Molecule-based photonically switched half-adder

A molecule-based binary half-adder with optical inputs and outputs has been demonstrated. The half-adder consists of two photochromic organic molecules in solution and a third-harmonic-generating crystal. One substance acts as an AND Boolean logic gate and the other as an XOR gate. Inputs are laser pulses at 1064 or 532 nm that initiate photoisomerization reactions. Outputs are the optical absorbance of a fullerene radical anion (AND gate) and fluorescence of a porphyrin (XOR gate). The system carries out binary addition based on the laser input pulses. Half-adders in combination are capable of carrying out all mathematical operations necessary for digital computing.     

Vibrational computing: simulation of a full adder by optimal control

Within the context of vibrational molecular quantum computing, we investigate the implementation of a full addition of two binary digits and a carry that provides the sum and the carry out. Four qubits are necessary and they are encoded into four different normal vibrational modes of a molecule. We choose the bromoacetyl chloride molecule because it possesses four bright infrared active modes. The ground and first excited states of each mode form the one-qubit computational basis set. Two approaches are proposed for the realization of the full addition. In the first one, we optimize a pulse that implements directly the entire addition by a single unitary transformation. In the second one, we decompose the full addition in elementary quantum gates, following a scheme proposed by Vedral et al. [Phys. Rev. A 54, 147 (1996)]. Four elementary quantum gates are necessary, two two-qubit CNOT gates (controlled NOT) and two three-qubit TOFFOLI gates (controlled-controlled NOT). All the logic operations consist in one-qubit flip. The logic implementation is therefore quasiclassical and the readout is based on a population analysis of the vibrational modes that does not take the phases into account. The fields are optimized by the multitarget extension of the optimal control theory involving all the transformations among the 2(4) qubit states. A single cycle of addition without considering the preparation or the measure or copy of the result can be carried out in a very competitive time, on a picosecond time scale.     

Fe3O4 nanoparticle-integrated graphene sheets for high-performance half and full lithium ion cells

We synthesized Fe(3)O(4) nanoparticle/reduced graphene oxide (RGO-Fe(3)O(4)) nanocomposites and evaluated their performance as anodes in both half and full coin cells. The nanocomposites were synthesized through a chemical co-precipitation of Fe(2+) and Fe(3+) in the presence of graphene oxides within an alkaline solution and a subsequent high-temperature reduction reaction in argon (Ar) environment. The morphology and microstructures of the fabricated RGO-Fe(3)O(4) nanocomposites were characterized using various techniques. The results indicated that the Fe(3)O(4) nanoparticles had relatively homogeneous dispersions on the RGO sheet surfaces. These as-synthesized RGO-Fe(3)O(4) nanocomposites were used as anodes for both half and full lithium-ion cells. Electrochemical measurement results exhibit a high reversible capacity which is about two and a half times higher than that of graphite-based anodes at a 0.05C rate, and an enhanced reversible capacity of about 200 mAh g(-1) even at a high charge/discharge rate of 10C (9260 mA g(-1)) in half cells. Most important of all, these fabricated novel nanostructures also show exceptional capacity retention with the assembled RGO-Fe(3)O(4)/LiNi(1/3)Mn(1/3)Co(1/3)O(2) full cell at different C rates. This outstanding electrochemical behavior can be attributed to the unique microstructure, morphology, texture, surface properties of the nanocomposites, and combinative effects from the different chemical composition in the nanocomposites.     

Computational investigation and experimental considerations for the classical implementation of a full adder on SO2 by optical pump-probe schemes

Following the scheme recently proposed by Remacle and Levine [Phys. Rev. A 73, 033820 (2006)], we investigate the concrete implementation of a classical full adder on two electronic states (X 1A1 and C 1B2) of the SO2 molecule by optical pump-probe laser pulses using intuitive and counterintuitive (stimulated Raman adiabatic passage) excitation schemes. The resources needed for providing the inputs and reading out are discussed, as well as the conditions for achieving robustness in both the intuitive and counterintuitive pump-dump sequences. The fidelity of the scheme is analyzed with respect to experimental noise and two kinds of perturbations: The coupling to the neighboring rovibrational states and a finite rotational temperature that leads to a mixture for the initial state. It is shown that the logic processing of a full addition cycle can be realistically experimentally implemented on a picosecond time scale while the readout takes a few nanoseconds.     

Construction of CoS_2 nanoparticles embedded in well-structured carbon nanocubes for high-performance potassium-ion half/full batteries

Metal sulfides have been widely investigated as promising electrode materials for potassium-ion batteries(PIBs) due to their high theoretical capacities.However,the practical application of metal sulfides in PIBs is still hindered by their intrinsic shortcomings of low conductivity and severe volume changes during the potassiation/depotassiation process.Herein,a simple template-based two-step annealing strategy is proposed to impregnate CoS_2 nanoparticles in the well-structured carbon nanocubes(denoted CoS_2/CNCs) as an advanced anode material for PIBs.The ex-situ XRD measurements reveal the K storage mechanism in CoS_2/CNCs.Benefiting from the unique structures,including abundant active interfacial sites,high electronic conductivity,and significantly alleviated volume variation,CoS_2/CNCs present a high specific capacity(537.3 mAh g~(-1) at0.1 A g~(-1)),good cycling stability(322.4 mAh g~(-1) at 0.5 A g~(-1) after 300 cycles),and excellent rate capability(153.1 mAh g~(-1) at5 A g~(-1)).Moreover,the obtained nanocomposite shows superior potassium storage properties in K-ion full cells when it is coupled with a KVP04 F cathode.     

Ultrafine SnSSe/multilayer graphene nanosheet nanocomposite as a high-performance anode material for potassium-ion half/full batteries

Layer-structured SnSSe attracts much attention as an anode material for potassium storage due to its large theoretical capacity.Unfortunately,their practical ap...     

Strategy for the elucidation of elemental compositions of trace analytes based on a mass resolution of 100 000 full width at half maximum

Elemental compositions (ECs) can be elucidated by evaluating the high‐resolution mass spectra of unknown or suspected unfragmented analyte ions. Classical approaches utilize the exact mass of the monoisotopic peak (M + 0) and the relative abundance of isotope peaks (M + 1 and M + 2). The availability of high‐resolution instruments like the Orbitrap currently permits mass resolutions up to 100 000 full width at half maximum. This not only allows the determination of relative isotopic abundances (RIAs), but also the extraction of other diagnostic information from the spectra, such as fully resolved signals originating from ³⁴S isotopes and fully or partially resolved signals related to ¹⁵N isotopes (isotopic fine structure). Fully and partially resolved peaks can be evaluated by visual inspection of the measured peak profiles. This approach is shown to be capable of correctly discarding many of the EC candidates which were proposed by commercial EC calculating algorithms. Using this intuitive strategy significantly extends the upper mass range for the successful elucidation of ECs. Copyright © 2010 John Wiley & Sons, Ltd.     

Bi2S3 spheres coated with MOF-derived Co9S8 and N-doped carbon composite layer for half/full sodium-ion batteries with superior performance

Bismuth sulfide (Bi2S3) has attracted particular interest as a potential anode material for sodium-ion batteries (SIBs).However,the low electrical conductivity ...     

分子基磁体[NCBzPy][Ni(dmit)2]的合成、表征和磁学性质

合成了一种新的取代苄基吡啶盐[NcBzpy]cl(1),1和NiCl2,dmit^2-反应生成分子基磁体[NCBzPy][Ni(dmit)2](2),其结构用元素分析、IR和UV进行了表征。并测定了2在2K～300K的变温磁化率,结果显示。相邻Ni^3 之间存在铁磁偶合作用。     

A potential and ion switched molecular photonic logic gate

A molecular photonic logic gate is demonstrated by integrating electrical (potential) and chemical (ionic) switching functions into molecules attached at an externally addressable semiconductor substrate.     

Synthesis of the western half of the lolicines and lolitrems

[reaction: see text] The synthesis of the highly substituted indole portion of the complex tremorgenic natural products lolicine A and B is presented. The Diels-Alder reaction of a quinone monoimine enables the synthesis of an appropriately substituted indole. The key step in the synthesis is a tandem isopropenyl cuprate addition/aldol cyclocondensation which provides the necessary functionality for elaboration to the 2,2,5,5-tetramethyltetrahydrofuran.     

Photo-induced colour generation and colour erasing switched by the sol-gel phase transition

The controlled colour generation and colour erasing phenomena of alkylammonium polyoxomolybdate complexes were first observed in the trans-(1R,2R)-1,2-bis(undecylcarbonylamino)cyclohexane organogel system using the sol-gel phase transition.     

苯甲醛衍生物的结构与其半波电位关系的研究

以半经验分子轨道方法计算苯甲醛衍生物的分子结构参数，以多元线性回归方法研究了苯甲醛衍生物的半波电位与其分子结构参数间的关系。研究发现，在所选择的２３个分子结构参数中，基态双中心总能量（ＥＴ（ｔｗｏ）、电离势（Ｉｐ）及分子的生成热（Ｈｆ）与其半波电位有较好的相关性。其回归方程为：ｙ＝－５．４２３２＋０．５４７７８Ｉｐ－３．３３１＊１０＾－３Ｅｔ（ｔｗｏ）－１．６７０＊１０＾－３Ｈｆ（ｒＲＣ＝０．９２     

Analytical chemistry and the law: progress for half a millennium

Chemistry has been used for the detection of adulteration since the earliest times of recorded history going back at least 3 1/2 millennia. Since the invention of printing the subject is easier to follow. Aspects of law and its application via chemistry in regard to precious metals, food, drink and medicinal materials are reviewed over the last half millennium with particular reference to the U.K.     

Electrospray liquid chromatography/mass spectrometry fingerprinting of Acanthophis (death adder) venoms: taxonomic and toxinological implications

Death adders (genus Acanthophis) are unique among elapid snakes in both morphology and venom composition. Despite this genus being among the most divergent of all elapids, the venom has been historically regarded as relatively quite simple. In this study, liquid chromatography/mass spectrometry (LC/MS) analysis has revealed a much greater diversity in venom composition, including the presence of molecules of novel molecular weights that may represent a new class of venom component. Furthermore, significant variation exists between species and populations, which allow for the LC/MS fingerprinting of each species. Mass profiling of Acanthophis venoms clearly demonstrates the effectiveness of this technique which underpins fundamental studies ranging from chemotaxonomy to drug design.     

Depolarization and fine structure effects in half collisions of sodium-noble gas systems

Population ratios and polarization of the Na3P _J fine structure states following far wing photon excitation of Na-noble gas collision pairs are studied with respect to the underlying interaction potentials and molecular coupling schemes. For this purpose spectral profiles of these quantities, i.e. its dependencies on excitation frequency, have been measured up to ±200 cm^?1 detuning from the NaD lines for NaAr and NaHe under nearly single collision conditions. Comparing the measured population ratios with quantummechanical coupled channels calculations the Σ potential well depths differ considerably from results of model potential calculations. Large residualJ=3/2 alignment observed in the far wings disagrees with simple models assuming incoherent excitation and/or full adiabatic reorientation of the radiating dipole along straight trajectories. By comparison with Lewis model calculations, using realistic trajectories and decoupling radius, it is found instead, that realistic trajectories are constitutive for alignment after Σ-excitation (blue wing), whereas coherence between the²Π_1/2 and²Π_3/2 states determine primarily alignment after Π-excitation (red wing).     

Calculation of standard electrode potential of half reaction for benzoquinone and hydroquinone

Geometric parameters, the vibrational frequencies and thermochemical values of benzoquinone and hydroquinone were computed using ab initio molecular orbital calculations (HF) and density function theory (B3LYP) methods with the 6-31G(d) basis set, respectively. The calculated frequencies for benzoquinone and hydroquinone were used for the assignment of the IR frequencies observed in the experimental IR spectrum. Cyclic voltammetry with a glassy carbon electrode of hydroquinone solutions in phosphate buffers at pH 7.0 showed that standard electrode potential of half reaction for benzoquinone and hydroquinone is 0.714V. Standard electrode potential of half reaction for benzoquinone and hydroquinone was calculated using the sum of electronic and thermal free energies, enthalpies of sublimation and energies of solvation for benzoquinone and hydroquinone.     

Dynamics of three-body half collisions: Ultraviolet and visible photodissociation of s-tetrazine

Ultraviolet (266 nm) and visible (532 nm) photodissociation of collision-free s-tetrazine show asymmetric dynamics with production of one translationally cool and one translationally hot HCN molecule. Furthermore, visible and ultraviolet dynamics are nearly identical, arguing that two-photon excitation is necessary for photodissociation in the visible.