Platinum catalysts for the high-yield oxidation of methane to a methanol derivative

Platinum catalysts are reported for the direct, low-temperature, oxidative conversion of methane to a methanol derivative at greater than 70 percent one-pass yield based on methane. The catalysts are platinum complexes derived from the bidiazine ligand family that are stable, active, and selective for the oxidation of a carbon-hydrogen bond of methane to produce methyl esters. Mechanistic studies show that platinum(II) is the most active oxidation state of platinum for reaction with methane, and are consistent with reaction proceeding through carbon-hydrogen bond activation of methane to generate a platinum-methyl intermediate that is oxidized to generate the methyl ester product.     

Tracking the evolution of a hydrothermal event plume with a RAFOS neutrally buoyant drifter

The migration and evolution of a deep ocean hydrothermal event plume were tracked with a neutrally buoyant RAFOS float. The float remained entrained in the plume for 60 days, and the plume vorticity was calculated directly from the anticyclonic motion of the float. Concentrations of suspended particles, particulate iron, and dissolved manganese in the plume did not decay significantly during the 60 days, which indicates that event plumes would be easily detectable a year after formation.     

Genital pathology of feral male goats

Genitalia from 1000 feral male goats derived from western Queensland and New South Wales were examined after slaughter at an abattoir and the prevalence of abnormalities determined. Ulcerative balanoposthitis, considered due to caprine herpesvirus infection, was observed in 11 animals (1.1%); acidophilic intranuclear inclusions were found in 7 of these. Other conditions included focal hypoplasia of seminiferous tubules in 2 bucks (0.2%), segmental aplasia of the epididymis (one buck, 0.1%), bulbourethral gland cysts with contained aggregations (33 bucks, 3.3%) and haemangiosarcoma of the bulbourethral gland in one animal. The low prevalence of several conditions such as spermatic granuloma, cryptorchidism, and testicular hypoplasia, was attributed largely to the fact that the bucks examined were horned so that the recognised association between genital abnormalities and polledness did not apply.     

Volatiles from the 1994 Eruptions of Rabaul: Understanding Large Caldera Systems

The 1994 eruption of Rabaul, in Papua New Guinea, involved a small plinian eruption at Vulcan and a vulcanian eruption on the opposite side of the caldera at Tavurvur. Vulcan's ash leachates indicate seawater interaction that is consistent with earlier observations of low sulfur dioxide emissions and the presence of ice crystals in the initial plinian eruption cloud. In contrast, Tavurvur ash leachates indicate no seawater interaction, and later sulfur dioxide emissions remained high despite low-level eruptive activity. Silicic melt inclusions indicate that the andesitic melt contained about 2 weight percent water and negligible carbon dioxide. Mafic melt inclusions in Tavurvur ash have water and carbon dioxide contents that vary systematically over the course of the eruption. The mafic melt inclusions suggest that a mafic dike intruded from below the silicic chamber and provide further evidence that mafic intrusions drive caldera unrest.     

第九届粳稻发展论坛之11＇全国优良食味粳稻品评结果报告

由国内外19位水稻专家对在全国范围内筛选的20个粳稻参评样品进行了品评。品评活动采取现场加密,现场评分,现场录入,现场统计,现场解密的方法。评选出特等奖1个、一等奖2个、二等奖7个、三等奖5个、优秀奖5个。同时分别分析了蛋白质含量、米饭食味计评分与感官食味评分间的相关性,结果表明蛋白质含量与感官食味评分呈极显著负相关,...     

苎麻生物脱胶复合菌群的构建

分别从沤麻池、苎麻脱胶厂污泥、老麻园土和腐烂麻堆等生境收集自然菌群,采用室内温水沤麻的方法检测它们的原始脱胶能力,结果表明:这些自然菌群的脱胶能力较弱,使苎麻分纤分别需要12 d、18 d、14 d和10 d,脱胶后的纤维强度极低,最高只有2.83 cN/dtex,失去了工业利用价值.将不同来源的菌群等比例混后用于脱胶试验,其分纤周期为8d,分纤时纤维强为2.58 cN/dtex.以苎麻为唯一碳源和能源对复合菌群进行长期驯化,分别在驯化至69 d、89 d、182 d和407 d发现其分纤周期缩短到了5d、4d、3d和2.2 d,而且随着分纤周期的缩短,纤维强度也逐渐提高.复合菌群驯化407d后,分纤周期稳定在50h左右,分纤状况良好,纤维强度达到了5.52 cN/dtex.     

Study on Salinity Tolerance of Tomatoes during Seed Germination under Different Salt Stress Conditions

[Objective] The aim of this study was to provide the theoretical basis for screening and utilizing salt-tolerant tomato varieties as well as for cultivating salt-resistance.[Method] Salinity tolerance of tomato during seed germination under simple salt sodium chloride and double salt calcium nitrate or sodium chloride stress were studied by Petri dish culturing.[Result] As the two kinds salt concentration increased,the germination regularity,the germination rate,the germination index and the growing vigor index of tomato seedlings decreased,but the germination losing rate increased.When salt concentration was from 0.2% to 0.4%,there was little difference among all indexes under two kinds of salt stress.However,when salt concentration was from 0.6% to 1.0%,the difference among all indexes under two kinds of salt stress was significant.[Conclusion] Salinity tolerance of tomato seeds under double salt calcium nitrate or sodium chloride stress was higher than that under simple salt sodium chloride stress.     

Post-cambrian trilobite diversity and evolutionary faunas

A cluster analysis of the stratigraphic distribution of all Ordovician trilobite families, based on a comprehensive taxonomic database, identified two major faunas with disjunct temporal diversity trends. The Ibex Fauna behaved as a cohort, declining through the Ordovician and disappearing at the end-Ordovician mass extinction. In contrast, the Whiterock Fauna radiated rapidly during the Middle Ordovician and gave rise to all post-Ordovician trilobite diversity. Its pattern of diversification matches that of the Paleozoic Evolutionary Fauna; hence, trilobites were active participants in the great Ordovician radiations. Extinction patterns at the end of the Ordovician are related to clade size: Surviving trilobite families show higher genus diversity than extinguished families.