非灌溉季节施加生物炭对滴灌棉田土壤结构及水热特性的影响

为探究在非灌溉季节施加生物炭对滴灌棉田耕层土壤水热特性和三相结构的调控效应。设置生物炭15(B₁),30(B₂),45(B₃),60(B₄),0(B₀) t/hm²5个施加量,分析其对新疆滴灌棉田非灌溉季节耕层土壤(0—40 cm)三相结构、总孔隙度、土壤温度和土壤含水率的影响。结果表明:与对照处理相比,施炭处理使土壤固相体积降低2.58%~10.74%,总孔隙度增加3.38%~12.05%;同时,施炭处理的融后土壤质量含水率较对照处理提高1.07%~2.65%;施炭处理的土壤导热系数降低,土壤耕层最低温度增加0.34~2.15℃,最大温差缩小0.47~2.14℃。基于以上土壤结构和水热特性指标进行主成分分析得出,综合得分最高的处理为B₃,其次为B₂。非灌溉季节施加生物炭有利于改善土壤三相结构,增加土壤总孔隙度,增强土壤保墒保温能力。新疆滴灌棉田非灌溉季节生物炭最佳施用量为30~45 t/hm²。     

降解地膜对河西干旱区土壤水热及制种玉米产量的影响

以制种玉米为供试材料,研究了诱导期分别为2,3,4个月的白色(WD1,WD2,WD3)和黑色(BD1,BD2,BD3)降解膜以及普通白膜覆盖(CK)对制种玉米土壤水热及产量的影响.结果表明:相同诱导期下,黑色降解膜的降解等级高于白色降解膜;土壤贮水量在灌浆期和成熟期,降解膜覆盖处理比CK低2.2%~7.5%和2.3%~7.0%,吐丝期BD2的土壤贮水量比CK高8.0%;可降解地膜覆盖在拔节期、吐丝期、灌浆期和成熟期,土壤日最高温度比CK低0.1~1.5,0~1.2,0.1~1.3和0.9~1.9 ℃,并且降解地膜诱导期越早,对地温影响越大;BD3成熟期的冠部湿基含水率比CK高3.2%;不同降解膜覆盖作物的产量和水分利用效率与CK相比较,BD3具有增产效应,产量和水分利用效率分别比CK高6.8%和4.7%.     

江西相山铀矿田热液蚀变与铀矿化

相山矿田是我国目前最大的火山岩型铀矿田,也是国内目前主要的铀矿产地之一。文章在收集总结前人研究资料的基础上,通过野外勘察和分析总结,探讨了矿区围岩蚀变与矿化的关系,对指导相山铀矿田的找矿勘查提供有效依据。     

溶剂萃取对螺旋藻水热液化生物原油储存稳定性的影响

为了研究生物原油所含不同组分对其储存稳定性的影响,该研究提出利用溶剂分步萃取法分离生物原油。采用螺旋藻为原料进行水热液化,利用极性不同的四氢呋喃、乙酸乙酯、丙酮和正己烷为萃取溶剂分离生物原油,以黏度和热值作为稳定性评价指标,利用热重分析仪、气相色谱质谱联用仪和傅立叶红外光谱仪分析生物原油的老化机理。结果表明：乙酸乙酯萃取得到的生物原油的黏度最低（316 mPa·s）,流动性最好,且在储存过程中黏度变化率最小（78.6%）,稳定性最好;利用溶剂可以分离生物原油中的重、轻组分和极性、非极性组分,生物原油的老化与极性大分子之间发生的酯化反应、聚合反应密切相关,而小分子非极性化合物的存在可显著降低生物原油的黏度,提高其流动性和稳定性;经储存后生物原油的热值降低了0.4%～6.2%,生物原油的极性组分、重组分和氮元素含量越多,黏度和热值的变化率越大。该研究可为生物质水热液化产物的定向调控及生物原油储存稳定性的提高提供参考。     

川西北高寒区冻融交替作用后土壤水热运移模拟研究

川西北高寒区在黄河和长江上游的水源涵养与补给、生态平衡中发挥着重要作用,该区土壤长期受到昼夜及季节性冻融作用影响,但土壤水分和热量在受到冻融交替作用后的变化规律,及其在草地退化及沙化过程中的作用还不明确。通过野外采集土样进行室内土柱模拟水热运移实验,利用有限元软件HYDRUS建立了一维土柱模型,开展基于冻融循环作用后的非饱和沙化草地和天然草地土壤水热迁移过程的数值计算研究,揭示不同冻融界面条件下沙化草地和天然草地土壤的水热分布特征、空间运移特性。结果表明：HYDRUS软件模拟沙化草地和天然草地土壤体积含水率的模拟结果R²>0.98,其平均值分别为0.997,0.996,模拟效果较理想;在土壤温度特性方面,模拟结果R²>0.98,平均值0.999,HYDRUS软件较好地模拟了川西北高寒区冻融交替作用后天然草地和沙化草地土壤温度和体积含水量的变化特征。通过模拟预测发现,反复冻融作用后,天然草地和沙化草地土壤体积含水率随时间变化均呈现上下波动的趋势,天然草地各土层体积含水率总体均高于沙化草地含水率;土壤温度模拟值呈现先波动上升后波动下降...     

水热-乙醇提取处理玉米秸秆促进酶解效率

针对水热预处理不能明显移除木质素、木质素在较高温条件下从细胞壁中分解游离并重新聚合的特点, 采用水热-乙醇提取处理玉米秸秆, 与水热预处理的效果进行了对比, 并对乙醇过程进行了优化。结果表明:水热-乙醇提取能够移除部分木质素, 提高预处理后固体中纤维素含量以及纤维素的酶解效率, 水热-乙醇提取后秸秆的木质素移除率随水热预处理温度的增加而增大。乙醇提取的较优工艺条件是液固比25、室温、120 r·min^-1,提取10 h.经210 ℃、20 min预处理的秸秆再经乙醇提取后, 酸不溶木质素含量由30.5%下降为18.2%,纤维素含量由62.2%提高到73.6%,酶解率为93.2%(15 FPU·g^-1纤维素),酶解时间由48 h缩短至24 h.     

油茶果壳水热碳化液相产物分析

采用气相色谱-质谱联用(GC-MS)方法对油茶果壳水热碳化后主要液相产物的组成进行了分析,并推测其水热反应的转化路径.结果表明,在230 ℃、12 h的水热条件下,油茶果壳水热碳化液相产物主要有糠醛、二甲氧基苯酚、甲氧基苯酚、苯酚以及乳酸和乙酰丙酸等.推测该条件下前体的转化过程为:果壳中的纤维素、半纤维素降解为糖类物质,然后糖类物质在水热条件下发生异构化、键断裂、脱水等反应,分解为呋喃衍生物、环状化合物、短链醇和有机酸类等,而果壳中的木质素和单宁则主要断链形成酚类化合物.     

Photoprotective Bioactivity Present in a Unique Marine Bacteria Collection from Portuguese Deep Sea Hydrothermal Vents

Interesting biological activities have been found for numerous marine compounds. In fact, screening of phylogenetically diverse marine microorganisms from extreme environments revealed to be a rational approach for the discovery of novel molecules with relevant bioactivities for industries such as pharmaceutical and cosmeceutical. Nevertheless, marine sources deliverables are still far from the expectations and new extreme sources of microbes should be explored. In this work, a marine prokaryotic collection from four Mid-Atlantic Ridge (MAR) deep sea hydrothermal vents near the Azores Islands, Portugal, was created, characterized and tested for its photoprotective capacity. Within 246 isolates, a polyphasic approach, using chemotaxonomic and molecular typing methods, identified 23-related clusters of phenetically similar isolates with high indexes of diversity. Interestingly, 16S rRNA gene sequencing suggested the presence of 43% new prokaryotic species. A sub-set of 139 isolates of the prokaryotic collection was selected for biotechnological exploitation with 484 bacterial extracts prepared in a sustainable upscalling manner. 22% of the extracts showed an industrially relevant photoprotective activity, with two extracts, belonging to new strains of the species Shewanella algae and Vibrio fluvialis, uniquely showing UV-A, UV-B and UV-C protective capacity. This clearly demonstrates the high potential of the bacteria MAR vents collection in natural product synthesis with market applications.     

玉树隆宝湿地土壤水热变化特征及对地表反照率的影响

利用青海玉树隆宝湿地2011年10月～2012年11月的观测资料,分析了该地区土壤湿度、土壤温度、土壤热通量、感热通量和潜热通量的年变化特征,以及地表反照率的日变化特征和地表反照率随土壤湿度的变化关系.结果表明,玉树隆宝湿地土壤湿度和土壤温度均呈夏秋季（融化期）高、冬春季（冻结期）低的特点;土壤热通量在10月～次年2月为负值,3～9月为正值;感热通量的年变化幅度较小,潜热通量的值呈现夏秋季高、冬春季低的特点,地表反照率冬季高夏季低,在春季和秋季土壤冻结和融化期间地表反照率的值上午高下午低,12月份地表反照率日平均值最高,为0.44,6月份地表反照率日平均值最低,为0.24,地表反照率年平均值为0.32;冻结和融化期间,地表反照率随土壤湿度的增大而减小.     

Effect of Long-Term Fertilization on Soil Enzyme Activities Under Different Hydrothermal Conditions in Northeast China

Human activities have altered weather patterns by causing an increase in greenhouse gas. The effects of climate change have been studied, including effects on some ecosystems throughout the world. There are many studies on changes in the soil due to climate change, but much of them did not extend their research to soil enzyme that integrates information on soil microbial status and soil physical-chemical conditions. Meanwhile, there are lots of experimental fields established to study effects of long-term fertilization on soil enzyme activities, but many did not compare the difference of soil enzyme activities and did not analyze the effect of climatic factors on soil enzyme activities with long-term fertilization under different hydrothermal conditions. In this study, we compared soil enzyme activities of three long-fertilization stations which had different hydrothermal conditions in Northeast China, and analyzed the relationship of hydrothermal condition,soil chemical properties with soil enzyme activities. Hydrothermal conditions (annual temperature and total rainfall)decreased in order of Gongzhuling (Jilin Province, China ) > Harbin (Heilongiiang Province, China) > Heihe (Heilongjiang Province, China) over the course of the long-term fertilization experiment. Sunshine hours showed the longest in Gongzhuling, the second in Heihe, and the last in Harbin. However, the order of soil enzymes was not in agreement with hydrothermal conditions. Overall, the order of soil enzymes for the same treatment among three stations was consistent in 2008 with in 2009. Correlation analysis demonstrated that different soil enzymes achieved the different affected levels by climatic factors under different fertilization treatments. Urease activity showed a significant relationship with sunshine hours in no fertilizer (CK) treatment (R=-0.91, P<0.01) and relative humidity in mineral fertilizers plus manure (MNPK)treatment (R=0.82,/'<0.05). Phosphatase activity exhibited a negative correlation with annual mean temperature, annual mean maximum temperature and annual mean minimum temperature, and their correlation coefficients were separately-0.83, -0.79, and -0.83 at P<0.05 in CK treatment. Invertase activity was highly and positively correlated with sunshine hours in CK treatment (R=0.94, P<0.01). Catalase activity showed significant negative correlations with minimum relative humidity in CK treatment (R=-0.81, P<0.05), and positive correlations with sunshine hours in M treatment (R=0.83, P<0.05).There were no climatic factors which strongly affected on dehydrogenase in all treatments. Soil enzyme activities were closely related to the soil chemical properties. Soil urease activity was positively correlated with available P (P<0.05).With exception of correlation between invertase and total P at P<0.05, phosphase, invertase, catalase, and dehydrogenase showed significant positive correlations with soil chemical properties (P<0.01). It was a comprehensive process that biologic and abiotic factors were effect on soil enzyme activities under different fertilization treatments. To sum up, the variation of hydrothermal conditions in different climate zones and soil chemical properties affect integrally metabolic activity and metabolic finger print of microbial communities in black soil.