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With the increasing development of micro aerial vehicle, the impact resistance of the structure has gradually become a research hotspot. The beetle's exoskeleton not only provides important protection for its body and flexible wings but also ensures its good flight performance. Therefore, the beetle's exoskeleton has become an important research content in the field of bio-mimetic micro aerial vehicles. In this study, taking the internal structure of the beetle's exoskeleton as the research object, a kind of bio-mimetic lightweight thin-walled impact-resistant structure that can be used in the micro aerial vehicle is proposed. The energy absorption characteristics of the bio-mimetic structure under axial impact loading are calculated and analyzed by the numerical simulation method, and the important parameters such as impact angle, protective layer thickness, and wall thickness are optimized and discussed. The main results include that the filling method of the hollow column has a certain correlation with the energy absorption characteristics of the structure under different impact angles, and among the different cross-sectional shapes, the hollow column with a circular cross-sectional configuration has the best energy absorption ability. In addition, as the internal space of the structure increase exponentially, the decrease of specific energy absorption value of the bio-mimetic structure is relatively small. Finally, the wall thickness with good energy absorption characteristics is about 1.5 mm, while the preferred span length of the structure is between 90 and 120 mm.

This paper proposed a prototype of flexible 7.1 inch full color micro‐LED display. The resolution is 320RGB×270 and pixel pitch is 0.432mm. Top‐gate IGZO backplane is suitable for flexible micro‐LED display with its high stability and good TFT characteristics. We adopted elastomer stamp transfer technology to transfer red, green, and blue micro‐LEDs to substrate. The micro‐LED size is 35um×25um and the luminance of the prototype can reach beyond 500nits.

A synchronous-traveling carrier photodetector (STC-PD) with a thick absorption region and large diameter is presented and investigated for 100 Gbps PAM4 applications. In the STC structure, a suitable electric field is introduced to synchronize the traveling of electrons and holes, which achieves high bandwidth while maintaining large responsivity. The characteristics of STC-PD, including electric field distribution, energy band diagram, responsivity, junction capacitance, and frequency response, have been studied carefully.

ABSTRACTThis paper aims to study the three-dimensional transient flow-field properties of the gas–liquid dual-fluid atomizer, which has high flow capacity and low energy consumption. The two-phase atomization process of air and water, the negative pressure gradient near the porous medium and the recirculation flow inside the atomizer were numerically simulated and analyzed. Primarily, the influence of the air flow velocity on the water flow velocity at the water inlet was numerically studied. Furthermore, it was proven that the simulated results agree well with the experimental data. Thereafter, the variations in the inlet’s water flow velocity and vortex current zone size were studied in detail with changes in the orifice diameter and outlet pipe length. The results indicated that the water absorption improves as the air flow velocity increases. There is a suitable orifice diameter to maximize water flow and maximize the secondary atomization. The water flow velocity becomes larger and the secondary atomization improves as the length of the outlet pipe increases. The larger the vortex region, the smaller the droplet size. This study could provide theoretical data and guidance for the optimization design of dual-fluid atomizers.

Daya Bay Nuclear Power Operations and Management (DNMC) company was established in March 2003 and manages both the two-unit Daya Bay and four-unit Ling Ao nuclear power plants. An equipment [...]

Eight new fungal polyketides named koningiopisins A-H (1-8) and four previously known polyketides (9-12) were isolated from the endophytic fungus Trichoderma koningiopsis YIM PH 30 002. Their structures were elucidated using extensive spectral data interpretation, and their antifungal and synergistic activities were also evaluated. Koningiopisin C (3) exhibited in vitro antifungal activity against the phytopathogenic fungus Plectosphaerella cucumerina with an MIC of 16µg/mL Although the antifungal activities of single compounds were not obvious, a mixture of six compounds (4-9) exhibited potent synergistic antifungal activity against P. cucumerina with an MIC of 16µg/mL, and the antifungal activity of the mixture of any two compounds with a 1:1 ratio was better than that observed from the individual compound. The synergistic biological activity of the metabolites in YIM PH 30 002 demonstrates the significant ecological function of the endophyte for its host plant, and provides additional insight into the search for and development of agents for biological control. [ABSTRACT FROM AUTHOR]

Searching for novel topological objects is always an intriguing task for scientists in various fields. We study a three-dimensional (3D) topological structure called a 3D dimeron in trapped two-component Bose-Einstein condensates. The 3D dimeron differs from the conventional 3D skyrmion for the condensates hosting two interlocked vortex rings. We demonstrate that the vortex rings are connected by a singular string and the complexity constitutes a vortex molecule. The stability of the 3D dimeron is examined in two different models using the imaginary time evolution method. We find that the stable 3D dimeron can be naturally generated from a vortex-free Gaussian wave packet incorporating a synthetic non-Abelian gauge potential into the condensates. [ABSTRACT FROM AUTHOR]

The aim of this paper is to propose a threat assessment method based on intuitionistic fuzzy measurement reasoning with orientaion to deal with the shortcomings of the method proposed in [Ying-Jie Lei et al., Journal of Electronics and Information Technology 29(9)(2007)2077-2081] and [Dong-Feng Chen et al., Procedia Engineering 29(5)(2012)3302-3306] the ignorance of the influence of the intuitionistic index's orientation on the membership functions in the reasoning, which caused partial information loss in reasoning process. Therefore, we present a 3D expression of intuitionistic fuzzy similarity measurement, make an analysis of the constraints for intuitionistic fuzzy similarity measurement, and redefine the intuitionistic fuzzy similarity measurement. Moreover, in view of the threat assessment problem, we give the system variables of attribute function and assessment index, set up the reasoning system based on intuitionistic fuzzy similarity measurement with orientation, and design the reasoning rules, reasoning algorithms and fuzzy-resolving algorithms. Finally, through the threat assessment, some typical examples are cited to verify the validity and superiority of the method.

We present an exact solution to the stationary coupled nonlinear Gross-Pitaevskii equations, which govern the motion of the spinor Bose-Einstein condensates. The solitonic solution is a twisted half-skyrmion in 3D space. By making a map from the Cartesian coordinates to the toroidal coordinates, we demonstrate it is a linked half-unknot with a fractional topological charge. [ABSTRACT FROM AUTHOR]

A novel two-photon absorption (TPA) material with phenanthrolin as acceptor (BSIPB) has been firstly synthesized and studied as possible fluorescence probe for nucleic acids detection. The single-photon and two-photon fluorescence properties of the dye in the unbound state and in DNA complexes were investigated. Some quantum yields and TPA cross sections at important points were calculated. The results showed that BSIPB can be used as an efficient fluorescent probes for DNA detection and imaging under both single-photon excitation (SPE) and two-photon excitation (TPE).

According to the problem of emitter characteristic parameters are showed by interval and uneasy to identify, an emitter fusion recognition method based on the PSO-BP neural network is proposed. The method train the network by training samples which are reasonable structured according to the distribution in the interval, so as to determine the network structure and confirm the emitter type through the emitter characteristics parameters. At the same time, the BP neural network is optimized by Particle Swarm Optimization (PSO) algorithm. The coding method of the network output, training data size and deviation rate on the influence of the recognition are researched by simulation, and the validity of this method are verified by the results.

Due to its buffer property, activity, absorbability and safety, magnesium hydroxide is widely used in environmental protection, pharmaceutics, pulp and paper industry, and as flame-retardant filling in composite materials. The hydrothermal synthesis of magnesium hydroxide at low temperature (< 100?) needs only simple equipment and is environmentally friendly and energy-saving, so the process is promising and easy for industrialization. In this study, we have investigated the effects of hexamethylenetetramine and ammonia additives on the hydrating synthesis of superfine Mg (OH)2 particles at 70?. Mg (OH)2 particles formed were of platelet shape and the mean diameter was approximately 200nm. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the crystal phase, size distribution and morphology of the crystal particles. Different morphologies of Mg (OH)2 particles were formed in hexamethylenetetramine and ammonia solutions. The generation velocity of hydroxyl (OH-) was found to play an important role in the distribution and morphology of Mg (OH)2 particles.

This article presents a new multichannel medium access control (MAC) protocol to solve the exposed-terminal (ET) problem for efficient channel sharing in multi-hop wireless networks. It uses request-to-send and clear-to-send (RTS/CTS) dialogue on a common channel and flexibly opts for conflict-free traffic channels to carry out the data packet transmission on the basis of a new channel selection scheme. The acknowledgment (ACK) packet for the data packet transmission is sent back to the sender over another common channel thus completely eliminating the exposed-terminal effects. Any adjacent communication pair can take full advantage of multiple traffic channels without collision and the spatial reuse of the same channel is extended to other communication pairs which are even within 2 hops from them. In addition, the hidden-terminal effect is also considerably reduced because most of possible packet collisions on a single channel are avoided due to traffic load balance on multichannels. Finally, a performance comparison is made between the proposed protocol and other typical MAC protocols. Simulation results evidence its obvious superiority to the MAC protocols associated with other channel selection schemes and traditional ACK transmission scheme as well as cooperative asynchronous multichannel MAC (CAM-MAC) protocol in terms of four performance indices: total channel utilization, average channel utilization, average packet delay, and packet dropping rate.

Numerical predictions of three‐dimensional flow and heat transfer are presented for rotating serpentine passages with and without rib turbulators. The coolant air is pressurized and its operating conditions are selected closely to match actual turbine operating parameters. Two different arrangements of rib turbulators were studied: (1) transverse ribs on the leading and trailing walls and (2) transverse ribs on all four walls. The rib height‐to‐hydraulic diameter ratio (e/Dh) is 0.143; the rib pitch‐to‐height ratio (s/e) is 7. Results for the rib‐roughened serpentine passages were compared with those of smooth ones calculated in the literature. It was shown that a significant enhancement is achieved by means of rib turbulators in a serpentine passage at a stationary state as well as in a rotating state. In the radially‐outward flow passages, the effect of rotation on heat transfer is relatively prominent. The secondary flows induced by the Coriolis forces are most intensive in the channel with four ribbed surfaces. The heat transfer after a 180° sharp turn in the smooth channel is influenced more by the sharp‐turn‐induced flow than the rib‐roughened ones. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(6): 410–420, 2006; Published online in Wiley InterScience (). DOI 10.1002/htj.20125

The fractal theory put forward by American mathematician B B Mandelbrot (1967) supplies an effective approach to solve complex problems. The complex problems in geography have become the main positive study field of fractal theory. Based on the works of China’s geographers and the summarization of contents of fractal theory, the authors comment on the present situation of its applications to almost every branch of geography and discuss the related problems and the prospects of fractal study in geography.

A new sesquiterpene of humulene type, named 2ß, a-epoxy-6Z, 9Z-humuladien-8a-ol (1) together with a known compound lactarinic acid was isolated from the fruiting bodies of Lactarius hirtipes. Their structures were established on the basis of spectral evidence (MS, IR, NMR, HMBC, HMQC, 1H-1H COSY, ROSEY experiments). Compound 1 was found as the first humulene-type sesquiterpene in higher fungi.

Two novel phenylacetoxylated p-terphenyl derivatives, namely ganbajunin F (6'-methoxy-2'-phenylacetoxy-3', 4, 4?, 5'-tetrahydroxy-p-terphenyl), and ganbajunin G (5'-methoxy-2'-phenylacetoxy-3', 4, 4?, 6'-tetrahydroxy-p-terphenyl), together with a known compound cycloleucomelone were isolated from the fruiting bodies of Thelephora ganbajun Zang. Their structures were established on the basis of spectral (MS, IR, NMR, HMBC, HMQC measure­ment) and chemical evidence.

The new substance albaconol (1) was isolated along with grifolin (2), emeheterone (3), and the pyrazinol derivative 4 from the fresh fruiting bodies of the basidiomycetes Albatrellus confluens. Structures were established by spectral analysis, including 2D NMR spectroscopy. Albaconol (1) possesses the skeleton of a drimane-type sesquiterpenoid, which is directly connected to a resorcinol (=benzene-1,3-diol) moiety; this prenylated resorcinol represents a new C skeleton.

Three new triterpenoids and two new aristolane sesquiterpenoids, namely (24E)-3β-hydroxycucurbita-5,24-diene-26-oic acid (1), (24E)-3,4-secocucurbita-4,24-diene-3,26-dioic acid (4), (24E)-3,4-secocucurbita-4,24-diene-3,26,29-trioic acid (5), rulepidadiol (6), and rulepidatriol (7), were isolated from the fruiting bodies of Basidiomycetes Russula lepida. Their structures were established by spectral methods. Acids 4, and 5 are the first examples of naturally occurring seco-ring-A cucurbitane triterpenoids. Alcohols 6 and 7, belonging to the aristolane-type sesquiterpenoids, are of a type rather rare in nature, especially among fungal species.

A novel monoterpenoid-derived metabolite, paeonilide, was isolated from the roots of Paeonia delavayi. Its structure was established by a combination of spectroscopic and X-ray crystallographic analyses. It showed an anti-PAF effect with an IC50value of ca.8 μg/ml.

Abstract: Let (S)⊄L 2(S′(∔),μ)⊄(S)* be the Gel'fand triple over the white noise space (S′(∔),μ). Let (e n ,n>-0) be the ONB ofL 2(∔) consisting of the eigenfunctions of the s.a. operator $$ - \left( {\frac{d}{{dt}}} \right)^2 + 1 + t^2 $$ . In this paper the Euler operator Δ E is defined as the sum $$\sum\nolimits_i {\left\langle { \cdot ,e_i } \right\rangle \partial _i } $$ , where ∂ i stands for the differential operatorD ei. It is shown that Δ E is the infinitesimal generator of the semigroup (T t ), where (T t ϕ)(x)=ϕ(e t x) for ϕ∈(S). Similarly to the finite dimensional case, the λ-order homogeneous test functionals are characterized by the Euler equation: Δ Eϕ =λϕ. Via this characterization the λ-order homogeneous Hida distributions are defined and their properties are worked out.

A novel compound, lepidolide 1, was isolated from the fruiting bodies of the Basidiomycete Russula lepida. Its structure was established by spectroscopic and chemical means.

A novel, highly symmetrical compound, named tremellin (1), was isolated from the fruiting bodies of the basidiomycete Tremella aurantilba. Its structure was established by spectroscopic means and X-ray analysis.

Quantum illumination is one of the most basic ways to realize the quantum radar for detection of low-reflectivity targets embedded in a thermal-noise bath. It preserves a strong advantage over the classical counterparts even though its fragile quantum entanglement is completely destroyed by a large amount of noise and losses. In this paper, we describe and analyze a discrete-variable quantum illumination system with ancillary degrees of freedom of entangled photon pairs. Comparing the error probability bound, i.e., the quantum Chernoff bound, we identify that this system indeed offers higher accuracy than the single-photon illumination and quantum illumination with single degree of freedom of entangled photon pairs. Furthermore, the utilization of ancillary degrees of freedom exponentially enhances signal-to-noise ratio over quantum illumination without ancillary degrees of freedom. It means that this system reduces the necessary amount of signal photons to accurately determine whether the object is present or absent in the target region, which is absolutely crucial to the stealthiness of the radar system. [ABSTRACT FROM AUTHOR]

In addition to macroscopic crack propagation and coalescence, the nonlinear deformation of rocks also includes mesoscopic damage buildup and transformation to macroscopic crack. To accurately model the progressive failure process of rocks, a novel damage-based numerical manifold method (NMM) is proposed in this study. The damaged-based NMM incorporates the Weibull statistical distribution, and the exponential function material softening model to describe damage evolution and strength reduction of heterogeneous material. When the damage accumulation of adjacent manifold elements satisfies the failure threshold, a real macroscopic crack is initiated from these two manifold elements, accompanied by cutting off these two manifold elements. The Mohr-Coulomb criterion with a tension cut-off was used to evaluate fracture modes of cracks. To verify the proposed method, a series of numerical tests were conducted and the numerical results were compared with laboratory experiments and other numerical results. On this basis, the effect of heterogeneity on the failure process in rock specimens with a single crack is clarified. Results from this study show that the simulations satisfactorily capture the failure process of brittle rocks from damage evolution to crack initiation, propagation, coalescence and large displacement, implying that the method is an appropriate and robust tool to model the damage and fracture behavior of rocks. [ABSTRACT FROM AUTHOR]

In this work, device cell with the Cu/VOx/Al structure was fabricated. The resistance switching performance was tested by Semiconductor Device Analyzer (Agilent B1500). This structure performs bipolar behavior. Controllable Set process and gradual Reset process, and various RLRSand RHRScould be obtained by controlling its current compliance (Icc) and reset stop voltage (Vstop), respectively. The Reset current could decrease to sub-10μA when Iccdropped to 40μA. The RHRScould be greater than 1E8 ohm with 1.5 V amplitude of applied reset voltage. This structure also has a good endurance (>1000 cycles) and reliable read disturbance times (>1000s) with 80oC ambient temperature. Local filament was observed in LRS by conducting atomic force microscope (CAFM), and Schottky barrier height modulation was obtained by I-V fitting in Reset process.

For Abstract see ChemInform Abstract in Full Text.

Protected deoxynucleoside 3′-O-ethyl-N, N-diisopropylphosphoramidite reagents were prepared for use in the automated synthesis of ethyl phosphotriester (Et) modified oligonucleotides. The title diastereomers were separated by reversed-phase HPLC, and chirality at phosphorus was assigned by an improved configurational correlation scheme that was verified by NMR spectroscopic studies (accompanying paper, Part VI). This generally applicable correlation scheme involved (1.) enzymatic digestions of each diastereomer to give the corresponding diastereomer of d[A(Et)T]; (2.) phosphite triester sulfurization to obtain diastereomer O-ethyl phosphorothioates, d[AS(Et)T], which were separated by HPLC for (3.) stereoretentive oxidation with H2O2 to give d[A(Et)T], and (4.) stereoretentive de-ethylation with PhSH-Et3N to give diastereomeric phosphorothioates, d[AST], whose configurations at phosphorus had been assigned previously. Neither the Rp−Rp nor Sp−Sp duplex, {d[GGAA(Et)TTCC]}2, was cleaved by EcoRI endonuclease under conditions that led to cleavage of both the unmodified duplex, [d(GGAATTCC)]2, and the mixture of diastereomeric phosphorothioate-modified duplexes, [d(GGAASTTCC)]2. Cleavage of the latter substrates was Sp-selective.

High-performance liquid chromatography (HPLC) and 1H/31P nuclear magnetic resonance (NMR) spectroscopy were used to measure the molar ratio of oligodeoxyribonucleotide products in mixtures obtained with automated DNA synthesizers that employed competitive coupling of either standard methyl- or newerβ-cyanoethyl-N, N-diisopropylamino phosphoramidite reagents, which include deoxylnosine. Mixtures of these reagents when used as freshly prepared solutions afforded ratios of products that indicated negligibly small differences among the rates of the various competitive coupling reactions. However, studies of reagent stability in solution revealed that both types of the N-isobutyryl deoxyguanosine reagent decompose faster than their corresponding dA, dC, and dT phosphoramidites, which led to significantly lower proportions of dG-containing sequences. This problem was attenuated for the β-cyanoethyl reagents due to their slower rate of decomposition.

We propose a scheme to construct the efficient universal quantum circuit for qubit systems with the assistance of possibly available auxiliary Hilbert spaces. An elementary two-ququart gate, termed the controlled-double-NOT gate, is proposed first in ququart (four-level) systems, and its physical implementation is illustrated in the four-dimensional Hilbert spaces built by the path and polarization states of photons. Then an efficient universal quantum circuit for ququart systems is constructed using the gate and the quantum Shannon decomposition method. By introducing auxiliary two-dimensional Hilbert spaces, the universal quantum circuit for qubit systems is finally achieved using the result obtained in ququart systems with the lowest complexity. [ABSTRACT FROM AUTHOR]

Single photons of subnatural linewidth and high spectral brightness are necessary for efficient light-matter interaction at the single-photon level, which lies at the heart of many quantum photonic technologies. Here we demonstrate a bright source of single photons with subnatural linewidth, controllable waveforms, and a high spectral brightness of 3.67×105s-1mW-1MHz-1. The interaction between the single photons and atoms is demonstrated by the controlled absorption of the single photons in an atomic vapor. Our work has potential applications in quantum information technologies. [ABSTRACT FROM AUTHOR]

We propose a systematic procedure to optimize quantum state tomography protocols for continuous variable systems based on excitation counting preceded by a displacement operation. Compared with conventional tomography based on Husimi or Wigner function measurement, the excitation counting approach can significantly reduce the number of measurement settings. We investigate both informational completeness and robustness, and provide a bound of reconstruction error involving the condition number of the sensing map. We also identify the measurement settings that optimize this error bound, and demonstrate that the improved reconstruction robustness can lead to an order-of-magnitude reduction of estimation error with given resources. This optimization procedure is general and can incorporate prior information of the unknown state to further simplify the protocol. [ABSTRACT FROM AUTHOR]