增压器转速适应性测量方法

提出一种以采集卡为测量平台的增压器转速测量方法。系统以软件方式实现了随转速变化进行自适应调整的数字滤波，给出一种基于转速信号极值点的周期识别方法。分析和实验结果表明，该方法能够在增压器转速信号受外界干扰而偏离的情况下，在较宽的范围内实时测量增压器转速。     

离心输油泵故障诊断专家系统的研究与实现

提出了一种新的对基本神经网络进行组合的思路，将基本神经网络分层联接，每一层对应对象的某一属性，并根据属性分类。以这一思路为指导，组建了BP网络与竞争网络组织相结合的神经网络，并以此为核心，搭建了离心输油泵故障诊断专家系统的框架。     

相继涡轮增压系统对D6114型柴油机性能的影响

在D6114型增压中冷柴油机上,分别采用原机增压器、大增压器、小增压器和同时使用大小2个增压器等4种方案,对柴油机的燃油消耗率和碳烟排放进行了试验.通过分析比较试验结果.提出大小涡轮相继涡轮增压方案,低速工况时小增压器单独工作,中高速工况时大小增压器并联运行.试验结果表明,采用大小涡轮相继增压系统在低速大负荷工况时,比原机燃油消耗率密度最多降低30g/(kW·h),排放烟度最多降低约22%,初步证实了车用柴油机采用相继涡轮增压技术效果良好.     

PWM间歇式变量喷雾的雾化特性

采用频率在20Hz以内可调、占空比可调的方波信号驱动开关电磁阀,改变电磁阀门开通和关断的时间,实现了基于脉宽调制(PWM)技术的间歇式脉动变量喷雾.以农业喷施中常用的平口扇形喷嘴为例,从间歇式脉动变量喷雾的流量调节范围、雾量分布、喷雾角、雾滴粒径、雾滴速度及喷雾动态特性随流量的变化规律等方面,分析讨论了PWM间歇式脉动变量喷雾的雾化特性.研究结果是,流量调节范围为4.17;随流量的减小,雾量分布向中央集中的趋势很小,雾滴粒径稍增大,喷雾角、雾滴粒径随流量的变化率分别为0.0433(°)/%、0.616μm/%,影响程度很微小;随流量的减小,雾滴速度基本无变化,动能中值直径(KEMD)和比能(SE)随流量的变化率分别为-0.63μm/%、0.2451J/(kg·%),流量控制对喷雾动态特性的影响也较小.     

泵站单机组变速运行优化方法研

考虑峰谷电价与站下水位变幅等因素,提出了以日开机运行总耗电费用最少为目标函数,各时段水泵转速为决策变量,规定时段内抽水总量为约束条件的单机组变速优化运行动态规划模型.对江都四站单机组变速优化运行与恒速运行进行了比较分析,结果表明:满负荷工作时,无论是否考虑峰谷电价,变速带来的效益不足以抵消安装变频装置产生的耗损;考虑峰谷电价、非满负荷工作时,效益明显;不考虑峰谷电价情况下,80%和60%负荷工作时,变速节省的电费偿还相应配套功率的变频装置投资约需15～18年和7～10年.     

螺旋锥齿轮网络化制造集成平台研究

为提高螺旋锥齿轮的加工精度与效率,实现螺旋锥齿轮制造信息化,深入分析了螺旋锥齿轮网络化制造的信息流程,提出了一种螺旋锥齿轮网络化制造集成平台的功能体系结构,并通过Web服务技术实现了集成平台的应用集成与软件架构。通过搭建集成平台的原型系统和螺旋锥齿轮的联网加工试验,对该集成平台的可行性和实用性进行了验证。     

Soil compaction and forest floor removal reduced microbial biomass and enzyme activities in a boreal aspen forest soil

Soil enzymes are linked to microbial functions and nutrient cycling in forest ecosystems and are considered sensitive to soil disturbances. We investigated the effects of severe soil compaction and whole-tree harvesting plus forest floor removal (referred to as FFR below, compared with stem-only harvesting) on available N, microbial biomass C (MBC), microbial biomass N (MBN), and microbial biomass P (MBP), and dehydrogenase, protease, and phosphatase activities in the forest floor and 0–10 cm mineral soil in a boreal aspen (Populus tremuloides Michx.) forest soil near Dawson Creek, British Columbia, Canada. In the forest floor, no soil compaction effects were observed for any of the soil microbial or enzyme activity parameters measured. In the mineral soil, compaction reduced available N, MBP, and acid phosphatase by 53, 47, and 48%, respectively, when forest floor was intact, and protease and alkaline phosphatase activities by 28 and 27%, respectively, regardless of FFR. Forest floor removal reduced available P, MBC, MBN, and protease and alkaline phosphatase activities by 38, 46, 49, 25, and 45%, respectively, regardless of soil compaction, and available N, MBP, and acid phosphatase activity by 52, 50, and 39%, respectively, in the noncompacted soil. Neither soil compaction nor FFR affected dehydrogenase activities. Reductions in microbial biomass and protease and phosphatase activities after compaction and FFR likely led to the reduced N and P availabilities in the soil. Our results indicate that microbial biomass and enzyme activities were sensitive to soil compaction and FFR and that such disturbances had negative consequences for forest soil N and P cycling and fertility.     

Influence of non-cellulose structural carbohydrate composition on plant material decomposition in soil

The C mineralisation pattern during the early stage of decomposition of plant materials is largely determined by their content of different carbohydrates. This study investigated whether detailed plant analysis could provide a better prediction of C mineralisation during decomposition than proximate analysis [neutral detergent solution (NDF)/acid detergent solution (ADF)]. The detailed analysis included sugars, fructans, starch, pectin, cellulose, lignin and organic N. To determine whether differences in decomposition rate were related to differences in hemicellulose composition, the analysis particularly emphasised the concentrations of arabinose and xylose in hemicelluloses. Carbon dioxide evolution was monitored hourly in soil amended with ten different plant materials. Principal component and regression analysis showed that C mineralisation during day 1 was closely related to free sugars, fructans and soluble organic N components (R ² = 0.83). The sum of non-cellulose structural carbohydrates (intermediate NDF/ADF fraction) was not related to C mineralisation between days 1 and 9. In contrast, a model including starch and protein in addition to the non-cellulose structural carbohydrates, with the hemicelluloses replaced by arabinose and xylose, showed a strong relationship with evolved CO₂ (R ² = 0.87). Carbon mineralisation between days 9 and 34 was better explained by xylan, cellulose and lignin (R ² = 0.72) than by lignocellulose in the ADF fraction. Our results indicated that proximate analyses were not sufficient to explain differences in decomposition. To predict C mineralisation from the range of plant materials studied, we propose a minimum set of analyses comprising total N, free sugars, starch, arabinose, xylan, cellulose and lignin.     

苏打盐渍土地区芦苇地土壤盐分离子空间变异与群落关系研究

对松嫩平原西部苏打盐渍土地区芦苇小区土壤盐分离子和植被群落进行了分析,结果表明土壤盐分离子空间变异显著,四种阳离子(Na+、K+、Ca2+、Mg2+)变异系数为0.60~1.22,四种阴离子(HCO3-、CO32-、C l-、SO42-)变异系数为0.35~1.41。离子中,Na+在阳离子中含量最高,HCO3-在阴离子中含量最高。群落间比较,碱茅+芦苇群落八大离子浓度均大于芦苇群落(p<0.05)。且土壤电导率、pH,以及株高、生物量、覆盖度也高于芦苇群落(p<0.01),因此随着土壤电导率、离子浓度的增加,芦苇小区土壤碱化程度加重,植被生长指标减小,植被群落也由芦苇群落向含有碱地植被的碱茅+芦苇群落过渡。     

家兔早期胚胎体外培养和移植研究

用ＦＳＨ，ＰＭＳＧ，ＨＣＧ和ＩＣＩ－８０９９６对２０只家兔进行超数排卵，平均每只排卵１９．１枚，回收胚胎１３．５枚。超排卵数和卵子回收数ＦＳＨ分别为２６．３枚和２１．１５枚，ＰＭＳＧ为２２枚和１３．５。将正常的２５枚１细胞，７枚２细胞和３２枚４细胞期胚胎在ＴＣＭ－１９９培养液，５％ＣＯ２和 ３８．５℃环境中培养６０－７ ０ｈ，６３．１７％的胚胎可发育至囊胚移植至５只体兔后，产出仔兔１３只。