Super-compact universal quantum logic gates with inversedesigned elements

Integrated quantum photonic circuit is a promising platform for the realization of quantum information processing in the future. To achieve the largescale quantum photonic circuits, the applied quantum logic gates should be as small as possible for the high-density integration on chips. Here, we report the implementation of super-compact universal quantum logic gates on silicon chips by the method of inverse design. In particular, the fabricated controlled-NOT gate and Hadamard gate are both nearly a vacuum wavelength, being the smallest optical quantum gates reported up to now. We further design the quantum circuit by cascading these fundamental gates to perform arbitrary quantum processing, where the corresponding size is about several orders smaller than that of previous quantum photonic circuits. Our study paves the way for the realization of largescale quantum photonic chips with integrated sources, and can possess important applications in the field of quantum information processes

Oxidative kinetic resolution of racemic secondary alcohols in water with chiral PNNP/Ir catalyst

National Natural Science Foundation of China [20423002, 20923004, 21173176]; NFFTBS [J1030415]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036]; State Key Laboratory of Physical Chemistry of Solid SurfacesUsing water as solvent, the oxidative kinetic resolution of a wide range of racemic secondary alcohols with a chiral PNNP/Ir catalyst was investigated. The catalytic reaction proceeded smoothly with excellent enantioselectivity (up to 97% ee) under mild conditions, providing an environmentally benign process to achieve optically active alcohols

Absolute asymmetric synthesis and resolution mechanism of chiral cis-bromoamminebis(ethylenediamine)cobalt(III) bromide

The absolute asymmetric synthesis of the title complexes Lambda-(+)(D)-cis-[CoBr(NH3)(en)(2)]Br-2(1) and Delta-(-)(D)-cis-[CoBr(NH3)(en)(2)]Br-2(2)(en=1,2-ethylenediamine) as well as the improved optical resolution of cis-[CoBr(NH3)(en)(2)]Br-2.2H(2)O(3) are described in detail. The products were characterized by means of elemental analysis, TG-DTA, optical rotation, UV-Vis, and CD spectra. The distribution of enantiomeric excess(ee) of cis-[CoBr(NH3)(en)(2)]Br-2 in the absolute asymmetric synthesis was obtained by the measurements of their CD spectra. It was found that the complete resolution of rac-cis-[CoBr(NH3)(en)(2)]Br-2.2H(2)O was achieved by use of NH4(d-BCS) (ammonium d-alpha-bromocamphor-pi-sulfonate) or NH4(l-BCS) while NH4(dl-BCS) could only be partially resolved by chiral cis-[CoBr(NH3)(en)(2)]Br-2 at the same condition. It is deduced that there are notable differences in the chiral discrimination of the reciprocal resolution between cis-[CoBr(NH3)(en)(2)]Br-2 and NH4BCS. Moreover, a new "catalysis-crystal induction" mechanism in the preparation of the chiral Co(III) complex is put forward

Iron-Catalyzed Highly Enantioselective Reduction of Aromatic Ketones with Chiral P2N4-Type Macrocycles

National Natural Science Foundation of China [20423002, 20923004, 21173176]; Program for Changjiang Scholars and Innovative Research Team in University [IRT1036]; State Key Laboratory of Physical Chemistry of Solid SurfacesNovel P2N4-donors containing chiral 22-membered macrocyclic ligands have been synthesized and the structures have been determined by an X-ray diffraction study. The catalytic systems in situ generated from triiron dodecarbonyl, Fe3(CO)12, and the chiral macrocyclic ligand exhibited high activity (TOF up to 1940 h-1) and excellent enantioselectivity with up to 99% ee in the asymmetric transfer hydrogenation of various aromatic ketones

Iron catalyzed asymmetric hydrogenation of ketones

Chiral molecules, such as alcohols, are vital for the manufacturing of fine chemicals, pharmaceuticals, agrochemicals, fragrances, and novel materials. These molecules need to be produced in high yield and high optical purity and preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetric hydrogenation with H2 (AH) is the most widely used in the industry. With few exceptions, these AH processes use catalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium and rhodium catalysts. By combining a chiral, 22-membered macrocyclic ligand with the cheap, readily available Fe 3(CO)12, a wide variety of ketones have been hydrogenated under 50 bar H2 at 45-65 C, affording highly valuable chiral alcohols with enantioselectivities approaching or surpassing those obtained with the noble metal catalysts. In contrast to AH by most noble metal catalysts, the iron-catalyzed hydrogenation appears to be heterogeneous. ? 2014 American Chemical Society

Iron Catalyzed Asymmetric Hydrogenation of Ketones

Chiral molecules, such as alcohols, are vital for the manufacturing of fine chemicals, pharmaceuticals, agrochemicals, fragrances, and novel materials. These molecules need to be produced in high yield and high optical purity and preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetric hydrogenation with H₂ (AH) is the most widely used in the industry. With few exceptions, these AH processes use catalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium and rhodium catalysts. By combining a chiral, 22-membered macrocyclic ligand with the cheap, readily available Fe₃(CO)₁₂, a wide variety of ketones have been hydrogenated under 50 bar H₂ at 45–65 °C, affording highly valuable chiral alcohols with enantioselectivities approaching or surpassing those obtained with the noble metal catalysts. In contrast to AH by most noble metal catalysts, the iron-catalyzed hydrogenation appears to be heterogeneous

Kinect-based objective evaluation of bradykinesia in patients with Parkinson's disease

Objective To quantify bradykinesia in Parkinson's disease (PD) with a Kinect depth camera-based motion analysis system and to compare PD and healthy control (HC) subjects. Methods Fifty PD patients and twenty-five HCs were recruited. The Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III) was used to evaluate the motor symptoms of PD. Kinematic features of five bradykinesia-related motor tasks were collected using Kinect depth camera. Then, kinematic features were correlated with the clinical scales and compared between groups. Results Significant correlations were found between kinematic features and clinical scales ( P  < 0.05). Compared with HCs, PD patients exhibited a significant decrease in the frequency of finger tapping ( P  < 0.001), hand movement ( P  < 0.001), hand pronation-supination movements ( P  = 0.005), and leg agility ( P  = 0.003). Meanwhile, PD patients had a significant decrease in the speed of hand movements ( P  = 0.003) and toe tapping ( P  < 0.001) compared with HCs. Several kinematic features exhibited potential diagnostic value in distinguishing PD from HCs with area under the curve (AUC) ranging from 0.684–0.894 ( P  < 0.05). Furthermore, the combination of motor tasks exhibited the best diagnostic value with the highest AUC of 0.955 (95% CI = 0.913–0.997, P  < 0.001). Conclusion The Kinect-based motion analysis system can be applied to evaluate bradykinesia in PD. Kinematic features can be used to differentiate PD patients from HCs and combining kinematic features from different motor tasks can significantly improve the diagnostic value