应用反演式气体扩散技术测定奶牛场甲烷的排放特征

为了准确揭示奶牛场的甲烷排放特征,在我国首次采用国际上最新的反演式气体扩散技术与开路式激光仪相结合的研究方法,分别于2009年冬季和2010年春季测定了保定市某奶牛养殖基地甲烷的排放特征,测定期间养殖基地的动物总量平均为1 200头.结果表明,奶牛养殖场尺度的甲烷排放在冬季和春季均呈现出规律性的日排放特征,即养殖场甲烷日排放高峰出现在05:00、11:30和16:30,排放高峰的出现时间与上料时间基本吻合;冬季和春季试验期间该养殖场的反刍和粪尿甲烷总排放量分别为0.31 t·d-1和0.36t·d-1,养殖基地内整个牛群平均每头牛的反刍和粪尿甲烷日排放总量分别为0.26 kg·d-1和0.30 kg·d-1,春季的甲烷日排放量比冬季约高16.7%,初步揭示了奶牛场尺度甲烷排放的季节性差异.     

一种基于集成光学声光作用的新型光谱分析仪的研制及测试

介绍了一种基于集成光学声光相互作用原理的集成光学光谱分析仪。在理论上分析了这种光谱仪的原理、色散本领和分辨本领。在实验中一对滤波器的透过率函数曲线进行了测量，得到的实验结果与理论值相吻合。在对光谱的测量当中，波长测量精度可达到0．008nm。     

长期紫云英还田与化肥配施下水稻土团聚体中铁氧化物的演变规律

铁氧化物是土壤团聚体重要的胶结物质,其主要存在于土壤黏粒中。为探索紫云英还田并配施化肥下土壤团聚体中铁氧化物的变化规律及其在不同粒级黏粒组分中的富集特点,以湖南省南县长期紫云英还田的水稻土为研究对象,选择单施紫云英（MV）、单施化肥（F100）、紫云英配施全量化肥（MV+F100）和紫云英配施80%化肥（MV+F80）4个处理,通过湿筛和离心分离土壤团聚体（>250、53~250 和2~53 μm）和黏粒（<2 μm）,测定不同处理土壤团聚体及其黏粒中铁氧化物的含量,并分析它们与团聚体稳定性的关系。结果表明：（1）与MV和F100相比,紫云英与全量化肥配施增加了>250 μm粒级团聚体的含量,降低了53~250 μm粒级团聚体含量,团聚体平均重量直径（MWD）和几何平均直径（GMD）分别提高了8.2%~20.5%和4.1%~8.5%。（2）与MV相比,紫云英与化肥配施显著提高了各粒级团聚体、2~53 μm团聚体黏粒和自由态黏粒非晶质铁的含量（12.7%~55.6%,52.4%~54.9%和45.9%~48.6%）,降低了>250和53~250 μm团聚体非晶质铁的富集率（32.8%~36.8%和17.2%~28.4%）。而与F100相比,2~53 μm团聚体和团聚体黏粒非晶质铁的含量以及富集率均显著降低（3.5%~21.3%、29.2%~30.4%和10.9%~26.9%）。（3）>250 μm团聚体含量与团聚体黏粒的非晶质铁含量、铁的活化度呈极显著正相关,与团聚体黏粒的游离铁含量、非晶质铁的富集率呈显著正相关。团聚体的MWD和GMD与>250μm团聚体含量呈极显著正相关,而与<2 μm团聚体含量呈极显著负相关。>250、2~53 μm团聚体黏粒和自由态黏粒的游离铁是团聚体MWD和GMD最重要的影响因子。紫云英与化肥配施,能够提高团聚体黏粒铁氧化物的含量,促进>250 μm团聚体的形成,从而增强团聚体的稳定性。     

Studie über die Möglichkeiten der Identifizierung von stau- and grundwasserbeeinflußten Böden durch die Anwendung von falschfarbigen Luftbildern und photographischen Äquidensiten

Two well drained pedons from deeply weathered level terrace of Madhupur Tract were studied. Silt and clay fractions were determined by pipette sampling method and sand fractions by dry sieving. The sand fraction distribution was bimodal. The pedons consisted of three weakly stratified segments. A large amount (78–95 %) of materials of these segments belonged to the suspension population during transportation. The saltation population contained 5–20 % of the sediment, whereas the traction population only 0–0.1 %. The increase of coarser material content against depth in these pedons indicate that the energy level of the transporting medium raised more and more as the phases of deposition proceeded.     

容重与含水率对砂质黏壤土静水崩解速率影响研究

崩解在土工试验中叫做湿化,是指土壤在静水中发生破裂解体、塌落或强度减弱的现象[1].土壤的崩解机制与土壤侵蚀的发生过程密切相关,是土壤侵蚀发生的必要条件之一.国内外对于土壤崩解的研究相对较少,而对于容重或含水对崩解性的影响的研究更少,国内仅有的研究目前大多限于黄土和南方的一些典型土壤,如燥红壤、红壤、褐红壤等.在降雨和地表灌溉作用下产生的土壤侵蚀过程中,崩解是侵蚀发生的一个前提条件.     

Evaluation of relationship between dispersibility of soils and charge characteristics using a modified ion adsorption method; An example of soils from Wakayama Prefecture,Japan

The relationship between the charge characteristics and the dispersibility of soils from reclaimed land (highly dispersive) and adjacent forest area (physically stable) was investigated.

To evaluate the amount of soil charges quantitatively, the measurement based on cation and anion adsorption (ion adsorption method) was attempted in two ways, where special attention was paid to the solution concentration. In the conventional ion adsorption method, the treatments with concentrated solutions (1 mol L^-1) were included in the process. In the modified method, soils were treated with dilute solutions (5 mmol L^-1), in taking account of the soil solution concentration in humid temperate regions. The amount of charges derived from the modified method was smaller than that from the conventional one, especially in the high pH zone. In a preliminary experiment, the extraction of polyvalent cations from soils was found to be significantly affected by the salt concentration. Thus, the use of solutions with an excessively high concentration was considered to result in an error in the estimation of the active charges in soils which would contribute to the dispersion behavior in the field.

The applicability of the modified method for analyzing the dispersion behavior of soils was evaluated by relating the dispersibility of silts and clays at different pHs with the charge characteristics determined under the same ionic strength. The dispersion ratio of silts of the reclaimed land reached maximum values at pH 5.5, above which the ratio decreased, whereas the ratio of clays began to increase in the pH range above 6. The dispersion ratio of silts of the forest area increased in the pH range above 6, whereas that of clays remained constant at a low level in all the pH ranges below 7. The changes in the dispersibility of silt plus clay fractions corresponded to total charge characteristics determined by the modified method. Thus, the evaluation of soil charges by the modified ion adsorption method was considered to be effective to predict soil dispersibility under field conditions, indicating that it could replace electrokinetic analyses such as electrophoresis in studies on the dispersion/flocculation behavior of soils.     

Effect of Addition of Al Hydroxides on Changes in Dispersibility and Charge Characteristics of Soils

Using a soil from a newly reclaimed area where high dispersibility of fine particles had led to poor physical properties in the field, changes in dispersibility and charge characteristics after artificial precipitation of Al hydroxides onto the soil were investigated. Al hydroxides were precipitated by neutralization with NaOH of an acidic A1C1₃ solution in which the soil samples were placed.

When the titration rates were changed, no significant differences in dispersibility were observed in the resultant soils. In the systems with the addition of 2 g kg^-1 or less of A1(OH)₃, dispersion ratios of clays were almost identical with those of blank samples although the specific surface areas were reduced. In the systems with 5 g kg^-1 or more of A1(OH)₃, considerable effects of Al hydroxides on reduction of clay dispersibility were recognized (e.g. 10 g kg^-1 addition yielded less than one-third of the original ratio of the clay dispersion). A slightly larger decrease in dispersion was observed by the addition of 15 g kg^-1 or more. As the amount of added Al increased, the amount of negative charges of the soil decreased while that of positive charges increased. The charge characteristics of the system with the addition of 20 g kg^-1 of A1(OH)₃ were closer to those of the adjacent forest soil which was characterized by a very low dispersibility. It was inferred that added Al hydroxides polymerized to form Al polycation species that were not readily exchangeable, neutralizing negative charges of clays, and acting as interparticle bonding between the clays. On the other hand, forest soils were considered to have acquired a physical stability against the dispersion of fine particles as free Al oxides had been accumulated in the process of natural weathering. It was concluded that charge characteristics primarily determined the dispersion and flocculation behavior of soils and that Al hydroxides were important modifiers of charge characteristics of soils.     

黏土矿物改良剂对新垦砂壤质耕地土壤有机碳积累的影响

为了解黏土矿物改良剂在新垦耕地地力提升中的作用,选择膨润土、高岭石、沸石和硅藻土4种黏土矿物,在添加量为10%的条件下,采用培养试验研究其对有机肥料矿化及土壤有机碳积累的影响。结果表明,与对照比较,添加黏土矿物可明显增加土壤有机碳的积累,其效果由强到弱为膨润土、高岭石、硅藻土、沸石;团聚体分析和重液分组结果表明,添加黏土矿物可显著增加土壤水稳定性团聚体数量,促进矿物结合态有机碳的形成。研究认为,黏土矿物增加有机碳稳定性是其促进土壤有机碳积累的主要原因。     

基于FLUENT的高含硫天然气管道泄漏扩散模拟

利用CFD软件FLUENT首次对高含硫天然气管道破裂泄漏扩散规律进行了数值模拟,得到了甲烷、硫化氢在一定风速、地形条件影响下的扩散规律,以及甲烷和硫化氢的浓度分布规律,为有效预测高含硫天然气泄漏扩散的影响范围提供了依据。研究结果对于认识高含硫天然气泄漏扩散规律以及相关安全事故的预警和救援具有指导意义。     

新疆北疆寒冷地区非烧土坯墙体材料力学性能的研究

对新疆北疆纯粘土、粘土中掺入一定量水泥、石灰和粉煤灰制成的材料试件进行试验,测试试件在不同配合比下的抗压、抗折强度及导热系数。研究不同含水率,不同掺量石灰、水泥和粉煤灰对混合材料的抗压、抗折强度、导热系数的影响。得到适合于强度高、保温性能好的非烧土坯墙体材料。