Combinatorial optimization solving by coherent Ising machines based on spiking neural networks

Spiking neural network is a kind of neuromorphic computing that is believed to improve the level of intelligence and provide advantages for quantum computing. In this work, we address this issue by designing an optical spiking neural network and find that it can be used to accelerate the speed of computation, especially on combinatorial optimization problems. Here the spiking neural network is constructed by the antisymmetrically coupled degenerate optical parametric oscillator pulses and dissipative pulses. A nonlinear transfer function is chosen to mitigate amplitude inhomogeneities and destabilize the resulting local minima according to the dynamical behavior of spiking neurons. It is numerically shown that the spiking neural network-coherent Ising machines have excellent performance on combinatorial optimization problems, which is expected to offer new applications for neural computing and optical computing.Comment: 10 pages, 5 figures, accepted by Quantu

Effect of Scrophularia ningpoensis extract on diabetes in rats

Purpose: To investigate the effect of Scrophularia ningpoensis extract (SNE) on streptozotocin-induced diabetic rats.Methods: SNE was obtained by steeping the dried Scrophularia ningpoensis in water at 60 oC three times, each for 1 h, before first drying in an oven at 100 oC and then freeze-drying the last extract thus obtained. Diabetic rats were prepared by a single intraperitoneal injection of a freshly prepared solution of streptozotocin (50 mg/kg). The rats were randomly divided into 6 groups of ten rats each: negative control group, control group, reference group (glibenclamide1 mg/kgbody weight) as well as SNE groups, (50, 100 and 200 mg/kg). Blood glucose and plasma insulin levels were evaluated in order to determine antihyperglycemic effect. Oxidative stress was evaluated in liver and kidney by antioxidant markers, viz, lipid peroxidation (LPO), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT); blood serum levels of creatinine and urea were determined in both diabetic control and treated rats.Results: Compared with diabetic rats, oral administration of SNE at a concentration of 200 mg/kg daily for 30 days showed a significant decrease in fasting blood glucose to 120.21 ± 3.37 mg/dL (p < 0.05) and increased insulin level to 13.31 ± 0.67 uU/mL (p < 0.05). Furthermore, it significantly reduced biochemical parameters (serum creatinine, 0.86 ± 0.24 mg/dL, p < 0.05) and serum urea (41.86 ± 1.59 mg/dL, p < 0.05).Conclusion: The results suggest that SNE may effectively normalize impaired antioxidant status in streptozotocin-induced diabetes in a dose-dependent manner. SNE has a protective effect against lipid peroxidation by scavenging free radicals and is thus capable of reducing the risk of diabetic complications.Keywords: Scrophularia ningpoensis, Diabetic, Antihyperglycemic, Antioxidant Oxidative stress, Fasting blood glucos

Isolation an Antimicrobial Action of Endophytic Fungi from Sophora Flavescens and Effects on Microorganism Circumstances in Soil

AbstractThe aim of this study was to isolate the endophytic fungi from Sophora flavescens and define its antimicrobial action and structure. The effects of this active substance on soil microorganism circumstances were also conducted. Column chromatography and freeze drying were used to isolate and purify the antimicrobial substance. TLC biological autoradiography was applied to trace. HPLC method was employed to measure the purity. Analysis of the structure used 1H-NMR, 13C-NMR and LC-MS methods. Plate method was applied to measure the effect on microorganism circumstances. The results showed that after isolating and purifying the fermentation liquor of BS001, the structure of bacteriostatic active composition was 6,7-(2′E)dibutenyl-5,8-dihydroxy-(Z)-cyclooct-2-ene-1,4-dione, which was identified by spectroscopy. The substance could increase the number of bacteria and fungi while decreased the number of antinomies in soil. A new antimicrobial substance 6,7-(2′E)dibutenyl-5,8 -dihydroxy- (Z)- cyclooct - 2- ene-1,4-dione was extracted from fermenting liquor of BS001 which was an endophytic fungi of Sophora flavescens. It could promote the beneficial flora but detrimental flora. This conclusion provides exploiture foreground for biopharmaceuticals and biopesticide

Electrons dynamics control by shaping femtosecond laser pulses in micro/nanofabrication: modeling, method, measurement and application

During femtosecond laser fabrication, photons are mainly absorbed by electrons, and the subsequent energy transfer from electrons to ions is of picosecond order. Hence, lattice motion is negligible within the femtosecond pulse duration, whereas femtosecond photon-electron interactions dominate the entire fabrication process. Therefore, femtosecond laser fabrication must be improved by controlling localized transient electron dynamics, which poses a challenge for measuring and controlling at the electron level during fabrication processes. Pump-probe spectroscopy presents a viable solution, which can be used to observe electron dynamics during a chemical reaction. In fact, femtosecond pulse durations are shorter than many physical/chemical characteristic times, which permits manipulating, adjusting, or interfering with electron dynamics. Hence, we proposed to control localized transient electron dynamics by temporally or spatially shaping femtosecond pulses, and further to modify localized transient materials properties, and then to adjust material phase change, and eventually to implement a novel fabrication method. This review covers our progresses over the past decade regarding electrons dynamics control (EDC) by shaping femtosecond laser pulses in micro/nanomanufacturing: (1) Theoretical models were developed to prove EDC feasibility and reveal its mechanisms; (2) on the basis of the theoretical predictions, many experiments are conducted to validate our EDC-based femtosecond laser fabrication method. Seven examples are reported, which proves that the proposed method can significantly improve fabrication precision, quality, throughput and repeatability and effectively control micro/nanoscale structures; (3) a multiscale measurement system was proposed and developed to study the fundamentals of EDC from the femtosecond scale to the nanosecond scale and to the millisecond scale; and (4) As an example of practical applications, our method was employed to fabricate some key structures in one of the 16 Chinese National S&T Major Projects, for which electron dynamics were measured using our multiscale measurement system

N′-(4-Hydr­oxy-3-methoxy­benzyl­idene)acetohydrazide monohydrate

In the title compound, C10H12N2O3·H2O, the Schiff base mol­ecule is approximately planar [within 0.189 (1) Å]. The inter­planar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, mol­ecules are linked into a three-dimensional network by strong and weak O—H⋯O and strong N—H⋯O hydrogen bonds. The hydr­oxy H atom deviates from the 4-hydr­oxy-3-methoxy­phenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O—H⋯O hydrogen bond. The weak O—H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R 1 2(4) motif. A weak C—H⋯π inter­action is also present

A Sodium laser guide star coupling efficiency measurement method

Large telescope's adaptive optics (AO) system requires one or several bright artificial laser guide stars to improve its sky coverage. The recent advent of high power sodium laser is perfect for such application. However, besides the output power, other parameters of the laser also have significant impact on the brightness of the generated sodium laser guide star mostly in non-linear relationships. When tuning and optimizing these parameters it is necessary to tune based on a laser guide star generation performance metric. Although return photon flux is widely used, variability of atmosphere and sodium layer make it difficult to compare from site to site even within short time period for the same site. A new metric, coupling efficiency is adopted in our field tests. In this paper, we will introduce our method for measuring the coupling efficiency of a 20W class pulse sodium laser for AO application during field tests that were conducted during 2013-2015