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41.
Several radioisotopes of the naturally occurring uranium and thorium decay series, in addition to fallout plutonium, have unusually high concentrations in the water column of Mono Lake, a natural alkaline, saline lake. Complexing by carbonate ions appears to be responsible for the enhanced solubility of actinide elements with oxidation states of IV to VI. In contrast, fallout strontium-90 has been largely removed from the water, probably as a result of coprecipitation with calcium carbonate. The daughter/parent activity ratios of thorium, radium, and uranium isotopes suggest that thorium is removed from the water column to the sediments on time scales substantially longer than a month and that the desorption of thorium from the sediments to the water column requires less than a few years.  相似文献   
42.
An extraction apparatus was equipped with a nitrogen-flushing vessel to purge volatiles from a 10-g miso prepared solution at 40 degrees C, a reflux condenser to recover water, a coiled cold-trap to separate ethanol in advance, and a glass-lined stainless (GLS) trap filled with Tenax TA for flavor adsorption. Volatiles in the GLS tube were released with a thermal desorption device and condensed with a Micro-cryo trap prior to connection with GC and GC-MS for characterization. After analysis, a broad volatile profile comprising 9 categories of functional group and 97 identified compounds was achieved. As affected by ethanol supplementation for miso fermentation, most volatiles except alcohols and acetals in the low-salt products fermented with 5% NaCl and 7.5% ethanol were higher than those in the control products fermented with 9% NaCl and 0% ethanol and the high-ethanol supplemented products fermented with 5% NaCl and 15% ethanol. It reveals that supplementation of ethanol in miso at an appropriate level not only enabled a low-salt miso fermentation but also enhanced flavor formation.  相似文献   
43.
Extensive dating of the fossil corals associated with the Waimanalo shoreline on Oahu has shown that 120,000 years ago the ocean was approximately 7.6 meters above its present level. Corals grown during that time constitute a major portion of the subaerial reef-derived material on the island, with exposures ranging from about 10 meters to near sea level. This evidence corroborates the notion that 120,000 years before the present was the last time during which the sea stood significantly higher than it does today. The reported benches at 3.7, 1.5, and 0.6 meters, if not of Recent origin, could be features created by brief halts of the sea during rapid regression shortly after the Waimanalo high stand.  相似文献   
44.
译者引言J.L.科尔普博士是美国著名的地球化学专家,曾在美国普林斯顿大学获化学 PhD学位,并获美国科学进步协会的 NewcombCleveland 奖。从1976年3月起担任美国维耶赫苏尔公司的研究和开发副总裁,指导该公司的林业、木材制品、纤维制品、能源、环境和社团、研究及开发活动。他具有非常广泛和渊博的知识,在本文中运用了系统科学的理论和观点,特别是系统经济学的原理,对林业和林产工业的生产、开发和科研提出了一些很有见地的看法,有较大的参考  相似文献   
45.
不同培养料栽培金针菇比较试验   总被引:3,自引:0,他引:3  
本试验用醋糟、麦秸、高粱秸和玉米秸为主料,适当搭配棉籽壳栽培全针菇。试验设五个配方,配方1、2、3和4为试验组,配方5为对照组。试验结果表明:除配方2外,其余试验组的生物效率均高于对照组,其中以配方4最好,菌丝生长过度快,长势好,产量高,品质好,生物效率高达132%,比对照提高33.3%。  相似文献   
46.
<正> 前言腐植酸属于几种相似族类羟基芳香羧酸组成的复杂的混合物,也是一类结构十分复杂的无定形的高分子胶体有机酸。进行分离可得到黄腐酸、棕腐酸和黑腐酸,这三种分子量不同的腐植酸均有不同强度的刺激生长的作用,对酶解也有一定的影响。从大量的分析研究中证明腐植酸符合刺激素的作用。由于腐植酸溶解度低,因此在用其做添加剂时多将它制成硝基腐植酸或腐植酸铵、腐植酸钠等盐类使用。  相似文献   
47.
Epidemiological studies on Mycobacterium avium are requisite for revealing infection sources and disease transmission. They are based upon genotyping methods like RFLP and MIRU–VNTR. In our study, MIRU–VNTR typing was applied to 121 previously RFLP typed M. avium field isolates to compare the discriminatory power of both methods. The applicability of MIRU–VNTR typing was studied for isolates from a limited geographic area, namely 41 M. avium subsp. avium and 80 M. avium subsp. hominissuis isolates. Among the former, exhibiting 12 IS901 RFLP types, five MIRU–VNTR types were found with discriminatory index (DI) of 0.716. Among the latter, exhibiting 56 IS1245 RFLP types, 18 MIRU–VNTR types were found with DI of 0.866. Concomitant use of both methods increased DI to 0.981 and 0.995, respectively. MIRU–VNTR typing employing the selected markers provided discernible discrimination among M. avium subsp. hominissuis isolates, but more discriminative markers are needed for M. avium subsp. avium isolates.  相似文献   
48.
Members of the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) superfamily share an intracytoplasmic Toll-IL-1 receptor (TIR) domain, which mediates recruitment of the interleukin-1 receptor-associated kinase (IRAK) complex via TIR-containing adapter molecules. We describe three unrelated children with inherited IRAK-4 deficiency. Their blood and fibroblast cells did not activate nuclear factor kappaB and mitogen-activated protein kinase (MAPK) and failed to induce downstream cytokines in response to any of the known ligands of TIR-bearing receptors. The otherwise healthy children developed infections caused by pyogenic bacteria. These findings suggest that, in humans, the TIR-IRAK signaling pathway is crucial for protective immunity against specific bacteria but is redundant against most other microorganisms.  相似文献   
49.
Two studies were conducted to assess the effect of dietary protein reduction on N utilization, N excretion, and AA digestibility in growing pigs. The objective was to determine whether pigs fed diets with a reduced CP concentration could maintain the same N retention as pigs fed an adequate diet. The second objective was to test whether reducing dietary CP concentration decreases AA digestibility. In each study, six barrows were allotted to one of six dietary treatments in a Latin square design. Treatments consisted of four corn-soybean meal-based diets containing 15, 12, 9, and 6% CP, a casein-based diet containing 15% CP, and a protein-free diet. Crystalline AA were included in the 12, 9, and 6% CP diets. The indispensable:dispensable AA ratio was maintained at 45:55 with the addition of L-glutamic acid to the 9 and 6% CP diets. The casein-based and protein-free diets were used to determine endogenous total tract N and ileal AA losses. In the first study, total N losses and N absorbed decreased linearly (P < 0.001) as dietary CP concentration decreased from 15 to 6%. Both a linear (P < 0.001) and a quadratic (P < 0.05) decrease in N retention were found with decreasing dietary CP concentration. Nitrogen retained as a percentage of intake and absorbed increased (P < 0.001) as dietary CP concentration was reduced from 15 to 6%. In the second study, six barrows were surgically fitted with a T-cannula at the terminal ileum to determine ileal AA digestibility. For all dispensable and most indispensable AA, apparent and standardized ileal digestibility increased linearly (P 0.01, and for arginine, P < 0.05) as dietary CP concentration decreased. These results indicate that dietary CP concentration can be decreased from 15 to 12% with crystalline AA supplementation to meet an ideal AA profile without adversely affecting N retention, and that decreasing dietary CP concentration from 15 to 6% increases both dispensable and indispensable AA ileal digestibility.  相似文献   
50.
A new source to produce a significant quantity of a naturally occurring polyphenol, piceatannol, was investigated in this study. Both resveratrol and piceatannol are recognized as important ingredients in functional foods due to their beneficial health effects. However, unlike resveratrol, the piceatannol concentration in plants is very low. Thus, calluses of peanuts, an easily obtainable source, were chosen as the material to induce piceatannol production under controlled conditions. To induce resveratrol and piceatannol, calluses were exposed to the ultraviolet (UV) irradiation. Significant quantities of resveratrol and piceatannol were produced by calluses upon UV irradiation in both static and suspension culture conditions. The amounts of piceatannol and resveratrol produced in 1 g of calluses ranged from 2.17 to 5.31 microg and from 0.25 to 11.97 microg, respectively, in static culture. In suspension culture, the amounts of induced piceatannol and resveratrol were somewhat lower. The quantities of induced piceatannol and resveratrol reached a maximum at 18 h after UV irradiation treatment in static culture. In contrast, the levels of resveratrol and piceatannol remained almost constant throughout the experiments in suspension culture. The piceatannol produced by calluses in all studies was much higher than the values reported in the literature, whereas the resveratrol produced was comparable to reported values.  相似文献   
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