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51.
Kanya TC Sankar KU Sastry MC 《Plant foods for human nutrition (Dordrecht, Netherlands)》2003,58(2):179-196
The sunflower seed waxes obtained from two sources (i) seed hull as astandard and (ii) crude wax from oil refineries were studied for theircrystallization, melting characteristics and morphology of crystals. Theresults of differential scanning calorimetry of wax obtained from seed hullsshowed the melting temperature range of 13.18 °C with the onsetat 62.32 °C, for purified wax, compared to the melting range of24.73 °C with the onset at 42.3 °C, for crude wax. Theenthalpy of fusion for both waxes were 57.55 mcal/mg and 7.63 mcal/mg,respectively. The DSC melt crystallization temperature range was15.79 °C with the onset of 64.58 °C for purified wax andtemperature range of 31.45 °C with an onset of 57.76 °C forcrude wax. A similar pattern was observed of wax obtained from thecrude wax of oil refineries. The enthalpy of crystallization was –64.27mcal/mg and –7.67 mcal/mg, respectively. The purified wax obtained fromthe two sources (i) and (ii) were comparable with completion temperaturesof 75.5 °C and 75.1 °C, respectively. The effect of inhibitor(lecithin) on crystallization of purified wax under light microscope andsurface structure by scanning electron microscope were observed. Lecithinat 0.2% inhibited the crystallization but nucleation was unaltered. Thewax crystal was inhibited to around 60% of the original size with 0.2%lecithin. It is concluded that the sunflower waxes studied were notcomparable in their crystal properties of crude and purified states.Lecithin inhibited the crystallization of sunflower seed wax. 相似文献
52.
HPPD抑制剂的机理与应用进展 总被引:2,自引:0,他引:2
HPPD是在植物光合作用过程中发现的一类新型除草剂靶标酶,可以催化对羟苯基丙酮酸氧化脱羧转变为尿黑酸。HPPD抑制剂的抑制作用会导致植物分生组织产生白化症状,最终死亡。本文对HPPD的作用机理以及HPPD抑制剂主要品种的应用作了综述。 相似文献
53.
大豆新品种中黄31是中国农业科学院作物科学研究所利用缺失Kunitz胰蛋白酶抑制剂的高产、优质、 抗花叶病毒病( SMV)的高代材料ti15176作母本,美国引进优良品种Century近等基因系、脂肪氧化酶缺失的优质 材料Century - 2. 3作父本进行有性杂交,采用未变性聚丙烯酰胺凝胶电泳(Native - PAGE)技术及等电聚焦聚丙烯 酰胺凝胶电泳( IEF - PAGE)技术,对杂种后代胰蛋白酶抑制剂( Ti) 、脂肪氧化酶(Lox)进行缺失检测及多年辅助选 择育成。该品种于2005年通过北京市品种审定委员会审定。其突出特点是高产、稳产、优质(蛋白质品质优异% 缺失Ti和Lox2) 、抗病、抗倒、综合性状优良。 相似文献
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Phenoloxidase (PO) is a key enzyme in the developmental process of insects that is responsible for catalyzing the hydroxylation of monophenols and the oxidation of o-diphenols. In the present investigation, the PO of Plutella Xylostella (L.)(Lepidoptera Plutellidae) was partially purified with 40% saturated (NH4)2SO4 and Sephadex G-100 gel filtration, and the effects of 4-dodecylresorcinol on the monophenolase and o-diphenolase activity of PO were studied. The results showed that 4-dodecylresorcinol could inhibit monophenolase and o-diphenolase activity. In addition, following 4-dodecylresorcinol treatments, the lag time of PO for oxidation of l-tyrosine was obviously lengthened and the steady-state activity was decreased. The inhibitor was found to be competitively reversible with a Ki of 0.201 mM and an estimated IC50 (inhibition concentration showing 50% of the maximum inhibition) of 0.160 mM for monophenolase and 0.369 mM for diphenolase. The ability of 4-dodecylresorcinol to inhibit PO activity may be associated with its ability to directly affect copper at the active site 相似文献
57.
三种母奶水牛血清碱性磷酸酶(ALP)的研究 总被引:1,自引:0,他引:1
用对一硝基苯基磷酸二钠法、聚丙烯酰胺凝胶圆盘电泳法,对三种母奶水牛—摩拉(Murra)、尼里(Nili-Ravi)及三品系杂交[Ni♂×(Mu♂×Nanning♀)♀]水牛血清ALP总活力、同工酶及其与产奶量的关系进行了测定和分析研究。结果表明:ALP总活力为,三品杂(0.0636μmol/min·ml)>摩拉(0.063μmol/min·ml)>尼里(0.0430μmol/min·ml);各品种内高、低产奶量比较为,高产>低产。其同工酶的特点是,共有三种同工酶,其中尼里为ALP_2》ALP_1>ALP_3、三品杂和摩拉为ALP2》ALP_3>ALP_1,但在尼里也出现了ALP_3>ALP_1、在三品杂和摩拉也出现了ALP_1>ALP_3的情况;在各品种内高、低产奶量比较是,ALP_2为高产>低产、ALP_1和ALP_3为低产>高产。并直接证实了两性载体电解质为水牛血清ALP的强烈抑制剂。 相似文献
58.
硫脲对脲酶活性和尿素氮转化的试验初报 总被引:9,自引:0,他引:9
本试验研究了硫脲(TU,0.1%,0.3%,0.5%,1.0%,5.0%)不同浓度对土壤脲酶活性、土壤尿素氮转化的影响。室内培养表明,硫脲既是一种弱脲酶抑制剂又是一种硝化抑制剂。硫脲对脲酶活性和尿素水解均有显著的抑制作用,但是作用时间较短;硫脲用量为0.1%时,就起到了抑制作用,用量0.3%~1.0%之间差异不显著,用量1.0%~5.0%之间抑制效果随用量增加而加强。硫脲不仅延缓了土壤NH4+-N的释放高峰期一周,而且降低了土壤中NO3--N的富集,使NO3--N的释放高峰期向后推迟了10天。本试验条件下,土壤中的NH4+-N向NO3--N转化的时间大约为7~10天;土壤中有效氮的释放曲线主要取决于土壤NH4+-N的浓度,受NO3--N的影响次之。 相似文献
59.
Résumé— Il existe deux inhibiteurs de croissance des insectes (ICI) sous forme orale pour le contrôle des puces. Le lufénuron s'administre une fois par mois à la dose de 10 mg/kg chez le chien et 30 mg/kg chez le chat. La cyromazine s'administre quotidiennement à la dose de 10 mg/kg en association avec la diethylcarbamazine chez le chien. Aucun des deux produits n'est actif sur la puce adulte, mais cause plutôt une interruption de la production de chitine normale par différents modes d'actions spécifiques. Ceci entraine la mort des formes immatures de puces. Par conséquent, les 2 produits contrôle l'infestation par les puces adultes sur l'animal par le biais de l'élimination des formes immatures présentes dans le milieu. Il existe un délai de 6 à 8 semaines entre 1'administration d'inhibiteurs de croissance des insectes (ICI) et la reduction du nombre de puces adultes sur les animaux traités. Cette période réfractaire est due à la survie de puces immatures présentes dans le milieu avant le traitement aux ICI; elle peut être réduite si l'on démarre le traitement oral par les ICI simultanément à un traitement insecticide du milieu environnant et de l'animal. [Shipstone, M. A., Mason, K. V. The use of Insect Development Inhibitors as an oral medication for the control of the fleas Ctenocephalides felis, Ct. canis in the dog and cat (Utilisation d'inhibiteurs de croissance des insectes sous forme orale pour le contrôle des puces Ctenocephalides felis, Ct. canis chez le chien et le chat). Resumen— Existen dos inhibidores del desarrollo de insectos (ICI) para el control de pulgas. El Lefenuron se administra una vez al mes a una dosis de 10 mg × Kg-1 en perros y 30 mg × Kg-1 en gatos. La Ciromacina se administra diariamente a una dosis de 10 mg × Kg-1 en combinación con citrato de dietilcarbamacina en perros. Ninguno de estos compuestos produce efecto en pulgas adultas, sino que causa una interrupción en la producción normal de quitina por distintos mecanismos de acción. Ello causa la muerte del parásito en estadíos de inmadurez y crecimiento. Así, ambos controlan la infestación por pulgas adultas en el animal mediante la eliminación de estadíos vitales de la pulga. Existe un espacio de tiempo de 6–8 semanas entre el inicio de la aministración de ICA y la reducción del número de pulgas en animales tratados. Ésto et debido a la supervivencia de pulgas inmaduras que se encontraban en el entorno antes del inicio del tratamiento con ICI; este periodo de tiempo se puede reducir iniciando el tratamiento oral con ICI junto con tratamiento insecticida de la vivienda y sobre el animal. [Shipstone, M. A., Mason, K. V. The use of Insect Development Inhibitors as an oral medication for the control of the fleas Ctenocephalides felis, Ct. canis in the dog and cat (El uso de inhibidores del desarrollo de insectos como medicación oral para el control de las pulgas Cenocephalides felis y Ct. canis en el perro y en el gato). Abstract— There are two oral Insect Development Inhibitors (IDI) for the control of fleas. Lufenuron is administered once a month at 10 mg × kg-1 for dogs and 30 mg × kg-1 for cats. Cyromazine is administered daily at 10 mg kg-1 in combination with diethylcarbamazine citrate for dogs. Neither compound exerts an effect on the adult flea, but rather causes an interruption in normal chitin production through different specific modes of action. This causes death of the immature, developmental life stages of the flea. Thus, both control the adult flea infestation on the animal via the elimination of the environmental life stages of the flea. There is a lag phase of 6–8 weeks between the initiation of IDI administration and reduction in the number of adult fleas on the treated animals. The lag phase results from the survival of immature fleas that were present in the environment before the onset of IDI treatment; it can be reduced by initiating oral IDI treatment in combination with premise and on-animal insecticide treatments. 相似文献
60.
Scase TJ Edwards D Miller J Henley W Smith K Blunden A Murphy S 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(1):151-158
The Patnaik histologic grading system is commonly used to predict the behavior of cutaneous mast cell tumors (MCTs) in dogs, but it is less useful for grade 2 MCTs because they exhibit considerable variation in biological behavior. In this retrospective study, immunohistochemical staining for Ki-67, proliferating cell nuclear antigen (PCNA), and survivin and a standardized argyrophilic staining of nucleolar organizer regions (AgNOR) protocol were performed on 121 archived paraffin-embedded specimens of canine cutaneous MCTs, for which clinical follow-up data were available. Cox regression models indicated that the Ki-67 score (hazard ratio, 1.92; P < .001) and mean AgNOR score (hazard ratio, 2.57; P < .001) were significantly associated with Patnaik grade and survival time. A binary Ki-67 variable (cutoff point Ki-67 score = 1.8) was a significant predictor of survival for dogs with grade 2 MCTs. The estimated 1-, 2-, and 3-year survival probabilities for dogs with grade 2 MCTs and Ki-67 scores less than 1.8 were 0.92, 0.86, and 0.77, respectively (SEs, 0.08, 0.14, and 0.23, respectively; median not estimable). The corresponding survival probabilities for dogs with grade 2 MCTs and Ki-67 scores higher than 1.8 were 0.43, 0.21, and 0.21, respectively (SEs, 0.19, 0.18, and 0.18, respectively; median survival time, 395 days). No significant association was identified between survival and survivin score or PCNA score. This study shows that both mean AgNOR score and Ki-67 score are prognostic markers for canine MCTs. The Ki-67 score can be used to divide Patnaik grade 2 MCTs into 2 groups with markedly different expected survival times. 相似文献