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排序方式: 共有374条查询结果,搜索用时 15 毫秒
371.
Urabe T Baker ET Ishibashi J Feely RA Marumo K Massoth GJ Maruyama A Shitashima K Okamura K Lupton JE Sonoda A Yamazaki T Aoki M Gendron J Greene R Kaiho Y Kisimoto K Lebon G Matsumoto T Nakamura K Nishizawa A Okano O Paradis G Roe K Shibata T Tennant D Vance T Walker SL Yabuki T Ytow N 《Science (New York, N.Y.)》1995,269(5227):1092-1095
A survey of hydrothermal activity along the superfast-spreading (approximately 150 millimeters per year) East Pacific Rise shows that hydrothermal plumes overlay approximately 60 percent of the ridge crest between 13 degrees 50' and 18 degrees 40'S, a plume abundance nearly twice that known from any other rige portion of comparable length. Plumes were most abundant where the axial cross section is inflated and an axial magma chamber is present. Plumes with high ratios of volatile ((3)He, CH(4), and H(2)S) to nonvolatile (Mn and Fe) species marked where hydrothermal circulation has been perturbed by recent magmatic activity. The high proportion of volatile-rich plumes observed implies that such episodes are more frequent here than on slower spreading ridges. 相似文献
372.
Isopropanol:NH3 and Methanol:KOH (saponification) alkaline treatments are usually applied in the study of soil organic matter. The first is used in studies of soil water repellency, and the latter in the extraction of ester-bound lipids from soil. In this study, isopropanol:NH3 and methanol:KOH treatments were applied separately in a solvent extracted repellent soil, in order to compare their efficiency in the extraction of water repellent compounds. The soil sample was taken from a site under a 16 year old Pinus taeda stand. The amount and class of organic compounds released by each treatment were compared using gas chromatography-mass spectrometry (GC-MS). Both treatments resulted in wettable soil after alkaline extraction. In general, alkaline treatments yielded extracts with the same class of organic compounds. Alkanoic acids, α,ω-alkanedioic acids, hydroxyalkanoic acids, aromatic compounds, and alkanols were identified, indicating the preservation of suberin and cutin biopolyester in the soil. Large differences were observed in the amounts of ω-hydroxyalkanoic acids, as well as in the quantity and distribution of dihydroxyalkanoic and trihydroxyalkanoic acids. In contrast to methanol:KOH, isopropanol:NH3 was not efficient in the extraction of whole aliphatic biopolyesters, mainly pine cutin-related products. Methanol:KOH was more effective in hydrolysis. The presence of biopolyesters in water repellent soil under the P. taeda stand seems to play an important role in water repellency. 相似文献
373.
IMAGING DIAGNOSIS—ECTOPIC SPLEEN MIMICKING HEPATIC TUMOR WITH INTRA‐ABDOMINAL METASTASES INVESTIGATED VIA TRIPLE‐PHASE HELICAL COMPUTED TOMOGRAPHY IN A DOG
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Kenji Kutara Toshiaki Konno Hirotaka Kondo Kotoyo Aoki Hinako Yamazoe Satoru Matsunaga 《Veterinary radiology & ultrasound》2017,58(3):E26-E30
A 10‐year‐old castrated male miniature dachshund was presented with an abdominal mass. The dog had a history of splenectomy. Triple‐phase helical computed tomography was utilized, revealing a hepatic mass and multiple intra‐abdominal solid masses. In triple‐phase helical computed tomography the images, hepatic mass and two of four intra‐abdominal masses were heterogenous in all phases. Therefore, we diagnosed a malignant hepatic tumor and presumed intra‐abdominal metastases. The masses were surgically removed and were histologically composed of normal spleen tissues, findings which were consistent with ectopic spleen. 相似文献
374.
Yasushi Yoshimoto Tamami Egashira Isao Hanashiro Hiroshi Ohinata Yoshikazu Takase Yasuhito Takeda 《Cereal Chemistry》2004,81(4):515-520
The molecular structure and pasting properties of starches from eight buckwheat cultivars were examined. Rapid viscograms showed that buckwheat starches had similar pasting properties among cultivars. The actual amylose content was 16–18%, which was lower than the apparent amylose content (26–27%), due to the high iodine affinity (IA) of amylopectin (2.21–2.48 g/100 g). Amylopectins resembled each other in average chain‐length (23–24) and chain‐length distributions. The long‐chains fraction (LC) was abundant (12–13% by weight) in all the amylopectins, which was consistent with high IA values. The amyloses were also similar among the cultivars in number‐average DP 1,020–1,380 with 3.1–4.3 chains per molecule. The molar‐based distribution indicated that all the amyloses comprised two molecular species differing in molecular size, although the weight‐based distribution showed a single species. A comparison of molecular structures of buckwheat starches to cereal starches indicated buckwheat amylopectins had a larger amount of LC, and their distributions of amylose and short chains of amylopectin on molar basis were similar to those of wheat and barley starches. 相似文献