A gamma spectrum of a Pu-C source is measured using a p-type HPGe detector, whose three peaks （full energy, single-escape and double-escape peak） can be used as a calibration source for the beam energy measurement s...A gamma spectrum of a Pu-C source is measured using a p-type HPGe detector, whose three peaks （full energy, single-escape and double-escape peak） can be used as a calibration source for the beam energy measurement system of BEPCII. The effect of fast neutron damage on the energy resolution of the HPGe detector is studied, which indicates that the energy resolution begins to deteriorate when the detector is subject to 2×107 n/cm^2 fast neutrons. The neutron damage mechanism and detector repair methods are reviewed. The Monte Carlo simulation technique is utilized to study the shielding of the HPGe detector from the fast neutron radiation damage, which is of great significance for the future commissioning of the beam energy measurement system.展开更多
目的研究右旋美托咪啶(dexmedetomidine,Dex)对异氟醚所致新生大鼠海马细胞凋亡的保护作用及与Akt/Bad信号通路的关系。方法出生7 d SD大鼠随机分为空气组(Air+NS)、二甲基亚砜组(Air+DMSO)、LY294002组(Air+LY)、异氟醚组(Iso+NS)、异...目的研究右旋美托咪啶(dexmedetomidine,Dex)对异氟醚所致新生大鼠海马细胞凋亡的保护作用及与Akt/Bad信号通路的关系。方法出生7 d SD大鼠随机分为空气组(Air+NS)、二甲基亚砜组(Air+DMSO)、LY294002组(Air+LY)、异氟醚组(Iso+NS)、异氟醚+Dex组(Iso+Dex)、异氟醚+Dex+LY294002组(Iso+Dex+LY)。前3组吸入空气6h,后3组吸入体积分数为0.0075异氟醚6h。吸入异氟醚前40min,Air+DMSO组、Air+LY组和Iso+Dex+LY组分别经侧脑室注射5μl体积分数为0.1的DMSO或25μg LY294002;Iso+Dex组和Iso+Dex+LY组分别在麻醉0、2、4 h腹腔内注射Dex 25μg·kg-1;Air+NS组和Iso+NS组在同时间点腹腔内注射等体积生理盐水。Western blot法检测海马激活型caspase-3、Akt、磷酸化Akt(p-Akt)、Bad、磷酸化Bad(p-Bad)、Bcl-xl蛋白表达变化(n=5),TUNEL法检测海马CA1区细胞凋亡(n=5)。结果 Dex可明显减少异氟醚引起的海马CA1区TUNEL阳性细胞表达(P<0.01),减低激活型caspase-3(P<0.01)和Bad蛋白表达(P<0.01),上调p-Akt/Akt、p-Bad/Bad和Bcl-xl/Bad比值(P<0.01)。LY294002逆转了Dex对上述蛋白表达的影响。结论Dex通过激活Akt/Bad信号通路减少异氟醚诱导的新生大鼠海马细胞凋亡。展开更多
In this paper,the authors introduce the discreteness criterion for n-dimensional subgroups in PU(1, n; C).These generalize the well-known discreteness criterion first established by T.Jorgensen.
基金Supported by National Natural Science Foundation of China (10491303, 10775412, 10825524)Instrument Developing Project of Chinese Academy of Sciences (YZ200713)+1 种基金Major State Basic Research Development Program (2009CB825200, 2009CB825203,2009CB825206)Knowledge Innovation Project of Chinese Academy of Sciences (KJCX2-YW-N29)
文摘A gamma spectrum of a Pu-C source is measured using a p-type HPGe detector, whose three peaks （full energy, single-escape and double-escape peak） can be used as a calibration source for the beam energy measurement system of BEPCII. The effect of fast neutron damage on the energy resolution of the HPGe detector is studied, which indicates that the energy resolution begins to deteriorate when the detector is subject to 2×107 n/cm^2 fast neutrons. The neutron damage mechanism and detector repair methods are reviewed. The Monte Carlo simulation technique is utilized to study the shielding of the HPGe detector from the fast neutron radiation damage, which is of great significance for the future commissioning of the beam energy measurement system.
文摘为降低HEVC帧间预测编码过程的计算复杂度,提出了一种新的基于运动特征的编码单元(Coding Units,CU)及预测单元(Prediction Units,PU)快速判决算法。首先,通过二阶帧差法检测运动剧烈程度,并分析运动特征对CU及PU时域相关性的影响。然后,利用前帧相同位置CU及PU的最优模式预测当前CU的深度范围,并根据运动剧烈程度优化预测范围。最后,根据预测范围跳过和终止部分不必要的CU深度和PU模式,从而加快帧间编码速度。在HM12.0平台上的实验测试表明,该算法在BDPSNR仅降低0.068 d B、BDBR只增加1.530%的情况下,提高了48.389%的编码速度。
基金Supported by the Scientific Research Foundation of Kaili University(Z1519)Guizhou Province Excellence Teacher Education Program(Mathematics and Applied Mathematics)
文摘In this paper,the authors introduce the discreteness criterion for n-dimensional subgroups in PU(1, n; C).These generalize the well-known discreteness criterion first established by T.Jorgensen.
