The influence of initial internal structure of coal sample on gas flow characteristic

Three kinds of coal samples with different components are chosen as study objects.Density calculation and SEM are adopted to study their internal structures,and a self made triaxial gas seepage instrument is used to study their internal gas flow characteristics.The results show that internal structures of coal samples made of different particle size coal powders under identical external conditions are various,and nonlinearity is presented on the influence caused by fabric.Gas flow characteristic is complex in complete stress strain process,generally it firstly increases and then decreases,initial gas flow velocity is lower than the one after the failure of coal sample,and obvious hysteretic nature of gas flow characteristic is showed.The influence of gas flow characteristic caused by initial internal structure of coal sample is nonlinear and the stress sensitivity is high on the influence of gas flow characteristic caused by initial internal structure.The more complex the initial internal structure of the coal sample is,the lower the axial tress sensitivity is,and the higher the confining pressure sensitivity is.     

The Influence of In-situ Stress Gradient and Geothermal Temperature on The Calculation of Coalbed Gas Pressure

On the basis of coal seam having outcrop of coal seam and outlet on ground,the method for calculating coalbed gas pressure from the one-dimensional stable gas flow equation by considering deeply the influence of in-situ stress gradient and geothermal temperature is presented. In some mine, the theoretically computing and measuring results of coalbed gas pressure show that the in-situ stress gradient and the geothermal temperature have important influence on the calculation of coalbed gas pressure, and if the factors are drew into the calculation of coaled gas pressure,it will make the results much more accurate.     

Analysis on AE characteristic and its confining pressure effect of outburst coal containing gas

Briquette samples made of outburst coal are taken as study objects to study AE characteristic and its confining pressure effect by using self-developed equipment, Shimazu servo test machine and AE monitor system, and the characteristic of AE parameters are analyzed, too. The results show that in the process of outburst coal containing gas triaxial compression, there is no serious dense or sparse area of AE events, but three relative dense appear in compression phase, middle area of linear elastic stage and near peaking phase area so that the characteristic of AE events look like three peaks. But the amplitude of AE events is small and the good consistency between energy change and amplitude change is showed. Microstructure change caused by external stress field change, fracture and fragmentation of particle of samples, movement besides particle of samples and microstructure change caused by dissipation of gas are the sources of AE events. The number of AE events is reduced as the confining pressure is increased, but the influence on total number of AE events caused by confining pressure show nonlinear, expressed by quadratic function. The number of larger amplitude of AE events show decreasing tendency as the confining pressure is increased, the relation between numbers of AE events whose amplitude is more than certain value and confining pressure is expressed by quadratic function.     

氮气与甲酸乙酯混合熏蒸对锯谷盗的毒力研究

采用广口瓶密闭熏蒸法,在实验室条件下研究了氮气与甲酸乙酯混合熏蒸对锯谷盗成虫的毒力。结果表明,氮气和甲酸乙酯混用具有良好的熏蒸效果。在81%、87%和95%的氮气浓度下,甲酸乙酯为10μL/L熏蒸处理24h,锯谷盗的校正死亡率分别为55%、75%和97%,表明氮气可显著提高甲酸乙酯的熏蒸毒力;温度对氮气和甲酸乙酯混合熏蒸效果具有显著影响作用,相同条件下,在30℃时校正死亡率为41%,在15℃时则提高至90%,表明低温条件下熏蒸效果比高温条件下更好。     

A method of production data analysis for multi-fractured horizontal well in shale gas reservoir

Production data analysis is an effective method of evaluating gas in place, parameters of reservoir and hydraulic fractures. Current model of production data analysis fails to make sense because of the existence of absorption, multi-fracturing, and stimulated reservoir volume (SRV). Considering the effect of desorption, fracture interacting and closed boundary, the authors calculate the productivity of multi-fractured horizontal well in shale gas by Laplace transform and pressure superposition principle. Then theoretical charts of Agarwal-Gardner production decline curves are presented by employing new definition of dimensionless material balance time and dimensionless production, which is based on asymptotic approximations. The result shows that Agarwal-Gardner curves can be divided into two parts where they are scattered in early transient period, and where their shape was influenced by parameters relevant to adsorption, position of each fracture and reservoir geometry, and then drawn to Arps harmonious decline in pseudo steady state period. Reservoir parameters, hydraulic fracture characteristics and gas in place are evaluated by using the type curve matching with actual production data.     

气相色谱法测定乳饮料中的甜蜜素含量

探讨了气相色谱法测定乳饮料中的环己基氨基磺酸钠的方法,利用环己基氨基磺酸钠在硫酸介质中与亚硝酸反应后生成环己醇亚硝酸酯,用正己烷提取后,利用气相色谱法进行测定,相对标准偏差小于5%,加标回收率为98.59%～100.62%。同时讨论了硫酸以及亚硝酸钠的用量对回收率的影响。该法简便、准确,稳定性好,适用于乳饮料中甜蜜素的测定。     

Multi-field coupling effect on coalbed methane seepage characteristics and numerical simulation

This paper studies the seepage of coal samples under the influence of each single factor, the axial stress, confining pressure, gas pressure, and temperature by experiments. It uses Ansys12.0 to numerically simulate the law of coalbed methane seepage, coal deformation, pore pressure, the distribution of flow field under the influence of each single field and multi-field coupled. The numerical simulation show that the result of numerical simulation of gas seepage law in the coal under each single fields is basically the same as the experimental result. The curve of gas seepage and average effective stress under the condition of multi-field coupled is negative exponential relationship. Stress influenced the deformation of the specimen is greater than the seepage field. The axial stress on the deformation of the specimen is greater than confining presses The influence on the flow field by confining pressure is greater than axial stress, the influence of axial stress on the pore pressure is greater than confining pressure, pore-pressure under the action of multi-field is bigger than pro-pressure under each single field. To study the seepage law of coalbed methane, it should consider the influence of gas-solid-heat at the same time.     

黑龙江省耐低磷水稻品种的初步筛选

以适合在黑龙江省第三积温带栽培的水稻品种（系）为材料,研究低磷对水稻形态特征及产量的影响,筛选出耐低磷材料,对黑龙江省水稻生产和土地持续利用具有重要意义。综合返青期叶片数和穗长分析认为：龙粳29、04-582 、龙粳21 、01-687 、05-4076 、06-2351等6份材料对低磷胁迫适应性较强。     

Experimental analysis of matrix shrinkage’s influence on mechanical permeability of gas filled coal

Based on the coal seam of Zhao zhuang coal mine and Si he coal mine belong to Jin cheng anthracite Mining Group in Shanxi province, by using the self developed three axial servo controlled seepage equipment for hot fluid solid coupling of coal containing methane, parallel experiments for permeability of helium and methane under different gas pressures are carried out to quantitatively study the influence of Klinkenberg effects on the permeability of coal. Meanwhile, the problem of permeability decreasing caused by fluid pressure decreasing and gas desorption is eliminated by controlling the effective stress. The results show thatthe Klinkenberg effect is obvious under low gas pressure. With the increase of gas pressure, the permeability of coal decreases at first and then increases. The inflection points of gas pressure for Klinkenberg effect are about 0.9 MPa both for coal samples in Zhao zhuang coal mine and Si he coal mine. When the effective stress is constant, with the increase of gas pressure, the permeability increment caused by Klinkenberg effect decreases, while permeability increment caused by coal matrix shrinkage increases. Coal matrix shrinkage has a close relationship with the mechanical properties of coal rock mass. For the coal sample with a poor mechanical property, coal matrix shrinkage is more obvious.     

基于能值改进模型的红米与烤烟作物系统可持续性评价——以贵州省盘州市为例

为准确测度农作物生产的可持续发展水平,进一步提高可持续发展能力。将碳排放与碳固定视为农田系统环境产出,纳入能值分析框架,建立能值改进指标,评价区域红米和烤烟2种不同作物生产模式的可持续性并进行灵敏性测试。研究发现,红米和烤烟系统的能值投入分别是1.26E+17sej/hm²和1.24E+17sej/hm²,产品能值产出分别是2.61E+16sej/hm²和6.55E+15sej/hm²,红米生产模式的产品产出效率较好。在环境能值产出方面,红米系统表现为净温室气体排放“源”,碳排放（5.97E+16sej/hm²）远大于碳固定（1.30E+15sej/hm²）,减排潜力较大;而烤烟系统则表现为碳固定盈余,碳排放（1.95E+14sej/hm²）小于碳固定（3.42E+14sej/hm²）。温室气体排放量变化对作物系统环境负载率和可持续发展水平的影响最大。结论表明,在传统能值分析体系中增设碳排放与碳固定指标可为农业系统可持续性评价提供更加全面的测算思路和方法借鉴。     

红叶石楠绿叶与红叶的光合蒸腾特性比较研究

为了研究红叶石楠绿叶与红叶光合蒸腾特性存在的差异，通过测量红叶石楠2种不同颜色叶片的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)，计算水分利用效率(WUE)和气孔限制值(L)等参数值，比较研究2种叶片的光合蒸腾特性，探讨二者对环境变化的适应性。结果表明：（1）红叶的光合作用比绿叶强，当光照强度较高时，绿叶出现“光合午休”现象（属于非气孔因子限制），而红叶未出现此现象；红叶Pn日均值较高，气体交换强于绿叶；（2）绿叶的Tr和Gs均比红叶弱，红叶的WUE始终低于绿叶，且两者的Gs存在显著差异。由此可见红叶石楠的红叶适应外界环境变化的调控机制没有绿叶强，同时抗旱能力也比绿叶弱。     

Experiments on triaxial mechanical properties of soft coal containing gas

Taking briquette specimens composed by soft coal with outbursting trends as research object, systematic research of the influence on triaxial mechanical properties of soft coal containing gas caused by confining pressure and gas pressure is done. The results show that confining pressure can significantly affect mechanical properties of soft coal containing gas, the compression phase of soft coal containing gas is obvious and the triaxial strength is increased gradually as confining pressure is increased; the influence on elastic modulus and shape of stress-strain curve is not obvious. The triaxial strength of soft coal containing gas shows decrease trend as gas pressure is increased; the influence on strength of soft coal containing gas caused by gas pressure is obvious when the confining pressure is smaller, but it is not obvious when the confining pressure is bigger. the influence caused by gas pressure on elastic modulus and deformation of yield step is not obvious; gas pressure has not only obvious mechanical effects,but also have chemical action on soft coal containing gas; stress-strain curve of soft coal containing gas can be expressed by conic, the influence caused by gas pressure can be considered as equivalent confining pressure effects.     

安徽省农业源温室气体排放特征研究

安徽作为农业大省,农业源温室气体排放量巨大,笔者旨在对其农业源温室气体排放特征进行研究。研究方法为省级温室气体清单编制方法《省级温室气体清单编制指南（试行）》。结果表明：安徽省2005、2010、2012、2014年的农业源温室气体排放量折合二氧化碳当量(CO₂ e)分别为3916.97万、3246.90万、3182.70万、3313.20万t,CH₄、N₂O各占一半左右;其中又以种植业为主,约占70%左右。种植业的排放量相对稳定,4个年度的上下变化约45.11万t,仅占2012年种植业排放量的1.85%,这是由于安徽省的种植业从种类、规模到产量处于基本稳定状态;养殖业排放量变化则非常大,2005年排放量显著高于其他3个年份,这是由于安徽省农业生产模式由畜力向机械化转变、耕牛存栏量大幅度减少造成。随着奶牛、肉牛存栏量的增加,养殖业的排放量呈增长趋势。综上,安徽省的农业源温室气体排放量可能发生较大的增加,有效措施应该采取起来以抑制畜牧业排放量的增长趋势。     

Physical simulation of production performance of fractured horizontal wells in low permeability reservoir

For the fractured horizontal wells with spindle and dumbbell-shaped distribution of fracture in the Changqing oil-field, 3-D scaled physical models are utilized to simulate their production performance in elastic drive and waterflooding. The experimental results indicate that the oil production and the experimental time of two models are closely exponential function. The oil production of the horizontal well with dumbbell-shaped fracture is higher, but its decline rate is faster. The productivity formula and material balance equation of closed reservoir with elastic drive are utilized to derive the exponential form of oil production. Influence factors of oil production and its decline rate are analyzed in elastic drive. In waterflooding, the water breakthrough time of the horizontal well with spindle fracture is later than the one with dumbbell-shaped fracture. And the rate of water cut increasing of the model with spindle fracture is slower. In the initial stage of waterflooding experiment, elastic drive is still the leading position, so the oil production of the model with dumbbell-shaped fracture is higher. When the cumulative water injected exceeds 0.2 PV, the recovery percent of the model with spindle fracture is higher than the one of the model with dumbbell-shaped fracture. When the percent water cut reaches 98%, the recovery percent of the model with spindle fracture is 33.67%, while the one of the model with dumbbell-shaped fracture is 27.48%.     

Laboratory investigation on stress sensitivity of carbonate reservoir considering vuggy connectivity

Due to the changes of pressure, fractures intersected with borehole open and stress sensitivity happens in the progress of drilling, which make the diameters of solid materials unmatched to the loss channels and aggravates mud loss controlling. The existence and connectivity of vugs affect the variation range of fracture width. Carbonate outcropping core samples with different vug types are taken as laboratory subject. Experimental results including 6 groups rock samples shows that stress sensitive coefficients of the single vug(5 mm), single vug(10 mm), double vugs(5 mm, disconnected), double vugs(5 mm, connected), double vugs(10 mm, disconnected), double vugs(10 mm, connected) core samples are respectively 0.66, 0.59, 0.47, 0.24, 0.66, 0.43, and the degree of stress sensitivity is respectively medium to strong, medium to strong, medium to weak, weak, medium to strong, medium to weak. It shows that the vugs intensify the rangeability of fracture width and the stress sensitivity. Though the vuggy connectivity weakens the stress sensitivity of fractures, it destabilizes the plugged zone and fails in lost circulation controlling, which causes severe lost circulation.     

Productivity and water use efficiency of sweet sorghum as affected by soil water deficit occurring at different vegetative growth stages

The growth and production of sweet sorghum [Sorghum bicolor (L.) Moench] crops under semi-arid conditions in the Mediterranean environment of southern Italy are constrained by water stress. The effects of temporary water stress on growth and productivity of sweet sorghum were studied during three seasons at Rutigliano (Bari, Italy). The aim of this research was to evaluate the sensitivity of phenological stages subjected to the same water deficit. In a preliminary study it was observed that stomata closed when pre-dawn leaf water potential (Ψ_b) became lower than −0.4 MPa. This criterion was used in monitoring plant water status in three different plots: one never stressed and two stressed at different phenological stages (‘leaf’ and ‘stem’) when mainly leaves or stems were growing, respectively. An evaluation of the sensitivity of phenological stages subjected to identical water stress was obtained by comparing the above-ground biomass and WUE of drought crops with those of the well-irrigated crop (up to 32.5 t ha⁻¹ of dry matter and 5.7 g kg⁻¹). The sensitivity was greatest at the early stage (‘leaf’), when a temporary soil water stress reduced the biomass production by up to 30% with respect to the control and WUE was 4.8 g kg⁻¹ (average of three seasons). These results help quantify the effects of water constraints on sweet sorghum productivity. An irrigation strategy based on phenological stage sensitivity is suggested.     

PEG预处理对水分胁迫下水稻叶片抗氧化酶同工酶及其表达的影响

采用聚乙二醇（PEG6000）模拟水分胁迫,研究水稻在10％PEG预处理及复水和更强的水分胁迫（15％PEG）处理条件下叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）同工酶及其基因表达的变化。结果表明PEG预处理能提高叶片SOD、CAT和POD同工酶的产生,并诱导产生新谱带。当水稻受到更强的水分胁迫（15%PEG）时SOD同工酶的酶II和IV的活性升高,并有新诱导出的酶III参与其中;对POD而言酶Ⅱ升高,酶Ⅴ减小,并有新诱导出的酶VI参与抗氧化过程;而对CAT同工酶却有着不同的调节作用。此外,直接15%PEG胁迫（即对照组2）的Cu/Zn-SOD、APX1和CAT1基因在转录水平有明显的上调,而预处理复水组和预处理组CAT1较对照组1略有降低,预处理组APX1与对照组1相似。说明15%PEG会使水稻受到伤害,但是经过预处理后的水稻能提高抗性使其抗氧化酶基因与对照组1有着相似的表达,表明植物在遇到较强的水分胁迫时,会通过调节自身的基因表达水平来抵抗外界水分胁迫。     

覆膜滴灌对温室气体产生及排放的影响研究进展

CO₂、CH₄与N₂O作为全球气候变化贡献较大的温室气体日益受到重视,而覆膜滴灌作为一种节水的田间农艺措施也受到广泛关注。笔者就土壤温湿度对土壤温室气体产生及排放的影响、覆膜滴灌造成土壤温湿度的改变及其对土壤温室气体排放的作用进行了综述。目前的研究成果表明：（1）土壤温度、湿度都通过影响土壤微生物菌群数量和活性、调节气体传输速率,对土壤温室气体产生和排放起作用;（2）土壤CO₂排放速率与浅层地温正相关,CH₄与N₂O的产生都有一定的最适温度,而CH₄的氧化与温度的关系呈多样性;（3）土壤湿度对CH₄产生、氧化与N₂O产生的作用都大于土壤温度,CH₄氧化速率与土壤湿度呈负相关,而CO₂与N₂O的排放都有一个最佳的湿润范围;（4）覆膜良好的增温保湿效应、对气体传输的自然阻隔作用以及滴灌的局部湿润作用又会影响温室气体的产生和排放。最后总结提出了有待进一步展开和完善的几方面研究工作：如何确定和控制土壤湿润范围以减少温室气体排放,如何定量确定覆膜滴灌的综合效应,如何通过调控土壤CO₂的排放以调控作物的生长过程。     

盐胁迫对乌拉尔甘草种子萌发的影响研究

研究了NaCl和Na2SO4不同浓度下两种中性盐胁迫对乌拉尔甘草种子萌发的效应。结果表明:280mmol/L浓度的NaCl和Na2SO4处理时,发芽率高于60%,高浓度的Na2SO4抑制种子发芽强于NaCl;不同浓度Na2SO4处理的发芽高峰期出现比对照早3～5d,比NaCl处理的早2～6d;Na2SO4处理种子的发芽势小于相同浓度的NaCl;溶液浓度大于200mmol/L时,种子发芽指数小于对照,NaCl溶液各梯度处理下的发芽指数均高于相应浓度的Na2SO4。发芽率、发芽势和发芽指数与NaCl和Na2SO4浓度之间呈极显著的负相关,发芽高峰期的出现与NaCl浓度之间呈正相关,与Na2SO4浓度之间呈负相关。     

接种量对醋渣干发酵的影响

以醋渣为原料,在严格控制厌氧发酵温度的条件下（38±1℃）,采用批量进料发酵工艺,研究不同接种量对其厌氧干发酵性能的影响。结果表明：醋渣与污泥质量比为2：1（干物质量比3.05）、质量比为1：1（干物质量比1.52）、质量比为1：2（干物质量比0.76）厌氧发酵TS产气潜力分别为270.35、314.67、408.22ml/g, VS产气潜力分别为295.56、344.02、446.95ml/g;加大接种量能够避免酸化、快速启动厌氧发酵、加快产气高峰的出现、减短发酵周期、提高原料产气率等。