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Phase decomposition influences significantly the mechanical properties of high entropy alloys (HEAs). Prediction of the phase decomposition of HEA is greatly hindered by the hyper-dimensional composition space of the alloys. In the present work, we propose to represent the HEAs as various pseudo-binary alloys of which the temperature dependent free energies as functions of compositions may be readily calculated by using first-principles methods in combination with thermodynamic models. With the calculated free energies, the phase diagrams of the pseudo-binary alloys may be constructed and the phase decomposition can be predicted. This procedure is applied to Hf-Nb-Ta-Ti-Zr alloy with body-centered cubic (BCC) structure. We predict that the equiatomic HfNbTaTiZr HEA suffers from phase decomposition below critical temperature of 1298 K. The HEA decomposes most favorably to BCC NbTa-rich and HfZr-rich phases. The BCC HfZr-rich phase transfers to a hexagonal close-packed structure (HCP) phase at low temperature. The predicted compositions of the decomposed phases are in good agreement with experiment and Thermal-Calc modeling. Furthermore, the effect of the phase decomposition on the strength of the HEA is evaluated by considering the solid-solution and precipitation strengthening mechanisms. The precipitation strengthening effect is stronger than the solid-solution strengthening at the low annealing temperature but becomes weaker at high annealing temperature.

This study demonstrates for the first time that easily accessible transition-metal acylnitrenoids can be used for controlled direct C(sp3 )-H oxygenations. Specifically, a ruthenium catalyst activates N-benzoyloxycarbamates as nitrene precursors towards regioselective intramolecular C-H oxygenations to provide cyclic carbonates, hydroxylated carbamates, or 1,2-diols. The method can be applied to the chemoselective C-H oxygenation of benzylic, allylic, and propargylic C(sp3 )-H bonds. The reaction can be performed in an enantioselective fashion and switched in a catalyst-controlled fashion between C-H oxygenation and C-H amination. This work provides a new reaction mode for the regiocontrolled and stereocontrolled conversion of C(sp3 )-H into C(sp3 )-O bonds.

A transformation of fluxional into configurationally stable axially chiral N-arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral-at-metal rhodium Lewis acid. Specifically, N-arylpyrroles were alkylated with N-acryloyl-1H-pyrazole electrophiles in up to 93 % yield and with up to >99.5 % ee, and follow-up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.

The solubility limit of elements plays a crucial role in alloy designing, as well as in the understanding of kinetic processes in alloys. Using first-principles calculations, we calculated the grou...

Local chemical ordering influences significantly the mechanical properties of refractory high entropy alloys. In this work, the effects of local chemical ordering on the structural stability and mechanical properties of AlNbVTiZr are investigated by using first-principles simulations. It is shown that the Al Zr bond dominates the chemical ordering for ordered configurations. The local ordering enhances the structural stability, elastic property and ideal strength. By taking into account the effects of temperature and pressure, we found that chemical ordering mediates the thermodynamic properties of the AlNbVTiZr alloy, but it has little effect at high pressure.

Many natural products and medicinal drugs are heterocyclic amines possessing a chiral quaternary carbon atom in their heterocyclic ring. Herein, we report the first catalytic and asymmetric Staudinger-aza-Wittig reaction for the desymmetrization of ketones. This highly enantioselective transformation proceeds at room temperature to provide high yields-even on multigram scales-of nitrogen heterocycles featuring a chiral quaternary center. The products of this reaction are potential precursors for the synthesis of pharmaceuticals. A commercially available small P-chiral phosphine catalyst, HypPhos, induces the asymmetry and is recycled through in situ reduction of its oxide, mediated by phenylsilane in the presence of a carboxylic acid. The efficiency, selectivity, scalability, mild reaction conditions, and broad substrate scope portend that this process will expedite the syntheses of chiral heterocyclic amines of significance to chemistry, biology, and medicine.

This article describes an experimental and computational investigation on the possible aryne reactivity modes in the course of the reaction of two highly energetic molecules, an aryne and a 1,2,4,5-tetrazine. Beyond the triple aryne-tetrazine (TAT) reaction, it was observed that combinations of several reactivity modes afford several heterocyclic compounds. Density Functional Theory (DFT) calculations of competition between a second Diels-Alder reaction and the nucleophilic addition pathways indicates the latter to be more favorable. Crossover experiments and computational study of the proton transfer step reveal that the reaction proceeds intermolecularly with the assistance of a water molecule, rather than intramolecularly. The resulting enamine intermediate was found to undergo either a stepwise formal [2 + 2] or [4 + 2] cycloaddition, and their energetic profiles were compared against each other. Isolation of an ene-product and a rearranged product shows the potential competition with oxidation/desaturation. These studies show how multiple arynes react with a highly reactive starting material and provide guidance for future applications of aryne-based multicomponent cascade reactions.

The fundamental mechanism of the precipitation kinetics and stability of nano-sized Cu-precipitates are crucial to the development of ultra-high strength low carbon ferritic steels. The effects of Al on the formation and stabilization of B2 Cu-rich precipitates in Fe–Cu based steels were studied using experimental method combining the first-principles calculations and molecular dynamics simulations. With increasing aging time, the Cu-rich particles with B2 structure precipitated in the ferritic matrix with cube-on-cube and coherent relationship, and Al addition leads to a relatively higher precipitation hardening effect. The first-principle calculations indicate that the metastable B2 FeCu phase has relatively higher mixing energy and small lattice mismatch with the ferritic matrix, and the addition of Al leads to the lower mixing energy of B2 precipitates and the B2 structure Fe(CuAl) compound possesses more smaller lattice mismatch with ferritic matrix. To better understanding the effect of Al on the evolution process of Cu-rich particles, it is essential to investigate the migration and clustering process of Cu atoms during the isothermal tempering at the atomic scale. To this end, we first developed a new interatomic potential of Fe–Cu–Al using the force-matching method based on ab initio calculations, then the formation and evolution of Cu clusters in the Fe–Cu–Al ternary were studied using molecular dynamics method with the new EAM potential. The simulation results indicate that Al addition promotes the clustering of Cu atoms due to the attractive interaction between Cu and Al atoms which enhances nucleation rate of the Cu-rich precipitates.

This paper presents a physics-based analytical model called PABAM. It is performed to estimate the bipolar amplification effect induced collected charge at circuit level. The PABAM is validated by TCAD simulation with different technologies and layout parameters. The collected charge obtained from combining the PABAM and the diffusion-collection model agrees well with TCAD simulation results, both in magnitude and trend. The proposed PABAM is implemented in the circuit-level SER prediction approach to evaluate SEU for twin- and triple-well SRAMs. The simulated cross sections have a good agreement with heavy ion experimental data, particularly for MCU prediction.

As chip technologies scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes. The so-called pulse quenching effect, induced by single-event charge sharing collection, has been widely explored in efforts to find mitigation techniques for single-event transients (SETs) or single-event upsets (SEUs), and the dummy gate isolation has been proven to be an efficient layout technique for pulse quenching enhancement. In this paper, the characterization of SET pulse quenching among dummy gate isolated logic nodes is performed in 65 nm twin-well and triple-well CMOS technologies. Four groups of heavy ion experiments are explored for the characterization, and the pulse quenching effect is quantitatively analyzed in detail. The pulse quenching effects show different characteristics in twin-well and triple-well CMOS technologies.

In this paper, a novel well structure for PMOS single-event transient (SET) mitigation is studied by way of technology computer-aided design (TCAD) numerical simulations. Based on a 90-nm CMOS technology, the simulation results show that the proposed selectively implanted deep-N-well (SIDNW) can significantly reduce the SET pulsewidth without area, power, and performance overheads, when compared with the conventional dual-well process. A comparison is also made with the triple-well process.

In this study, we investigated the impact of pulse quenching effect on the soft error vulnerabilities in combinational circuits. Simulation results illustrate that soft error vulnerabilities could be reduced by 4-16% for the benchmark circuits when the pulse quenching effect is introduced. By adjusting the cell orientations of the quenching cells in the layout, the soft error vulnerabilities could be further reduced. It is suggested that new placement algorithm considering circuit reliability should be designed to reduce the circuit soft error vulnerabilities.

Heavy ion experiments on 65 nm bulk CMOS inverter chains demonstrate the impact of circuit placement on single-event transients (SETs). Experimental data and simulations show that the horizontal placement design significantly reduces the SET pulse width and SET cross-section compared to the vertical placement design due to the existence of pulse quenching.

Based on 28-nm bulk-Si FinFET and planar transistors, 3D-TCAD simulations are performed to investigate the charge collection mechanisms and single-event transient (SET) pulse widths for nanoscale PMOS devices. Simulation results show that charge collection and SET pulse widths for FinFET are smaller than those of the planar device. An overall analysis indicates that for linear energy transfer (LET) less than 20 MeV-cm2/mg, the reduced charge collection in FinFET is induced mainly by the narrow sensitivity drain volumes; however, the parasitic bipolar amplification effect presents an important effect on the charge reduction for high ion LETs. An in-depth analysis shows that the reduced bipolar amplification effect in FinFET is owing to the conduction channel (fin body) rather than source/drain region.

Charge sharing induced SEU and SEMT are investigated using heavy ion and pulsed laser. Measurement results are compared and it indicates pulsed laser could generate charge sharing similar to heavy ion. 3D-TCAD simulation is performed to investigate the factors to impact on pulsed laser induced chare sharing. Simulation results show that the beam spot size impact on charge sharing in the high laser energy while the variation of the calculated equivalent LET impact on charge sharing in the low laser energy.

Two novel phenylethene-carbazole derivatives containing dimesitylboron groups, 3-(dimesitylboryl)-9-ethyl-6-(1,2,2-triphenylvinyl)-9H-carbazole and 1,2-bis(6-(dimesitylboryl)-9-ethyl-9H-carbazol-3-yl)-1,2-diphenylethene are presented. The foregoing mono- and bis-carbazole containing compounds combine the aggregation-induced emission properties of phenylethene and the hole and electron transporting properties of carbazole and dimesitylboron substituents respectively. An extensive investigation of their optical and electrical properties reveals that these aggregation-induced emission active scaffolds exhibit excellent thermal stability (Td up to 254 °C) with high electrochemical stability. Compared to our previous systems, the OLED device using the mono-carbazole derivative as a sky-blue emitter shows improved parameters such as the maximum luminance and maximum luminance efficiency of 13,930 cd m-2 and 4.74 cd A-1, respectively. The device based on the blue-green emitting biscarbazole derivative features equally high maximum luminance and maximum luminance efficiency of 15,780 cd m -2 and 6.90 cd A -1, respectively.

To explore the effect and safety of topical propranolol hydrochloride gel for treatment of infantile hemangioma. METHODS Thirty nude mice (BALA/c, nu/nu) were divided into three groups, experimental group, control group and normal group. Human hemangioma endothelial cells cultured in vitro were injected subcutaneously in experimental group and control group to establish infantile hemangioma model. Topical propranolol hydrochloride gel was applied on the surface of the hemangioman in experimental group and normal group. Tumor volumn change and the skin situations (edema, erythema, ulceration) were observed at different periods. 45 days after cell injection, the mice were killed and plasma concentration was detected in the experimental group and the control group by high performance liquid chromatography with evaporative light scattering detector, and tumors were subjected to histopathologic examination and immunohistochemistry for CD31 and CD34. The correlation between volumes and plasma concentration was statistically analyzed with SPSS 13.0 paired samples t test with α = 0.05 as statistical standard.At 45 days, the volume of the tumor in control group was (366.57 ± 17.08) mm³, which has a significant difference as compared to the experimental group (13.36 ± 2.09) mm³ (P0.05); and the plasma concentration was (16.83 ± 1.53) ng/ml in experimental group, and (18.42 ± 2.21) ng/ ml in normal group (P0.05 ). Topical propranolol hydrochloride gel (3%) has no irritation to nude mice's skin.Topical application of 3% propranolol hydrochloride gel is effective and safe for the treatment of infantile hemangioma.

Four novel aggregation-induced emission (AIE)-active luminogens (p-DPDECZ, p-DBPDECZ, m-DPDECZ and m-DBPDECZ) with triphenylethene-carbazole skeleton and para-/meta-substituted arylboron groups have been synthesized. Their structures are fully characterized using elemental analysis, mass spectrometry and proton nuclear magnetic resonance spectroscopy. The thermal stabilities, photophysical properties, electronic structures, and electrochemical properties of these molecules are investigated systematically using thermal analysis, UV-vis absorption spectroscopy, fluorescence spectroscopy, theoretical calculation and electrochemical methods. The effects of donor–acceptor interaction and conjugation degree on the photoluminescent and electroluminescent properties of these compounds are investigated. The results show that these donor–AIE–acceptor type compounds exhibit good thermal stability and electrochemical stability as well as AIE properties. Non-doped fluorescent OLEDs fabricated by using para-linked p-DPDECZ as an emitting layer emits a green light with a turn-on voltage of 4.8 V, a maximum brightness of 30210 cd m-2 and a maximum current efficiency of 9.96 cd A-1. While the OLED prepared with meta-linked m-DBPDECZ exhibits efficient blue light emission with a maximum current efficiency of 4.49 cd A-1 and a maximum luminance of 16410 cd m-2. The electroluminescence properties of these compounds demonstrate their potential application in OLEDs.

A radiation hardening algorithm named as state-conservation on 2nd order clock and data recovery (CDR) system is presented in this paper. This proposed algorithm is used to resist the single event transient (SET) of CDR tracking loop. A MATLAB model is established to fast evaluate the sensitive position of the system. A circuit model of 5 Gbps half rate CDR together with the hardening algorithm is set up to verify the effect of the proposed algorithm in Cadence design environment. The simulation result shows that SET does not lead to any error data and no loop delay is added. Compared to the RHBD standard-cell technique, the hardening algorithm saves area about 15.3% and reduces power consumption about 47.8%.

To investigate the effect of topical propranolol gel on the levels of plasma vascular endothelial growth factor (VEGF), basic fibroblastic growth factor (bFGF) and matrix metalloproteinases-9 (MMP-9) in proliferating infantile hemangiomas (IHs) of superficial type.33 consecutive children with superficial IHs were observed pre-treatment, 1 and 3 months after application of topical propranolol gel for the levels of plasma VEGF, MMP-9 and bFGF by enzyme-linked immunosorbent assay (ELISA) in Department of General Surgery of Dongfang Hospital from February 2013 to February 2014. The plasma results of IHs were compared with those of 30 healthy infants. The clinical efficacy in IHs was evaluated by Achauer system. Differences of plasma results between the healthy group and the IHs group pre-treatment were analyzed using Mann-Whitney U-test. Paired sample comparisons of any two time points of pre-treatment, 1 month and 3 months after treatment in IHs were evaluated by Wilcoxon signed-rank test.The clinical efficiency of topical propranolol gel at 1, 3 months after application were 45.45%, 81.82% respectively. The levels of plasma VEGF and MMP-9 in patients pre- treatment were higher than those in healthy infants [(362.16 ± 27.29) pg/ml vs (85.63 ± 8.14) pg/ml, (1376.41 ± 42.15) pg/ml vs (687.27 ± 44.1) pg/ml, P0.05], but the level of bFGF did not show significant difference [(176.03 ± 13.60 ) pg/ml vs (235.94 ± 35.43 ) pg/ml, P0. 05 ]. The concentrations of VEGF and bFGF at 1, 3 months after treatment decreased obviously [(271.51 ± 18.59) pg/ml vs (362.16 ± 27.29 ) pg/ml, (135.85 ± 12.66) pg/ml vs (176.03 ± 13.60) pg/ml], 1 month after treatment vs pre-treatment, P0.05; (240.80 ± 19.89) pg/ml vs (362.16 ± 27.29) pg/ml, (107.31 ± 5.82) pg/ml vs (176.03 ± 13.60) pg/ml, 3 month after treatment vs pre-treatment, P0.05, whereas the levels of plasma MMP-9 declined slightly [(1321.18 ± 48.74) pg/ml vs (1376.41 ± 42.15 ) pg/ml, (1468.68 ± 32.78) pg/ml vs (1376.41 ± 42 2.15 ) pg/ml, P0.05 ].Propranolol gel may suppress the proliferation of superficial infantile bemangiomas by reducing VEGF and bFGF.

Detailed analysis is presented on the effect of re-convergence on SER estimation in combinational circuits. The results show that the ignoring of re-convergence by previous independent pulse methods introduces significant errors in SER results. Furthermore, independent pulse methods miscalculate the SET sensitive nodes, leading to improper hardening strategy.

Using three-dimensional mixed-mode simulation, temperature dependence of digital SET pulse width in bulk and PD SOI inverter chains has been studied. It was found that temperature has a very important impact on digital SET. Using a LET of 60 MeVmiddotcm2 /mg, when temperature rises from -55 to 125degC , the digital SET pulse width in bulk and floating SOI inverter chains rises remarkably, while in a SOI inverter chain with ideal body tie, the digital SET pulse width is almost constant with rising temperature. Detailed analysis showed that pulse broadening with rising temperature is primarily due to enhancement of bipolar amplification.

Two bifunctional red AIE luminogens with efficient solid-state emission and good hole-transporting characteristics are reported. Efficient non-doped OLEDs are fabricated with high external quantum efficiencies of up to 3.9%. Bilayer EL devices using them as both EMLs and HTLs are fabricated with good performances.

Polyhydroaminations for the synthesis of stable nitrogen-substituted conjugated polymers with welldefined structures remain a great challenge and the control of the regio- and stereochemistry of the enamine product of the hydroamination is non-trivial. Herein we report an efficient tandem polymerization of alkynes, carbonyl chlorides and primary amines to afford regio- and stereoregular conjugated poly(enaminone)s. The atom-economical one-pot sequential polycoupling–hydroamination polymerization catalyzed by Pd(PPh3)2Cl2/CuI proceeded smoothly under mild conditions, furnishing nitrogensubstituted conjugated polymers with high molecular weights (up to 46 100) and high regio-/stereoregularities (100%) in nearly quantitative yields (up to 99%). The single crystal structure of the model compound, together with the NMR spectra comparison of the model compound and polymers provided direct insight into the stereoselectivity of the polymerization, verifying the sole Z-vinylene isomer of the polymers. Through the exquisite structural design strategy of the intramolecular hydrogen bond of the resulting hydroamination product, the tautomerization between enamine and imine as well as E/Z isomerization was successfully avoided, providing products with high chemical stability and sole Z-vinylene isomers. The conjugated polymers display excellent solubility in common organic solvents, good filmforming ability, and high thermal stability. The hydrogen bond formation of the polymer helps to block the potential photo-induced electron transfer process and the polymer shows a unique aggregation-enhanced emission phenomenon: their solutions are weakly emissive, while their nanoaggregates or thin films are brightly emissive. Furthermore, thin films of the polymers enjoy high refractive indices (1.9103–1.6582) in a wide wavelength region of 400–1000 nm, which can be further modulated by UV irradiation. Meanwhile, well-resolved fluorescent photopatterns of the polymers can be fabricated through the UV irradiation of thin films via a copper photomask.

N,N′-Di-(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) possesses high thermal and morphological stability and is one of the well-known hole-transporting materials for the fabrication of organic light-emitting diodes (OLEDs). Modification of NPB by the covalent integration of tetraphenylethene (TPE) into its structure dramatically changes its emission behavior: the resulting adduct (TPE–NPB) is highly emissive in the aggregated state, showing a novel phenomenon of aggregation-induced emission (AIE). The adduct is thermally and morphologically stable. Non-doped multilayer electroluminescence (EL) devices using TPE–NPB as an emitting layer were fabricated, which emitted green light with a maximum luminance and current efficiency of 11[thin space (1/6-em)]981 cd m−2 and 11.9 cd A−1, respectively. Even better device performances are observed in the bilayer device without NPB. Our strategy takes the full advantage of the AIE property in the solid state and retains the inherent properties of conventional luminophores. It opens a new avenue in the development of stable and efficient solid-state fluorescent materials for OLED application.

Enlarged tetrasubstituted alkenes with high fluorescent efficiency and good thermal stability are constructed. They exhibit luminance up to 35[thin space (1/6-em)]160 cd m−2 and efficiency of 16 cd A−1 in OLEDs.

4,4′-bis(1,2,2-triphenylvinyl)biphenyl (BTPE) nanowires have been facilely grown by either post-annealing its vacuum-sublimed amorphous film or slowly evaporating its chloroform solution. The morphology and density of the nanowires can be easily tuned by changing the growth conditions. For example, isolated single nanowires were readily obtained by thermally depositing the BTPE on a heated substrate, while bundles of nanotubes can be achieved by slowly evaporating a droplet of the BTPE solution. The self-assembled BTPE nanowires show enhanced and blue-shifted photoluminescence compared with that of its amorphous film. The nanowires exhibit a highly hydrophobic surface with a water contact angle of 126°. Also, the BTPE nanowires scatter the light effectively due to the random orientation of the wires. By depositing the BTPE nanowires on the backside of the glass substrate as a scattering media for organic light-emitting diodes, a 31.5% efficiency improvement has been achieved.

In organic light-emitting devices, materials with efficient electron-transporting properties, are essential. In this report, oxadiazole-containing tetraphenylethene TPE-Oxa is synthesized and its optical physics and electronic properties are investigated. The dye is almost nonluminescent when molecularly dissolved in solutions, but becomes highly emissive when aggregated in poor solvents or fabricated as thin films in the solid state. A quantum yield of unity has been achieved in its solid thin film. Inherited from the oxadiazole component, the dye molecule enjoys low-lying electronic band energies. Benefiting from the good electron-transporting and hole-blocking properties of the dye, the two-layer OLED devices using TPE-Oxa as both light-emitting and electron-transporting materials show superior performance, i.e., lower turn-on voltage, higher brightness and efficiencies, to the devices of typical configuration with a dedicated electron-transporting layer.

Benzene-cored luminogens with multiple triarylvinyl units are designed and synthesized. These propeller-shaped molecules are nonemissive when dissolved in good solvents, but become highly emissive when aggregated in poor solvents or in the solid state, showing the novel phenomenon of aggregation-induced emission. Restriction of intramolecular motion is identified as the main cause for this effect. Thanks to their high solid-state fluorescence quantum yields (up to unity) and high thermal and morphological stabilities, light-emitting diodes with the luminogens as emitters give sky-blue to greenish-blue light in high luminance and efficiencies of 10800 cd m−2, 5.8 cd A−1, and 2.7%, respectively. The emissions of the nanoaggregates of the luminogens can be quenched exponentially by picric acid, or selectively by Ru3+, with quenching constants up to 105 and ∼2.0 × 105 L mol−1, respectively, making them highly sensitive (and selective) chemosensors for explosives and metal ions.

Identifying information telling real identity of users from emails is an important topic in email mining. This paper focuses on the problem to identify the most authoritative aliases of email users. Based on the facts that different aliases of the same user take different positions in the user's email communication relation and that af final aliases of the same user have similar morphology in linguistics, a novel method to rank alias authority and obtain the authoritative aliases of an email user by email communication relation analysis and morphologically similar alias clustering is proposed. Experimental results show that the proposed approach can efficiently find the authoritative aliases of a user and can be applied to many applications on emails such as identity identifying, social relation discovering, important people finding and so on.

Full color luminogens are constructed from tetraphenylethene, benzo-2,1,3-thiadiazole and thiophene building blocks. OLED fabricated using one of the luminogens exhibits orange-red electroluminescence with high luminance and efficiencies of 8330 cd m−2, 6.1 cd A−1 and 3.1%, respectively.

Combination of an aggregation-induced emission (AIE) moiety and a dimesitylboron group yields a new three-coordinate boron compound exhibiting a synergistic effect: the resultant TPEDMesB shows AIE feature with solid-state emission efficiency up to unity and good electron-transport property, and thus remarkable electroluminescence (EL) performances.

This paper introduces a large-scale heterogeneous Multi-Core Digital Signal Processors (MC-DSP) prototype constructed with super-nodes, PolyDSP, and proposes a data speculation technique based on customized Data Streams Transmission Control Engine (DSTCE). This technique improves the efficiency of data streams transmissions within single super-node and among super-nodes. The innovation of this technique is that it combines a data speculation solution with the programming model of MC-DSPs, avoids complex cache coherence problems, and increases the parallelism between data processing and memory accessing for MC-DSPs significantly. Our simulation results show that, the performance of single super-node of PolyDSP is improved by 22% on average, and the performance of PolyDSP with two super-nodes based on DSTCE is 14% higher than that of based on CC-NUMA structure1.

3D mixed-mode simulation is used to research current components of SET current pulse in inverter chain, compared with that in a single NMOS. It is found that parasitic bipolar conduction current is the major component in SET current of single NMOS, but not in deep-submicron CMOS circuit. The paper provides a detailed discussion of source current in SET and it shows that negative and positive components of source current are related to bipolar amplification and diffusion of carriers respectively.

In this paper, a design method of MRACS (Model Reference Adaptive Control System) is propose& for continuous time plants in the presence of slowly-varying disturbance, by which it is possible to make the output error arbitrarily small. Considered that the control law of MRACS is easy to be realized by digital controller, the structure of this paper is composed as follows : First, the continuous time system is transformed to discrete time system by using sampler and zero-order holder, where the effect of disturbance on the plant output is described by a convolution integral.Next, in order to reduce the effect of disturbance, an integral precompensator is introduced to the sampled system, and an adaptive adjustment law with dead-zone is utilized. as analyzed theoretically, for any reference signals this reaches the results that if a small sampling period is chosen, the influence of disturbance on output can be controlled small.Finally, that the control system is stable and that the signals of the system are bounded are proved. The effectiveness of the proposed method is illustrated by computer simulations.

Soft error induced by SET (single event transient) has been more and more substantial. It has been proved that previously decoupled SET pulse models will induce great error, such as double exponential model and piecewise linear model. In this paper, we present a novel LUT (look up table) based SET pulse model which can reflect the coupled effect of charge collection and circuit response. We realize this model in SPICE circuit simulator. Experiments show that the SET pulses obtained by our methods agree with device/circuit mix-mode simulation, and our method is much faster.

Soft error induced by SET (single event transient) has been more and more substantial. Previously SET transient current has been careful measure and modeled. However the voltage pulse is more concerned in SET analyze and it is difficult to be measured directly. In this paper, we deduce the relationship between current pulse and voltage pulse and present a numerical technique to accurately estimate transient voltage pulses from measured transient current. The method is validated through device simulation. Experiment results show our method agrees with device simulation, while speed is much faster.

Much effort has been made to estimate SER (Soft error rate) in combinational logic. However, little of them involve glitch reconvergence. In this paper, we discuss how to estimate SER in combinational logic when considering reconvergence. We present Boolean difference expressions for the sensitization condition of six reconvergence categories so that symbolic technique can be used to compute logical masking of reconvergence. We develop an equivalent glitch method so that STA (Static Timing Analysis) like pre- characterization method can be applied to compute electrical masking of reconvergence. Furthermore, latching window masking of reconvergence is discussed. Experiment results of ISCAS'85 benchmark circuit show that considering of reconvergence will cause overall 13.9% SER reduction. The time and memory cost of our method is moderate. And the average error of our method is 3.3% relative to SPICE.

In SMT processor, every thread's executing time will be enlarged due to sharing resource by several threads. It will result in task lost in real time system. In this paper, we present two methods to alleviate the cache conflict in multithread chip, one is protecting the last instructions of master thread, and the other is locking loop. Both methods only need several additional registers. Simulations show that not only the performance of master thread is improved by 14%, but also the IPC of all threads is improved about 6%.

In order to promote the development and utilization of renewable energy, improve the energy structure, diversify energy supplies, safeguard energy security, protect the environment, and realize the sustainable development of the economy and society, the Chinese government is now paying more attention to develop and utilizing the renewable energy in China. The available biomass resources (e.g. straw and crop residues) for energy use in China are abundant. As one bioenergy technology, straw-fired cogeneration technology can provide clean energy in rural areas in China. In recent years, some investors have shown their interests in developing straw-fired cogeneration plants. Some projects are already in the pipeline and the number of projects is expected to increase in the near future. However, there exist technical as well as economic barriers hindering the implementation of straw-fired cogeneration projects. These barriers include 1) feedstock preparation barrier regarding the straw collection, transportation, treatment and storage and less incentives from farmers; 2) some technical and production operation management barriers; 3) over-expected market demands; 4) economic barriers; 5) lack of strong policy support, etc. In this paper, all these barriers have been studied and analyzed. In addition, good management experiences of straw-fired cogeneration plants from European countries have been reviewed as a comparison with those plants in China and based on that, some recommendations have been made to improve the implementation conditions for straw-fired cogeneration projects in China. Godkänd; 2007; 20071121 (joakim)

Chip multi-processors (CMP) are rapidly emerging as an important design paradigm for both high performance and embedded processors[1]. The shared on-chip cache will cause data inconsistent. This paper proposes a specification methodology that documents and specifies a cache coherence protocol in chip multi-processor. This protocol contains five states and we use three state bits to describe these states. In this protocol, we take full advantage of the rapid data exchanging between the processors in CMP. All the processors? level one caches (L1D) link on a ring bus. Every processor can access all L1D?s Tag simultaneously to judge whether or not the memory access hit other L1Ds. We then take a detailed compare between this protocol and MESI protocol. Simulation results show that the MID protocol has an improvement of up to 30% comparing with MESI protocol.

In this paper we present the algorithm of a 16-bit hybrid multiplier, which can work in two modes. In normal mode, it performs a 16-bit multi-plication. In SIMD mode, it performs two parallel 8-bit multiplications. The proposed algorithm is based on the raix-4 modified Booth's algorithm. Our algorithm generates ten partial products and a modifier, which is five less than the other algorithms. We can get one 32-bit product or two 16-bit products by directly accumulating the ten partial products and the modifier, easing the design of the tree structures for compressing the partial products and the final adder. The proposed algorithm is adopted by YHFT-DSP/800, a high perfor-mance fixed-point DSP. The multiplier was full custom designed in 0.18um CMOS technology. We also designed a test chip. The test results show the multiplier works well at 400MHz in normal mode, 480MHz in SIMD mode. The simulated power is 35.8 mW at 400MHz, and 42.5 mW at 480MHz.

To analyze the trap depth and ion heating rate of a surface ion trap under the influence of substrate power loss and voltage loss, in this paper we proposes analytic expressions of trap depth and ion heating rate. The results show that the voltage loss of Si substrate can reduce the trap depth by 17.19%, and the power loss would accelerate the ion heating rate by 13.37%. In order to reduce the influence of substrate effect, a new surface ion trap with low self-heating and voltage-loss is proposed in this paper, whose substrate is insulated by some vacuum trench to reduce the equivalent conductivity and capacitance. The simulation results illuminate that compared with the surface ion trap with normal Si-SiO2 substrate, the one with vacuum trench insulation exhibits a 20.22% increase in trap depth and a 54.44% reduction in power loss.

We propose a configurable surface-electrode ion trap design to alleviate the poor reusability of the existing traps. It can architecturally and electrically support 5 mainstream modes by design reuse, thus enhancing the trap reusability and reducing the experiment setup overhead. We also develop a corresponding simulation suite which can optimize trap geometries and calculate trap parameters to control the trapped ion's classic motion. According to our analytical and simulated results, the configurable design can serve as a unified platform for basic research of large-scale quantum information processing.

This paper investigates the temperature dependence of single-event transients (SETs) in 90-nm complementary metal—oxide semiconductor (CMOS) dual-well and triple-well negative metal—oxide semiconductor field-effect transistors (NMOSFETs). Technology computer-aided design (TCAD) three-dimensional (3D) simulations show that the drain current pulse duration increases from 85 ps to 245 ps for triple-well but only increases from 65 ps to 98 ps for dual-well when the temperature increases from −55 °C to 125 °C, which is closely correlated with the NMOSFET sources. This reveals that the pulse width increases with temperature in dual-well due to the weakening of the anti-amplification bipolar effect while increases with temperature in triple-well due to the enhancement of the bipolar amplification.

In this paper, we investigate the charge sharing collection induced by heavy ion radiation in a tripe well CMOS technology with n+ deep well though 3-D TCAD device simulation. Result shows that n+ deep well will induce the parasitical NPN bipolar transistor, and therefore enhance the charge sharing between NMOS remarkably. The enhancement factor is 24 times that in PNP bipolar in dual well technology. Furthermore, the effects of n-well contact and p-well contact on NPN bipolar are studied. The result shows that the NPN bipolar enhancement factor will decrease with the increase of p-well contact area and with the decreasing of its distance to device, while the NPN bipolar enhancement factor will increase with the increase of n-well contact area.

Annular gate nMOSFETs are frequently used in spaceborne integrated circuits due to their intrinsic good capability of resisting total ionizing dose (TID) effect. However, their capability of resisting the hot carrier effect (HCE) has also been proven to be very weak. In this paper, the reason why the annular gate nMOSFETs have good TID but bad HCE resistance is discussed in detail, and an improved design to locate the source contacts only along one side of the annular gate is used to weaken the HCE degradation. The good TID and HCE hardened capability of the design are verified by the experiments for I/O and core nMOSFETs in a 0.18 μm bulk CMOS technology. In addition, the shortcoming of this design is also discussed and the TID and the HCE characteristics of the replacers (the annular source nMOSFETs) are also studied to provide a possible alternative for the designers.

We propose a hierarchical interconnection network with two-phase bufferless resonant clock distribution, which mixes the advantages of mesh and tree architectures. The problems of skew reduction and variation-tolerance in the mixed interconnection network are studied through a pipelined multiplier under a TSMC 65 nm standard CMOS process. The post-simulation results show that the hierarchical architecture reduces more than 75% and 65% of clock skew compared with pure mesh and pure H-tree networks, respectively. The maximum skew in the proposed clock distribution is less than 7 ps under imbalanced loading and PVT variations, which is no more than 1% of the clock cycle of about 760 ps.

The effect of negative bias temperature instability (NBTI) on a single event transient (SET) has been studied in a 130 nm bulk silicon CMOS process based on 3D TCAD device simulations. The investigation shows that NBTI can result in the pulse width and amplitude of SET narrowing when the heavy ion hits the PMOS in the high-input inverter; but NBTI can result in the pulse width and amplitude of SET broadening when the heavy ion hits the NMOS in the low-input inverter. Based on this study, for the first time we propose that the impact of NBTI on a SET produced by the heavy ion hitting the NMOS has already been a significant reliability issue and should be of wide concern, and the radiation hardened design must consider the impact of NBTI on a SET.