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81.
82.
为有效地提取黑木耳中的成分以利于黑木耳深层次开发,以可溶性物质含量为指标,应用均匀设计法研究了高温蒸煮(121℃)时间(20~120min)、碳酸钠和碳酸氢钠浓度(0~0.5%)对黑木耳破壁的影响。结果表明:可溶性物质(y)与Na2CO3浓度(x1)和时间(x3)以及NaHCO3浓度(x2)呈函数关系,即y=-1.392 1+135.864 4x1+0.101 9x2-70.209 6x12(R2=0.992 8,P0.01);y=12.957 2+154.161 7x22(R2=0.902 2,P0.01)。根据方程理论计算和实际验证,Na2CO3浓度为0.5%,时间为120min,破壁效果最好;NaHCO3浓度为0.5%,破壁效果最好。  相似文献   
83.
碳酸盐岩与碎屑岩母质土壤地球化学特征及质量差异   总被引:1,自引:0,他引:1  
为研究云贵高原南部碳酸盐与碎屑岩两类型不同时代母质的残坡积土壤的地环质量,找寻两种类型母质间土壤元素的差异,了解两母质类型土壤元素的丰度及环境质量概况,为区域农业的持续发展和长远规划提供理论依据,以滇东南广南县南屏至珠街等地区不同时代母质的残坡积土壤为研究对象,通过调查、采样和检测,对两类型土壤的地化特征、元素丰度和环境质量进行分析评价。结果表明:A类土从母质风化至成土过程中元素活跃程度高、流失量多、风化程度好,成土后元素富集量大,土壤元素丰度高,但土壤环境质量差;B类土壤元素含量低,元素多贫乏,但环境质量良好。B类土元素丰度稍差,土壤环境质量良好,A类土元素丰度高,土壤环境质量差。  相似文献   
84.
To determine a suitable culture environment to maximize growth and survival, the hatchery‐reared juvenile spotted babylon, Babylonia areolata, were held in plastic rearing tanks at four calcium carbonate additions of 0, 100 and 300 g tonne?1, and four water exchange regimes of 0‐, 15‐, 30‐ and 60‐day intervals in a recirculating grow‐out system for 120 days. The results clearly showed that growth was greatest between water exchange regimes of 15‐ and 30‐day intervals and all calcium carbonate additions, with water exchange regimes of 0‐ and 60‐day intervals resulting in poor growth. Final survival was highest between water exchange regimes of 15‐ and 30‐day intervals, and all calcium carbonate additions, with water exchange regimes of 0‐day intervals and all calcium carbonate additions resulting in high mortalities. This study showed that water exchange regimes had a stronger influence on the growth of juvenile B. areolata than calcium carbonate additions. It is recommended that B. areolata juveniles be maintained within the water exchange regimes range of 15–30‐day intervals and at calcium carbonate additions between 0 and 500 g tonne?1, providing optimum conditions for production of this species in a recirculating grow‐out system.  相似文献   
85.
  1. Methane‐derived authigenic carbonate (MDAC) is a biogenic rocky substrate formed by microbial assemblages below the seabed. It performs important ecosystem functions, including the provision of reef‐like habitats on soft sediments and the sequestration of carbon.
  2. The protection of MDAC is limited at the global scale; however, 27 marine protected areas (MPAs) have been designated in European waters for ‘cold seep’ MDAC, mainly in shallow waters (<200 m). Few studies have been conducted on these habitats from a conservation perspective.
  3. The effective management of MDAC structures requires an understanding of their ecology and physical characteristics in a healthy condition. This is best achieved using a multidisciplinary approach to provide evidence on predefined aspects of MDAC structures, termed feature attributes, which can be assessed to determine habitat condition over time.
  4. This article presents the first UK effort to develop a multidisciplinary approach to monitoring shallow MDAC feature attributes, using the Croker Carbonate Slabs Special Area of Conservation (SAC) as a case study. A range of remote and physical survey methods were used to characterize the MDAC and associated relatively unimpacted and healthy biological communities.
  5. The data confirm that the SAC contains the largest known area of shallow MDAC in European waters, that methane release is ongoing, and that MDAC is still likely to be forming. Specialized chemoautotrophic fauna were not recorded, possibly due to the dominance of fauna that derive carbon (ultimately) from photosynthesis. Five epifaunal taxa were found to be associated with MDAC, but not with the surrounding sediments.
  6. The broad multidisciplinary survey allowed a detailed characterization of shallow MDAC but was resource intensive. We recommend a low‐resource monitoring strategy to deliver cost‐effective and robust evidence for condition assessment and suggest further studies to contextualize future interpretations of change.
  相似文献   
86.
聚碳酸乙烯酯代替乙二醇碳酸酯液化玉米秸秆的效果研究   总被引:2,自引:0,他引:2  
通过催化液化技术和环状碳酸酯的开环聚合技术的结合,提高秸秆液化产率以及改进液化产物在交联成大分子后存在的生物降解缓慢问题。研究采用Lewis酸盐作催化剂,对乙二醇碳酸酯(EC)进行开环聚合,并利用聚合产物——聚碳酸乙烯酯(PEC)代替传统液化剂EC对玉米秸秆进行了液化。对液化产物的定量分析表明,该新工艺固定液化剂中碳酸酯基团从而将液化产率提高了31.4%。同时,新的液化产物的化学结构中引进了脂肪族碳酸酯,其聚氨酯产品的生物降解速率得到较大提高。  相似文献   
87.
One of the significant features of loess-derived soils in Kansas is the occurrence of clay-rich subsurface horizons above a layer enriched with pedogenic carbonates. In order to examine the extent of clay increase and pedogenic carbonate enrichment in a precipitation gradient, ten soil profiles from three different precipitation regions were studied using micromorphological and mineralogical techniques. The precipitation gradient was divided into three groups: 400–550 mm, 550–750 mm, and 750–1100 mm regions. The objectives were to (1) understand the cause of clay orientation in clay-rich horizons (2) investigate the reasons for the clay increase, and (3) observe the interaction of clay and pedogenic carbonate accumulation features along a precipitation gradient in Kansas. Although clay films were identified in the field for soils in the 400–550 mm regions, illuvial clay films were not observed in thin section analysis. The clay accumulations mostly occurred as grain coatings. The rest of the clay accumulations observed were very thin, striated, and mostly associated with voids. The argillic horizons had a granostriated b-fabric, which indicates stress orientation of micromass caused by high shrink–swell activity. Thick and continuous illuvial coatings were observed in the buried horizons of paleosols. In the other two regions where precipitation exceeds 550 mm, illuvial clay coatings with strong orientation were observed along with thin and striated stress-oriented clay. Both types of clay orientations exceeded 1% of the cross-sectional area for the thin section. Although illuvial clay features and pedogenic carbonates were observed in all soils at approximately the same depth, complete obliteration of clay coatings was not observed in these horizons. In-situ weathering of biotite was one of the reasons for the clay increase in all soil profiles. In all soils studied, the clay increase and cause of clay orientation cannot be attributed to a single genetic process or event. Both illuviation and shrink–swell activity were involved in the orientation of clay. Although orientation of clay and pedogenic carbonates were observed in all soils at approximately the same depth, the decomposition of clay coatings was not observed in these horizons.  相似文献   
88.
利用烧失量方法精确测定土壤有机质   总被引:3,自引:0,他引:3  
Wet oxidation procedure,i.e.,Walkley-Black (WB) method,is a routine,relatively accurate,and popular method for the determination of soil organic matter (SOM) but it is time-consuming,costly and also has a high potential to cause environmental pollution because of disposal of chromium and strong acids used in this analysis.Therefore,loss-on-ignition (LOI) procedure,a simple and cheap method for SOM estimation,which also avoids chromic acid wastes,deserves more attention.The aims of this research were to study the statistical relationships between SOM determined with the LOI (SOMLOI) and WB (SOMWB) methods to compare the spatial variability of SOM in two major plains,Shahrekord and Koohrang plains,of Chaharmahal-va-Bakhtiari Province,Iran.Fifty surface soil samples (0-25 cm) were randomly collected in each plain to determine SOM using the WB method and the LOI procedure at 300,360,400,500 and 550 ℃ for 2 h.The samples covered wide ranges of soil texture and calcium carbonate equivalent (CCE).The general linear form of the regression equation was calculated to estimate SOM LOI from SOM obtained by the WB method for both overall samples and individual plains.Forty soil samples were also randomly selected to compare the SOM and CCE before and after ignition at each temperature.Overall accuracy of the continuous maps generated for the LOI and WB methods was considered to determine the accordance of two procedures.Results showed a significant positive linear relationship between SOM LOI and SOM WB.Coefficients of determination (R2) of the equations for individual plains were higher than that of the overall equation.Coefficients of determination and line slopes decreased and root mean square error (RMSE) increased with increasing ignition temperature,which may be due to the mineral structural water loss and destruction of carbonates at higher temperatures.A temperature around 360 ℃ was identified as optimum as it burnt most organic carbon,destroyed less inorganic carbon,caused less clay structural water loss,and used less electrical energy.Although the trends of SOM in the kriged maps by the two procedures accorded well,low overall accuracy was observed for the maps obtained by the two methods.While not suitable for determination where high accuracy is required,determination of organic carbon through LOI is likely suitable for exploratory soil surveys where rough estimation of organic matter is required.  相似文献   
89.
刘莉  刘霞  包永华 《北方园艺》2011,(23):145-147
利用一定浓度的碳酸钠、碳酸氢钠和山梨酸钾对柑橘酸腐病菌进行处理,以体外试验筛选对柑橘酸腐病菌有抑制作用的物质.结果表明:在一定的浓度范围内,碳酸钠、碳酸氢钠和山梨酸钾对柑橘酸腐病菌的生长有抑制作用,并且随着培养基中浓度的增加,对柑橘酸腐病的病斑大小抑制效果越好.当培养基中碳酸钠和山梨酸钾浓度分别为16、8 g/L时,菌丝生长受到完全抑制.表明碳酸钠、碳酸氢钠和山梨酸钾对柑橘酸腐病有很好的防治潜力.  相似文献   
90.
合成了碳酸酯类化合物23个和苯氨基甲酸苯酯类化合物7个。杀螺初筛试验发现,8个碳酸酯化合物具有杀螺活性,其中,化合物I1和I11,10ppm的杀螺率为100%和96.7%。碳酸苯酯的苯环上,用硝基或3个以上的氯原子取代,有利于增强该类化合物的杀螺作用。杀螺效果较好的三氯苯碳酸酯改变成同电异素体类似物,苯氨基甲酸酯后,杀螺作用明显下降。  相似文献   
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