This paper mainly covers a method for preparing a highly alkaline magnesium linoleate solution with a total base number(TBN) value of 328 mg KOH/g using linoleic acid as the biodegradable raw material, which can subst...This paper mainly covers a method for preparing a highly alkaline magnesium linoleate solution with a total base number(TBN) value of 328 mg KOH/g using linoleic acid as the biodegradable raw material, which can substitute for traditional lubricant detergents as an environmentally friendly detergent. Reaction conditions, including the molar ratio of magnesium oxide to linoleic acid, the molar ratio of methanol to magnesium oxide, the carbonation temperature, the molar ratio of water to magnesium oxide, the flow rate of CO2 gas and the duration for injection of CO2 to magnesium oxide system, were optimized.展开更多
This article describes a method for synthesizing an excellent oil soluble calcium isostearate detergent using isostearic acid and calcium hydroxide as main starting materials. Reaction conditions, including the molar ...This article describes a method for synthesizing an excellent oil soluble calcium isostearate detergent using isostearic acid and calcium hydroxide as main starting materials. Reaction conditions, including the molar ratios of calcium hydroxide to isostearic acid, methanol to calcium hydroxide and water to calcium hydroxide, the carbonation temperature, the CO_2 flow rate, and the volume of injected CO_2, were optimized. Under the optimized conditions, a high alkalinity calcium isostearate detergent with a total base number(TBN) of 358 mg KOH/g and an overbased calcium isostearate detergent with a value of TBN equating to 406 mg KOH/g could be obtained. Finally, the properties of the calcium isostearate detergent were evaluated by the size distribution analysis, the thermogravimetric analysis(TGA) and the coking tendency tester.展开更多
In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including t...In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including the molar ratio of 12-hydroxystearic acid to acrylic acid, the catalyst amount, the esterification temperature, and the esterification time, were optimized. Under the optimized conditions, the 12-acryloyloxystearic acid with an acid value of 159 mg KOH/g and a melting range of between 70.4 ℃ and 71.4 ℃ was obtained. The structure of 12-acryloyloxystearic acid was confirmed by FTIR spectroscopy. Results of preparing magnesium 12-acryloyloxy stearate detergent showed the existence of acryloyloxy radical in 12-hydroxystearic acid could improve the quality of lubricant detergent greatly.展开更多
Przewalski’s gazelle Procapra przewalskii is an endangered species endemic to China. A question remains about subspecific variation in this species. Skulls of Przewalski’s gazelle collected from its current remnant ...Przewalski’s gazelle Procapra przewalskii is an endangered species endemic to China. A question remains about subspecific variation in this species. Skulls of Przewalski’s gazelle collected from its current remnant ranges around the Qinghai Lake in combination with those collected prior to the 20th century were measured and analyzed using Hierarchical Cluster Analysis in order to clarify the question. Unexpectedly, P. p. diversicornis, extirpated from its historic range, has spread to the Qinghai Lake region where it has replaced nominotypical P. p. przewalskii and is now restricted to a few small isolated populations around the lake. We discuss the causes of this unexpected replacement. In this study, we discuss the possibility of a new form, possibly a new subspecies, in the Guide Basin, adjacent to Qinghai Lake; it is unclear whether the new form has long existed and was only discovered in recent years, or whether it evolved in recent times due to the geographical isolation and anthropogenic landscape features. The study sheds light on the processes of microevolution and subspeciation in Procapra przewalskii, and based on the findings, we propose measures for conservation strategies for Przewalski’s gazelle.展开更多
文摘该文以温和酸催化条件下的木质素磺酸盐解聚产物为研究对象,建立系统分离和分析测试木质素磺酸盐解聚后获得的低分子酚类产物的方法。选用4根油溶性的ACQUITY APC XT小孔径刚性填料色谱柱串联,在高分辨紫外检测器条件下,采用超高效凝胶渗透色谱(APC)对解聚产物实现了高效分离,获得了高灵敏度的木质素基酚类产物的相对分子质量及其分布色谱信息。探讨了反应温度、时间和催化剂浓度等对酸催化木质素磺酸盐解聚行为的影响,结果表明,对于木酚比(木质素:苯酚)为25%(质量分数)的木质素磺酸盐解聚体系,在催化剂和木质素物质的量比为2.334、130 ℃酸催化反应60 min时,获得了解聚效率高达80%以上的木质素基酚类产物,解聚获得的产物相对峰高分子质量( M p)组成均分布在720、490和260 Da 3个低聚物区间,均具有很窄的分子质量分布指数(接近1)。由此可以初步推断,木质素磺酸盐在该研究采用的温和酸催化条件下,催化反应机理不受反应时间、温度以及催化剂浓度的影响,具有特定的解聚途径。
基金supported by the Natural Science Research Project of Anhui Educational Committee (No. KJ2013B273)the National Students’ Innovative Training Program (No. 201210375035)the Scientific Research Foundation for Introduced Scholars, Huangshan University (No. 2013xkjq004 ).
文摘This paper mainly covers a method for preparing a highly alkaline magnesium linoleate solution with a total base number(TBN) value of 328 mg KOH/g using linoleic acid as the biodegradable raw material, which can substitute for traditional lubricant detergents as an environmentally friendly detergent. Reaction conditions, including the molar ratio of magnesium oxide to linoleic acid, the molar ratio of methanol to magnesium oxide, the carbonation temperature, the molar ratio of water to magnesium oxide, the flow rate of CO2 gas and the duration for injection of CO2 to magnesium oxide system, were optimized.
基金supported by the Anhui Province Students’Innovative Training Program(No.201510375015)the Scientific Research Foundation of Huangshan University(No.2015xkjq002)
文摘This article describes a method for synthesizing an excellent oil soluble calcium isostearate detergent using isostearic acid and calcium hydroxide as main starting materials. Reaction conditions, including the molar ratios of calcium hydroxide to isostearic acid, methanol to calcium hydroxide and water to calcium hydroxide, the carbonation temperature, the CO_2 flow rate, and the volume of injected CO_2, were optimized. Under the optimized conditions, a high alkalinity calcium isostearate detergent with a total base number(TBN) of 358 mg KOH/g and an overbased calcium isostearate detergent with a value of TBN equating to 406 mg KOH/g could be obtained. Finally, the properties of the calcium isostearate detergent were evaluated by the size distribution analysis, the thermogravimetric analysis(TGA) and the coking tendency tester.
基金This work was supported by the National Undergraduate Innovative Training Program(201410375004)the Scientific Research Foundation for Introduced Scholars,Huangshan University(2015xkjq002)the Scientific Research Foundation of Huangshan University(2014xkj012)
文摘In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including the molar ratio of 12-hydroxystearic acid to acrylic acid, the catalyst amount, the esterification temperature, and the esterification time, were optimized. Under the optimized conditions, the 12-acryloyloxystearic acid with an acid value of 159 mg KOH/g and a melting range of between 70.4 ℃ and 71.4 ℃ was obtained. The structure of 12-acryloyloxystearic acid was confirmed by FTIR spectroscopy. Results of preparing magnesium 12-acryloyloxy stearate detergent showed the existence of acryloyloxy radical in 12-hydroxystearic acid could improve the quality of lubricant detergent greatly.
基金supported by the Key Program of Knowledge Innovation Program of Chinese Academy of Sciences (KSCX2-EW-Z-4)Sir Peter Scott Fund of SSC/IUCN and National Natural Science Foundation of China (30670267, 30430120)
文摘Przewalski’s gazelle Procapra przewalskii is an endangered species endemic to China. A question remains about subspecific variation in this species. Skulls of Przewalski’s gazelle collected from its current remnant ranges around the Qinghai Lake in combination with those collected prior to the 20th century were measured and analyzed using Hierarchical Cluster Analysis in order to clarify the question. Unexpectedly, P. p. diversicornis, extirpated from its historic range, has spread to the Qinghai Lake region where it has replaced nominotypical P. p. przewalskii and is now restricted to a few small isolated populations around the lake. We discuss the causes of this unexpected replacement. In this study, we discuss the possibility of a new form, possibly a new subspecies, in the Guide Basin, adjacent to Qinghai Lake; it is unclear whether the new form has long existed and was only discovered in recent years, or whether it evolved in recent times due to the geographical isolation and anthropogenic landscape features. The study sheds light on the processes of microevolution and subspeciation in Procapra przewalskii, and based on the findings, we propose measures for conservation strategies for Przewalski’s gazelle.
