Search Results - (Author, Cooperation:C. Y. Huang)

0025-116X

Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Physics

Um ein „härtbares“ Harz zu erhalten, das nur aus Kohlenstoff und Wasserstoff besteht, wurde ein Xylol-Formaldehyd-Harz (XF-Harz) mit einem Kohlenwasserstoff (CH) wie folgt umgesetzt: Es wurde dabei angenommen, daß hierbei eine elektrophile Substitution erfolgt. Auf der Suche nach reaktionsfähigen Kohlenwasserstoffen wurden 15 verschiedene aromatische Verbindungen in Gegenwart von Perchlorsäure mit Formaldehyd umgesetzt. Dabei reagierten Acenaphthen, Polyacenaphthylen, Anthracen und Mesitylen leicht mit Formaldehyd. Es wurden nunmehr XF-Harze hergestellt und mit den erwähnten aromatischen Kohlenwasserstoffen umgesetzt. Dabei waren Acenaphthen, Polyacenaphthylen und Acenaphthen-Formaldehydharz besonders wirksam.Da ein ω,ω'-Dimethylol-XF-Harz bei der Umsetzung noch wirksamer als ein normales Harz sein sollte, wurde eine brauchbare Methode für die Herstellung eines ω,ω'-Dimethylol-XF-Harzes entwickelt. Durch Umsetzung des ω,ω'-Dimethylol-XF-Harzes mit Acenaphthen-Formaldehyd-Harz in Gegenwart von Xylolsulfonsäure wurde schließlich ein gezielt vernetztes Harz erhalten, das nur aus Kohlenstoff und Wasserstoff bestand. Es ist unschmelzbar und in Benzol unlöslich.(Unter geänderten Bedingungen kann auch Anthracen oder Mesitylen das XF-Harz vernetzen).

A study to obtain a resin consisting only of carbon and hydrogen and yet having thermosetting properties was made. The process was a reaction of xylene-formaldehyde resin (XF-resin) with a hydrocarbon (CH) The reaction was assumed to proceed through an electrophilic substitution. To find some reactive hydrocarbons, 15 different aromatic hydrocarbons have been reacted with formaldehyde in the presence of perchloric acid. It was found that acenaphthene, acenaphthylene, anthracene and mesitylene easily reacted with formaldehyde. Some XF-resins were prepared, and reacted with the mentioned aromatic hydrocarbons.Of these hydrocarbons, acenaphthene, polyacenaphthylene and acenaphthene-formaldehyde resin were especially effective.It is understandable that an ω,ω'-dimethylol-XF-resin is more effective than a normal XF-resin. So an useful method for the synthesis of the ω,ω'-dimethylol-XF-resin was investigated.By the reaction of ω,ω'-dimethylol-XF-resin with acenaphthene-formaldehyde resin in the presence of xylene sulfonic acid, the desired cured resin was obtained. The resin consisted only of carbon and hydrogen. It was insoluble in benzene and non-melting. (However, by changing the conditions, anthracene or mesitylene can also cure XF-resins).

32 Ill.

Electronic Resource

2018-04-05

Royal Society

2054-5703

Natural Sciences in General

behaviour, physiology, ecology

2018-02-08

Wiley-Blackwell

0148-0227

Geosciences

Physics

2015-01-17

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2016-03-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Climate ; *Global Warming ; *Seasons ; *Temperature ; Vertebrates/*physiology

2013-04-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Agouti Signaling Protein/metabolism ; Animals ; Birds/*anatomy & histology/physiology ; Cell Differentiation ; Cell Lineage ; Cell Proliferation ; Chickens/anatomy & histology/physiology ; Columbidae/anatomy & histology/physiology ; Feathers/*cytology/growth & development ; Female ; Galliformes/anatomy & histology/physiology ; Male ; Melanocytes/*cytology/physiology ; Models, Biological ; *Pigmentation ; Regeneration ; *Stem Cell Niche ; Stem Cells/*cytology/physiology

2013-01-22

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Ants/*genetics ; *Behavior, Animal ; Chromosomes/genetics ; Female ; Gene Expression Profiling ; Gene Expression Regulation ; Genome, Insect/genetics ; Insect Proteins/genetics/metabolism ; Male ; Polymorphism, Genetic ; Receptors, Odorant/genetics/metabolism ; *Social Behavior

2018-08-07

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2018-08-11

The American Society for Pharmacology and Experimental Therapeutics

0022-3565

1521-0103

Medicine

1089-7550

AIP Digital Archive

Physics

Spectroscopic ellipsometry measurements have been used as a probe to provide information on the structure of a hydrogenated amorphous silicon based n-i two-layer system. The n-i structure is prepared under the same conditions as an a-Si:H p-i-n cell with a thin (∼150 A(ring)) n layer deposited in a glow discharge from a mixture of SiF4, SiH4, H2, and PH3 on top of intrinsic a-Si:H. An effective medium approximation and a linear regression analysis have been used to determine the bulk microstructure of the thick (0.3 μm) n layer on quartz as a mixture of volume fractions of a-Si (0.74±0.01), c-Si (0.09±0.02), and void (0.17±0.03). When applied to the thin n layer in the solar-cell configuration, however, the corresponding analysis shows evidence of a 100-A(ring) overlayer of very low density a-Si, not observed on the thicker n-type material, which dominates the dielectric properties of the thin layer. These results are suggestive of nucleation and growth surface microstructure on the 150-A(ring) n layer and lead to the conclusion that, in the fabrication of high-performance a-Si:H based devices using thin layers, such structure must be minimized.

Electronic Resource

1365-2230

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Hypohidrotic ectodermal dysplasia (HED) is found worldwide with an estimated incidence of 1 per 100 000 births. X-linked hypohidrotic ectodermal dysplasia (XLHED, OMIM 305100) is the most common form of the ectodermal dysplasias (ED), a rare group of hereditary diseases characterized by abnormal development of eccrine sweat glands, hair, and teeth. Heterozygous carriers of XLHED often manifest minor or moderate degrees of hypotrichosis, hypodontia, and hypohidrosis. ED1, the gene for XLHED encodes ectodysplasin A, which is a new member of the tumour necrosis factor family. The majority of mutations in XLHED are missense mutations, but one-fifth are insertion/deletions. Here we report a novel 7-bp deletion mutation (nt1242–1248) in exon 9 of the ED1 gene that results in a frameshift and premature stop codon (PTC + 38 amino acids). Mutation analysis in families with XLHED allows for genetic counselling, prenatal diagnosis and confirmation of carrier status.

Electronic Resource

1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Primary cutaneous amyloidoses are rare in Western countries, but are relatively common in Taiwan. Anosacral cutaneous amyloidosis is a rare type of primary cutaneous amyloidoses, first reported in Japanese patients. Patients/methods In the present study, we investigated the age of onset, sites of involvement, associated systemic diseases, and histopathological findings in 10 cases of anosacral cutaneous amyloidosis seen during the past 27 years. Results In previous reports the aetiology of anosacral cutaneous amyloidosis was thought to be a senile change, but half of our patients developed the disease before the age of 60 years. Based on our histopathological findings, apoptosis may be the initial event causing amyloid deposition, although the precise mechanism causing apoptosis needs further investigation. Three patients were found to have diabetes mellitus, but any relationship to anosacral cutaneous amyloidosis is unclear. Conclusions No cases of this cutaneous disorder have been reported in the Western literature; there seems to be a racial difference accounting for the disease, although the precise factor is not clarified yet. The disease could easily be misdiagnosed as lichen simplex chronicus, postinflammatory hyperpigmentation or tinea cruris; therefore, a thorough history, a careful physical examination and a skin biopsy is needed to establish a firm diagnosis.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The use of polymer-dispersed liquid crystal films to fabricate gratings was demonstrated. The written gratings are permanent, but are electrically switchable. In this article, we report the results obtained from the dynamical studies of gratings formed in polymer-dispersed liquid crystal films having various liquid crystal-polymer mixing ratios. The results showed that during the initial phases of formation, a thermal grating effect dominated. Later, it was offset or quenched by the photopolymerization effect which eventually dominated and determined the characteristics of the final grating. © 1998 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We have investigated two antiferromagnetic superconductors, NdRh4B4 and SmRh4B4, which exhibit two quite different temperature dependencies of the upper critical field arising from two different mechanisms1 of the modification of superconductivity by the presence of antiferromagnetism. In order to further study these mechanisms, we have investigated the electromagnetic properties and have measured the penetration depths λ(T) of NdRh4B4 (Tc=5.45 K, TN1=1.31 K, and TN2=0.89 K) and SmRh4 B4 (Tc=2.2 K, TN=0.9 K), employing a tunnel diode oscillator at ∼30 MHz. Above the antiferromagnetic transition temperature (TN1 for NdRh4B4 and TN for SmRh4B4), the temperature dependencies of the penetration depths of these two superconductors fit the BCS theory well. We have found λ(0)=2170 and 980 A(ring) for NdRh4B4 and SmRh4B4, respectively. However, as temperature is lowered, λ(T) for NdRh4B4 increases near TN1 and then saturates near TN2, presumably owing to the molecular field effect.2 The spin-fluctuation effects,2 expected to be significant near TN2 for NdRh4B4 and TN for SmRh4B4, have not been observed within our experimental accuracy.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We report that in BaTiO3:Rh the carrier-type depends not only on the postprocessing condition but also on the incident wavelength in two beam coupling. Carriers are the holes for the as-grown sample, and change to electrons for the sample reduced in the atmosphere of 10−14 atm oxygen partial pressure. However, for the sample reduced in the atmosphere of 10−10 atm oxygen partial pressure, the carrier is an electron for the incident wavelength of 514 nm, and a hole for 633 nm. Its absorption, photoinduced absorption, and two beam coupling are investigated and discussed. © 1998 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

High quality Y3Fe5O12/Gd3Ga5O12 (YIG/GGG) superlattices have been grown on (111)GGG substrates by pulsed laser deposition. The superlattices are investigated with the thickness of the YIG layer varied from six to one unit cells while keeping the GGG layer fixed at one unit cell. The thicknesses of the YIG and GGG layers are confirmed with grazing angle x-ray reflectivity (GAXR). The good quality of the samples is indicated by the small interface roughness, no more than 6 A(ring), also measured with GAXR. While the magnetization of the samples decreases when the thickness of the YIG layer is decreased, the superlattice remains magnetic even when the YIG layer is only one unit cell. Ferrimagnetic resonance indicates that there exists a surface anisotropy favoring in-plane magnetization. © 1996 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The photorefractive properties of BaTiO3 are gradually modified by the addition of Nb which change the charge carrier from hole to electron. Before the compensation point, the dark conductivity decreases and the response time increases with increasing Nb concentration. Two beam coupling gain can be explained by using the deep and shallow trap model with hole as the major carrier. Near the compensation point, the deep and shallow trap model is needed, in addition to the electron–hole competition to explain this. After the compensation point, an absorption around 600 nm evolves, the dark conductivity increases very fast, and the electron becomes the major carrier. © 1999 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We report evidence which suggests surface ferromagnetism in a ferromagnetic superconductor arising from the competition between the Meissner current shielding effect and the fluctuations of the localized magnetic moments. We have measured the surface impedance penetration depth Λ of ErRh4B4 and Er0.5Ho0.5Rh4B4 by employing a spectrometer operated at 9 GHz. For ErRh4B4, owing to the critical spin fluctuations just above Ts (〉Tc2), the critical temperature at which surface ferromagnetism appears, Λ−1 decreases smoothly as temperature decreases toward Ts. For Er0.5Ho0.5Rh4B4, the decrease of Λ−1 arising from spin fluctuations for T〉Tc2 is very small, and Λ−1 decreases abruptly at Tc2. We will discuss the theory and show how the predicted values of Λ(T) compare well with the observed values.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Data on zero-field μSR in ErRh4B4 are presented for temperatures from 4 to 300 K. Due to the large erbium moment, most of the muons have a relaxation time of less than 10 ns for temperatures below about 50 K. The data have been analyzed in terms of two distinct muon sites in the material. The deduced erbium relative fluctuation rate versus temperature is related to the crystalline electric field levels of erbium in the RERh4B4 structure.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Haemoglobin, methaemoglobin, blood nitrite concentration and acid-base balance were measured in European eel Anguilla anguilla following exposure to 0 (control), 0·142, 0·356, 0·751 and l·549 mM nitrite in fresh water for 24 h. Blood GOT (glutamate oxaloacetate transaminase) and GPT (glutamate pyruvate transaminase) activities and whole animal ammonia-N and urea-N excretions were also measured. Blood nitrite, methaemoglobin, PO2 (oxygen partial pressure), GOT, and whole animal ammonia-N excretion and urea-N excretion increased directly with increasing ambient nitrite concentrations, whereas blood pH, PCO2, and HCO−3 were inversely related to ambient nitrite concentration. An accumulation of nitrite in the blood of A. anguilla following 24 h exposure to elevated ambient nitrite as low as 0·751 mM increased its blood methaemoglobin, PO2, GOT and nitrogen excretion, but decreased its PCO2 (carbon dioxide partial pressure), HCO−3 and functional haemoglobin.

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