[en] In early 1977, while working for NSLS at Brookhaven National Lab., Dr. Ohnuma noticed that tunes of NSLS calculated with code SYNCH were significantly different from those obtained with code PATRICIA. This problem surfaced again in 1991 when people at BNL discovered discrepancies in their compact ring SXLS chromaticities calculated with different code. One potential source of the ambiguities is the different treatment of the edge field and the combined function field of dipole magnet. There are two dipoles each of which with the bending angle of 180 degrees instead of at most a few degrees which is common in high energy synchrotrons. The calculation of a three-dimensional field using TOSCA indicates that the fringe field extends to cover the whole region between the dipole and the quadrupole, having a vertical field strength of 250 gauss at the edge of the quadrupole. In this case, the fringe multiple field will undoubtedly play a nontrival role in determining basic machine parameters. Therefore, the classical treatment for simulating particle motion in synchrotron, which uses the isomagnetic approximation plus then lens kicks, no longer accurately models the closed orbit of the machine. In order to correctly calculate tunes, chromaticities as well as the dynamic aperture in such kind of machine with a large magnetic bending angle, it is necessary to integrate the exact equations of motion in a realistic representation of the magnetic field

[en] An on-line preconcentration time resolved fluorimetric method was developed for the determination of trace thorium in water, based on luminescence of complex Th-morin-TOPO (or TRPO)-sodium lauryl sulfate in sulfuric acid medium. Interferences from companied cations, such as Al³⁺ and Zr⁴⁺, which emit fluorescence with much slower rising rate at the same condition were effectively eliminated through optimization of the manifold parameters and precisely controlling of the elution flow rate. Effects of nearly 40 ions were also investigated. The detection limit, the liner range and relative standard deviation for 50 ng Th are 2.5 ng/L, 0∼80 ng and 3.6%, respectively. Sampling rate is 30 per hour

[en] To improve the lipid accumulation of diatom cells, Nitzschia sp. was mutated by ⁶⁰Co-γ-ray irradiation and cultivated with high salinity. The biomass and lipid yields of Nitzschia sp. mutated by ⁶⁰Co-γ-ray irradiation at 900 Gy were increased by 53.8% and 28.1%, respectively. The lipid content of Nitzschia sp. mutant cells cultivated with gradually increased salinity of up to 30‰ was increased from 11.9% to 27.2%. This was because that the increased demand for nitrogen to keep cells healthy growth under high salinity conditions resulted in lipid accumulation, which was beneficial to prevent cell membranes from being destroyed by changing osmotic pressure. When the Nitzschia-ZJU1 strain obtained from Nitzschia sp. by irradiation mutation and salinity domestication was cultured in the growth media with no nitrogen and no silicon, the lipid content of cells was dramatically increased to 51.2%. - Highlights: • Nitzschia species were mutated by ⁶⁰Co-γ irradiation for high lipid production. • Mutants were domesticated with high salinity to increase lipid content in cells. • Lipid content of domesticated mutants was 1.3 times higher than original strain. • Lipid content reached 51.2% under 30‰ salinity, nitrogen and silicon deprivation

[en] A detailed study is performed for the decomposition of simulated waste vitrification glass formed specimens which contain not only the main components of glass (B, Si, Na, etc.) but also the elements existing in the HLLW, such as fission products, corrosion products (Zr, Ti, R.E., Fe, Cr, Mn, etc.). The glass specimens can be decomposed thoroughly by LiBO₂ fusion method. Since glass is of large molecule arranged without order and noncrystal in structure, the amount of flux with two times that of specimen is enough for its decomposition. The decreasing amount of flux is advantageous for eliminating the blockage of nebulizer and the requirment for purity of the flux reagent is not so strict. The LiBO₂ fusion method for decomposition of glass specimens is verified by using of the certified glass standard 75-1

[en] When adsorbed on a specially functioned fiber comprising an ion exchanger having a cation-exchange group, produced by grafting copolymerization with the radiation of Co⁶⁰-γ ray, rare earth metals like Sm, Gd can be eluted with an aqueous solution of a chelating agent in order, resulting in a successfull separation in rare earth metals. The exchange characteristics of the cation-exchange fiber have been determined and the influence of technological conditions in separation, such as Ph value, column ratio, linear velocity of eluting agent, concentration of eluting agent, concentration of weak acid and temperature, on the separation efficiency of Sm from Gd have been studied. It is confirmed that this separation process is better than the previous ones. (author) 35 figs., 8 tabs., 4 refs

[en] A pot experiment was conducted to investigate the effects of ¹⁵N-urea and 4 kinds of plant materials (P₁, P₂, P₃ and P₄) as urease inhibitor on sorghum and rice nutrition and soil characters. The results indicated that the growth, above-ground parts and roots weight of rice and sorghum were respectively promoted by 4 plant urease inhibitors and P₁ with little change of chl.a/chl.b ratios in these treatments. The content of amino acid in rice leaf and utilization rate of nitrogen by rice were enhanced by 12.9%-25.1% and 5.2%-7.7% respectively, and the utilization rate of nitrogen by sorghum was improved by urease inhibitor treatments (except P₁). Plant urease inhibitor could obviously increase the apparent utilization rate of nitrogen by 4.3%-19.2% for two crops and improve phosphorus and potassium uptake by rice plant but decrease phosphorus and potassium uptake by sorghum plant. The contents of soil alkali-hydrolyzable nitrogen were increased by plant urease inhibitor under two cultivated condition. The inhibition time of plant urease inhibitor to soil urease was short and it disappeared as 36 days of rice growth under flooded condition, while the activities of soil urease were decreased by 10.6%-18.3% at 48 days of sorghum growth in upland soil

[en] In this paper, we investigate the control of the molecular wave packet of a linear molecule by two femtosecond laser pulses. It is shown that the odd and the even rotational wave packets created by a single laser pulse can be selectively excited by accurately controlling the time delay of another laser pulse. By inserting the peak of the second laser pulse at the position of maximum or minimum value around quarter or three quarter rotational period of the slope curve with odd (or even) rotational wave packet contribution that is created by the first laser pulse, the odd rotational wave packet can be enhanced (or suppressed) while the even rotational wave packet is suppressed (or enhanced). As a result, the molecular alignments around quarter and three quarter rotational periods can be obtained. Moreover, it is also shown that by inserting the second laser pulse around the quarter or three quarter rotational periods, the changes in the maximum degree of the molecular alignment for the odd and the even rotational wave packet contributions are consistent with their corresponding slope curves at these positions. (atomic and molecular physics)

[en] The composition and principle of characteristic X-ray measurement system are introduced in detail, and the method of data processing is explained in this article. This experiment selects and uses copper and iron being target matter, uses characteristic X-ray measuring paper thickness. While the thickness paper is measured arrives at 43.2 mg/cm² from 7.2 mg/cm², the curvilinear relevance modulus of d_m and ln I is more than 0.999, relative error within 2%. (authors)

[en] On the basis of introducing the structure of the X ray thickness gauge and system function, we design a software system for X ray thickness gauge by C++ builder 5.0. The system mainly read data from data processor and applicants least squares to get the thickness of the material and make some data processing. (authors)

[en] The theory of transmission characteristic X-ray measurement thickness are discussed, hardware including equipment for characteristic X-ray producing, X-ray detector, data processor and monitoring software are introduced. Properties of the thickness gauge are tested, results show thickness gauge is sensitive, higher accuracy when tested material is thin, relative error within 5%, according with design request. (authors)