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71.
Photodegradation of incombustible polymer materials [high-density (HD) and low-density (LD) polyethylene (PE) containing 0.5 to 2.0 phr of decabromodiphenyl ether (DBDE) or tetrabromobisphenol A (TBA) as a flame retardant] were studied using an Okazaki Large Spectrograph (OLS). Samples were irradiated in air at 23°C with monochromatic light of wavelengths at 260, 280, 300, 320, 340, and 360 nm. Ultraviolet and Fourier transform infrared (FTIR) spectra were taken to estimate the chemical changes caused by photoirradiation. Molecular weight change was followed by gel permeation chromatography (GPC) measurements. It was found that the photostability of PE samples was reduced by the addition of flame retardants. The threshold wavelengths of photodegradation are 320 nm and 360 nm for PE–TBA samples and PE–DBDE samples, respectively. Main-chain scission is favored when the irradiation was carried out with the light of wavelength 300 nm for HDPE–DBDE and HDPE–TBA samples. The most effective irradiation wavelengths for crosslinking are found to be 300 nm and 280 nm for LDPE–DBDE and LDPE–TBA samples, respectively. 1995 John Wiley & Sons, Inc. 相似文献
72.
Min?-Ho?LeeEmail author Dong?-Joo?Yoon Dae?-Hee?Won Tae?-Sung?Bae Fumio?Watari 《Metals and Materials International》2003,9(1):35-42
In the present study, commercial pure Ti and Ti-6Al-4V alloy specimens with and without alkali and heat treatments were implanted
in the abdominal connective tissue of mice. Conventional stainless steel 316L was also implanted for comparison. After three
months, their biocompatibility was evaluated byin vitro andin vivo experiments. Surface structural changes of specimens due to the alkali treatment and soaking in Hank’s solution were analyzed
by XRD, SEM, XPS and AES. An apatite layer, which accelerates the connection with bone, was formed more easily on the alkali
treated specimens than the non-treated specimens. The number of macrophages, which is known to increase as the inflammatory
reaction proceeds, was much lower for the alkali and heat treated specimens than for the others. The average thickness of
the fibrous capsule formed around the implant was much thinner for the alkali and heat treated specimens than for the others. 相似文献
73.
Grinding a mixture of polyvinylidene fluoride (PVDF) and NaOH was conducted by a planetary ball mill at atmospheric condition to investigate mechanochemical reaction between the two substances. The grinding stimulates the reaction to form NaF and organic composites. Yield of fluorine converted from PVDF to NaF increases with an increase in grinding time and reaches 90% at 60 min or more. As for the organic phase, oxygen-bearing compounds are formed due to substitution of fluorine by OH base. The organic compounds are classified into water-soluble and insoluble ones, depending on their structures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2249–2252, 2001 相似文献
74.
Hideo Yamauchi Junichi Ikejiri Fumio Sato Hiroyuki Oshita Tsuyoshi Honma Takayuki Komatsu 《Journal of the American Ceramic Society》2019,102(11):6658-6667
In recent years, the expansion of demand for lithium ion batteries has resulted in soaring prices of the constituent resources. From the viewpoint of safety, studies on all-solid-state batteries are actively being carried out. In this study, we succeeded in driving all-solid-state batteries derived from nontoxic oxide glasses at room temperature without requiring scarce resources such as lithium and cobalt. The main structure of the ceramic batteries with a simple structure in which Na2FeP2O7 crystallized glass and β″-alumina solid solution are joined by pressureless cofiring at 550°C. During the crystallization of Na2O-Fe2O3-P2O5 glass, fusion with the β″-alumina solid solution is achieved. Reversible charge and discharge of 80 mAh/g were achieved at room temperature. It is not necessary to apply pressure during cell preparation or the use of the batteries. Furthermore, the strong junction at the cathode and electrolyte interface does not peel off during charge and discharge over a long period of 623 cycles. Ex situ X-ray photoelectron spectroscopy revealed partial Fe4+ induction and a reversible charge and discharge reaction even after overcharging to 9 V. It was demonstrated that Na2FeP2O7 is very stable against overcharging to 9 V. 相似文献
75.
76.
K Tomoda T Yoneda K Tsukaguchi M Yoshikawa T Tokuyama A Fu N Narita 《Canadian Metallurgical Quarterly》1993,68(9):559-564
A clinical investigation was carried out in 39 patients with atypical mycobacteriosis (AM). The patients at our hospital diagnosed as having AM during an 11-year period from 1981 to 1991 were reviewed in this study. The incidence of AM among all of mycobacterial infections has been increasing since 1988. The atypical mycobacteria detected included M. avium complex (MAC) in 79%, M. kansasii in 26%, and other organisms in 5%. Patients who had primary infection without underlying respiratory disease were compared with those who had secondary infection. In secondary infection, MAC was detected in the sputum of a high percentage of patients and was positive for more than 6 months despite therapy. Gamma globulin levels were also increased in patients with secondary infection. Cell mediated immunity was examined by the DNCB reaction and the detection of CD4- and CD8- positive T lymphocytes. The DNCB skin reaction was positive in 6 out of 26 patients with secondary infection. The percentage of CD8- positive T lymphocytes was higher in patients with secondary disease. Fischer's ratio (indicating the balance of plasma amino acids) was also examined as an index of the nutritional status. It was significantly lower in secondary infection compared with primary infection. Moreover, secondary infection was associated with a lower positive rate for the DNCB skin reaction and a lower Fischer's ratio when compared with pulmonary tuberculosis. Thus impairment of cell-mediated immunity, malnutrition, and a poor prognosis were significantly more common in secondary infection compared with primary infection. 相似文献
77.
Takuya Kitabatake Tetsuo Uchikoshi Fumio Munakata Yoshio Sakka Naoto Hirosaki 《Journal of the European Ceramic Society》2012,32(7):1365-1369
The compaction of a Eu-doped Ca-α-SiAlON phosphor powder was performed by electrophoretic deposition (EPD). The effect on the adhesion and optical properties of the silica precursor as both a binder of the powder and a filler of the air voids were evaluated. The adhesion of the silica impregnated composite film to the silica glass substrate was characterized by the tape test. The improvement of the external quantum efficiency was confirmed from the PL spectra measurement after the silica impregnation. The temperature dependence of the external quantum efficiency was also investigated in order to discuss the advantage of using the silica precursor as a binder for high-brightness LED applications. 相似文献
78.
Ronaldo Fumio Hashimoto Junior Barrera 《Journal of Mathematical Imaging and Vision》2001,15(3):197-216
W-operators are discrete set operators that are both translation invariant and locally defined within a finite window W. A particularly interesting property of W-operators is that they have a sup-decomposition in terms of a family sup-generating operators, that are parameterized by the operator basis. The sup-decomposition has a parallel structure that usually is not efficient for computation in conventional sequential machines. In this paper, we formalize the problem of transforming sup-decompositions into purely sequential decompositions (when they exist). The techniques were developed for general W-operators, specialized for increasing W-operators and applied on operators built by compositions of dilations and erosions. 相似文献
79.
This study has investigated potential links between tribological performance and the morphology of tribofilms formed from
anti-wear additives with application to metal V-belt pushing type continuously variable transmission fluids (B-CVTFs). The
influence of metal–metal tribological properties of anti-wear additives was evaluated using a ball on plate tribometer, enabling
friction and lubricant film formation to be monitored during reciprocating tests. Contact mode atomic force microscopy was
utilised to investigate the nature of tribofilms at the nanometre scale. As a result, an additive formulation composed of
hydrogen phosphite and over-based calcium sulphonate in a hydro-cracked mineral Group II base oil demonstrated a synergism
with 8% higher friction coefficient and more stable film formation than the individual additive cases, providing a positive
outcome for a B-CVTF. Tribofilm species produced by a chemical reaction between hydrogen phosphite and over-based calcium
sulphonate were densely deposited on the wear scar to form a rougher surface, which may explain the higher friction observed. 相似文献
80.