溶液堆物理计算程序FMCAHR开发

针对溶液型燃料反应堆,基于蒙特卡罗输运计算方法,开发了溶液堆物理计算程序FMCAHR,该程序具有共振处理、搜索临界棒位、热工水力参数计算、气泡体积含量计算和燃耗计算的功能。对程序进行校算的结果证明该程序计算精度较高。

RIGHT INFERIOR FRONTAL GYRUS PROCESSING OF VISUAL EROTIC INFORMATION BASED ON fMRI

Visually-induced erotic arousal evoked by pornographic visual stimuli, such as films or photographs, is a common occurrence in human behavior. The brain activation associated with visual erotic stimuli in heterosexual right handed females is studied. Functional magnetic resonance imaging is used to investigate 15 female partici- panterotic arousal induced by visual stimuli in film and picture forms, respectively, performing three or more times during their menstrual cycle on a 3.0T magnetic resonance imaging scanner. There is activation of a set of bilateral brain areas, including the inferior lateral occipital cortex, the anterior supramarginal gyrus, the parietal operculum cortex, the superior parietal lobules, the right inferior frontal gyrus, the cerebellum, the hypothalamus, the thalamus, the hippocampus, and the mid-brain. From different regions, the brain activation is observed and the inferior frontal gyrus has found to be task-independent. Furthermore, the right inferior frontal gyrus has more activation than the left inferior frontal gyrus. The result shows that the right inferior frontal gyrus plays an important role in pornographic information processing rather than being activated stimuli property specific. It is presented for the first time that the functional laterization of the inferior frontal gyrus is bi-directional rather than single （left） directional.

Corresponding Factors Influencing Crude Oils Assay Using Low-field Nuclear Magnetic Resonance

In this study, the main factors influencing the measurements by means of the off-line low-field 1H NMR in the lab were discussed base on a robust calibration model established by the PLS algorithm using 255 crude oil samples. The preheating temperature had a great influence on the viscosity of oil samples and the resolution of spectral analysis. The repeatability of spectral measurements was impacted by the metal and wax content of the oil samples. For the case of high wax content oils, the wax species began to crystallize in the course of determination that could affect the repeatability of spectral measurements. These factors have evidenced why the preheating devices and filter unit are necessary when low field NMR system is used in the online analysis process. The investigation is very important for the on-line application of the low field NMR.

同步齿轮箱初始故障在线监测与诊断装置研究

该装置提出一种同步齿轮箱初始故障的在线监测与诊断的装置,即可以在设备的运行中或基本不拆卸全部设备的情况下监测出问题的装置。该装置与故障诊断专(家)系统与诊断技术相结合,使监测系统的安全性和稳定性得到保障,更便于工作人员操作使用。

基于无监督学习的医学图像分割算法

图像分割是研究大脑结构和功能的基础。本文基于无监督机器学习提出一种面向猕猴脑图像的自动化分割算法。基于非线性最小二乘法构建主成分流程框架,确定图像分割聚类数,通过谱聚类算法得到感兴趣区域的分割结果,使用克莱姆相关系数和拓扑相似性指标交叉对比验证结果。实验结果表明,本文算法可靠性较好,能够自动、高效、快速的实现脑图像分割,具有广阔的优势和应用前景。

Neural Mechanism in Emotion Regulation by Simultaneous Recording of EEG and fMRI

The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive study of cognitive brain function. In this paper, we record simultaneous EEG-fMRI of the same subject in emotional processing experiment in order to explore the characteristics of different emotional picture processing, and try to find the difference of the subjects' brain hemisphere while viewing different valence emotional pictures. The late positive potential(LPP) is a reliable electrophysiological index of emotional perception in humans. According to the analysis results, the slow-wave LPP and visual cortical blood oxygen level-dependent (BOLD) signals are both modulated by the rated intensity of picture arousal. The amplitude of the LPP correlate significantly with BOLD intensity in visual cortex, amygdala, temporal area, prefrontal and central areas across picture contents.

Wavelet-Based Diffusion Approach for DTI Image Restoration

The Rician noise introduced into the diffusion tensor images （DTIs） can bring serious impacts on tensor calculation and fiber tracking. To decrease the effects of the Rician noise, we propose to consider the wavelet-based diffusion method to denoise multiehannel typed diffusion weighted （DW） images. The presented smoothing strategy, which utilizes anisotropic nonlinear diffusion in wavelet domain, successfully removes noise while preserving both texture and edges. To evaluate quantitatively the efficiency of the presented method in accounting for the Rician noise introduced into the DW images, the peak-to-peak signal-to-noise ratio （PSNR） and signal-to-mean squared error ratio （SMSE） metrics are adopted. Based on the synthetic and real data, we calculated the ap- parent diffusion coefficient （ADC） and tracked the fibers. We made comparisons between the presented model, the wave shrinkage and regularized nonlinear diffusion smoothing method. All the experiment results prove quantitatively and visually the better performance of the presented filter.

The Status of the Isotope Separation by PSP

Experiments, prqiects and patents, concerning practical usage of a separation method, based on ICR （ion cyclotron resonance） in plasma, carried out in the 2000s in USA, EU and in Russia, are discussed in this article. It was planned to use ICR method for production of isotopically enriched burnable poisons for nuclear reactor fuel, and also to use this method for extraction of neutron-excess isotopes for the purpose of observation of neutrinoless double beta decay （ββ0v）. One more application of this method can be a nuclear waste treatment technology. Current situation with realization of these plans is considered.

Experimental quantum deletion in an NMR quantum information processor

We report an NMR experimental realization of a rapid quantum deletion algorithm that deletes marked states in an unsorted database.Unlike classical deletion,where search and deletion are equivalent,quantum deletion can be implemented with only a single query,which achieves exponential speed-up compared to the optimal classical analog.In the experimental realization,the GRAPE algorithm was used to obtain an optimized NMR pulse sequence,and the efficient method of maximum-likelihood has been used to reconstruct the experimental output state.

Experimental realization of single-shot nonadiabatic holonomic gates in nuclear spins

Nonadiabatic holonomic quantum computation has received increasing attention due to its robustness against control errors. However, all the previous schemes have to use at least two sequentially implemented gates to realize a general one-qubit gate. Based on two recent reports, we construct two Hamiltonians and experimentally realized nonadiabatic holonomic gates by a single-shot implementation in a two-qubit nuclear magnetic resonance （NMR） system. Two noncommuting one-qubit holonomic gates, rotating along .~ and ~ axes respectively, are implemented by evolving a work qubit and an ancillary qubit nonadiabatically following a quantum circuit designed. Using a sequence compiler developed for NMR quantum information processor, we optimize the whole pulse sequence, minimizing the total error of the implementation. Finally, all the nonadiabatic holonomic gates reach high unattenuated experimental fidelities over 98%.

Quantum state and process tomography via adaptive measurements

We investigate quantum state tomography(QST) for pure states and quantum process tomography(QPT) for unitary channels via adaptive measurements. For a quantum system with a d-dimensional Hilbert space, we first propose an adaptive protocol where only 2d. 1 measurement outcomes are used to accomplish the QST for all pure states. This idea is then extended to study QPT for unitary channels, where an adaptive unitary process tomography(AUPT) protocol of d2+d.1measurement outcomes is constructed for any unitary channel. We experimentally implement the AUPT protocol in a 2-qubit nuclear magnetic resonance system. We examine the performance of the AUPT protocol when applied to Hadamard gate, T gate(/8 phase gate), and controlled-NOT gate,respectively, as these gates form the universal gate set for quantum information processing purpose. As a comparison, standard QPT is also implemented for each gate. Our experimental results show that the AUPT protocol that reconstructing unitary channels via adaptive measurements significantly reduce the number of experiments required by standard QPT without considerable loss of fidelity.

Ag nanoparticles preparation and their light trapping performance

Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis ratio decreases with the increase of annealing temperature,and a shape transformation from ellipsoid to sphere occurs when the temperature increases to a critical point.The experimental results showed that the surface plasmon resonances depend greatly on the nanoparticles'shape and size,which is in accordance with the theoretical calculation based on discrete dipole approximation.The results of forward-scattering efficiency(FSE) and light trapping spectrum(LTS) showed that Ag nanoparticles annealed at 400°C could strongly enhance the light harvest than those annealed at 300 and 500°C,and that the LTS peak intensity of the former is 1.7 and 1.5 times stronger than those of the later two samples,respectively.The conclusions obtained in this paper showed that Ag ellipsoid nanoparticles with appropriate size is more favorable for enhancing the light trapping.