分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-09
摘要: The multi-sector SUSY breaking predicts pseudo-goldstino which can couple to the visible sector more strongly than the ordinary gravitino and thus induce the decays of the lightest neutralino and chargino (collectively called electroweakinos) inside the detector. In this note we study the electroweakino pair productions via VBF processes followed by decays to pseudo-goldstino at the LHC. Our Monte Carlo simulations show that at the 14TeV LHC with 3000 fb(-1) luminosity the dominant production channel pp ->chi(+/-)(1)chi(0)(1)jj can have a statistical significance above 2 sigma while other production channels are not accessible.
分类: 地球科学 >> 地理学 提交时间: 2023-10-17 合作期刊: 《干旱区科学》
摘要: Analysis of environmental significance and hydrochemical characteristics of river water in mountainous regions is vital for ensuring water security. In this study, we collected a total of 164 water samples in the western region of the Altay Mountains, China, in 2021. We used principal component analysis and enrichment factor analysis to examine the chemical properties and spatiotemporal variations of major ions (including F, Cl, NO3, SO42, Li+, Na+, NH4+, K+, Mg2+, and Ca2+) present in river water, as well as to identify the factors influencing these variations. Additionally, we assessed the suitability of river water for drinking and irrigation purposes based on the total dissolved solids, soluble sodium percentage, sodium adsorption ratio, and total hardness. Results revealed that river water had an alkaline aquatic environment with a mean pH value of 8.00. The mean ion concentration was ranked as follows: Ca2+>SO42>Na+>NO3>Mg2+>K+>Cl>F>NH4+>Li+. Ca2+, SO42, Na+, and NO3 occupied 83% of the total ion concentration. In addition, compared with other seasons, the spatial variation of the ion concentration in spring was obvious. An analysis of the sources of major ions revealed that these ions originated mainly from carbonate dissolution and silicate weathering. The recharge impact of precipitation and snowmelt merely influenced the concentration of Cl, NO3, SO42, Ca2+, and Na+. Overall, river water was in pristine condition in terms of quality and was suitable for both irrigation and drinking. This study provides a scientific basis for sustainable management of water quality in rivers of the Altay Mountains.
分类: 生物学 >> 生物物理学 >> 肿瘤学 提交时间: 2016-05-11
摘要: Granzyme M is a serine protease known to be often expressed by natural killer cells and induce target cells apoptosis in combination with perforin. However, we detected granzyme M expression in murine and human cancer cell lines and human tumor samples in our study. Granzyme M increased chemoresistance, colony-formation, cytokine secretion and invasiveness in vitro. Most importantly, granzyme M facilitated tumor growth and metastasis in vivo. Granzyme M induced the epithelial-mesenchymal transition (EMT) in cancer cells associated with STAT3 activation. Our study revealed the role of granzyme M expressed by tumor in chemoresistance, invasion, metastasis and EMT.
分类: 物理学 >> 地球物理学、天文学和天体物理学 提交时间: 2024-01-09 合作期刊: 《Research in Astronomy and Astrophysics》
摘要: Ground-based radio observations below 30 MHz are susceptible to the ionosphere of the Earth and the radio frequency interference. Compared with other space mission concepts, making low frequency observations using an interferometer array on lunar orbit is one of the most feasible ones due to a number of technical and economic advantages. Different from traditional interferometer arrays, the interferometer array on lunar orbit faces some complications such as the three-dimensional distribution of baselines and the changing sky blockage by the Moon. Although the brute-force method based on the linear mapping relationship between the visibilities and the sky temperature can produce satisfactory results in general, there are still large residual errors on account of the loss of the edge information. To obtain the full-sky maps with higher accuracy, in this paper we propose a novel imaging method based on reweighted total variation (RTV) for a lunar orbit interferometer array. Meanwhile, a split Bregman iteration method is introduced to optimize the proposed RTV model so as to decrease the computation time. The simulation results show that, compared with the traditional brute-force method, the RTV regularization method can effectively reduce the reconstruction errors and obtain more accurate sky maps, which proves the effectiveness of the proposed method.
分类: 化学 >> 物理化学 提交时间: 2017-11-05 合作期刊: 《结构化学》
摘要: Er3+/Yb3+ co-doped Li3Ba2Gd3(MoO4)8 phosphors were synthesized by conventional solid state reaction method, and their structure and spectral properties were investigated. The diffuse reflectance spectra showed that the 4I15/2 → 4I11/2 transition of Er3+ and the 2F7/2 → 2F5/2 transition of Yb3+ ions were highly overlapped. Under the excitation of 980 nm, three up-conversion (UC) luminescence bands around 530, 555 and 660 nm were observed, corresponding to the 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The effects of the concentration and pumping power on the UC intensities of Li3Ba2Gd3(MoO4)8:Er3+/Yb3+ phosphors were investigated, and the possible UC mechanism was proposed based on the results.
分类: 核科学技术 >> 核探测技术与核电子学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Hefei Light Source (HLS)-II is a vacuum ultraviole (VUV) synchrotron light source. A major upgrade of the light source was finished at the end of 2014. The timing system was rebuilt using compact peripheral component interconnect (cPCI) event-driven hardware to meet synchronization requirements of the machine. In the new system, the cPCI event-driven products manufactured by the micro-research finland (MRF) Oy are employed to achieve about 100 output signals with different interfaces. Device supports and drivers developed for common Experimental Physics and Industrial Control System (EPICS) records are used to access the registers on the timing modules. Five cPCI-bus input/output controllers (IOCs) distributed in different areas of the light source host timing modules for various subsystems. The delay resolution of this system is 9.8 ns for most channels and 9 ps for the channels used for triggering the electron gun and the injection kickers. The measured rms jitter of the output signal is less than 27 ps. Using the bucket chooser, this system enables the HLS-II to fill the storage ring with any designated bunch pattern. Benefitting from this upgrade, brightness and performance of the light source are significantly improved.
分类: 医学、药学 >> 临床医学 分类: 生物学 >> 遗传学 提交时间: 2020-03-06
摘要: Germline polymorphisms have been linked with differential survival outcomes in cancers but have not been well studied in nasopharyngeal carcinoma (NPC). Here, two-phase association study is conducted to discover germline polymorphisms that are associated with the prognosis of NPC. The discovery phase includes two consecutive hospital cohorts of patients with NPC from Southern China. Exome-wide genotypes at 246,173 single nucleotide polymorphisms (SNPs) are determined, followed by survival analysis for each SNP under Cox proportional hazards regression model. Candidate SNP is replicated in another two independent cohorts from Southern China and Singapore. Meta-analysis of all samples (n = 5,553) confirm that the presence of rs1131636-T, located in the 3′-UTR of RPA1, confers an inferior overall survival (HR = 1.33, 95% CI = 1.20-1.47, P = 6.31 × 10-8). Bioinformatics and biological assays show that rs1131636 has regulatory effects on upstream RPA1. Functional studies further demonstrate that RPA1 promoted the growth, invasion, migration, and radioresistance of NPC cells. Additionally, miR-1253 has been identified as a suppressor for RPA1 expression, likely through regulation of its binding affinity to rs1131636 locus. Collectively, these findings provide a promising biomarker aiding in stratifying patients with poor survival, as well as a potential drug target for NPC.