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Light-driven carbon dioxide (CO2) capture and utilization is one of the most fundamental reactions in Nature. Herein, we report the first visible-light-driven photocatalyst-free hydrocarboxylation ...

Over the past decades, organometallic complexes with precious elements, such as ruthenium and iridium, are widely used as visible-light photoredox catalysts. Recently, more and more complexes based on earth-abundant and inexpensive elements have been used as sensitizers in photochemistry. Although the photoexcited state lifetimes of iron complexes are typically shorter than those of traditional photosensitizers, the utilization of iron catalysts in photochemistry has sprung up owing to their abundance, low price, nontoxicity, and novel properties, including exhibiting ligand to metal charge transfer states. This concept focuses on recent advances in light-driven iron catalysis in organic transformations, including iron/photoredox dual catalysis, light-induced iron photoredox catalysis and light-induced generation of active iron catalysts. The prospect for the future of this field is also discussed.

Herein we report a novel visible-light-mediated external reductant-free reductive cross coupling for the construction of C sp2 – C sp3 bonds. A variety of benzylammonium salts underwent selective coupling with (hetero)aryl nitriles to deliver important diarylmethanes under mild reaction conditions. Importantly, photocatalysts can be omitted for many cases, which might involve the electron donor acceptor (EDA) complex. Mechanistic studies indicated benzylic radicals might be involved as the key intermediates. Moreover, the in situ generated NMe3 via cleavage of C–N bond in ammonium salts acts as the electron donor, thus avoiding the use of external-reductant.

Background The less volatile fraction of perfumes is susceptible to contamination by phthalate esters (PAEs), which are endocrine-disrupting chemicals encountered during the production, bottling, and transportation processes. There is a need to establish an innovative and rapid method for the determination of trace PAEs in commercial perfumes. Objective Therefore, self-built spray-inlet microwave plasma torch (MPT) ionization coupled with quadrupole time-of-flight (QTOF) tandem MS (MS/MS) was developed for the direct analysis of PAEs in perfumes without sample pretreatment. Methods Perfumes were sprayed directly onto the flame of the MPT by means of a sampling pump at a rate of 10 µL/min and the ions produced by the MPT were introduced into the QTOF-MS equipment with the MPT operating at 2450 MHz and 40 W at a flow rate of 800 ml/min of argon. Results For the established method, excellent linearity was obtained with a correlation coefficient of 0.9799 for di-n-pentyl phthalate and of greater than 0.99 for the other substances tested. The LOD and LOQ obtained were in the ranges of 1.452–18.96 and 4.839–63.19 ng/g, respectively. The spiked recoveries of PAEs ranged from 100.1 to 105.2% with satisfactory intraday RSDs and interday RSDs ranging from 1.51 to 4.34% and 3.45 to 5.65%, respectively. PAEs in commercial perfumes were successfully detected by spray-inlet MPT-MS/MS with low concentrations ranging from 0.036 to 1.352 µg/g. Conclusions The method is a promising tool for the on-site analysis of PAEs in cosmetic solutions requiring rapid qualitative and quantitative analysis. Highlights The method was successfully applied to the analysis of the commercial perfume samples within 30 s, and displayed the merits of simplicity, sensitivity, environmental friendliness and ease of operation.

Diode trigger SCR (DTSCR) structure is introduced in FinFET technology for low voltage circuit ESD protection. The current direction is chosen to flow vertically down through the fins to make full use of the bulk silicon region. Further optimization of DTSCR is investigated to improve layout efficiency.

Late expression factor 3 (LEF3) is a single-stranded DNA binding protein of Bombyx mori nucleopolyhedrovirus (BmNPV) with multiple functions. It is an essential factor for viral DNA replication and plays an important regulatory role during BmNPV infection. Our recent quantitative analysis of protein acetylome revealed for the first time that LEF3 can be acetylated at four lysine residues during the viral infection, but the underlying mechanism is unknown. Among the modification sites, two of them (K18 and K27) are located in the conserved nuclear localization sequence region. The acetylation level for K18 especially was up-regulated approximately 7.4 times after 36 h of post-infection. To understand the regulatory function of this modification, site-direct mutagenesis for acetylated mimic (K18Q) or deacetylated mimic (K18R) mutants was performed on LEF3. The fluorescence analysis results showed that the replication capacity of the virus was significantly reduced after K18 acetylation. Meanwhile, co-localization analysis revealed that acetylation at K18 caused LEF3 to lose its nuclear targeting ability and affected the interaction between LEF3 and P143, retaining P143 in the cytoplasm. And further Yeast two-hybrid analysis results also confirmed that the acetylation at K18 did affect the interaction between LEF3 and P143. In conclusion, the acetylation of LEF3 at K18 might act as one of the antiviral strategies for silkworm host by affecting nuclear localization of LEF3, interaction with P143, and then blocking viral replication.

Drug resistance in bacteria is becoming a significant threat to global public health, and the development of novel and efficient antibacterial compounds is urgently needed. Recently, rhodium complexes have attracted attention as antimicrobial agents, yet their antibacterial mechanism remains unknown. In this study, we observed that the dirhodium (II) complex Rh2Ac4 inhibited Streptococcus. pneumoniae growth without significant cytotoxic side-effects on host cells in vitro. We subsequently investigated the antibacterial mechanism of Rh2Ac4 using iTRAQ-based proteomics combined with cellular and biochemical assays. Bioinformatics analysis on the proteomic alterations demonstrated that six molecular functional groups, including metal ion binding and twelve metabolic pathways, were significantly affected after treatment with Rh2Ac4. The interaction network analysis of metal ion binding proteins suggested that Rh2Ac4 decreased the protein expression levels of SPD_1652, SPD_1590 and Gap, which are associated with haem uptake/metabolism. Cellular and biochemical assays further confirmed that Rh2Ac4 could be taken up by bacteria via the PiuABCD haem-uptake system. The structurally similar Rh complex may compete with Fe-haem to decrease Fe-uptake via the PiuABCD system, disrupting iron metabolism to exert its antibacterial activity against S. pneumoniae. These data indicate that Rh2Ac4 is a promising new drug for the treatment of S. pneumoniae infections.

Activated carbons have been prepared by phosphoric acid activation of lignocellulosic precursors, an industrial method, followed by heat treatment in ammonia. Thus, a cost-effective, scalable and metal-free electrocatalyst was developed for use in oxygen reduction reaction (ORR) at fuel cell cathodes. The physicochemical properties of the activated carbons have been analyzed by elemental analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and nitrogen adsorption. The ORR electrocatalytic performances of the activated carbons have been investigated by cyclic voltammetry and linear sweep voltammetry in an alkaline electrolyte. The results showed that phosphorus-containing groups are key to endowing phosphoric-acid-activated carbons with comparable electrocatalytic activity to that of commercial Pt/C. This was because these phosphorus-containing groups facilitated the formation of both nitrogen-containing groups and defects in the microstructure. Besides, heat treatment of phosphoric-acid-activated carbons in ammonia produced a highly developed mesopore structure and thus kinetically facilitated the ORR.

The demand for insulating polymeric composites with high thermal conductivity has increased remarkably for electronic packaging. Since polymers usually suffer from low thermal conductivity, boron nitrides (BN) are emerging as advanced fillers in polymeric composites. BN nanomaterials strikingly reinforce thermal conductivity of polymers and simultaneously improve insulation, thermal expansion, and dielectricity. We herein introduce diverse BN nanomaterials and summarize the progress about thermal conductive composites with various BN fillers from 0D BN particles via 1D nanotubes to 2D nanosheets. 3D fillers, multi-scale and multi-dimensional mixed BN fillers developed recently are also presented. The functionalization and the controlled orientation of fillers are reviewed, and current challenges towards higher thermal conductivity of BN/polymer composites are additionally discussed.

Silkworm (Bombyx mori) is a model organism with great agricultural economic value that plays a crucial role in biological studies. B. mori nucleopolyhedrovirus (BmNPV) is a major viral pathogen found in silkworms, which leads to huge silk loss annually. In a recent lysine acetylome of silkworm infected with BmNPV, we focused on the heat shock cognate protein 70-4 (HSC70-4) lysine acetylation change due to the consequent nuclear accumulation and viral structure assembly. In this study, the genome replication, proliferation, and production of budded viruses (BVs) were arrested by HSP/HSC70 inhibitor treatment. However, HSC70-4 overexpression enhanced BmNPV reproduction. Furthermore, site-direct mutagenesis for acetylated mimic (K/Q) or deacetylated mimic (K/R) mutants of HSC70-4 demonstrated that lysine 77 (K77) deacetylation promotes HSC70-4 stability, viral DNA duplication, and HSC70-4 nuclear entry upon BmNPV challenge, and the nuclear propulsion of HSC70-4 after viral stimulus might be dependent on the interaction with the carboxyl terminus of HSC70-interacting protein (CHIP, an E3 ubiquitin ligase), followed by ubiquitin-proteasome system assistance. In this study, single lysine 77 deacetylation of HSC70-4 was deemed a part of the locomotive pathway for facilitating BmNPV proliferation and provided novel insights into the antiviral strategic development.

A predictive ESD TCAD deck including the workflow is developed for the 12nm FinFET technology. ESD failure in the I/O FET and ESDNFET is analyzed through TCAD simulation with calibrated silicon fin dimension-dependent thermal conductivity.

For Rh2-organic molecular wires, we found that weaker coupling systems built using longer bridging ligands exhibit better electrical conductance., Layer-by-layer assembly of the dirhodium complex [Rh2(O2CCH3)4] (Rh2) with linear N,N′-bidentate ligands pyrazine (LS) or 1,2-bis(4-pyridyl)ethene (LL) on a gold substrate has developed two series of redox active molecular wires, (Rh2LS)n@Au and (Rh2LL)n@Au (n = 1–6). By controlling the number of assembling cycles, the molecular wires in the two series vary systematically in length, as characterized by UV-vis spectroscopy, cyclic voltammetry and atomic force microscopy. The current–voltage characteristics recorded by conductive probe atomic force microscopy indicate a mechanistic transition for charge transport from voltage-driven to electrical field-driven in wires with n = 4, irrespective of the nature and length of the wires. Whilst weak length dependence of electrical resistance is observed for both series, (Rh2LL)n@Au wires exhibit smaller distance attenuation factors (β) in both the tunneling (β = 0.044 Å–1) and hopping (β = 0.003 Å–1) regimes, although in (Rh2LS)n@Au the electronic coupling between the adjacent Rh2 centers is stronger. DFT calculations reveal that these wires have a π-conjugated molecular backbone established through π(Rh2)–π(L) orbital interactions, and (Rh2LL)n@Au has a smaller energy gap between the filled π*(Rh2) and the empty π*(L) orbitals. Thus, for (Rh2LL)n@Au, electron hopping across the bridge is facilitated by the decreased metal to ligand charge transfer gap, while in (Rh2LS)n@Au the hopping pathway is disfavored likely due to the increased Coulomb repulsion. On this basis, we propose that the super-exchange tunneling and the underlying incoherent hopping are the dominant charge transport mechanisms for shorter (n ≤ 4) and longer (n > 4) wires, respectively, and the Rh2L subunits in mixed-valence states alternately arranged along the wire serve as the hopping sites.

Obtaining a high-performance nonprecious electrocatalyst for oxygen and hydrogen evolution reactions (OER and HER) under mild conditions is highly desirable yet challenging. Transition metal nitrides are emerging as cost-effective substitutes for state-of-the-art noble metal based catalysts, but large OER overpotentials plague these nitrides. Herein, we developed the heterostructure of CoO-domain-anchored Co4N nanowhiskers as an effective bifunctional electrocatalyst for both OER and HER in neutral media. The exterior CoO targets OER, and the CO4N matrix is active for HER. The periodically-aligned {111} crystalline planes between Co4N and CoO provide good electron transport through their interface. The heterostructure performs dual functions of elevating activity and diminishing interior resistance of the catalyst. Moreover, the porous metallic Co4N nanowhiskers were integrated on a nickel foam, and this configuration contributes an arterial channel for collecting current as well as a spacious surface area for increasing the reaction cross section for heterocatalysis. These advantages actuate our bifunctional 3D catalytic electrode to achieve low OER and HER overpotentials in neutral systems. It finally provides an unprecedentedly low cell voltage (1.79 V for 10 mA cm−2) for catalyzing overall water splitting in neutral media.

Disclosed herein is a versatile and practical strategy for catalytic radical dearomatization. By means of this strategy, we realized the trifluoromethylative dearomatization of indoles and furans with CO2 via Cu catalysis. We also demonstrated the dearomatization of indoles with C-3 C–O bond formation to generate spirocyclic indolines. A variety of important CF3-containing spirocyclic indolines and spiroacetals can be synthesized with atmospheric CO2 under mild reaction conditions. Moreover, these multicomponent reactions feature high selectivity, good functional group tolerance, broad substrate scope, and easy scalability. Further theoretical investigation indicates that this transformation starts with deprotonation of the amine and CO2 insertion, after which CF3· radical addition to the indole followed by intramolecular C–O coupling affords the oxazolidone product.

The first thiocarboxylation of styrenes and acrylates with CO2 was realized by using visible light as a driving force and catalytic iron salts as promoters. A variety of important β-thioacids were obtained in high yields. This multicomponent reaction proceeds in an atom- and redox-economical manner with broad substrate scope under mild reaction conditions. Notably, high regio-, chemo-, and diasteroselectivity are observed. Mechanistic studies indicate that a radical pathway can account for the unusual regioselectivity.

Using first-principles calculations, the activation of the metal clusters (Mx = Ni6, Co6, Fe6) and clusters on graphene for ammonia decomposition was investigated. It is found that the Ni6 cluster on graphene is more active for the NH3 adsorption and dissociation, and for the most important steps of ammonia decomposition, namely the initial cleavage of the NH2 − H bond, the migration of N and the N + N recombination, they are all easier to perform on the graphene-supported Ni6 catalyst than that on the Ni6 cluster, the energy barriers are reduced from 1.29 eV, 0.92 eV, 2.25 eV to 1.11 eV, 0.41 eV, 1.47 eV, respectively. This study provides new insights into the potential applications of a cheap metal-based catalysts functionalized by graphene for the current reaction.

The transition-metal-free lactonization of heteroaryl and alkenyl C–H bonds with carbon dioxide is reported to synthesize important coumarin derivatives in moderate to excellent yields. These redox-neutral reactions feature a broad substrate scope, good functional group tolerance, facile scalability, and easy product derivatization.

Fluorescent carbon quantum dots (CQDs) were synthesized using polyethylene glycol (PEG) as both the carbon source and solvent in various atmospheres including air, nitrogen, carbon dioxide and oxygen by following a microwave irradiation method. The CQDs were characterized by performing ultraviolet-visible absorption spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and fluorescence spectroscopy. We found that different reaction atmospheres yielded significantly different reaction rates and properties of the CQDs. In particular, including oxygen in the synthesis of the CQDs clearly shortened the reaction time, significantly enhanced the photoluminescence (PL) intensity and quantum yield (PLQY) of the CQDs, and extended their average lifetime. The PLQY and fluorescence lifetime of the CQDs were improved from 5.78% and 2.4 ns, respectively, when synthesized in a medium open to air to 7.84% and 3.0 ns, respectively, when synthesized in an O2 atmosphere. The CQDs synthesized using microwave irradiation showed strong blue fluorescence under ultraviolet light.

In this work, N-doped reduced graphene oxides (NRGO) was synthesized via a facile urea-hydrothermal treatment of graphene oxide and used as support for ultrafine Pd nanoparticles (NPs). It was found that N in NRGO can improve the dispersion of Pd NPs. NRGO supported Pd catalyst (Pd/NRGO) is highly active and selective for the hydrogenation of CC bond in cinnamaldehyde and hydrogenation of phenol to cyclohexanone under mild conditions. X-ray diffraction, X-ray photoelectron spectra and transmission electron microscopy characterizations confirmed the interaction between NRGO and Pd enhanced with the amount of N atom in NRGO. Raman spectroscopy of adsorbed cinnamaldehyde on Pd/NRGO suggested that NRGO played a positive role in the selective activation of CC bond in cinnamaldehyde.

We present an ESD P-direction STI diode fabricated in an advanced bulk FinFET technology. The impact on process and design parameters are evaluated in detail. With design optimization, the ESD P-direction STI diode achieves 46% and 16% performance improvement for It2/C and It2/Area relative to the C-direction design.

Study the effects of different admixtures and different dosages on Basic Magnesium Sulfate Cement (BMS) composite sheets, the effects of sodium citrate and phosphoric acid on the flexural strength and compressive strength of basic magnesium sulfate cement sheets were studied, XRD and SEM were used to analyze the composition and microstructure of hydration products. The results show, the addition of admixtures has a great influence on the properties of composite sheets. Adding the corresponding proportion of admixture to the plate, the mechanical properties are significantly improved. Therefore, the properties of sheet metal can be greatly improved by choosing appropriate additives.

Magnesium oxysulfide cement (MOS) is an emerging building material. The application of MOS in practical engineering is affected by the low mechanical properties, which can now be modified by some admixtures. In this paper, the mechanical properties and hydration heat release of citric acid (CA)-modified MOS were studied, and the phase composition and microstructure of hydration products were analyzed by SEM and XRD. The results show that the addition of CA modified MOS can reduce MgO direct hydration of Mg(OH)2, promote the formation of a large number of needle-shaped 5Mg(OH)2 ·MgSO4·7H2O (5·1·7) phase crystals, and the compressive strength is greatly improved. When the CA dosage is 0.5%, the mechanics of MOS Best performance. The clotting time of the MOS modified with CA is slightly prolonged.

Adding different types and amounts of water reducing agent to Dolomite-based magnesium sulfate cement (DBMSC), and analysing the effect of water reducing agent on DBMSC by studying its setting time, water reduction effect and mechanical strength. on the one hand, Experimental results show that adding water reducing agent to DBMSC has a retarding effect on dolomitic magnesium sulfate cement, and reduces the hydration heat of cement; on the other hand, the water reduction effect of the water reducing agent on DBMSC prepared by light burning dolomite is not too obvious, and even the mechanical strength of DBMSC is lowered.

Silicon nitride (SiN) metal-insulator-metal capacitors (MIMCAPs) are components of most GaAs and GaN integrated circuits and integrated passive devices (IPD). To analyze the dielectric breakdown mechanisms and predict the lifetime of SiN MIMCAPs under electrostatic discharge (ESD) conditions, characteristics of MIMCAPs with different dimensions (dielectric thickness and area) and various ambient temperatures under ESD stresses are investigated. Measurements are conducted using the Barth 4002 transmission line pulse (TLP) system and the Signatone S1060 heating module. Then, the breakdown voltage variation of MIMCAPs with respect to dimensions and temperatures under different types of transmission line pulsing (TLP) stresses is discussed. Furthermore, with the transformative version of power law employed, the lifetime (time dependent dielectric breakdown, TDDB) of MIMCAPs is analyzed.

Defective rutile TiO2 (110) surfaces with one bridging-oxygen vacancy pair (OVP) and two next nearest neighbored bridging-oxygen vacancies belonging to the same row (NNN-OVs, i.e., two bridging-oxygen vacancies separated by a single oxygen atom) were studied using density functional theory (DFT) calculations. The results of a perfect surface and a defective surface with single bridging-oxygen vacancy (OV) were also shown. The reactivity of these surfaces was investigated by studying their interaction with a water molecule. Results show the NNN-OVs site is the most favorable site for water adsorption of two modes, molecular and dissociated adsorption, especially for dissociated adsorption. Upon dissociated adsorption on the NNN-OVs site, the whole system would release energy of 2.07 eV, much more than the energy released in any other site. It indicates the high reactivity of NNN-OVs as the best trap center. The 5-fold Ti sites show similar behaviors despite the existence of different defects. Adsorption on...

The interaction between methanol and the rutile TiO2 (1 1 0) surface with bridging oxygen-vacancy pairs (OVPs) defects is studied with DFT method. The OVP is the most stable site for adsorption of molecular methanol and dissociated fragments, but not the most active one for dissociation process since OVP exhibits slightly higher energy barrier than single bridging oxygen vacancy. In addition, the defect of OVP does not have significantly different influence on the adsorption structure and dissociation process of adsorbed methanol on 5-fold Ti atoms at diverse positions: close to the vacancy or a little further from the vacancy.

In this paper, characteristics of electrostatic discharge (ESD) protection devices operating under ESD stress and various ambient temperatures are investigated. The devices considered are a P +/NW diode and several silicon controlled rectifiers (SCRs) including Lateral SCR (LSCR), Modified Lateral SCR (MLSCR), No Snapback SCR (NS-SCR), Low Voltage Triggering SCR (LVTSCR), and P-Substrate Triggered SCR (PSTSCR) fabricated in a 0.35 μm BCD (Bipolar-CMOS-DMOS) technology. Measurements are conducted using the Barth 4002 transmission line pulse (TLP) tester and the Signatone S1060 heating module, and the TLP I–V characteristics are analyzed in details. TCAD simulation is carried out and underlying physical mechanisms related to the effect of temperature on key ESD parameters are provided.

Using calculations from first principles and harmonic transition state theory, we investigated the permeability of a single graphene sheet to protons and hydrogen atoms. Our results show that while protons can readily pass through a graphene sheet with a low tunneling barrier, for hydrogen atoms the barriers are substantially higher. At the same time, the presence of defects in the membrane can significantly reduce the penetration barrier in a region that extends beyond the defect site itself.

Using first-principles calculations we have studied the reactions of water over Ti adatoms on the (110) surface of rutile TiO(2). Our results provide fundamental insights into the microscopic mechanisms that drive this reaction at the atomic level and assess the possibility of using this system to activate the water dissociation reaction. In particular, we show that a single water molecule dissociates exothermically with a small energy barrier of 0.17 eV. After dissociation, both H(+) and OH(-) ions bind strongly to the Ti adatom, which serves as an effective reactive center on the TiO(2) surface. Finally, clustering of Ti adatoms does not improve the redox activity of the system and results in a slightly higher energy barrier for water dissociation.

A capacitance coupling complementation silicon controlled rectifies (CCCSCR) for electrostatic discharge (ESD) protection application is proposed and verified in 0.5µm BCD process. Compared with traditional complementation silicon controlled rectifies (CSCR), the CCCSCR has a lower trigger voltage. The coupling capacitance, as a tunable trigger of SCR, can meet different protection application demands. And the CCCSCR can fulfill all dual direction ESD stress mode protection, including I/O-VSS, I/O-VDD and VDD-VSS.

Activation of the Ti4 cluster on defective graphene for water adsorption and dissociation was investigated via density functional theory. Both the vacancy and the Ti cluster can promote the water dissociation reaction. The vacancy can efficiently enhance the adsorption of Ti atoms to stabilize the cluster. However, compared to the role of the vacancy, the cluster plays a more important role in activating water dissociation. A single water molecule and a second one can almost freely dissociate with (or without) a low barrier on the Ti4 cluster, the barriers are substantially lower than that on a single Ti atom. The Ti4 cluster decorated graphene is a promising candidate for activation of the dissociation of water molecules.