Kinetic energy spectrum and polarization of neutrons from the reaction 12C(p,n)X at 590 MeV

Abstact: The kinetic energy spectrum and the polarization of the PSI neutron beam produced in the reaction ¹²C(p,n)X at 0° with 590 MeV polarized protons were investigated. A strong energy dependence of the neutron beam polarization is observed which was not expected at the time the neutron beam was built. Received: 3 April 1998     

K-拟可加模糊数值积分的自连续性

本文在K-拟可加模糊测度空间上建立了K-拟可加模糊数值积分,利用其积分转换定理和诱导算子的性质,将这种积分整体看成可测空间上取值于模糊值和集函数,从而使得这种模糊积分不仅具有自连续性,而且也满足逆自连续性。这些特性能更好地描述模糊值可测函数列和K-拟可加模糊数值积分序列的收敛性。     

中国的百岁老人研究Ⅰ.百岁老人的地区分布、性别差异和民族特征

利用全国人口普查资料及部分地区的调查资料,统计分析了百岁老人的百岁比和性别比。结果显示,中国百岁老人存在明显的地区分布不均衡性、性别差异的可变化性,以及民族长寿的特异性。我国至少有4个省和自治区的百岁老人数男性多于女性,有13个民族的百岁老人比例达到联合国规定的长寿之乡标准,这些民族可称作长寿民族。     

New data on the p + N → [Σ0K+] + N reaction at E p= 70 GeV and the search for exotic baryons

New data for the diffractive reaction p+N→ [Σ⁰ K ⁺] +N at E _p= 70 GeV were obtained with partially upgraded SPHINX setup. The data are in a good agreement with the results of our previous study of this reaction. In the mass spectrum M(Σ⁰ K ⁺) a structure at the threshold region with a mass ∼1810 MeV and a distinct X(2000) peak with M= 1989 ± 6 MeV and γ= 91 ± 20 MeV are observed. Unusual features of the massive X(2000) state (narrow decay width, anomalously large branching ratio for the decay channel with strange particle emission) make it a serious candidate for cryptoexotic pentaquark baryon with hidden strangeness |qqqsˉs>. We also present new results on the narrow threshold structure X(1810) with M= 1807 ± 7 MeV and γ= 62 ± 19 MeV which is produced in the region of very small P ² _T < 0.01 GeV². The possibility of the Coulomb production mechanism for X(1810) is discussed. Received: 28 April 1999     

The mixed problem for degenerate elliptic equations of second order

The present paper deals with the mixed boundary value problem for elliptic equations with degenerate rank 0. We first give the formulation of the problem and estimates of solutions of the problem, and then prove the existence of solutions of the above problem for elliptic equations by the above estimates and the method of parameter extension. We use the complex method, namely first discuss the corresponding problem for degenerate elliptic complex equations of first order, afterwards discuss the above problem for degenerate elliptic equations of second order.     

SULFATION OF PACHYMAN WITH CHLOROSULFONIC ACID USING THE IMPROVED WOLFROM METHOD

High purity polysaccharide of pachyman was isolated from the powder of Poria cocos sclerotium with an yield of 77.8%. The intrinsic viscosity of polysaccharide was found to be 78.95 mL/g in DMSO solution at 25℃. The isolated polysaccharide was reacted with chlorosulfonic acid to obtain pachyman sulfate using the improved Wolfrom method. The results of the orthogonality experiment on the sulfation reaction identified that the effectiveness of the reaction conditions on the degree of sulfation and the value of intrinsic viscosity is in the following order: molar ratio of chlorosulfonic acid to glucoside (3-5) ＞ reaction temperature (60-80℃) ＞ reaction time (1-2 h). The kinetic studies of the pachyman sulfationindicated that the hydrolysis is accompanied with the sulfation process. The decrease in intrinsic viscosity of the sulfated pachyman is proportional to the increase in the degree of sulfation under the mild reaction conditions of ＜ 80℃,chlorosulfonic acid/glucoside mole ratio ＜ 5, and reaction time ＜ 2 h. Beyond the above reaction conditions, excessive loss of -OH group occurs during hydrolysis. The NMR results indicated a complete sulfation on C-6 and a partial sulfation on the C-2 and C-4 of glucoside.     

Ekeland's variational principle, minimax theorems and existence of nonconvex equilibria in complete metric spaces

In this paper, we introduce the concept of τ-function which generalizes the concept of w-distance studied in the literature. We establish a generalized Ekeland's variational principle in the setting of lower semicontinuous from above and τ-functions. As applications of our Ekeland's variational principle, we derive generalized Caristi's (common) fixed point theorems, a generalized Takahashi's nonconvex minimization theorem, a nonconvex minimax theorem, a nonconvex equilibrium theorem and a generalized flower petal theorem for lower semicontinuous from above functions or lower semicontinuous functions in the complete metric spaces. We also prove that these theorems also imply our Ekeland's variational principle.     

Improving the quality of instant tea with low-grade tea aroma

Refuse tea is industrially identified as broken mixed fannings (BMF). It is a primary raw material for instant tea production. The aroma escape during the process affects the quality of instant tea used for application in the food and beverage industries. Capturing and adding back aroma to the instant tea is commercially important to overcome this drawback. Hence, the study was focused on profiling the aroma of BMF and respective instant tea based on low country (0–300 m MASL) and upcountry (>600 m MASL) elevation categories of Sri Lanka to identify the impact of growing elevation on aroma profiles to explore blending proportions for better aroma profiles. Furthermore, volatiles that escaped with steam during the instant tea production process were condensed, and this aroma extract was added back to the tea concentrate prior to spray drying to produce the aroma blended instant tea sample (ABIT). Solid-phase microextraction followed by gas chromatography–mass spectrometry was used to identify the volatile compounds in the headspace of instant tea, BMF and ABIT samples. BMF samples significantly contained linalool (9.94 ± 2.94 %), cis-linalool oxide (Furanoid) (4.69 ± 1.80 %), geraniol (2.47 ± 1.44 %), and 3-hexen-1-ol (3.46 ± 2.06 %); however, the volatile profile of instant tea samples had high amounts of hydrocarbons (51.60 ± 9.34 %) that did not contribute to creating a pleasant aroma for the product. Hexanal, geraniol, citral, cis-jasmon, α-ionone, nerol and E-2-Z-4-hexadienal are characteristic in upcountry BMF and were absent in the low country tea, indicating a difference in the aroma profiles with elevation. ABIT sample showed that there is a clear improvement in the aroma profile by retaining compounds such as linalool (5.48 %), geraniol (0.95 %), hotrienol (0.92 %), and γ-muurolene (0.22 %), which give a pleasant flowery aroma to the product. This study concluded the possibility to improve the aroma profile of instant tea to give the unique aroma of Ceylon tea as per customer requirements in an economically viable manner and this technology can be applied globally.     

K-拟可加模糊数值积分的伪自连续及结构特征

在K-拟可加模糊测度空间上,针对给出的K-拟可加模糊数值积分,将这种积分整体看成可测空间上取值于模糊数值的集函数,进而研究这种K-拟可加模糊积分的伪上(下)自连续、伪一致上(下)自连续和伪双零渐近可加性等结构特征.     

On the upper semicontinuity of Choquet capacities

The Choquet capacity T of a random closed set X on a metric space E is regarded as or related to a non-additive measure, an upper probability, a belief function, and in particular a counterpart of the distribution functions of ordinary random vectors. While the upper semicontinuity of T on the space of all closed subsets of E (hit-or-miss topology) is highly desired, T is not necessarily u.s.c. if E is not compact, e.g. E=Rⁿ. For any locally compact separable metric space E, this controversial situation can be resolved in the probabilistic context by stereographically projecting X into the Alexandroff compactification E_∞ of E with the “north pole” added to the projection. This leads to a random compact set that is defined on the same probability space, takes values in a space homeomorphic to the space of X, and possesses an equivalent probability law. Particularly, the Choquet capacity of is u.s.c. on the space of all closed subsets of E_∞. Further, consequences of the upper semicontinuity of are explored, and a proof of the equivalence between the upper semicontinuity of T and continuity from above on F(E) is provided.