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1. chinaXiv:201707.00113 [pdf]

A New Measurement of the Spectral Lag of Gamma-Ray Bursts and its Implications for Spectral Evolution Behaviors

Shao, Lang; Zhang, Bin-Bin ; Wang, Fu-Ri; Wu, Xue-Feng; Cheng, Ye-Hao; Zhang, Xi; Yu, Bang-Yao; Xi, Bao-Jia; Wang, Xue; Feng, Huan-Xue; Zhang, Meng; Xu, Dong
Subjects: Astronomy >> Astrophysics

We carry out a systematical study of the spectral lag properties of 50 single-pulsed Gamma-Ray Bursts (GRBs) detected by Fermi/GBM. By dividing the light curves into multiple consecutive energy channels we provide a new measurement of the spectral lag which is independent on energy channel selections. We perform a detailed statistical study of our new measurements. We find two similar power-law energy dependencies of both the pulse arrival time and pulse width. Our new results on the power-law indices would favor the relativistic geometric effects for the origin of spectral lag. However, a complete theoretical framework that can fully account for the diverse energy dependencies of both arrival time and pulse width revealed in this work is still missing. We also study the spectral evolution behaviors of the GRB pulses. We find that the GRB pulse with negligible spectral lag would usually have a shorter pulse duration and would appear to have a ``hardness-intensity tracking'' (HIT) behavior and the GRB pulse with a significant spectral lag would usually have a longer pulse duration and would appear to have a ``hard-to-soft'' (HTS) behavior.

submitted time 2017-07-13 Hits6531Downloads1228 Comment 0

2. chinaXiv:201609.00914 [pdf]

Aging effect in the BESIII drift chamber

DONG Ming-Yi; XIU Qing-Lei; WU Ling-Hui; WU Zhi; QIN Zhong-Hua; SHEN Pin; AN Fen-Fen; JU Xu-Dong; LIU Yi; ZHU Kai; OU-YANG Qun; CHEN Yuan-Bo
Subjects: Physics >> Nuclear Physics

As the main tracking detector of BESIII, the drift chamber works for accurate measurements of the tracking and the momentum of the charged particles decayed from the reaction of BEPCII e+ and e-. After operation six years, the drift chamber is suffering from aging problems due to huge beam related background. The gains of the cells in the first ten layers experience an obvious decrease, reaching a maximum of about 29% for the first layer cells. Two calculation methods for the gains change (Bhabha events and accumulated charges with 0.3% aging ratio for inner chamber cells) get almost the same results. For the Malter effect encountered by the inner drift chamber in Jan., 2012, about 0.2% water vapor was added to MDC gas mixture to solve this cathode aging problem. These results provide an important reference for MDC operation high voltage setting and the upgrade of the inner drift chamber.

submitted time 2016-09-13 Hits1265Downloads711 Comment 0

3. chinaXiv:201609.00906 [pdf]

Study of cluster reconstruction and track fitting algorithms for CGEM-IT at BESIII

GUO Yue; WANG Liang-Liang; JU Xu-Dong; WU Ling-Hui; XIU Qing-Lei; WANG Hai-Xia; DONG Ming-Yi; HU Jing-Ran; LI Wei-Dong; LI Wei-Guo; LIU Huai-Min; OU-YANG Qun; SHEN Xiao-Yan; YUAN Ye; ZHANG Yao
Subjects: Physics >> Nuclear Physics

Considering the aging effects of existing Inner Drift Chamber (IDC) of BES\uppercase\expandafter{\romannumeral3}, a GEM based inner tracker is proposed to be designed and constructed as an upgrade candidate for IDC. This paper introduces a full simulation package of CGEM-IT with a simplified digitization model, describes the development of the softwares for cluster reconstruction and track fitting algorithm based on Kalman filter method for CGEM-IT. Preliminary results from the reconstruction algorithms are obtained using a Monte Carlo sample of single muon events in CGEM-IT.

submitted time 2016-09-13 Hits1002Downloads550 Comment 0

4. chinaXiv:201609.00018 [pdf]

Track segment finding with CGEM-IT and matching to tracks in ODC

Xin-Hua Sun; Liang-Liang Wang; Ling-Hui Wu; Xu-Dong J; Qing-Lei Xiu; Liao-Yuan Dong; Ming-Yi Dong; Wei-Dong Li; Wei-Guo Li; Huai-Min Liu; Qun Ou-Yang; Ye Yuan; Yao Zhang
Subjects: Physics >> Nuclear Physics

The relative differences in coordinates of Cylindrical-Gas-Electron-Multiplier-Detector-based Inner Tracker (CGEM-IT) clusters are studied to search for track segments in CGEM-IT. With the full simulation of single muon track samples, clear patterns are found and parameterized for the correct cluster combinations. The cluster combinations satisfying the patterns are selected as track segment candidates in CGEM-IT with an efficiency higher than 99%. The parameters of the track segments are obtained by a helix fitting. Some chi-squared quantities, evaluating the differences in track parameters between the track segments in CGEM-IT and the tracks found in Outer-Drift-Chamber (ODC), are calculated and used to match them. Proper chi-squared requirements are determined as a function of transverse momentum and the matching efficiency is found reasonable.

submitted time 2016-09-02 Hits849Downloads432 Comment 0

5. chinaXiv:201608.00212 [pdf]

Design and optimization of resistive anode for a two-dimensional imaging triple-GEM detector

JU Xu-Dong; DONG Ming-Yi; ZHAO Yi-Chen; ZHOU Chuan-Xing; OUYANG Qun
Subjects: Physics >> Nuclear Physics

The optimization of resistive anode for two dimensional imaging detectors which consists of a series of high resistive square pads surrounding by low resistive strips has been studied by both numerical simulations and experimental tests. It has been found that to obtain good detector performance, the resistance ratio of the pad to the strip should be larger than 5, the nonuniformity of the pad surface resistivity had better be less than?20%, a smaller pad width leads to a smaller spatial resolution and when the pad width is?6mm, the spatial resolution (σ) can reach about?105μm. Based on the study results, a 2-D GEM detector prototype with the optimized resistive anode is constructed and a good imaging performance is achieved.

submitted time 2016-08-31 Hits1185Downloads598 Comment 0

6. chinaXiv:201605.01503 [pdf]

Effects of application of corn straw on soil microbial community structure during the maize growing season

Lu, Ping; Lin, Yin-Hua; Xu, Yan-Peng; Tan, Fei; Jia, Xu-Dong; Lu, Ping; Yang, Zhong-Qi; Wang, Xi-Zhuo; Xu, Yan-Peng; Tan, Fei; Wang, Miao; Xu, De-Rong
Subjects: Biology >> Biophysics

This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon-to-nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p<0.05). We also found a high ratio of fungal-to-bacterial PLFAs in black soil and significant variations in the ratio of monounsaturated-to-branched fatty acids with different straw treatments that correlated with SR (p<0.05). These results indicated that the application of corn straw positively influences soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition.

submitted time 2016-05-12 Hits1456Downloads645 Comment 0

7. chinaXiv:201605.01490 [pdf]

Prefrontal dysfunction and a monkey model of schizophrenia

Ma, Yuan-Ye; Mao, Ping; Cui, Ding; Zhao, Xu-Dong; Ma, Yuan-Ye; Ma, Yuan-Ye
Subjects: Biology >> Biophysics >> Neurosciences

The prefrontal cortex is implicated in cognitive functioning and schizophrenia. Prefrontal dysfunction is closely associated with the symptoms of schizophrenia. In addition to the features typical of schizophrenia, patients also present with aspects of cognitive disorders. Based on these relationships, a monkey model mimicking the cognitive symptoms of schizophrenia has been made using treatment with the non-specific competitive N-methyl-D-aspartate receptor antagonist, phencyclidine. The symptoms are ameliorated by atypical antipsychotic drugs such as clozapine. The beneficial effects of clozapine on behavioral impairment might be a specific indicator of schizophrenia-related cognitive impairment.

submitted time 2016-05-12 Hits2623Downloads1205 Comment 0

8. chinaXiv:201605.01286 [pdf]

Mild Prenatal Stress Exposure Contributed to Behavioral Changes Induced by Postnatal Injections and Blocked The Effects of Olanzapine

Shan Liang; Liu Tian-E; Zhao Xu-Dong; Ma Yuan-Ye; Shan Liang
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

Exposure of pregnant females to strong prenatal stress generally induces psychotic-like behavioral impairments in their offspring. In contrast to strong stress exposure, mild prenatal stress exposure (MPSE) has been reported to increase the vulnerability of the nervous system to adverse environmental stimuli. However, the impacts of MPSE on treatment with antipsychotic medication have not been well investigated. In addition, although commonly utilized in animal experiments, the potential influences of injections per se on animal behavior have not been evaluated. Here, we investigated how MPSE, postnatal injections and olanzapine (OLZ) treatment might interact to affect the behavior of rats. Pregnant female rats were exposed to mild stress or left undisturbed during the last week of gestation. Their offspring were divided into three sub-groups and subjected to injections with saline or OLZ (2 mg/kg) on postnatal days (PDs) 7, 9 and 11 or were left undisturbed without injection. Social and olfactory discrimination tests were performed during adolescent (PD 35) and adult (PD 60) periods. Total exploratory time and the degree of preference in the discrimination tests were measured. We found that postnatal injections changed the degree of preference in adolescent prenatally stressed rats but had no effect on the degree of preference in the non-stressed rats. OLZ treatment increased the social exploratory time in the non-stressed rats during the adolescent and adult periods. However, these enhancing effects were diminished in the prenatally stressed rats. Our results indicate that MPSE could contribute to the behavioral changes induced by adverse stimuli such as postnatal injections and could reduce the treatment effects of antipsychotic medication.

submitted time 2016-05-11 Hits974Downloads550 Comment 0

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