连香树人工幼林群落营养元素含量、积累分配和循环

研究了 1 0年生连香树人工群落 8种营养元素的含量、积累分配和循环。主要结论是 :( 1 )连香树营养器官中各种元素的平均含量顺序为Ca>N >Al>K >Mg>P >Fe >Mn。 ( 2 )元素量在各营养器官的分配顺序为根 >叶 >去皮干 >皮 >枝 ,各元素含量顺序为Ca>N >K >Al>Mg>P >Fe >Mn。 ( 3)连香树群落 8种元素的吸收量、存留量和归还量分别是 72 9 82kg·hm- 2 a- 1 、2 0 6 72kg·hm- 2 a- 1 和 52 3 1 0kg·hm- 2 a- 1 。 ( 4) 51 2 %的归还总K量靠降水淋溶归还 ,其余元素总归还量的 55 7%～ 96 5%靠凋落物归还。Fe、Al归还量的 4 1 3%和 4 4 3%通过死根归还。 ( 5) 8种元素的利用系数、归还比和周转期分别为 0 2 3～ 0 54、0 57～ 0 82和 2 2 6～7 63。文中改进了降水淋溶归还的算法 ,提出了群落归还系数、积累系数和吸收系数 ,讨论了落叶树种元素生物循环的算法     

压缩-热处理联合改性对杨木尺寸稳定性的影响

为改善杨木质软、强度低的特点,同时提高其尺寸稳定性,首先对杨木试样进行压缩处理,再进行热处理,并检测压缩杨木和热处理压缩杨木的吸湿、吸水膨胀率.结果表明:压缩率愈大,压缩杨木试样厚度方向和体积膨胀率愈大;经热处理后,试样的尺寸稳定性明显提高.     

干旱对不同种源喜树苗木生长及叶片喜树碱产量的影响

以长江以南8个不同种源的1年生喜树实生苗为研究对象,采用温室土培盆栽模拟干旱环境,研究干旱对不同种源喜树苗期生长的影响,同时利用超高效液相色谱测定干旱胁迫下各种源叶片喜树碱含量,计算单株叶片喜树碱产量。结果表明:干旱胁迫限制喜树苗期的生长,不同喜树种源地径和苗高的生长以及总生物量的积累均受到抑制,不同干旱处理间和种源间喜树的地径增粗、苗高增长、总生物量及叶产量等均存在显著差异(P<0.05);干旱对叶片喜树碱含量有显著影响(P<0.05),且不同种源之间存在显著差异(P<0.05),随干旱处理程度加深,叶片喜树碱含量呈先升高后降低的变化趋势;干旱导致大部分种源的单株叶片喜树碱产量降低,仅有桂林种源和南京种源的单株叶片喜树碱产量在轻度干旱胁迫下有所升高,不同种源之间存在显著差异(P<0.05),轻度干旱下种源桂林的喜树碱产量最高,达到27.904mg。轻度干旱可以提高喜树苗木叶片喜树碱含量,同时种源桂林在所有受试种源中均有较高的叶片喜树碱含量和产量。     

概论道路路面的历史、作用、分类及发展

在查阅了大量国内外道路发展史及道路路面设计、施工相关书籍的前提下,基于我国道路路面技术水平现状,对道路路面的历史及路面在整个道路工程中的作用、分类以及路面未来的发展前景进行了综合论述。     

“桥头堡”战略下云南国际物流人才培养探讨

指出了随着云南桥头堡建设的不断深入,云南对东南亚、南亚的贸易将不断增长,国际物流人才需求将日益增加。在桥头堡建设的大背景下,分析了云南国际物流人才培养的现状和存在的问题,提出了相应的培养目标和策略。     

Preparation and evaluation of self-microemulsifying drug delivery system of baicalein

The main object of this work is to prepare self-microemulsifying drug delivery system (SMEDDS) for oral bioavailability enhancement of a poorly water-soluble drug, baicalein. SMEDDS is the mixture of surfactants, cosurfactants, and oils, which are emulsified in aqueous media under conditions of gentle agitation or gastrointestinal motility. Solubility of baicalein was determined in various vehicles. Pseudo-ternary phase diagrams were constructed to identify the efficient self-emulsification region and droplet size distributions of the resultant microemulsions were determined using a particle size analyzer. Optimized SMEDDS formulations for baicalein were Cremophor RH40 (53.57%) as surfactant, Transcutol P (21.43%) as cosurfactant, and Caprylic capric triglyceride (ODO, 25%) as oil. The drug release rate of SMEDDS was significantly higher than that of the baicalein suspension. Comparison of the pharmacokinetics between baicalein-loaded SMEDDS and baicalein suspension was also performed in rats. The plasma concentrations of baicalein and baicalin, its mainly conjugated metabolite, were determined by HPLC method. The in vivo results showed that the absorption of baicalein from SMEDDS resulted in about 200.7% increase in relative bioavailability compared with that of the baicalein suspension. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as baicalein by the oral route.     

不同酿造工艺对树莓酒中单体酚的影响

为提高树莓酒品质,采用4种传统工艺和CO2浸渍工艺进行小容器(10L)树莓干酒的酿造,测定各种酒中单体酚。结果表明:CO2浸渍法酿制的树莓干酒中除芦丁外,其他酚类物质均要高于传统酿造法酿制的树莓干酒。2年陈酿的11%(v/v)干型树莓酒与未经陈酿的11%(v/v)干型树莓酒相比,阿魏酸、香豆酸和芦丁含量有所下降,水杨酸含量基本未发生变化,其余均有不同程度提高,特别是陈酿过程中槲皮素和安息香酸增量明显。高酒度利口酒芦丁含量远低于其他酒类,且有芦丁含量随酒度增高而降低的趋势。与传统工艺相比,CO2浸渍酿造的酒更适合酚类物质的转化,陈酿过程有利于芦丁含量下降,进一步改善酒的风味,实现口感的平衡。     

唐代林业职官和护林诏令及造林活动

唐代是我国封建社会经济高度发展的时期,也是自然环境相对较好的一个时期。唐代森林保护与植树造林工作取得了一定成绩,政府既设有林业职官又颁布护林法规典章,还积极组织造林活动。这些都值得当今借鉴。       

牡丹江林区土壤分布规律浅析

牡丹江林区土壤分布规律为由东向西地带性土壤的垂直分布特点显著,随山体自下而上的土壤分布规律为:沼泽土→草甸土→暗棕壤→棕色针叶林土→亚高山灌丛草甸土;由西南向东北土壤的水平分布也有一定的变化趋势;因受各种成土条件及人为因素制约,不同地区土壤的小区分布也各有差异。     

Recent spread and climatic ecological niche of the invasive guava fruit fly, Bactrocera correcta, in mainland China

The guava fruit fly, Bactrocera correcta (Bezzi) (Diptera:Tephritidae), is a harmful exotic insect pest in mainland China, which was first recorded in Yuanjiang County of Yunnan province in 1982. In order to elucidate its rate of spread, extensive field surveys were conducted during 2003–2011. Through 2011, B. correcta was found in areas below 1,500 m in altitude within the Longitudinal Range-Gorge Region of southwestern China (21–28°N latitude, 97–107°E longitude). The northernmost site where B. correcta was found was in Miyi County (26.48°N Latitude, 102.00°E longitude, Alt. 1,060 m) in Sichuan province. Within the currently infested area of mainland China, B. correcta mainly occurred in low-altitude valleys and basins, and displayed a patchy distribution. The mountain chains tend to run south to north, forming a natural barrier to insect flight eastward and westward. Human-assisted transport of infested fruits was the likely factor by which B. correcta moved across mountain chains. The analysis indicated that high-altitude portions of the northern Longitudinal Range-Gorge Region may block B. correcta spread northward.