不同海拔下甲醇替代率和主喷正时对RCCI发动机性能的影响

为探究不同海拔条件下甲醇/柴油反应活性控制压燃（reactivity controlled compression ignition, RCCI）发动机的运行特性,该研究基于甲醇/柴油双燃料发动机试验台架,试验研究1 800r/min、100%负荷和3 200r/min、100%负荷下不同甲醇替代率、柴油喷射正时对发动机燃烧与排放性能的影响规律。结果表明：不同海拔条件下随着甲醇替代率的增加,缸压和瞬时放热率峰值逐渐升高,燃烧始点和燃烧中心前移,当量有效燃油消耗率（equivalent brake specific fuel consumption, ESFC）降低,有效热效率升高,NO_x和碳烟排放大幅降低,THC（total hydrocarbons）和CO排放增加。1 800 r/min、100%负荷工况下,甲醇替代率由0增至20%,0、1 000、2 000m海拔下最大缸压平均增加1.72MPa,瞬时放热率峰值平均升高25.08J/(°),ESFC平均降低4.67%,有效热效率平均升高4.90%,NO_x和碳烟排放分别平均降低16.63%和50%,THC和CO排放量分别平均增加142.03、388.18 mg/kg。3 200 r/min下甲醇替代率由0增至7%,不同海拔高度下ESFC平均降低1.76%,有效热效率平均升高1.79%,NO_x和碳烟排放量分别平均降低8.17%和20.70%。海拔高度由0升至2 000m,1 800r/min、20%甲醇替代率与3 200r/min、7%甲醇替代率下,瞬时放热率峰值分别降低4.80和8.08J/(°),燃烧中心分别推迟1.44°和1.43°,有效热效率分别降低0.82%和0.68%,ESFC分别升高2.10%和1.99%,NO_x排放量分别减少10.61%和7.35%,碳烟排放分别增加26.54%和32.12%,THC排放分别升高29.88%和15.45%,CO排放量分别增加22.42%和18.15%。固定甲醇替代率后,随着柴油主喷正时提前,不同海拔条件下缸压和放热率峰值逐渐升高,燃烧中心向上止点靠近,ESFC逐渐降低,有效热效率升高,碳烟排放减少,NO_x、THC和CO排放增加。1 800 r/min、15%甲醇替代率下,主喷正时从-1.5°提前至-7.5°,不同海拔高度下ESFC平均降低8.27%,有效热效率平均升高9.08%,碳烟排放平均减少90.94%。为提升高海拔条件下甲醇/柴油RCCI发动机的热效率和燃油经济性,可以适当增大柴油主喷正时。研究结果可为不同海拔环境下甲醇/柴油RCCI发动机燃烧与污染物排放控制优化提供参考。     

胚培杏新品种———山农凯新1号

 ‘山农凯新1号’是以丰产性强的‘凯特’杏为母本, 以品质优良的‘新世纪’杏为父本进行有性杂交, 结合胚培技术育成的新品种, 具有成熟早、香味浓、品质优、自交坐果率高、丰产性强等特点。     

番茄不同部位中糖含量和相关酶活性的研究

 试验将番茄光合产物运转途径上叶片(源) 、运输系统以及果实(库) 区分开, 分别测定其糖的组成和含量以及糖代谢相关酶的活性。结果表明: 番茄光合产物运转途径上从“源”到“库”各部位糖的组成和含量不同。叶肉中果糖的含量最高, 蔗糖的含量最低; 中筋中以果糖和葡萄糖为主; 叶柄维管束中葡萄糖含量最高, 蔗糖含量次之, 果糖含量最低。节间和果柄维管束中主要含有蔗糖。果实维管束以及果实内各部位中则主要含有葡萄糖和果糖, 且两者含量无显著差异, 蔗糖含量很低。萼片中葡萄糖含量最高, 蔗糖含量最低; 果蒂中3种糖含量均较高且无显著差异。番茄叶肉及光合产物运转组织中转化酶活性很低, 而在库器官的非维管组织中转化酶活性较高。果蒂中的蔗糖合成酶( SS) 活性最高, 其次是叶肉和运转组织, 果实内各部位中SS活性较低。在合成蔗糖的器官—叶肉中, 有较高的蔗糖磷酸合成酶( SPS) 活性, 运转组织中的SPS活性较叶肉中降低, 但果柄维管束和果实维管束中则表现出较高SPS活性, 果肉、果胶质胎座及心室隔壁中的SPS活性最低。     

乌梁素海生态恢复机理与工程技术的研究

在我国干旱区典型草型湖泊—乌梁素海设立试验基地 ,进行生态恢复工程试验研究。研究表明 :乌梁素海受富营养化影响 ,正在向芦苇沼泽—碱蓬盐化草甸—白刺荒漠方向演化。生态恢复机理是 :( 1 )减少大型水生植物有机氮、磷向底质的沉降 ,削弱内源性营养物负荷的积累与储备 ;( 2 )减少大型水生植物死亡后矿化成氨态氮 ;( 3)控制底质中有机氮向水体释放生成氨态氮。采用机械化方式收割大型水生植物转移营养盐 ,抑制生物促淤效应以及对芦苇区进行园田化生态管理是乌梁素海生态恢复的关键技术 ,也是乌梁素海环境与资源持续发展的核心问题     

内蒙古地区提高天然降水利用率实用技术及其评价

本文针对内蒙古地区水资源短缺 ,旱灾发生频繁的现状及天然降水利用效率不高的特点 ,结合国内外现有的科研与技术成果 ,根据地处干旱、半干旱地区内蒙古的气候特点 ,提出提高天然降水利用率的各种实用技术方法。并利用地理信息技术 ,根据各种实用技术方法的指标要求 ,结合内蒙古的地形、坡度状况、土壤类型和气象条件 ,在雨养农业区进行实用技术方法的优化分区 ,区划出适宜区域。     

水稻白叶枯病菌对噻枯唑的抗药性监测

采用活体寄主法和离体含药平板法 ,测定了 1999年安徽省滁州市田间水稻白叶枯病菌对噻枯唑的抗药性。结果表明 ,在水稻活体上存在噻枯唑抗药突变体 ,其比例为67.65%,比1997、1998年有较大程度升高 ,但是离体含药平板上未能监测到抗药突变体。     

培养条件对酸枣叶片不定梢再生率的影响

以酸枣无菌苗叶片为外植体,选用基本培养基ＮＮ６９和ＷＰＭ,外源激素包括ＴＤＺ、ＩＡＡ、ＩＢＡ和ＮＡＡ,暗培养时间为２、３、４周。采用正交实验设计方法,研究了基本培养基、外源激素及暗培养时间对叶片不定梢再生的影响。结果表明在附加ＴＤＺ１~３ｍｇ/Ｌ的ＷＰＭ和ＮＮ６９上都可诱导不定梢再生,但ＷＰＭ比ＮＮ６９更有效。暗培养时间对不定梢再生也有影响,暗培养３周比２、４周更有利于提高叶片的不定梢再生率。在附加ＴＤＺ１ｍｇ/Ｌ、ＩＡＡ０．１ｍｇ/Ｌ的ＷＰＭ培养基上,暗培养３周后转到光下培养,获得的不定梢再生率达８７．５%。     

Effect of heat shock precondition on reperfusion arrhythmia in rats

AIM:To investigate the effect of the heat shock response on the reperfusion arrhythmias(RAs) and the possible mechanism involved. METHODS:Fifty-five Sprague Dawley rats were randomly divided into 2 groups: the heat shock group (group H,n=29) and the control group (group C,n=26). The rats in group H were preconditioned with heat shock 24 hours before, and that in group C were not. The hearts of 16 rats in group H and 16 in group C were exercised and mounted on a non-circulating Langendorff perfusion apparatus and perfused retrogradely with modified K-H buffer and mimic ischemia/reperfusion was applied. Additionally, conventional intracellular microelectrode techniques were used for recording such electrophysiological parameters as resting potential(RP), action potential amplitude(APA), over shot(OS), maximum depolarization velocity(Vmax) of the hearts of other 13 rats in group H and 10 in group C. RESULTS:①Prior heat stress significantly decreased reperfusion arrhythmia. ②The amount of CK release in the effluent in group H was much less than that in group C. ③Myocardial HSP70 content was elevated significantly in group H. ④Heat stress significantly increased myocardial anti-oxydases activity and decreased lipid peroxydative products. Additionally, heat stress significantly reduced the Vmax of action potential. It indicated that rapid Na⁺ channel of papillary muscles may be inhibited by heat shock. The degree of change of Vmax after ischemia in H group was significantly less than that in group C. And the time of reperfusoin with Tyrode's solution till the action potential appeared as large as that before perfusion with mimic ischemic solution is shorter in group H than in group C. CONCLUSION:Heat shock pretreatment markedly reduces ischemia/reperfusion-induced injury of heart and ventricular arrhythmias in rats and this effect may be associated with the inhibition of rapid Na⁺ channel of papillary muscles by heat shock and the increase in myocardial HSP70 and anti-oxydase activity.     

In vitro growth inhibition effects of rhHGF/cHGF on SMMC-7721 human HCC cell line

AIM:To examine the effects of recombinant human hepatocyte growth factor(rhHGF) and native calf HGF(cHGF) on SMMC-7721 human hepatocellular carcinoma(HCC) cell line. METHODS:Human HCC cell line culture, photometric assay, and flow cytometric assay were used in this study .RESULTS:A similar type of dose-dependent cell growth inhibition effect on SMMC-7721 human HCC cells by rhHGF(5-20 μg/L) as well as by cHGF(25-100 mg/L) had been found, with the maximal effect at the highest concentration used. Approximately over 50% of the cells treated with rhHGF(5 μg/L, 10 μg/L, 20 μg/L) accumulated in the quiescent G₀/G₁ phase of the cell cycle over incubation periods for 3 d. CONCLUSION:The growth of SMMC-7721 human HCC cells was strongly inhibited by both rhHGF and cHGF. This might be because the cells exposed to HGF became arrested in the G₀/G₁ phase.     

Effects of Taoren Honghua Jian on the hyperlipidemia without symptom

AIM: To examine the effect of traditional chinese medicine recipe, Taoren Honghua(semen persicae-flos carthami) decoction, on hyperlipidemia without symptom. METHODS: The plasma TC, TG, LDL, HDL, apolipoprotein(Apo) A, Apo Bof the patients with hyperlipidemia without symptom were measured using automatic analyzer (shimadiu CL-7200), the production of nitric oxide(NO) was detected by Greiss reaction, and SODactivity and MDAformation were examined using o-trihydroxy benzene and barbituric methotheds, respectively. RESULTS: After oral administration of Taoren Honghua decoction, the plasma levels of TC, TG, LDL, and MDAof the patients were markedly decreased, however, the plasma levels of ApoA, HDL, SODand NOwere significantly increased and almost no change was detected in the plasma level of Apo B. In control group, it was found that although the plasma level of TC, TG and LDL were decreased ( P<0.05 ) and ApoAas well as HDLwere increased, ApoB, SOD, MDA and NO production were all unchanged. CONCLUSION: The traditional chinese medicine recipe, Taoren Honghua decoction,has a significant therapeutic effect on patients with hyperlipidemia by removing blood stasis, promoting qi circulation and in turn reducing blood lipid level.