反应堆热工水力中CATHARE与TRIO_U程序耦合分析研究

采用区域覆盖的耦合方法对一维系统程序CATHARE与三维计算流体力学(CFD)程序TRIO_U进行耦合分析研究,对文中建立的简易模型进行稳态计算,通过耦合前程序误差、耦合平台误差测试,确认解析解、系统程序计算结果、TRIO_U程序计算以及单个程序均与耦合平台耦合计算结果吻合。分别对3个不同的源项区域(热源、动量源、热交换区域)进行耦合计算,并与CATHARE计算结果进行比较。研究结果表明,耦合方法可以模拟算例中所建立的整个反应堆的简易模型。

Orf1/SpcS Chaperones ExoS for Type Three Secretion by Pseudomonas aeruginosa

Objective Pseudomonas aeruginosa is a ubiquitous and opportunistic pathogen that uses the type Ⅲ secretion system （TTSS） to inject effector proteins directly into the cytosol of target cells to subvert the host cell＇s functions. Specialized bacterial chaperones are required for effective secretion of some effectors. To identify the chaperone of ExoS, the representative effector secreted by the TTSS of P aeruginosa, we analyzed the role of a postulated chaperone termed Orfl. Methods By allelic exchange, we constructed the mutant with the deletion of gene Orfl. Analysis of secreted and cell-associated fractions was performed by SDS-PAGE and Western blotting. Using strain expressing in trans Orfl, tagged by V5 polypeptide and histidine, protein-protein interaction was determined by affinity resin pull-down assay in combination with MALDI-TOF The role of Orfl in the expression of exoS was evaluated by gene reporter analysis. Results Pull-down assay showed that Orfl binds to ExoS and ExoT. Secretion profile analysis showed that Orfl was necessary for the optimal secretion of ExoS and ExoT. However, Orfl had no effect on the expression of exoS. Conclusion Orfl is important for the secretion of ExoS probably by maintaining ExoS in a secretion-competent conformation. We propose to name Orfl as SpcS for ＂specific Pseudomonas chaperone for ExoS＂.

A Newly Designed 14.5 GHz All Permanent ECR Ion Source in IMP

A new all permanent ECR (Electron Cyclotron Resonance) ion source LAPECR2 (Lanzhou All Permanent ECRIS No. 2) is now under developing in IMP. This source will be used to set up on thc IMP 400 HV (High Voltage) platform. This HV platform aims to deliver high ion beams from low charge state to very high charge state, so the rigorous requirement to this ECRIS is obvious. To satisfy this requirement, the ion source is designed to be a very large one, which has very large volumc plasma chamber, larger ECR length and mirror length, and very strong 3 -dimension magnetic field. The detail parameters, are shown in Table 1 listed below.

Impedancemetry of multiplexed quantum devices using an on-chip cryogenic complementary metal-oxide-semiconductor active inductor

In the pursuit for scalable quantum processors,significanteffort has been devoted to the development of cryogenic classical hardware for the control and readout of a growingnumber of qubits.The current work presented a novelapproach called impedancemetry that is suitable for measuringthe quantum capacitance of semiconductor qubits connected toa resonant LC-circuit.The impedancemetry circuit exploits theintegration of a complementary metal-oxide-semiconductor(CMOS)active inductor in the resonator with tunable resonance frequency and quality factor,enabling the optimizationof readout sensitivity for quantum devices.The realized cryogenic circuit allows fast impedance detection with a measuredcapacitance resolution down to 10 aF and an input-referrednoise of 3.7 aF/Hz p.At 4.2 K,the power consumption of theactive inductor amounts to 120μW,with an additional dissipation for on-chip current excitation(0.15μW)and voltageamplification(2.9 mW)of the impedance measurement.Compared to the commonly used schemes based on dispersiveRF reflectometry which require millimeter-scale passive inductors,the circuit exhibits a notably reduced footprint(50μm360μm),facilitating its integration in a scalable quantumclassical architecture.The impedancemetry method has been applied at 4.2 K to the detection of quantum effects in the gatecapacitance of on-chip nanometric CMOS transistors that areindividually addressed via multiplexing.

ECR离子源六极永磁体的设计研究

分别从材料、结构、尺寸等方面全面地研究了Halbach结构六极永磁铁的设计方法 .针对个别磁块可能存在的退磁问题给出了相应的解决方案 .通过优化结构 ,使六极磁铁在离子源等离子体弧腔内壁产生的磁场达到最大 .用POISSON ,PERMAG ,TOSCA等多个磁场模拟程序计算模拟了六极磁场的大小与分布 。

Ion Channels in Plant Bioenergetic Organelles, Chloroplasts and Mitochondria： From Molecular Identification to Function

Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioenergetic organelles, chloroplasts and mitochondria, leading to the molecular identification and functional characterization of several ion transport systems in recent years. Here we focus on channels that mediate relatively high-rate ion and water flux and summarize the current knowledge in this field, focusing on targeting mechanisms, proteomics, electrophysiology, and physiological function. In addition, since chloroplasts evolved from a cyanobacterial ancestor, we give an overview of the information available about cyanobacterial ion channels and discuss the evolutionary origin of chloroplast channels. The recent molecular identification of some of these ion channels allowed their physiological functions to be studied using genetically modified Arabidopsis plants and cyanobacteria. The view is emerging that alteration of chloroplast and mitochondrial ion homeostasis leads to organelle dysfunction, which in turn significantly affects the energy metabolism of the whole organism. Clear-cut identification of genes encoding for chan- nels in these organelles, however, remains a major challenge in this rapidly developing field. Multiple stra- tegies including bioinformatics, cell biology, electrophysiology, use of organelle-targeted ion-sensitive probes, genetics, and identification of signals eliciting specific ion fluxes across organelle membranes should provide a better understanding of the physiological role of organellar channels and their contribution to signaling pathways in plants in the future.

Meta-Analysis of Retrograde Signaling in Arabidopsis thaliana Reveals a Core Module of Genes Embedded in Complex Cellular Signaling Networks

Plastid-to-nucleus signaling is essential for the coordination and adjustment of cellular metabolism in response to environmental and developmental cues of plant cells. A variety of operational retrograde signaling path- ways have been described that are thought to be triggered by reactive oxygen species, photosynthesis redox imbalance, tetrapyrrole intermediates, and other metabolic traits. Here we report a meta-analysis based on transcriptome and pro- tein interaction data. Comparing the output of these pathways reveals the commonalities and peculiarities stimulated by six different sources impinging on operational retrograde signaling. Our study provides novel insights into the interplay of these pathways, supporting the existence of an as-yet unknown core response module of genes being regulated under all conditions tested. Our analysis further highlights affiliated regulatory cis-elements and classifies abscisic acid and auxin-based signaling as secondary components involved in the response cascades following a plastidial signal. Our study provides a global analysis of structure and interfaces of different pathways involved in plastid-to-nucleus signaling and a new view on this complex cellular communication network.

A convolutional neural network for defect classification in Bragg coherent X-ray diffraction

Coherent diffraction imaging enables the imaging of individual defects,such as dislocations or stacking faults,in materials.These defects and their surrounding elastic strain fields have a critical influence on the macroscopic properties and functionality of materials.However,their identification in Bragg coherent diffraction imaging remains a challenge and requires significant data mining.The ability to identify defects from the diffraction pattern alone would be a significant advantage when targeting specific defect types and accelerates experiment design and execution.Here,we exploit a computational tool based on a three-dimensional(3D)parametric atomistic model and a convolutional neural network to predict dislocations in a crystal from its 3D coherent diffraction pattern.Simulated diffraction patterns from several thousands of relaxed atomistic configurations of nanocrystals are used to train the neural network and to predict the presence or absence of dislocations as well as their type(screw or edge).Our study paves the way for defect-recognition in 3D coherent diffraction patterns for material science.

Targets for high repetition rate laser facilities:needs,challenges and perspectives

A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.

Assembly of a parts list ofthe human mitotic cell cycle machinery

The set of proteins required for mitotic division remains poorly characterized. Here, an extensive series of correlation analyses of human and mouse transcriptomics data were performed to identify genes strongly and reproducibly associated with cells undergoing S/G2-M phases of the cell cycle. In so doing, 701 cell cycle-associated genes were defined and while it was shown that many are only expressed during these phases, the expression of others is also driven by alternative promoters. Of this list, 496 genes have known cell cycle functions, whereas 205 were assigned as putative cell cycle genes, 53 of which are functionally uncharacterized. Among these, 27 were screened for subcellular localization revealing many to be nuclear localized and at least three to be novel centrosomal proteins. Furthermore, 10 others inhibited cell proliferation upon siRNA knockdown. This study presents the first comprehensive list of human cell cycle proteins, identifying many new candidate proteins.