加速器质谱测量129I方法的改进

在筑波大学的12UD串列加速器上开发了一套改进的129I加速器质谱(AMS)测量方法,包括在120°磁铁后安装了一副自行设计制作有静电偏转板,有效改善了对127I束流和129I计数的测量;采用97MoO2分子导航束稳定加速器端电压,加速器的端电压能稳定在几天内不超过0.1%,结合二次剥离,取得了满意的测量效果.用该方法测得AgI试剂样品的本底水平为7.83×10-13.对129I/127I比值范围为(4.92～0.28)×10-10的一系列样品的测量不确定度在7%以下,准确度较前有所提高.     

Two dimensional nano-dot array engineering of block copolymer surface micelles on water surface

When an amphiphilic block copolymer is directly spread from an organic solution, the morphology of the surface micelles is not in general controlled because the structure is rapidly frozen after the solvent evaporation. In contrast, we have developed a new versatile method to generate highly regular ordered nanopatterns of the surface micelles on water, which involves the process of two dimensional (2D) hybridization with a polar liquid crystal molecule, 4′-pentyl-4-cyanobiphenyl (5CB) [Langmuir 22 (2006) 5233]. The present work extends this approach using a family of diblock copolymers of polystyrene-block-poly(4-vinylpyridine) changing the chain length of the two polymer blocks. It is found here that the dot-to-dot distance and the dot size can be precisely controlled on-demand by the length of the polymer blocks. Such structural regulations cannot be attained without the 5CB hybridization. Due to the high reproducibility of the morphology formation, this process should be of practical significance to ‘engineer’ the 2D patterns in the range of some tens of nanometers.     

Spring bloom in a hypereutrophic lake, lake Kasumigaura, Japan—II Succession of phytoplankton species

Numerous phytoplankton species in Lake Kasumigaura were shown to comprise the Spring bloom in 1980. The predominant phytoplankton species that appeared during the Spring bloom belonged to 28 genera. A few species among them increased at any time to form a phytoplankton pulse, but the few species of phytoplankters that comprised a phytoplankton pulse did not exclude completely other phytoplankters. During the Spring bloom, one pulse was replaced by another pulse composed of a new grouping of different species. Throughout these replacements by natural selection in the bloom were numerous other species by phytoplankters at levels of abundance somewhat less than those which formed phytoplankton pulse.     

The advanced set-up and control system for Dofasco's tandem coldmill

The new coupled pickle line and cold mill (CPCM) has been processing steel since December 1991 at Dofasco Inc. in Hamilton, Ontario, Canada. This mill rolls both sheet and tin plate. The work rolls for the last stand are often textured by grit blasting to roll “matte” finished strip. A new computer-targeted control system was developed for the roll speeds and gaps, specifically for matte rolling. The new set-up system uses Stone's model, which is more appropriate for the limited reductions evident with the rougher rolls. Conventional automatic gauge control (AGC) systems using thickness measurements after the last stand are limited in performance by the effect of long transport delays. These limitations are particularly critical during mill acceleration and deceleration. The use of a thickness gauge before the stand with matte rolls allows the development of AGC systems using shorter control loops for final gauge control. The AGC system uses a Smith predictor for transport lag, (phase shift), and compensation. The combination of the shorter AGC loop and the Smith predictor allows higher gains to be used in the control system. This set-up and control system has contributed to Dofasco's position as a market leader in thickness performance     

Superstructure-based design and operation for biomass utilization networks

This paper is providing a design and evaluation methodology for biomass utilization networks (B-NETs) planning in local areas. The methodology is an effort to integrate various exertions of many researchers as well as stakeholders in the biomass field including process technologies, local area classification and renewable energy mechanisms to design and evaluate B-NETs. The proposed design methodology has three steps: classification, problem formulation and suggesting solution methods. The core part of planning the B-NETs utilization methodology is the superstructure that is a super class model for the processes of biomass utilization networks that has to be built for the local area. The biomass utilization superstructure (BUSS) relates the biomass resources to their products, available processes, and possible future processes of utilization in static manner. Although the local area BUSS is static in nature, it shows the decision makers what kinds of B-NETs are, or can be, available in their area. It is important to note that for each super class process there exists a number of elemental technologies, or what we call unit process (UP), that can perform the job under the same condition with different processing constraint. To support the design and operation process a technological information infrastructure (TII) needs to be built to work as an information pool and simulation tool. With the support of TII and the BUSS different scenarios can be synthesized, analyzed and compared. Scenarios development enables the designer to check processing alternatives as well as biomass promotion mechanisms that fit the concerns of various stakeholders. The results of the methodology application can be given in the form of suggestions of a specific network class(es) or scenarios that can be applied in a class of localities with the same characteristics. Following to methodology configuration, a proposal for optimization methods is discussed and a case study for comparing biomass network scenarios in mountainous city is introduced.     

A patient with psoriatic arthritis due to generalized pustular psoriasis (von Zumbusch type)

Pustular psoriasis is a rare skin disease that is observed in about 1% of all patients with psoriasis. We encounted a patient with psoriatic arthritis (PsA) due to pustular psoriasis. The patient was a 31-year old male. He visited our hospital due to generalized eruption and pain in multiple joints. Treatment was initiated under a diagnosis of psoriasis vulgaris and associated PsA. However, eruption extended to the entire body and became pustular, and fever developed. Since PsA symptoms were simultaneously aggravated, and body movements become difficult, he was admitted. A diagnosis of generalized pustular psoriasis (von Zumbusch) and associated symmetrical polyarthritis was made. Local therapy was performed. As systemic treatment, oral administration of an corticosteroid and weekly low-dose pulse methotrexate therapy were performed. The skin symptoms and PsA symptoms rapidly improved. At present, about one year after the initiation of treatment, the eruption almost completely disappeared, and joint pain does not present any problem in daily life.     

A 60-GHz multilayer parasitic microstrip array antenna on LTCC substrate for system-on-package

This letter describes a compact and high-gain multilayer parasitic microstrip array antenna (MPMAA). The design and performance of the proposed array antenna are presented. The antenna employs three layers with a 2/spl times/2 parasitic array on each layer. The developed prototype MPMAA employs a multilayer low-temperature co-fired ceramic (LTCC) substrate that is well suited to the assembly of MMIC chips. The fabricated MPMAA achieves a 7.17 dBi absolute gain at 60 GHz including the loss derived from the feeding parts and RF probe to measure its antenna performance. The spacing of the top layer of the parasitic array constructed by 2/spl times/2 elements has a free-space wavelength of 0.36 and the chip size is 10 mm/sup 2/. The fabricated MPMAA achieves both compact and high directional gain and satisfies the requirements for a millimeter-wave system-on-package (SOP).