基于工况偏差在线计算的PHEV能量补偿控制方法

针对车辆真实工况与标准工况实时偏差导致的整车能量管理性能下降问题,提出一种基于工况偏差在线计算的插电式混合动力汽车(PHEV)能量补偿控制方法。根据车辆工况识别结果建立实际工况与标准工况之间偏差的数学表达式;以油电耗比为指标函数,构建能量管理系统控制偏差数学模型,给出工况偏差与控制偏差函数关系的离线建模方法;在此基础上,以工况偏差为输入,以控制偏差为被控对象,设计能量补偿模糊控制器,给出控制偏差的模糊控制规则和动力补偿分配权值。基于某控制策略对本文所提出的方法进行仿真验证,结果表明:所提出的能量分配补偿控制方法能够进一步降低整车燃油消耗,进而提升PHEV能量管理性能。     

Performance analysis of transcritical organic rankine cycle

The performance analysis of a transcritical organic Rankine cycle system driven by exhaust heat is presented by using 24 organic working fluids. Four parameters, such as the net power output, thermal efficiency, exergy efficiency, and mass flow rate of working fluid, are used to evaluate the performance of this recovery cycle. The results reveal that the maximum net power can be obtained for the saturated ORC, when T1/TC is about 0.98～0.99,and the working fluid with higher critical temperature has more net power output. For the supercritical ORC, the higher expander inlet temperature will benefit the net power output, thermal efficiency, and exergy efficiency, as long as the expander inlet pressure isnnot too low. However, the influences of expander inlet pressure on these performance parameters are linked with the expander inlet temperature and working fluids. The capability of doing power output of supercritical ORC is not always better than that of subcritical ORC. Parameters, such as net power, thermal efficiency, and exergy efficiency, and mass flow rate are discontinuous in the process from subcritical conditions to supercritical conditions.     

冷却剂参数对铣槽喷管低周疲劳寿命的影响

采用有限体积流固耦合计算方法、非线性有限元热结构耦合分析方法和局部应变法研究大面积比铣槽喷管三维再生冷却槽道在循环工作条件下的热结构变形与低周疲劳寿命,并对比分析了冷却剂质量流量与入口温度对铣槽喷管疲劳使用寿命的影响。计算结果表明,铣槽喷管热结构响应呈现复杂的三维效应,应变较大位置主要分布在与肋连接的内衬区域,喷管中部的残余应变量最大;冷却槽道低周疲劳寿命分布和热结构响应基本一致,最小寿命位于喷管中部与肋相连的内衬区域燃气侧;随冷却剂质量流量增加,铣槽喷管低周疲劳寿命不断提高;随冷却剂入口温度增加喷管尾部低周疲劳寿命值不断降低,而喷管中前部的低周疲劳寿命值却不断提高,当冷却剂入口温度为280K左右时,本文的铣槽喷管总体使用寿命达到最大。      

牛体细胞核移植技术

对牛体细胞核移植技术中核供体细胞周期同期化处理，电融合条件及去核方法等进行了研究。结果表明，血清－饥饿组（细胞周期同期化处理组）的移核重构胚细胞融合率（83．3％），卵裂率（70％）和囊胚发育率（33．8％）与血清－选择组对应指标间无显著性差异（82．3％，69．2％，32．4％，P＞0．05）；但上述2组分别极显著高于血清－随机组（64．8％，33．8％，4．35％，P＜0．01），试验确立了场强1.025kV/cm，脉冲宽度50μs，连续2次脉冲为最佳电融合条件。摸索出的点击去核法，对卵母细胞进行去核，去核成功率达90％，极显著高地吸引法的68．3％（P＜0．01）；其囊胚发育率为34．1％，显著高于吸引法的18．0％（P＜0．05），与挤压法（20．9％）相比差异不显著（P＞0．05），移植重构胚胎移植后，产2头成活的体细胞克隆牛。     

Changes in vasotocin immunoreactivity of paraventricular nuclei and adrenal function of Japanese quail in relation to different phases of sexual development

In relevance to osmoregulatory and reproductive functions, activity of hypothalamic neurosecretory neurons may also vary seasonally. The current study was performed to determine annual changes in ir-AVT neurons of hypothalamus and adrenal gland function. We examined changes in ir-AVT neuron by immunohistochemical method and plasma testosterone was measured by enzyme immunoassay. The steroidogenic interrenal activity was studied by histological and biochemical methods. Birds were sampled in February (quiescent), April (recrudescent), June (breeding) and November (regressive). A significant and gradual increase in the number of ir-AVT neurons was observed from quiescent to breeding phase which decreased during regressive phase of annual gonadal cycle. The gradual increase in ir-AVT neurons along with annual gonadal activity of quail were accompanied by increase in plasma levels of testosterone. These results indicate a functional interaction between sex steroid and AVT synthesizing neurons. Adrenal activity (as judged by weight, ascorbic acid content, cortical cord width and cortico-medullary ratio) was also maximum during breeding phase. It is thus postulated that domesticated quail when exposed to natural day length (NDL), exhibits seasonal/annual cyclicity in vastocinergic activity and adrenal function which may be due to difference in sex steroid hormone.     

Involvement of steroid hormones in the preovulatory gonadotropin surge in female goldfish

Goldfish,Carassius auratus, spawn several times within a spawning season. A gonadotropin (GtH) surge occurs at the time of ovulation in this cyprinid species. This ovulatory GtH surge mediates the processes of final oocyte maturation and ovulation, and occurs at the end of each spawning cycle. Within a cycle, there is a shift in the predominant plasma steroid from estradiol to testosterone, and finally 17α, 20β-dihydroxy-4-pregnen-3-one at the time of the ovulatory GtH surge. High levels of testosterone were always observed before ovulation. When ovariectomized or sexually regressed female goldfish were implanted with testosterone, they exhibited a GtH surge which was similar to those normally observed at ovulation. These results strongly suggest that elevated plasma testosterone is an important physiological requirement for the occurrence of the GtH surge.     

六种杀菌剂对黄瓜霜霉病菌不同发育阶段的影响

用Calcofluor荧光染色和显微观察的方法研究了6种常用杀菌剂对黄瓜霜霉病菌Pseudoperonospora cubensis不同发育阶段的影响。结果表明:烯酰吗啉和氟吗啉对黄瓜霜霉病菌孢子萌发、芽管伸长、附着胞形成、菌丝扩展、孢囊梗和孢子囊的形成具有明显的抑制作用,其EC50值分别在0.07~5.98 μg/mL和0.10~3.50 μg/mL之间,而对游动孢子释放、游动孢子游动和休止孢形成没有抑制作用;霜脲氰对休止孢萌发和芽管伸长的EC50值分别为1.10和0.002 μg/mL,对其他阶段无明显的抑制效果;腈嘧菌酯对休止孢萌发、菌丝扩展和孢囊梗产生无影响,对游动孢子释放、芽管伸长和附着胞形成的EC50值分别为0.018、0.008和0.010 μg/mL;代森锰锌对游动孢子释放、休止孢萌发和芽管伸长的EC50值分别为2.40、2.88和1.53 μg/mL;甲霜灵对该菌的整个发育期均没有影响,这可能是因为供试菌株对甲霜灵已经产生了抗药性。     

The Use of Faecal Progestin Measurements to Monitor Reproductive Activity in Mashona Cows in a Smallholder Farming Area of Zimbabwe

The objectives of this study were to investigate the relationship between the concentrations of progesterone (P₄) in the peripheral circulation and progestins in the faeces of cows in a smallholder farming area and to monitor the ovarian activity of such cows. The study was carried out in Sanyati smallholder farming area, located 250 km southwest of Harare. Blood and faecal samples for P₄ and progestin determination, respectively, were obtained once a week from 35 Mashona type cows that belonged to farmers from three different villages. The cows were weighed once every month and all births were recorded. The concentrations of progestins in faeces and P₄ in plasma were positively correlated (r = 0.72, p<0.01). Most of the non-pregnant cows (65%) cycled during the rainy season. Most of those that were acyclic at this time were undergoing post-partum anoestrus. During the dry season, most cows (58%) became acyclic as forage became scarce and of poor quality. Thirty-two calves were born during the study period, mostly during the first or last two months of the year, when there was enough forage. The mean calving to first oestrus in 14 cows that recalved was 71±49 days. Eight of these 14 cows conceived again, the calving to conception interval being 173±94 days. The cows' liveweights were highest in April, at the end of the rainy season. By the end of the dry season, the cows had lost, on average, 15% of their peak weight.     

Growth-Oriented Logging (GOL): A new concept towards sustainable forest management in Central Amazonian várzea floodplains

Against a background of increasing human populations in developing countries, and global climate change, conservation of tropical forests remains one of the most important ecological challenges of our time. One of the biggest difficulties for ecologically sustainable management of tropical forests is obtaining reliable growth data for trees, which is a prerequisite for determining harvesting volumes and cutting cycles. GOL is the first concept for sustainable management of tropical timber resources in Amazonian floodplain forests (várzea) based on species-specific management criteria, such as minimum logging diameters (MLDs) and cutting cycles. From timber species with varying wood densities of different successional stages, volume stocks have been estimated in 1-ha plots and 12 growth models have been developed based on tree rings, which are annually formed as a consequence of the regular, long-term flooding. The MLDs of timber species vary between 47 and 70 cm and the estimated cutting cycles differ the 10-fold, from 3 to 32 years. These enormous differences in the growth rates between tropical timber species are not considered in current management practices, which apply only one diameter cutting limit and one cutting cycle to harvest many tree species. This practice risks the overexploitation of slow-growing timber species, while the fast-growing timber species with low wood densities cannot be efficiently used. Based on the timber stocks and lifetime growth rates, the GOL concept has been created as an aid to improve forest management in the Central Amazonian várzea. The model is unique for tropical silviculture.     

云南松纵坑切梢小蠹危害及生物学特性研究

纵坑切梢小蠹Ｔｏｍｉｃｕｓｐｉｎｉｐｅｒｄａ在云南分布很广，８０年代以来，在昆明、红河、楚雄３地、州３０个县的云南松人工林内猖獗危害，直接经济损失６０００余万元。该虫在云南１ａ一代，全年危害，无明显的越冬现象。每年５～１１月蛀梢，１１～翌年５月蛀干，树皮下各虫态种群高峰期出现在２～５月，此时是清理蠹害木的最佳时期。成虫干转梢及由梢转干在林间扬飞期１～１４ｄ，集中扬飞３～４ｄ，扬飞期对防治成虫有重要意义