranes. Chloromethyl groups in the structure of the PECH benefit its modification with no need for highly toxic and carcinogenic chloromethylation reagents. Both methylimidazole (MeIm) and triethoxysilylpropyldihydroimidazole (SiIm) were used to carry out the SN2 nucleophilic substitution for grafting the imidazolium groups onto the PECH. Meanwhile crosslinking of the modified PECH was achieved by forming a crosslinked silane network via the hydrolysis reaction of SiIm in an acid medium. Moreover, porous poly(tetrafluoroethylene) (PTFE) was used as the membrane matrix to enhance the mechanical strength of the fabricated membranes. The obtained PECH–SiIm–MeIm/PTFE membranes displayed phosphoric acid doping capacities of 110–170 wt% with low volume swelling ratios of less than 120%. Anhydrous proton conductivities of 0.010–0.063 S cm−1 were reached at elevated temperatures of 100–180 °C by the membranes with adequate mechanical strength. Fuel cell tests demonstrated the technical feasibility of acid doped PECH–SiIm–MeIm/PTFE membranes for high temperature proton exchange membrane fuel cells.

This is the first report of successful potassium metal battery anode cycling with an aluminum-based rather than copper-based current collector. Dendrite-free plating/stripping is achieved through improved electrolyte wetting, employing an aluminum-powder-coated aluminum foil "Al@Al," without any modification of the support surface chemistry or electrolyte additives. The reservoir-free Al@Al half-cell is stable at 1000 cycles (1950 h) at 0.5 mA cm-2 , with 98.9% cycling Coulombic efficiency and 0.085 V overpotential. The pre-potassiated cell is stable through a wide current range, including 130 cycles (2600 min) at 3.0 mA cm-2 , with 0.178 V overpotential. Al@Al is fully wetted by a 4 m potassium bis(fluorosulfonyl)imide-dimethoxyethane electrolyte (θCA = 0°), producing a uniform solid electrolyte interphase (SEI) during the initial galvanostatic formation cycles. On planar aluminum foil with a nearly identical surface oxide, the electrolyte wets poorly (θCA = 52°). This correlates with coarse irregular SEI clumps at formation, 3D potassium islands with further SEI coarsening during plating/stripping, possibly dead potassium metal on stripped surfaces, and rapid failure. The electrochemical stability of Al@Al versus planar Al is not related to differences in potassiophilicity (nearly identical) as obtained from thermal wetting experiments. Planar Cu foils are also poorly electrolyte-wetted and become dendritic. The key fundamental takeaway is that the incomplete electrolyte wetting of collectors results in early onset of SEI instability and dendrites.

Silicon carbide (SiC), especially 4H-SiC, is an ideal semiconductor in power electronics due to its outstanding electrical and thermal properties. It has high hardness and brittleness, which makes it difficult to machine. To understand the nanomachining characteristics of off-axis 4H-SiC and provide suggestions on 4H-SiC substrate thinning, the nanocutting process of 4 ∘ off-axis 4H-SiC was simulated by molecular dynamics. The results showed that the stacking fault induced by cutting propagates in the basal plane, and propagates deep into the SiC workpiece when the angle between the cutting direction and the c-axis is smaller than 90 ∘ . Bond reconstruction is found near the slip plane. The cutting depth is also a key parameter in nanocutting. With smaller cutting depth, machining is more like scratching than cutting. With larger cutting depth, more atoms are involved in the cutting, cutting force and workpiece temperature are higher, and more defects exist.

Silicon carbide (SiC) is gradually entering into commercialization as one of the next-gen semiconductor materials. In order to improve its yield and quality, it is important to understand its nanometric grinding mechanism. Silicon (Si) has been used in semiconductor industry for several decades, and its nanometric machining mechanism has been widely studied. However, the machining mechanism of Si can't be directly applied to SiC due to the differences in their physical properties. In this paper, nanometric grinding simulations of monocrystalline Si, 4H-SiC, and 6H-SiC have been performed by molecular dynamics. Rigid and dynamic cutting tool models have been applied and assessed. The results show that rigid cutting tool model can be applied to the simulations of Si for simplicity and dynamic cutting tool model is more appropriate for the simulations of SiC. Grinding force of SiC is much larger than that of Si, and the difference in grinding force between 4H-SiC and 6H-SiC is small.

Long-term stability is desired for developing high temperature proton conducting membranes as electrolytes for clean energy conversion of fuel cells. To understand the correlation of the grafted imidazolium structure and the stability of the polymer, six kinds of imidazolium polysulfones were synthesized from various imidazole compounds and the chloromethylated polysulfone, as proved by 1H NMR and FT-IR spectra. Membranes with electron-withdrawing or long hydrophobic alkyl groups in the imidazolium pendants exhibited higher chemical stability than those with electron-donating short alkyl groups. After doping with phosphoric acid, the imidazolium polysulfone membranes showed acid doping levels of 8.2–13.0. The membrane with a long tail side-chain of decyl in the imidazolium pendant achieved the highest conductivity of 0.038 S cm−1 at 160 °C without humidifying. Based on this membrane, fuel cell tests demonstrated the technical feasibility as the high temperature proton exchange membrane electrolyte in fuel cells.

Covalently cross-linked hexafluoropropylidene polybenzimidazole (F 6 PBI) was prepared and used to fabricate high temperature proton exchange membranes with enhanced mechanical strength against thermoplastic distortion. Three different epoxides, i.e. bisphenol A diglycidyl ether (R 1 ), bisphenol A propoxylate diglycidyl ether (R 2 ) and poly(ethylene glycol) diglycidyl ether (R 3 ), were chosen as the cross-linkers to investigate the influence of their structures on the properties of the cross-linked F 6 PBI membranes. All the cross-linked F 6 PBI membranes displayed excellent stability towards the radical oxidation. Comparing with the pure F 6 PBI membrane, the cross-linked F 6 PBI membranes showed high acid doping level but less swelling after doping phosphoric acid at elevated temperatures. The mechanical strength at 130 °C was improved from 0.4 MPa for F 6 PBI membrane to a range of 0.8–2.0 MPa for the cross-linked F 6 PBI membranes with an acid doping level as high as around 14, especially for that crosslinking with the epoxide (R 3 ), which has a long linear structure of alkyl ether. The proton conductivity of the cross-linked membranes was increased accordingly due to the high acid doping levels. Fuel cell tests demonstrated the technical feasibility of the acid doped cross-linked F 6 PBI membranes for high temperature proton exchange membrane fuel cells.

Simultaneously improving the proton conductivity and mechanical properties of a polymer electrolyte, especially to phosphoric acid doped membranes, is a challenge for the preparation of membrane materials in application in proton exchange membrane fuel cells. We prepared a novel composite membrane by introducing triazole functionalized graphene oxide into the polybenzimidazole for use as a high temperature proton exchange membrane. Increases in both proton conductivity and tensile strength were achieved by the composite membrane compared with the pure PBI membrane after doping with phosphoric acid. The triazole modified graphene oxide could disperse well in the polar organic solvent, which resulted in easy fabrication of the homogeneous membranes. The proposed material is a demonstration for designing and preparing inorganic composite polymer electrolytes with superior properties.

Matrix metalloproteinases (MMPs), mostly abundant in the tumor extracellular matrix (ECM), tumor cells, and tumor vasculatures, are closely correlated with tumor progression and metastasis. In this case, making use of MMPs was supposed to achieve site-specific drug delivery and a satisfactory tumor treatment effect. Herein, we rationally developed a novel tumor microenvironment and tumor cell dual-targeting nanoparticle by integrating a chemotherapeutic-loaded drug-loaded carrier and a versatile polypeptide-LinTT1-PVGLIG-TAT (LPT) which is composed of a multitargeting peptide-LinTT1 and a cell-penetrating peptide-TAT. The functionalized nanoparticles exhibited a superior affinity to A549 lung-cancer cells and microenvironment including angiogenesis and tumor-associated macrophages (TAMs) in our study. In addition, cellular experiments demonstrated that the cell-penetrating ability of TAT was significantly shielded by the addition of LinTT1 to the fourth lysine of the TAT via an MMP cleavable linker PVGLIG and could be recovered under the catalysis of MMPs. This design was supposed to efficiently decrease the toxicological risk to normal tissues induced by the unselectivity of TAT. The finally treatment effect investigation showed that tumor-bearing mice treated with LPT-modified nanoparticles achieved an enhanced efficacy for inhibiting tumor growth and the longest survival time as compared to other groups. Collectively, this study provides a novel robust nanoplatform which could simultaneously target the tumor microenvironment and tumor cell drug delivery for increasing the efficacy of cancer therapy.

This paper presents the design and measurement of electrostatic energy harvesting. A spray coated electret based electrostatic energy harvester with out-of-plane gap closing scheme is fabricated using advanced MEMS technology. The size of this device is 13×18 mm2. With the matched resistance of 21 MΩ, an output power of 12 μW is harvested when the resonant frequency is 154 Hz under the acceleration of 28.5 m/s2. The thermal stability of this device is tested on 100 °C, decent power can be output after 34 hours.

The novel phenylenedisilane, 1,4-bis(dimethoxyphenylsilyl)benzene (BDMPD), was successfully synthesized via the reaction between trimethoxyphenylsilane (TMPS) and a Grignard reagent originating from 1,4-dibromobenzene. In comparison to common Grignard reactions, this process was a facile one-pot method. 1H NMR spectroscopy, FT-IR measurements, and elemental analysis confirmed the predicted structure of BDMPD. In addition, vinyl-terminated polysiloxanes containing silphenylene units (VPSSP), which were hydrolytically copolymerized from BDMPD, TMPS, and divinyltetramethyldisiloxane, exhibited excellent thermal stabilities (T10%: 502 &deg, C, Rw%: 76.86 beyond 700 &deg, C) and suitable refractive indices (1.542). Furthermore, water contact angle and water vapor permeability tests confirmed that the fully cured siloxane resins containing VPSSP-based silphenylene units exhibited strong hydrophobicity (water contact angle: 119&deg, ) and superior water vapor barrier properties, thereby indicating their potential to serve as strong waterproof coatings for moisture-proof applications or as adhesives for use in immersed equipment.

In this paper, we propose an electrostatic energy harvester with an out-of-the-plane gap closing scheme. Using advanced MEMS technology, two components of the energy harvesting device are fabricated from two silicon wafers. A spray coated CYTOP polymer is used both as an electrets material and an adhesive layer for low temperature wafer bonding. The overall size of the device is about 13 × 18 mm2. With an external load resistance of 16 MΩ, a power output of 4.04 μW is achieved when vibration amplitude of 1g (∼9.9 m/s2) is applied at the resonant frequency of 155.8 Hz. The frequency response of the device is characterized and broader bandwidth is observed at higher acceleration amplitude due to the squeezed air damping. The response on random vibrations is also tested. An average power output of 2.22 μW is harvested when vibration is applied at random frequency in a range of 160 ± 12.5 Hz with RMS acceleration of 10.5 m/s2.

In this paper, we have proposed a spray coating method for electret material deposition. With this method, the thickness of electret can be well controlled and the surface potential of the charged electret can be improved comparing to the traditional spin coated polymer electrets. Furthermore, we have added some polystyrene nano particles into the electret, which can improve the surface charge stability of the electret at high temperature or in high humidity environment. We have also confirmed that our new electret could be used in the energy harvesting devices and may have promising applications on other MEMS devices.

Two silane compounds, i.e., ((chloromethyl)phenylethyl)trimethoxysilane (Ph-Si) and 3-chloropropyltriethoxysilane (Pr-Si), are employed as covalent crosslinkers to fabricate high temperature proton exchange membranes based on polybenzimidazole (PBI) in order to better understand the correlation between the structure and the property of the crosslinked membranes. All the crosslinked PBI membranes display longer morphology durability over the neat PBI membrane toward the radical oxidation. The crosslinked membranes with the crosslinker containing a rigid group of phenylene (PBI-Ph) show superior acid doping level, high conductivity, and excellent mechanical strength simultaneously, comparing to those with the crosslinker having a flexible alkyl chain (PBI-Pr) and the pristine PBI based membrane. The technical feasibility for using as high temperature proton exchange membranes is demonstrated by the acid doped crosslinked PBI-Ph membranes via fuel cell tests.

Lysozyme-like proteins (LYZLs) belong to the c-type lysozyme/α-lactalbumin family and are selectively expressed in the mammalian male reproductive tract. Two members, human sperm lysozyme-like protein (SLLP) -1 and mouse LYZL4, have been reported to contribute to fertilization but show no bacteriolytic activity. Here, we focused on the possible contribution of LYZL6 to immunity and fertilization. In humans, LYZL6 was selectively expressed by the testis and epididymis and became concentrated on spermatozoa. Native LYZL6 isolated from sperm extracts exhibited bacteriolytic activity against Micrococcus lysodeikticus. Recombinant LYZL6 (rLYZL6) reached its peak activity at pH 5.6 and 15 mM of Na+, and could inhibit the growth of Gram-positive, but not Gram-negative bacteria. Nevertheless, the bacteriolytic activity of rLYZL6 proved to be much lower than that of human lysozyme under physiological conditions. Immunodetection with a specific antiserum localized the LYZL6 protein on the postacrosomal membrane of mature spermatozoa. Immunoneutralization of LYZL6 significantly decreased the numbers of human spermatozoa fused with zona-free hamster eggs in a dose-dependent manner in vitro. Thus, we report here for the first time that LYZL6, an acidic, bacteriolytic and human sperm-related protein, is likely important for fertilization but not for the innate immunity of the male reproductive tract.

Polycrystals of stoichiometric Ni3Ai are brittle in air at room temperature, at least at strain rates from 10-4 s-1 to 7 s-1. This is indicative of intrinsic brittle behavior. Nickel-rich (Ni24A1) polycrystals, on the other hand, undergo a brittle-to-ductile transition upon raising the strain rate to above about 10-2 s-1. It is argued that the transition reflects the suppression of environmental embrittlement, not of the intermetallic per se but of a Ni-rich solid solution that decorates the grain boundaries of the off-stoichiometric alloy.

The notch-tip deformation field of Ni3AI single crystals doped with boron is characterized by fan-shaped sectors within which one slip system dominates. Cracks initiate and propagate along slip planes on both sides of the notch plane.

Amidst the recent progress in improving the ductility of intermetallic compounds, another problem is beginning to emerge; viz., the degradation of both ductility and strength by a notch. The problem is important because, from a practical point of view, notches in other than laboratory specimens are difficult to avoid. They may even be part of the design. Here, the notch-sensitivity of the ductile L1{sub 2} aluminides Ni-rich Ni{sub 3}Al doped with boron and Zr{sub 3}Al is attributed to the triaxial tensile state of stress induced by a notch.

Tensile tests have been carried out on notched Ni3Al(B) specimens with different thickness/width ratios. The result indicate a transition in the fracture mode upon increasing the specimen thickness, from ductile transgranular to intergranular fracture. Experiments at high strain rates show that the transition cannot be explained in terms of the strain rate at the root of the notch. Rather, it is explained in terms of an increasing degree of triaxiality of the stress state.