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The potential geographic distribution of Fagus longipetiolata and its climatic controls are studied, based on the maximum entropy (MaxEnt) model and actual geographic distribution data of F. longipetiolata, together with the climatic factors (annual precipitation, annual average daily minimum temperature, annual average daily maximum temperature, and annual solar radiation) reflecting the effects of solar radiation, heat and water resources on plant growth, as well as annual temperature range reflecting seasonal change. The results indicate that the MaxEnt model is suitable for simulating the geographic distribution of F. longipetiolata. The importance of the five factors and their thresholds of climatic adaptability are ranged as annual precipitation ( P > 770 mm) > annual average daily minimum temperature (7 °C < T < 20 °C) > annual temperature range (DTY < 23 °C) > annual average daily maximum temperature (16 °C < T) > annual solar radiation (1.10 × 10 W/m < Radi < 1.42 × 10 W/m). The general distribution area is controlled by precipitation. Specifically, the western distribution boundary of F. longipetiolata (in Gansu, Sichuan and Yunnan provinces) relies on both temperature and solar radiation, and its northern boundary in China (in Shaanxi, Hubei and Hunan provinces) depends on the seasonal change. [ABSTRACT FROM AUTHOR]

The article proposes a novel scheme for full-duplex radio-over-fiber transmissions with frequency-octupling millimeter-wave and wavelength reuse. In this scheme, the base station is simplified greatly as there is no laser, and the uplink millimeter-wave signal is down-converted to a low frequency using a 60-GHz local oscillator, which is optically obtained from the downlink signal. The scheme can utilize optical power efficiently, and thus, a cost-effective radio-over-fiber system is achieved. Transmission performance for both down- and uplink data are theoretically analyzed and investigated by simulation; results show that the performance of the system is not sensitive to fiber dispersion. [ABSTRACT FROM AUTHOR]

XueShuanTong (XST) comprising therapeutically active ginsenosides, a lyophilized extract of Panax notoginseng roots, is extensively used in traditional Chinese medicine to treat ischemic heart and cerebrovascular diseases. Our recent study shows that treatment with XST inhibits shear-induced thrombosis formation but the underlying mechanism remained unclear. This study aimed to investigate the hypothesis that XST inhibited shear-induced platelet aggregation via targeting the mechanosensitive Ca2+-permeable Piezo1 channel by performing platelet aggregation assay, Ca2+ imaging and Western blotting analysis. Exposure to shear at physiologically (1,000–2000 s−1) and pathologically related rates (4,000–6,000 s−1) induced platelet aggregation that was inhibited by treatment with GsMTx-4. Exposure to shear evoked robust Ca2+ responses in platelets that were inhibited by treatment with GsMTx-4 and conversely enhanced by treatment with Yoda1. Treatment with XST at a clinically relevant concentration (0.15 g L−1) potently inhibited shear-induced Ca2+ responses and platelet aggregation, without altering vWF-mediated platelet adhesion and rolling. Exposure to shear, while resulting in no effect on the calpain-2 expression in platelets, induced calpain-2-mediated cleavage of talin1 protein, which is known to be critical for platelet activation. Shear-induced activation of calpain-2 and cleavage of talin1 were attenuated by treatment with XST. Taken together, our results suggest that XST inhibits shear-induced platelet aggregation via targeting the Piezo1 channel to prevent Piezo1-mediated Ca2+ signaling and downstream calpain-2 and talin1 signal pathway, thus providing novel insights into the mechanism of the therapeutic action of XST on platelet aggregation and thrombosis formation. [ABSTRACT FROM AUTHOR]

MBIP is a component of the Ada2A containing complex (ATAC) and has been identified as a susceptibility gene in several cancers. However, the role and molecular mechanism of MBIP in esophageal squamous cell carcinoma (ESCC) remain unclear. Our finding indicated that the expression level of MBIP in ESCC was higher than that in normal tissue (P < 0.05) based on the data from the Cancer Gene Atlas (TCGA) and Gene Expression Omnibus (GEO). Kaplan-Meier analysis showed that high MBIP expression was closely associated with deeper invasion and worse prognosis. Transwell assay and mouse xenograft assay demonstrated that MBIP overexpression promoted migration and invasion in vitro and in vivo, while MBIP knockdown played the opposite role. Furthermore, the results of RNA-seq, qRT-PCR, western blotting and rescue experiments revealed that MBIP promoted epithelial-mesenchymal transition (EMT) via the phosphorylation JNK/p38 in ESCC. Our study indicates that MBIP plays a significant role in the prognosis and metastasis of ESCC, suggesting that MBIP might serve as an ESCC prognostic biomarker. • This paper firstly reports the expression level of MBIP in ESCC is higher than that in normal tissue. • High MBIP expression was associated with deeper invasion and worse prognosis. The effect of MBIP on ESCC metastasis was proven in vivo and in vitro. • MBIP promoted the EMT process in ESCC by activating the phosphorylation of JNK/p38 pathway. • MBIP may serve as a prognostic biomarker for ESCC and BIRB796 may offer theoretical evidence for drug selection in ESCC. [ABSTRACT FROM AUTHOR]

Currently, targeted alpha therapy (TAT) is a new therapy involving the administration of a therapeutic drug that combines a substance of α-emitting nuclides that kill cancer cells and a drug that selectively accumulates in cancer cells. It is known to be effective against cancers that are difficult to treat with existing methods, such as cancer cells that are widely spread throughout the whole body, and there are high expectations for its early clinical implementation. The nuclides for TAT, including 149Tb, 211At, 212/213Bi, 212Pb (for 212Bi), 223Ra, 225Ac, 226/227Th, and 230U, are known. However, some nuclides encounter problems with labeling methods and lack sufficient preclinical and clinical data. We labeled the compounds targeting prostate specific membrane antigen (PSMA) with 211At and 225Ac. PSMA is a molecule that has attracted attention as a theranostic target for prostate cancer, and several targeted radioligands have already shown therapeutic effects in patients. The results showed that 211At, which has a much shorter half-life, is no less cytotoxic than 225Ac. In 211At labeling, our group has also developed an original method (Shirakami Reaction). We have succeeded in obtaining a highly purified labeled product in a short timeframe using this method. [ABSTRACT FROM AUTHOR]

Targeted alpha therapy (TAT) has garnered significant interest as an innovative cancer therapy. Owing to their high energy and short range, achieving selective α-particle accumulation in target tumor cells is crucial for obtaining high potency without adverse effects. To meet this demand, we fabricated an innovative radiolabeled antibody, specifically designed to selectively deliver 211At (α-particle emitter) to the nuclei of cancer cells. The developed 211At-labeled antibody exhibited a superior effect compared to its conventional counterparts. This study paves the way for organelle-selective drug delivery. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation to methanol was conducted using a set of activated carbon-supported Cu/ZnO/Al2O3 catalysts (CCZA) prepared by an incipient wetness impregnation approach. The effect of the Cu/Al ratio on the physicochemical properties of the catalysts, as well as their catalytic performance, were investigated. As Cu/Al ratio increased, the metallic Cu surface area displayed a reducing trend from 6.88 to 4.18 m2∙gcat−1, while the CO2 adsorption capacity exhibited an increasing trend. Meanwhile, aluminum content will have an important effect on the catalysts' reducibility and, thus, on their catalytic performance. The CCZA-2.7-de catalyst demonstrated the highest selectivity to methanol at 83.75% due to the excellent distribution and synergistic effect of copper and zinc. Although the CO2 conversion of CCZA-2.2-de and CCZA-3.5-de exceeded 10%, the CH3OH selectivity was less than 60%, which may be attributed to the larger particle sizes of ZnO and poor interactions in Cu–Zn. The present study offers a novel approach to increase the number of active sites, optimize the activated carbon-aided Cu/ZnO/Al2O3 catalyst's composition, and finally elucidate the mechanism for CO2 hydrogenation to methanol. [ABSTRACT FROM AUTHOR]

Transition metal nitrides present superior electrocatalytic activities on the air electrode for fuel cells or metal-air batteries. Despite that, the weak intrinsic activity and ease of aggregation have hampered their catalytic kinetic properties and practical application. Herein, vanadium nitride (VN) particles of different sizes, micron to molecular level, have been fabricated using a facile, in-situ urea-nitridation method, and embedded in an N-doped graphitic carbon aerogel electrocatalyst (VN@CA), the doped material serving as an oxidation catalyst. Having a balance of atomic-level dispersed VN clusters and a high active site density, the obtained VN@CA catalytic material exhibits enhanced catalytic efficiency for the oxygen reduction reaction (ORR), the values of onset and half-wave voltages were measured to be 0.97 V and 0.90 V, respectively, compared to Pt/C (which had voltages of 0.95 V and 0.87 V). Furthermore, the assembled Zn-air battery using VN@CA as catalyst exhibits a high-power density of 176 mW cm−2, a substantial specific discharge capacity of 851 mAh g Zn −1 at 20 mA cm−2, a narrow gap between charging and discharging voltages (0.73 V at 50 mA cm−2), and an excellent charge-discharge cycling stability, exceeding 270 cycles with a 66 % round-trip efficiency. This work confirms that the particle size and the density both are responsible for the enhanced electrochemical activity. • Vanadium nitride (VN) particles with the sizes from micron to molecular level, have been fabricated using a facile method. • The active sites VN nanoparticles anchored on an N-doped graphitic carbon aerogel with a pore volume of 1.55 cm3 g−1. • The size evolution mechanism of VN nanoparticles is investigated. • The VN@CA catalyst as the air cathode in Zn-air batteries (ZABs) shows superior catalytic activities. [ABSTRACT FROM AUTHOR]

MoO 2 anode displays excellent potential in the alkali ion batteries owing to its large capacity, high conductivity and stability. However, exploiting the stable and high performance MoO 2 anode endowed with triple roles for the storage of lithium/sodium/potassium ions is still a challenge. Herein, a two-dimensional sheet-like MoO 2 /NPC@rGO composites were in-situ synthesized and utilized as anode materials for alkali metal ion batteries. Applied as an anode in lithium ion batteries (LIBs), superior cycling capability and rate performance were obtained, which kept a large reversible capacity of 1233.1 mAh/g in the 200th cycle at 100 mA/g. Impressively, it displayed superior long cycling performance over 1000 cycles with a 249.5 mAh/g capacity at a high current density of 10 A/g. Simultaneously, MoO 2 /NPC@rGO displayed enhanced electrochemical performance both in sodium and potassium ion batteries (NIBs/KIBs). Furthermore, the ex-situ X-ray photoelectron spectroscopy results verified the reversible reaction during Li+ insertion-extraction process. The improved energy storage properties were attributed to the typical two dimensional structure and synergistic effects between various constituents, which suppressed the volume change, created more active sites, increased the conductivity and facilitated reaction kinetics. More significantly, our design provides a simple and green route to synthesize transition metal oxide anode and promote their applications in energy storage devices. [Display omitted] • The in-situ method with the assistance of polyoxometalates provides a green route to synthesis transition metal-based anode. • The sheet-like structure ensures the uniform dispersion of MoO 2 nanoparticles, providing superior structure stability. • The ex-situ XPS results verifies the reversible reaction and conversion mechanisms during lithiation/delithiation process. [ABSTRACT FROM AUTHOR]

Panax notoginseng saponins (PNS) are the major effective components of Panax notoginseng (burk) F.H.Chen which is one of the classic promoting blood circulation herbs in traditional Chinese medicine. PNS is widely used in China for the treatment of cerebral ischemic stroke. Pathological low shear stress is a causal factor in endothelial inflammation and thrombosis. However, the mechanism of PNS against low shear related endothelial inflammation is still unclear. This study aims to investigate the effects of PNS against endothelial inflammation induced by low shear stress and to explore the underlying mechanical and biological mechanisms. Mouse model of carotid partial ligation for inducing low endothelial shear stress was established, the pharmacodynamic effect and mechanism of PNS against endothelial inflammation induced by low shear stress through Piezo1 were explored. Yoda1-evoked Piezo1 activation and expression in human umbilical vein endothelial cells (HUVECs) were determined at static condition. Microfluidic channel systems were used to apply shear stress on HUVECs and Piezo1 siRNA HUVECs to determine PECAM-1, p-YAP and VCAM-1 expression. And platelet rich plasma (PRP) was introduced to low shear treated endothelial cells surface to observe the adhesion and activation by fluorescence imaging and flowcytometry. PNS attenuated endothelial inflammation and improved blood flow in a reasonable dose response pattern in carotid partial ligation mouse model by influencing Piezo1 and PECAM-1 expression, while suppressing yes-associated protein (YAP) nuclear translocation. We found Piezo1 sensed abnormal shear stress and transduced these mechanical signals by different pathways in HUVECs, and PNS relieved endothelial inflammation induced by low shear stress through Piezo1. We also found Piezo1 signalling has interaction with PECAM-1 under low shear stress, which were involved in platelets adhesion to endothelial cells. Low shear stress increased YAP nuclear translocation and increased VCAM-1 expression in HUVECs which might activate platelets. PNS inhibited low shear induced Piezo1 and PECAM-1 expression and YAP nuclear translocation in HUVECs, furthermore inhibited platelet adhesion and activation on dysfunctional endothelial cells induced by low shear stress. PNS ameliorated endothelial inflammation and thrombosis induced by low shear stress through modulation of the Piezo1 channel, PECAM-1 expression, and YAP nuclear translocation. PNS might serve as a potential therapeutic candidate for ameliorating endothelial inflammation induced by abnormal blood shear stress. [Display omitted] • PNS attenuates endothelial inflammation and thrombosis induced by abnormal low shear stress. • PNS shows inhibitory effects on mechanosensitive Piezo1 channel under pathological shear flow. • PNS participates in the crosstalk between endothelial cells and platelets under low shear flow throughPiezo1/PECAM-1/YAP. [ABSTRACT FROM AUTHOR]

Classical prescriptions are not only a primary method of clinical treatment in traditional Chinese medicine (TCM) but also represent breakthroughs in the inheritance and development of this field. Kuntai capsule (KTC), a formulation based on a classical prescription, comprises six TCMs: Rehmanniae Radix Praeparata, Coptidis Rhizoma, Paeoniae Radix Alba, Scutellariae Radix, Asini Corii Colla, and Poria. This formulation possesses various beneficial effects, such as nourishing yin and blood, clearing heat and purging fire, and calming the nerves and relieving annoyance. The investigation of the efficacy and mechanism of KTC in regulating anti-aging factors in the treatment of premature ovarian insufficiency (POI) is not only a prominent topic in classical prescription research but also a crucial issue in the treatment of female reproductive aging using TCM. To evaluate the therapeutic effect of KTC on POI and its underlying mechanism. Healthy and specific pathogen-free (SPF) female Kunming mice aged 6–8 weeks were selected. After acclimatization, the mice were randomly divided into a control, model, and high, middle, and low dose groups of KTC (1.6, 0.8, and 0.4 mg/kg, respectively). Except for the control group, the animals in the other groups were administered a single intraperitoneal injection of 120 mg/kg cyclophosphamide and 30 mg/kg Busulfan to induce the model of POI. After modeling, the mice were treated with the corresponding drugs for 7 days. Serum and ovarian tissues were collected, and the levels of serum follicle-stimulating hormone (FSH), estradiol (E2), and superoxide dismutase 2 (SOD2) were determined using enzyme-linked immunosorbent assay (ELISA). The chemical composition of KTC was characterized and analyzed using ultra-high-pressure liquid chromatography-linear ion trap-Orbitrap tandem mass spectrometry. A "drug-component-target-pathway-disease" network was constructed using network pharmacology research methods to identify the key active components of KTC in treating POI and to elucidate its potential mechanism. The protein expression of the FOXO3/SIRT5 pathway was detected by western blotting. Compared to the model group, the high-dose group of KTC showed a significant increase in ovarian index, significant increase in levels of E2 and SOD2, and a significant decrease in FSH levels. Through systematic analysis of the chemical constituents of KTC, 69 compounds were identified, including 7 organic acids, 14 alkaloids, 28 flavonoids, 15 terpenoids, 2 lignans, 2 phenylpropanoids, and 1 sugar. Based on network pharmacology research methods, it was determined that KTC exerts its therapeutic effect on POI through multiple components (paeoniflorin and malic acid), multiple targets (FOXO3 and SIRT5), and multiple pathways (prolactin signaling pathway, longevity regulating pathway, and metabolic pathways). The accuracy of the network pharmacology prediction was further validated by detecting the protein expression of SIRT5 and FOXO3a, which showed a significant increase in the middle and high-dose groups of KTC compared to the model group. KTC may effectively treat POI through a multi-component, multi-target, multi-pathway approach, providing an experimental basis for using KTC based on classical prescriptions in the treatment of POI. [Display omitted] [ABSTRACT FROM AUTHOR]

• PAO/GH is prepared to enhance the uranium selectivity of graphene hydrogel. • PAO/GH is characterized by different methods. • The uranium selectivity and sorption capacity of PAO/GH increased obviously. • Uranium sorption mechanism by PAO/GH is revealed by various characterizations. • PAO/GH has relative high uranium sorption capacity in natural slain lake brine. In order to increase the selectivity of graphene hydrogel (GH) for uranium and ensure its possible application in uranium extraction from complicated systems, such as seawater and saline lake brines, GH with amidoxime groups needs to be prepared. However, it is not an easy task to grafting amidoxime groups on GH. At present work, an innovative method is used to fabricate the amidoximated graphene hydrogel, polyarylonitrile nanoparticle/graphene composite hydrogel (PAO/GH), through simultaneously encapsulating polyacrylonitrile (PAN) nanoparticles in hydrogel formation process and then amidoximation. The prepared adsorbent is characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and BET specific surface area analyses. All the results prove that PAO/GH with amidoxime groups is successfully obtained. The effects of initial solution pH, ionic strength, time and initial uranium concentration on uranium sorption by PAO/GH are studied systematically and compared with the blank graphene hydrogel (GH). The uranium selectivity of PAO/GH increases obviously after introducing amidoxime groups. Moreover, the mechanism of uranium sorption by PAO/GH is also explored with different characterization methods. Amidoxime groups are revealed to be the main functional groups involved in uranium sorption by PAO/GH and served as electron donor. Basis on the above results, uranium extraction from natural saline lake brine by PAO/GH is also performed and PAO/GH is testified to be a promising adsorbent for recovering uranium from complicated systems. [ABSTRACT FROM AUTHOR]

Optical mode switch is a crucial component for the mode-division multiplexing (MDM) system. In this paper, we demonstrate a thermo-optical (TO) mode-selective switch on silica-based planar lightwave circuit (PLC) platform. The 2 × 1 thermo-optical (TO) mode-selective switch based on Mach–Zehnder interferometer consists of an adiabatic coupler and a symmetric Y-branch. The input optical mode E 00 (E 10) is converted to E 10 (E 00) mode while the light is coupled from different input ports by changing the working state of heater. With 2% index-contrast, a compact mode switch on silica-based PLC platform is fabricated. According to experimental results, the fabricated mode-selective switch shows an insertion loss lower than 5 dB and a mode extinction ratio higher than 24 dB for two modes at 1550 nm. The crosstalk is lower than −10.54 dB from 1500 nm to 1600 nm. The power consumption for two modes are 433.24 mW and 440.15 mW, respectively. The rise time and fall time of the switch are 560. 9 μ s and 794. 8 μ s. • We demonstrate a thermo-optical (TO) mode-selective switch on the silica-based planar lightwave circuit (PLC) platform. • The input optical mode E00 (E10) is converted to E10 (E00) mode by changing the working state of heater. • The insertion loss lower than 5 dB and a mode extinction ratio higher than 24 dB for two modes at 1550 nm. • The fabricated mode switch holds great promise for future reconfigurable MDM systems. [ABSTRACT FROM AUTHOR]

Uranium carbide (UC) ceramic microspheres filled into a cladding are a potential nuclear fuel format for nuclear reactors. Uniform sized ceramic UC microspheres with a diameter of 675 ± 10 µm were successfully prepared by an improved microwave-assisted rapid internal gelation process combined with carbothermic reduction. First of all, the nanoparticle carbon was dispersed into the HMUR stock solution, and the C-UO 3 ·2H 2 O gelled microspheres were prepared using an improved microwave-assisted internal gelation process without cooling the initial stock solutions. Next, the gelled microspheres were subjected to a carbothermic reduction process to obtain ceramic UC microspheres. TG and XRD investigations indicated that the C-UO 3 ·2H 2 O microspheres were firstly reduced into UO 2 at a temperature of 700 °C, and were further converted into UC at 1500 °C in argon atmosphere. Crack-free ceramic UC microspheres with a smooth and metallic shiny surface were obtained at a sintering temperature of 1500 °C for 5 h with an initial C/U molar ratio of 3.5. [ABSTRACT FROM AUTHOR]

Single-photon emission computed tomography is a widely used modality based on single-photon detection of radionuclides. However, research still needs to be conducted on further increasing the image contrast. We recently proposed a novel method called double-photon emission coincidence imaging (DPECI) using the coincidence detection of two cascade gamma photons emitted from a radionuclide, such as 111In or 177Lu. Compared with single-photon detection, the coincidence detection of two gamma photons can be used to theoretically identify the position at a single point free of detector rotation and image reconstruction. In this study, we demonstrate DPECI using parallel-hole and slat collimators to improve detection efficiency and verify the feasibility of simultaneous imaging using 67Cu and 111ln. [ABSTRACT FROM AUTHOR]

The defect engineering is of vital importance for electrocatalysts because it can provide an additional yet advanced tier to further boost catalysis, especially for ultrathin nanosheets of transitional metal compounds with a high surface to bulk ratio and more importantly the ability to engineer the defect along the longitudinal direction of the grain boundaries. Herein, we developed super-thin and ordered face-centered cubic VN nanosheets with grain boundaries using a new facile and in-situ method. The structural and morphological properties of the prepared samples were investigated, finding that the temperature has significant effects on the distribution of sheets. The thickness of nanosheets is only 1.3 nm the same as that of three cubic VN crystal unit cells, which is pivotal to the electrochemical reaction. The detailed electrocatalysts results show that the VN nanosheets (NSs) exhibit interesting ORR performance with the onset potential of 0.93 V and a half-wave potential of 0.86 V. The evenly distributed VN NSs display the highest durability with only 5% attenuation after 50000s operation for the oxygen reduction reaction. We provide a new strategy to synthesize super-thin nitrides nanosheet structure, highlighting the strong correlation between surface engineering and the performance of electrocatalysts for potential practical oxygen reactions. • Highly active atomic-thin VN nanosheets anchored on layers of N-doped carbon are prepared by an in-situ and facile method. • The thickness of the atomic-thin VN nanosheets is only 1.3 nm the same as that of three VN unit cells. • The VN nanosheet is approximately tens of nanometers in size. • Our results give strong evidence to prove the correlation between the crystal plane of nanosheet and ORR performance. [ABSTRACT FROM AUTHOR]

ZIF/CN and Ni-contained ZIF/CN composite catalysts were successfully synthesized via two-step strategy. The physicochemical properties characterized by various methods indicated that the two composite catalysts possessed a higher surface area than as-prepared CN. Ni-ZIF/CN catalyst showed the beneficial effects on visible light absorption, electron-hole carrier generation, transfer and separation. The photocatalytic properties of the catalysts were examined via methyl orange (MO) degradation. Both of ZIF/CN and Ni-ZIF/CN exhibited the high decolorization rates above 99%, and the high reaction rate constant which is twice than that of CN. It can be concluded that ZIF-modified carbon nitride photocatalysts possess excellent photoelectrochemical properties and photocatalytic activity, giving a new pathway for modifying the band structures of materials to enhanced photocatalytic properties. [Display omitted] • Successful synthesis of Ni-contained ZIF by replacing part of Co with Ni. • Current density increasing over 45 times after the addition of Ni-component. • Synergistic effect between the photoelectric properties and adsorption. [ABSTRACT FROM AUTHOR]

• A 20 channel O-band AWG is designed and fabricated for high-speed communication system. • The SSC and parabolic taper structure are adopted to reduce the loss. • The flat-top spectrum is obtained by using multimode output waveguide. • 1 Tb/s or higher transmission capacity can be realized. A 20-channel 800 GHz spacing silica based arrayed waveguide grating (AWG) is designed and fabricated. We extend the wavelength allocation in IEEE 802.3bs from 8 channels to 20 channels in the O-band, which improves the transmission capacity of the chip to meet the increasing demand of network traffic. The insertion loss is less than 1.59 dB by adopting a spot-size converter (SSC). The polarization-dependent loss (PDL) is less than 0.3 dB at the center wavelength of each channel. With a flat-top of spectrum, 1 dB bandwidth is more than 2.8 nm, and the adjacent crosstalk is less than −20 dB. The transmission of 28.9 Gb/s NRZ and 57.8 Gb/s PAM4 signals in a single channel are successfully realized. [ABSTRACT FROM AUTHOR]

Exploring economically efficient electrocatalysts with robust oxygen reduction catalytic activities and developing appropriate structures are necessary to understand fuel cells with high open-circuit voltages and long lifespans. In this work, a high-performance ORR catalyst was prepared with a one-spot method by pyrolysis of a urea, FeCl 3 , and NaCl mixture. The surface element distribution was studied by XPS etching, showing the active sites ϵ-Fe 3 N with active Fe–N bonding. Benefiting from the double layer protection, in which the ϵ-Fe 3 N nanoparticles were covered by an N-doped carbon layer encapsulated in carbon bamboo-like nanotubes, the catalysts showed abnormal stability with 5000 cycles, a negative shift of only 15 mV by the CV test and a 3% attenuation after 60,000 s of operation. The onset potential is found to be 0.96 V, which is a positive shift of 12 mV compared to that of the state-of-the-art Pt/C catalyst. The ORR kinetic analysis indicates that the catalyst shows a Tafel slope of 82 mV decade−1 at high potential and 130 mV decade−1 at low potential close to that of the reference catalyst, suggesting a similar reaction mechanism. Therefore, successfully synthesized nonnoble electrocatalysts offer a novel strategy and promising candidates to promote the further development of clean energy devices. • ϵ-Fe 3 N@N-doped carbon core-shell nanoparticles encapsulated in bamboo-like nanotube is prepared by a facile method. • The active sites ϵ-Fe 3 N nanoparticles are protected by double N-doped carbon layers and show excellent stability. • The nanotube structure can enhance the electrocatalytic performance. • The FN@NC catalyst shows excellent ORR catalytic activities with a Tafel slope of 82 mV decade−1 at high potential. [ABSTRACT FROM AUTHOR]

To relax the requirements on wavelength control of arrayed waveguide grating (AWG) in InP-based photonic integrated circuits (PIC), two kinds of 10-channel InP-based AWGs with flat-top spectral response are designed and fabricated by introducing a rectangle multi-mode interference (MMI) or a parabolic MMI at the end of input waveguide. The test results demonstrate that these two kinds of flat-top AWGs have obtained flattened spectral response with 3 dB-bandwidth of about 1.7 nm, and the parabolic MMI-based flat-top AWG has 0.7 dB superiority in on-chip loss. [ABSTRACT FROM AUTHOR]