关于正规双曲方程组的不完全Huygens现象

文中将不完全Ｈｕｙｇｅｎｓ现象这一概念推广到双正规曲型方程组上，并给出了几个定理和例子     

Glucocorticoid localization by radioautography in the rabbit eye following systemic administration of3H-dexamethasone

Summary Dexamethasone was localized radioautographically in the nuclei of target cells of the rabbit eye, following i.v. administration of the labeled steroid. Nuclear receptors in stromal and endothelial cells of the outflow pathway region suggest that glucocorticoids may alter the outflow facility by specific responses of target cells.Acknowledgments. This work was supported by grant EY-01313 of the National Eye Institute, National Institutes of Health, Bethesda, Md, USA.     

Serienbestimmung der Phospholipase-A-Aktivität in chromatographischen Fraktionen

Summary A simple assay is described for phospholipase A in chromatographic fractions. 0.01 ml of the fraction is added to 1 ml of a 1% solution of purified lecithin in ether (100 vol) — picoline (10 vol) — 4.5 mmol CaCl₂ (1 vol). The presence of phospholipase A is indicated by the appearance of a turbidity due to precipitation of lysolecithin. The lag period until precipitation occurs gives an indication of the relative concentration of enzyme present.     

黄骅坳陷北大港油田古近系碎屑岩储层成岩作用及其对储层质量的影响

为了明确黄骅坳陷北大港油田古近系碎屑岩储层的成岩作用特征及其影响因素,在综合分析大量岩石薄片、扫描电镜、阴极发光、X衍射及物理性质等分析化验资料的基础上,对研究区古近系碎屑岩储层成岩作用类型及特征、成岩演化阶段及成岩作用影响因素进行了综合研究,并在此基础上划分了成岩相类型,探讨了成岩作用对储层质量的影响作用.结果表明,研究区东营组砂岩主要处于早成岩B期,部分达到中成岩A1期;沙河街组砂岩主要处于中成岩A期,部分达到中成岩B期.压实作用和胶结作用使储层原生孔隙迅速减少,渗透率降低,大大降低了砂岩的储集物性;后期的溶解作用促使砂岩次生孔隙发育,改善了砂岩的储集性能.研究区砂岩可划分为压实固结成岩相、碳酸盐胶结成岩相、弱胶结成岩相和不稳定组分溶蚀成岩相4种成岩相类型,其中不稳定组分溶蚀成岩相控制的储层物性最好,弱胶结成岩相控制的储层物性次之,碳酸盐胶结成岩相和压实固结成岩相控制的储层物性较差.明确研究区成岩作用特征及成岩相分布特点,对寻找该区有利储层具有重要指导意义.     

新疆桑皮纸的口头与非物质文化遗产的价值体现

本文根据《保护非物质文化遗产公约》和《人类口头与非物质文化遗产申报书编写指南》的要求,详细介绍了新疆传统手工艺——桑皮纸的基本情况、独特性、历史传承价值、生活价值、文化价值、艺术价值及保护情况等内容,对新疆桑皮纸的价值体现进行了研究。认为桑皮纸是维吾尔族人民为中华民族留下的宝贵的非物质文化遗产。     

Atomic inner-shell X-ray laser at 1.46 nanometres pumped by an X-ray free-electron laser

Since the invention of the laser more than 50 years ago, scientists have striven to achieve amplification on atomic transitions of increasingly shorter wavelength. The introduction of X-ray free-electron lasers makes it possible to pump new atomic X-ray lasers with ultrashort pulse duration, extreme spectral brightness and full temporal coherence. Here we describe the implementation of an X-ray laser in the kiloelectronvolt energy regime, based on atomic population inversion and driven by rapid K-shell photo-ionization using pulses from an X-ray free-electron laser. We established a population inversion of the Kα transition in singly ionized neon at 1.46 nanometres (corresponding to a photon energy of 849 electronvolts) in an elongated plasma column created by irradiation of a gas medium. We observed strong amplified spontaneous emission from the end of the excited plasma. This resulted in femtosecond-duration, high-intensity X-ray pulses of much shorter wavelength and greater brilliance than achieved with previous atomic X-ray lasers. Moreover, this scheme provides greatly increased wavelength stability, monochromaticity and improved temporal coherence by comparison with present-day X-ray free-electron lasers. The atomic X-ray lasers realized here may be useful for high-resolution spectroscopy and nonlinear X-ray studies.