Early-warning Indicators of Acidification in the Single-phase Anaerobic Digestion Process for Food Wastes

The commonly used indicators are often too slow to reflect the operating status in time.Confronted with lacking reliable early-warning indices in the single-phase anaerobic digestion for kitchen waste which is easy to decay,lab-scale experiments of start-up and continuous operation process of anaerobic digestion for kitchen waste were carried out in the single-phase anaerobic reactor which is self-designed under mesophilic conditions.Those values which reflect the capacity of acidity-basicity resistance,including the ratio of bicarbonate alkalinity to total alkalinity (BA/TA),absolute testing value of volatile fatty acid (VFA) and the ratio of total concentration for volatile fatty acid to bicarbonate alkalinity (VFA/BA),are determinated to be the early-warning indices for acidification and imbalance of single-phase anaerobic digestion for kitchen waste.It is considered that,when VFA/BA＞0.8,BA/TA＜0.4 and VFA＞3000mg/L,buffering capacity of the system is very poor,and the system might be out of control.Therefore,an immediately steps must be taken.While,when BA/TA≥0.7~0.8 and VFA/BA＜0.4,the alkalinity of system is relatively better and the process can be operated with higher organic volumetric loading,which can raise the biogas-producing efficiency and get economic benefit.     

A simulated experiment on the high titanium slag rheological behavior

The rheological property of high titanium slag is a main factor to influence the vanadium titanomagnetite smelting in blast furnace. It plays a great role in discharging slag, separating iron and slag and even the life of blast furnace hearth. The acrylonitrile-butadiene-styrene multipolymer(ABS) dense suspension is taken to simulate the system of high titanium slag. Apparent viscosity is measured by a NXS-11A rotating cylinder viscometer. The impact of temperature, volume fraction and particle sizes on the suspension apparent viscosity is studied. The results show that temperature and volume fraction have a strong influence on the suspension apparent viscosity, while the particle size has a weak effect. The suspension shows Bingham behavior within a wide concentration range. The dependence of the appear viscosity on temperature and amount of solid addition can be described by a binary function equation.     

Effect of silicon on the eutectic carbides in as-heated M2 high speed steel

The effect of silicon on the eutectic carbides in as-heated M2 high speed steels is investigated by using optical microscope, scanning electron microscope, energy dispersive spectrometer and X-ray diffraction analysis. The high speed steel ingots with different silicon additions are produced by electroslag remelting process (the mass content of silicon is 0.3%, 0.8%, 1.6% and 2.4%, respectively). The ingots are annealed at 780 ℃ for 10 h and heated at 1 165 ℃ for 2.5 h. The results show that the eutectic carbides distributed in the dendrites with continuous or semi-continuous net-shape in the as-annealed ingots. The eutectic carbides change from lamellar-like M2C to herringbone-like M6C with the increase of silicon content. After 2.5 h heating at 1 165 ℃, the lamellar-like M2C decomposes into granular M6C and MC, and the size of granules in M2 high speed steel ingot with 0.8%Si addition is smaller than that in the 0.3%Si. Whereas herringbone-like M6C is unchanged during heating treatment, and coarse primary blocky carbides which are harmful for properties still exists after the deformation.     

利用农杆菌介导法获得RNAi转基因枫香的研究

随着我国林业生态工程和退耕还林的开展，木材生产与需求之间的矛盾愈加严重，培育速生优质大径材的研究更加重要。基于LEAFY基因在植物生长发育中的特性，利用PCR和Gateway技术构建了含有LEAFY基因保守序列的RNA干涉植物表达载体LFY-RI，利用根瘤农杆菌Agrobacterium tumefaciems介导法获得转基因植株，利用RNA干涉技术抑制转基因植株中LEAFY基因的表达，从而获得枫香Liquidambar formosana不育转基因植株。并利用聚合酶链式反应（PCR）技术和PCR-Southern杂交技术检测了转基因植株中外源基因整合情况。共获得了5株枫香转基因植株，分子检测表明，其中4株为转基因阳性植株。由于转基因植株还比较幼嫩，对它们生长发育以及木材品质的变化尚处于在观察中。图5参12     

土壤水盐信息的稳健性分析

本文根据区域水环境预测中水盐监测与评价的要求，进行了水盐空间变异性与稳健变异函数的研究。利用内蒙古河套灌区内一个试验区春季水盐采样数据，计算了传统地质统计学变异函数，进行了剔除特异值后计算变异函数的尝试，并直接计算了两种稳健变异函数，通过计算与分析表明，稳健地质统计学方法可以移植到农田水利与水土科学中应用。     

天津天嘉湖渔业生物学基础调查

按照《内陆水域渔业自然资源调查手册》对天嘉湖水化学、浮游生物、底栖动物、鱼类状况进行了调查。结果表明:天嘉湖水质良好,适合鱼类生长;鱼类天然饵料生物量相对较低,不适合鲢鳙生长;主要渔获物为人工放养的异育银鲫Carassiusauratusgibelio.,今后应依据其自然条件以放养异育银鲫为主,少放鲢鳙;放养12cm以上的大规格的鱼种,提高成活率和回捕率;控制凶猛鱼类的种群数量。     

番茄愈伤组织和植株耐盐性的比较研究

对2份野生种和4份栽培种的研究证明,子叶,下胚轴和叶片外植体诱导的愈伤组织对NaCl的反应是一致的,将4份野生种和2份栽培种带有2叶一心的小苗扦插于附加不同浓度NaCl的MS培养基中,发现在150mmolNaCl处理10d时,1号,2号,3号和4号材料的相对生根率分别为65．8％,87．5％,86．8％和100％,4份野生种在附加有75 mmol/NaCl的 培养基上的生长优于对照,随着NaCl浓度的不断提高,株高和叶片数都表现下降,3号材料下降幅度最小,当NaCl浓度提高到300mmol时,4份野生种的鲜重可达对照的0．90倍,1．07倍,1．60倍和1．53倍,而]2份栽培种则为对照的0．55倍和0．33倍。     

雷竹笋采后生理及其贮藏技术研究

采用不同的处理方法研究了雷竹笋的采后生理变化和保鲜技术.结果表明,臭氧(O3)、0.3% VC+0.5%柠檬酸、0.05%多菌灵处理对雷竹笋均有较好的保鲜效果.采后雷竹笋经O3处理、4 ℃下贮藏可显著抑制多酚氧化酶的活性和丙二醛的生成,降低呼吸强度,延长保鲜期25 d以上.而对照的试样由于微生物的侵染不到10 d就腐败变质.另外,O3处理结合气调包装能有效降低竹笋总糖的消耗,减缓纤维化作用,较好地保持原有的风味和营养品质.     

保持耕作技术对旱区坡耕地水土流失的影响

研究了保持耕作技术对治理旱区坡耕地水土流失的作用,表明高留茬深松技术可以减少降雨中的产流次数及径流量,大幅度降低径流量中NO_3~--N的浓度及流失量,在土壤侵蚀中氮和钾具有养分富集作用,而磷的流失仅与流失的土壤总量有关。     

温室番茄水肥耦合数学模型及其优化方案研究

采用三因素二次回归通用旋转组合设计,研究了灌水量、氮肥、钾肥的耦合效应对番茄的影响,得到番茄产量对三因素的回归数学模型。结果表明:三因素影响番茄产量的顺序依次为施氮量、灌水量、施钾量,各因素间存在交互作用。经计算机模拟得出,番茄产量达到最高值89.15.thm-2时,其对应的灌水量、施氮量和施钾量分别为2 637.2 m3.hm-2、374.1 kg.hm-2和51.6 kg.hm-2。对模拟结果进行的验证试验表明,模型优选所得到配施方案的番茄产量最高。