This paper presents a description and performance evaluation of a new bit-level, lossless, adaptive, and asymmetric data compression scheme that is based on the adaptive character wordlength （ACW（n）） algorithm. Th...This paper presents a description and performance evaluation of a new bit-level, lossless, adaptive, and asymmetric data compression scheme that is based on the adaptive character wordlength （ACW（n）） algorithm. The proposed scheme enhances the compression ratio of the ACW（n） algorithm by dividing the binary sequence into a number of subsequences （s）, each of them satisfying the condition that the number of decimal values （d） of the n-bit length characters is equal to or less than 256. Therefore, the new scheme is referred to as ACW（n, s）, where n is the adaptive character wordlength and s is the number of subsequences. The new scheme was used to compress a number of text files from standard corpora. The obtained results demonstrate that the ACW（n, s） scheme achieves higher compression ratio than many widely used compression algorithms and it achieves a competitive performance compared to state-of-the-art compression tools.展开更多
Current animal models of chronic peripheral nerve compression are mainly silicone tube models. However, the cross section of the rat sciatic nerve is not a perfect circle, and there are differences in the diameter of ...Current animal models of chronic peripheral nerve compression are mainly silicone tube models. However, the cross section of the rat sciatic nerve is not a perfect circle, and there are differences in the diameter of the sciatic nerve due to individual differences. The use of a silicone tube with a uniform internal diameter may not provide a reliable and consistent model. We have established a chronic sciatic nerve compression model that can induce demyelination of the sciatic nerve and lead to atrophy of skeletal muscle. In 3-week-old pups and adult rats, the sciatic nerve of the right hind limb was exposed, and a piece of surgical latex glove was gently placed under the nerve. N-butyl-cyanoacrylate was then placed over the nerve, and after it had set, another piece of glove latex was placed on top of the target area and allowed to adhere to the first piece to form a sandwich-like complex. Thus, a chronic sciatic nerve compression model was produced. Control pups with latex or N-butyl-cyanoacrylate were also prepared. Functional changes to nerves were assessed using the hot plate test and electromyography. Immunofluorescence and electron microscopy analyses of the nerves were performed to quantify the degree of neuropathological change. Masson staining was conducted to assess the degree of fibrosis in the gastrocnemius and intrinsic paw muscles. The pup group rats subjected to nerve compression displayed thermal hypoesthesia and a gradual decrease in nerve conduction velocity at 2 weeks after surgery. Neuropathological studies demonstrated that the model caused nerve demyelination and axonal irregularities and triggered collagen deposition in the epineurium and perineurium of the affected nerve at 8 weeks after surgery. The degree of fibrosis in the gastrocnemius and intrinsic paw muscles was significantly increased at 20 weeks after surgery. In conclusion, our novel model can reproduce the functional and histological changes of chronic nerve compression injury that occurs in humans and it will be a useful new tool for investigating the mechanisms underlying chronic nerve compression.展开更多
By means of density functional theory calculations, an orthogonal boron-carbon-nitrogen compound called （3,0）- BC2N is predicted, which can be obtained by transversely compressing （3,03 carbon nanotubes （CNTs） an...By means of density functional theory calculations, an orthogonal boron-carbon-nitrogen compound called （3,0）- BC2N is predicted, which can be obtained by transversely compressing （3,03 carbon nanotubes （CNTs） and boron nitride nanotubes （BNNTs）. Its structural stability, elastic properties, mechanical properties and electronic structure are systematically investigated. The results show that （3,0）-BU2N is a superhard material with a direct bandgap. However, its similar structures, （3,0）-C and （3,0）-BN are indirect semiconductors. Strikingly, （3,0）-C is harder than diamond. We also simulate the x-ray diffraction of （3,0）-BC2N to support future experimental investigations. In addition, our study shows that the transition from （3,03 CNTS and BNNTs to （3,0）-BC2N is irreversible.展开更多
为了理解甲醇/柴油双燃料机的自燃特性并为燃烧计算所需骨架机理提供理论依据,以正庚烷作为柴油替代物,应用快速压缩机对宽广实验条件下甲醇/正庚烷混合燃料的自燃特性进行了研究。实验条件覆盖了甲醇/柴油双燃料机的典型工况。实验研...为了理解甲醇/柴油双燃料机的自燃特性并为燃烧计算所需骨架机理提供理论依据,以正庚烷作为柴油替代物,应用快速压缩机对宽广实验条件下甲醇/正庚烷混合燃料的自燃特性进行了研究。实验条件覆盖了甲醇/柴油双燃料机的典型工况。实验研究结果显示,随着压力升高、甲醇比例减少或当量比增大,混合燃料滞燃期变短。根据实验数据验证了爱尔兰国立大学(National University of Ireland,NUI)的正庚烷详细机理对甲醇/正庚烷的适用性,并利用该机理在CHEMKIN PRO软件中进行了化学动力学分析。结果表明,甲醇与正庚烷竞争羟基(hydroxyl,OH)从而抑制系统氧化过程。敏感性分析结果显示,超氧化氢(HO_(2))反应生成过氧化氢(H_(2)O_(2))是燃烧过程中最敏感的反应,抑制系统氧化过程的进行。本研究可为获得适用于甲醇/柴油双燃料机燃烧计算的骨架机理提供理论依据。展开更多
文摘This paper presents a description and performance evaluation of a new bit-level, lossless, adaptive, and asymmetric data compression scheme that is based on the adaptive character wordlength （ACW（n）） algorithm. The proposed scheme enhances the compression ratio of the ACW（n） algorithm by dividing the binary sequence into a number of subsequences （s）, each of them satisfying the condition that the number of decimal values （d） of the n-bit length characters is equal to or less than 256. Therefore, the new scheme is referred to as ACW（n, s）, where n is the adaptive character wordlength and s is the number of subsequences. The new scheme was used to compress a number of text files from standard corpora. The obtained results demonstrate that the ACW（n, s） scheme achieves higher compression ratio than many widely used compression algorithms and it achieves a competitive performance compared to state-of-the-art compression tools.
基金supported by the National Natural Science Foundation of China,No.81471270
文摘Current animal models of chronic peripheral nerve compression are mainly silicone tube models. However, the cross section of the rat sciatic nerve is not a perfect circle, and there are differences in the diameter of the sciatic nerve due to individual differences. The use of a silicone tube with a uniform internal diameter may not provide a reliable and consistent model. We have established a chronic sciatic nerve compression model that can induce demyelination of the sciatic nerve and lead to atrophy of skeletal muscle. In 3-week-old pups and adult rats, the sciatic nerve of the right hind limb was exposed, and a piece of surgical latex glove was gently placed under the nerve. N-butyl-cyanoacrylate was then placed over the nerve, and after it had set, another piece of glove latex was placed on top of the target area and allowed to adhere to the first piece to form a sandwich-like complex. Thus, a chronic sciatic nerve compression model was produced. Control pups with latex or N-butyl-cyanoacrylate were also prepared. Functional changes to nerves were assessed using the hot plate test and electromyography. Immunofluorescence and electron microscopy analyses of the nerves were performed to quantify the degree of neuropathological change. Masson staining was conducted to assess the degree of fibrosis in the gastrocnemius and intrinsic paw muscles. The pup group rats subjected to nerve compression displayed thermal hypoesthesia and a gradual decrease in nerve conduction velocity at 2 weeks after surgery. Neuropathological studies demonstrated that the model caused nerve demyelination and axonal irregularities and triggered collagen deposition in the epineurium and perineurium of the affected nerve at 8 weeks after surgery. The degree of fibrosis in the gastrocnemius and intrinsic paw muscles was significantly increased at 20 weeks after surgery. In conclusion, our novel model can reproduce the functional and histological changes of chronic nerve compression injury that occurs in humans and it will be a useful new tool for investigating the mechanisms underlying chronic nerve compression.
基金Supported by the National Natural Science Foundation of China under Grant No 11464028the Science Foundation of Department of Education of Jiangxi Province under Grant No GJJ150025
文摘By means of density functional theory calculations, an orthogonal boron-carbon-nitrogen compound called （3,0）- BC2N is predicted, which can be obtained by transversely compressing （3,03 carbon nanotubes （CNTs） and boron nitride nanotubes （BNNTs）. Its structural stability, elastic properties, mechanical properties and electronic structure are systematically investigated. The results show that （3,0）-BU2N is a superhard material with a direct bandgap. However, its similar structures, （3,0）-C and （3,0）-BN are indirect semiconductors. Strikingly, （3,0）-C is harder than diamond. We also simulate the x-ray diffraction of （3,0）-BC2N to support future experimental investigations. In addition, our study shows that the transition from （3,03 CNTS and BNNTs to （3,0）-BC2N is irreversible.
文摘为了理解甲醇/柴油双燃料机的自燃特性并为燃烧计算所需骨架机理提供理论依据,以正庚烷作为柴油替代物,应用快速压缩机对宽广实验条件下甲醇/正庚烷混合燃料的自燃特性进行了研究。实验条件覆盖了甲醇/柴油双燃料机的典型工况。实验研究结果显示,随着压力升高、甲醇比例减少或当量比增大,混合燃料滞燃期变短。根据实验数据验证了爱尔兰国立大学(National University of Ireland,NUI)的正庚烷详细机理对甲醇/正庚烷的适用性,并利用该机理在CHEMKIN PRO软件中进行了化学动力学分析。结果表明,甲醇与正庚烷竞争羟基(hydroxyl,OH)从而抑制系统氧化过程。敏感性分析结果显示,超氧化氢(HO_(2))反应生成过氧化氢(H_(2)O_(2))是燃烧过程中最敏感的反应,抑制系统氧化过程的进行。本研究可为获得适用于甲醇/柴油双燃料机燃烧计算的骨架机理提供理论依据。
