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     

黄粉莲  佘超杰  万明定  杨仕臣  雷基林  申立忠 《农业工程学报》2024,40(5):71-81

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。  相似文献   

Mycoplasma (M.) bovis antiserum "Dessau"--a diagnostic material for the identification of M. bovis     

H Pfützner 《Archiv fuer experimentelle veterinaermedizin》1989,43(5):697-698

Mycoplasma bovis antiserum "Dessau" was used to investigate 4,553 mycoplasma strains, between 1985 and 1987, using a method described elsewhere. This diagnostic Agent is successfully used at present at all Regional Institutes of Veterinary Services throughout the GDR.  相似文献   

Enzyme arrangement of various tissues in swine. 1. Studies of the effect of 32 hours of fasting, administration of actinomycin D, and fasting in combination with administration of actinomycin D on crude protein level, activities of GOT, GTP, fructose-1,6-diphoaphatase as well as ATPase of liver, kidneys and semitendinous muscle in newborn piglets]     

E Kolb  E Grün  C Schineff  U Schmidt 《Archiv fuer experimentelle veterinaermedizin》1979,33(2):177-189

The effects of sufficient milk intake as well as of 32 hours of fasting after birth, administration of actinomycin D (intraperitoneal application of 1 mg/kg five weight), and fasting in combination with actinomycin D on the development of body and liver weights, crude protein levels in homogenate and supernatant of liver, kidneys, and M. semitendinosus as well as on the activities of certain tissue enzymes were analysed with four groups of piglets (n = 4). Fasting, administration of actinomycin, and fasting in combination with actinomycin D resulted in rapid reduction in body and liver weights, while the crude protein levels in those tissues were not affected with significance. GOT and fructose-1,6-diphosphatase activities in supernatant from liver tended to decline under fasting conditions. The ATPase activity in the homogenate of the above tissues did not change in response to differentiated treatment.  相似文献   

The subacute and subchronic toxicity of chlorophacinone in Japanese quail (Coturnix c. japonica)     

B Riedel  G Grün  P Clausing 《Archiv fuer experimentelle veterinaermedizin》1990,44(3):341-346

Accordingly to the subacute toxicity of chlorphacinone to Japanese quail (LC 50: 60 mg/kg feed), the uptake of Delicia-chlorphacinone-baits for several days can be lethal to birds as a matter of principle. A subchronic study resulted in a "no-observed-effect-level" of 1 mg chlorphacinon/kg feed. Reproduction is not affected until dose levels which resulted in lethality or are accompanied by physiological changes (coagulability of blood, microcytic anaemia). Increased sensibility of descendants to chlorphacinone cannot be derived from the findings.  相似文献   

Epizoologic studies of the detection of antibodies against Aujeszky's disease virus in sera and blood eluates of swine from Thailand using ELISA ("Enzygnost," Behring), serum neutralization test and "Aujeszky Latex Kit" (Iffa Merieux)     

P Leamcharaskul  I C Renner-Müller  E Munz  M Reimann 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1990,37(6):418-429

The results of three tests for Aujeszky's disease were analysed and compared. The presence of Aujeszky's antibodies was determined by "Enzyme-linked-Immunosorbent-Assays" (ELISA, "Enzygnost"), Behring company, Marburg; "Serum-Neutralization-Tests" (SNT); and "Latex Agglutination-Tests" (LT, "Aujeszky-Latex-Kit"), Iffa Merieux company, Laupheim. Whole blood and sera samples were taken from 805 swine from 26 of Thailand's provinces. These samples were analysed to determine if eluates of whole blood on filter paper were as effective as corresponding sera samples in determining the presence of Aujeszky's disease antibodies. From a total of 805 samples, 26% of the serum and 18% of the blood eluate samples showed a positive result when tested by the ELISA method. Clearly, testing whole blood eluates provides results which are inferior to results from sera samples. Therefore the ELISA whole blood eluates test can only be recommended with reservations. Further testing was done on 645 serum samples using SNT. Samples tested were those which gave negative, suspicious, or weakly positive results when tested by ELISA. Using SNT, 23% of these showed a positive result. Many serum and blood eluate samples were also tested by LT. Most of these test samples were chosen because they were deemed suspicious. Suspicious samples were defined as those which had deviant test results. According to these results the sensitivity of LT was between the sensitivity of SNT and ELISA. Owner survey responses tended to state that few animals had been vaccinated. This coupled with the frequency of antibody occurrence proves the high rate of infection among Thailand's swine population.  相似文献   

A quest for human traces     

Müller-Beck H 《Science (New York, N.Y.)》1981,213(4513):1241-1242

  相似文献   

Influence of temperature and day length after chilling and short-day period on the flowering of Calceolaria × herbeohybrida Voss     

W. Rünger 《Scientia Horticulturae》1978,9(1):71-81

  相似文献   

Arbovirus isolations from mosquitoes in South Slovakia.     

V Danielová  D Málková  J Minár  B Rehse-Küpper  Z Hájková  J Halgos  L Jedlicka 《Folia parasitologica》1978,25(2):187-190

In the years 1973 and 1975 mosquitoes and some other Diptera (Tabanidae, Simuliidae, Hippoboscidae) were tested for virus. 13,924 mosquitoes, 75 horseflies and 60 blackflies were processed in 1973. Five strains of Tahyna virus were isolated from mosquito species Aedes vexans. 3,378 mosquitoes and 12 sheep keds were tested for virus in 1975. Twelve strains of Calovo virus were isolated from Anopheles maculipennis and one strain of Tahyna virus was obtained from Aedes vexans mosquitoes.  相似文献   

Endocrine and sperminogenic testicular function. 8. Relationships between testicular and plasma testosterone concentrations as well as between the number of Leydig cells in testicular tissue and their cell nucleus volume in boars of different ages]     

H T?nhardt  J Dorst  B Schülke  H Sajonski 《Archiv fuer experimentelle veterinaermedizin》1976,30(5):733-738

Testicular tissue and blood samples (V. spermatica interna) were taken from 32 boars during castration. The animals were different age groups. Against this background, studies were conducted into the correlations between testicular and plasma testosterone, on the one hand, and the amount of interstitial cells of Leydig in testicular tissue as well as the latters' cell nuclei volumes, on the other. The results seemed to support the conclusion that any age-dependent increase of testicular and plasma testosterone concentrations was caused unambigously by an absolute increase in volume of androgenic testicular tissue, in concomitance with testicular growth, in other words, by rise in the total number of interstitial cells of Leydig.  相似文献   

Excessive oral administration of iron to sheep. 1. Digestibility of rations, results of fattening and carcass yields]     

G Flachowsky  A Hennig  H J L?hnert  M Grün 《Archives of Animal Nutrition》1976,26(11):765-771

4 digestibility trials (4 male sheep per group) and 2 growth trials were carried out with 24 (V 1) and 32 (V 2) fattening lambs to investigate the effect of abundant oral Fe doses on the digestibility of crude nutrients in a ration of barley + dried green feed and on the results of fattening and carcass yields. Fe supplementation (less than 1400 mg per sheep/day) did not significantly change the digestibility coefficients of crude nutrients. Increasing Fe levels in the concentrates decreased the rates of liveweight increase and food consumption in both growth trials. Well-established statistical evidence was provided for the decline in absolute carcass yields resulting from the lower weight of the lambs at the end of the fattening period after Fe supplementation.  相似文献