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81.
聚丙烯和毛竹共热解的研究   总被引:2,自引:1,他引:1  
在自制固定床反应器中,对聚丙烯和毛竹共热解进行研究,得到了反应气氛、热解温度、反应物配比、反应时间对共热解的影响规律。实验结果表明,由于毛竹与聚丙烯在热解过程中的相互影响,两者共热解时的液体收率和产物分布均与两者单独热解时不同,油相液体产物的辛烷值随毛竹加入量的增加而增大,在聚丙烯和毛竹的最佳配比下,两者共热解的协同作用最明显,不仅原料的转化率最大,而且所得液体产物的收率最高,H2气氛较之N2气氛更有利于油相产物的生成和毛竹中木质素成分的热解。本文条件下,获得最佳油相液体收率的条件为,聚丙烯/毛竹配比8∶2,热解温度520℃,反应时间4h,H2气氛,油相液体收率达53.9wt.%,辛烷值为77.3。  相似文献   
82.
毛黄栌枝叶挥发性化学成分研究   总被引:2,自引:0,他引:2  
采用分析型超临界二氧化碳流体萃取技术(SFE-CO2)与传统水蒸汽蒸馏法(SD)分别提取毛黄栌枝叶挥发油,并通过气相色谱/质谱联用技术测定了提取物的化学成分.从中分别鉴定出47个和48个化合物,主要包括石竹烯、氧化石竹烯、大根香叶烯D、马鞭草烯醇等成分,均有较多生理活性,为进一步研究开发这一植物资源提供了基础数据.比较两种方法所得结果,认为SFE-CO2法比SD法可萃取出更多较高极性组分,因此广泛用于中草药成分研究中.  相似文献   
83.
天然抗癌药物--紫杉醇   总被引:18,自引:0,他引:18  
王正平 《应用科技》2004,31(1):56-58
介绍了人们在不断提高天然植物红豆杉——紫杉醇提取技术的同时,利用人工栽培、半合成、全合成、生物合成、真菌发酵、植物组织细胞培养等现代科技手段获取紫杉醇,为解决天然资源的严重不足和紫杉醇的临床应用提供了可能.  相似文献   
84.
采用固定床反应器,在氢气气氛下研究了高密度聚乙烯(HDPE)与两种典型生物质(杉木、毛竹)(8:2wt%)的共热解及在Y型分子筛上的催化共热解。结果表明,与HDPE单独热解相比,共热解生成的油相液体的碳数分布变窄,使C5-C11汽油馏分的含量显著增加,而C12-C20以及C20 组分相应降低。共热解最高的总液体收率出现在NaY催化剂上,毛竹与HDPE共热解中达到58·9%。在Y型分子筛加入后,共热解水相产物中乙酸含量明显增加,苯酚类产物含量则显著下降。乙酸生成量最多的是USY催化剂,其次是HY、NaY。在USY催化剂作用下,毛竹与HDPE共热解水相液体所含有机物中,乙酸含量达到38·3%。  相似文献   
85.
独活挥发油化学成分的气相色谱-质谱法测定   总被引:5,自引:1,他引:5  
采用水蒸气蒸馏法从独活中提取挥发油。采用不同类型的毛细管柱进行分析 ,找出最佳分析条件 ,共分离出50个峰 ,用归一化法测定其相对含量 ,并用气相色谱 -质谱法对化学成分进行鉴定 ,共鉴定了40个成分 ,占挥发油总成分的80 %以上。  相似文献   
86.
豌豆不同生长期用不同浓度的硫酸锰溶液进行叶面喷施,结果表明,在幼苗期、现蕾期和开花期喷施不同浓度硫酸锰溶液,能增强豌豆叶片的SOD活性和CAT活性,降低O2^*-生成速率和MDA含量.在豌豆生长的幼苗期、现蕾期和开花期叶面喷施0.1%~0.2%的硫酸锰溶液能促进豌豆的生长和产量的增加。  相似文献   
87.
<正>辛硫磷防治竹长蠹危害竹材、竹制品在实验室或在生产现  相似文献   
88.
Columbianadin, one of the main bioactive constituents of the roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan, has been found to possess obvious pharmacological effects in previous studies. In this study, a valid and sensitive reverse‐phase high‐performance liquid chromatography (RP‐HPLC) method was established and validated for the determination of columbianadin (CBN) and its active metabolite columbianetin (CBT) in rat tissue samples. Sample separation was performed on an RP‐HPLC column using a mobile phase of MeOH–H2O (75:25, v/v) at a flow rate of 1.0 mL/min. The UV absorbance of the samples was measured at the wavelength 325 nm. The calibration curves for CBN were linear over the ranges of 0.5–20 µg/g for brain, testes and muscle, 1.0–10.0 µg/g for stomach and intestine, and 0.2–20.0 µg/g for heart, liver, spleen, lung and kidney. The calibration curves for CBT were linear over the ranges of 0.5–25 µg/g for stomach and intestine, and 0.1–10.0 µg/g for heart, liver, spleen, lung and kidney. The analysis method was successfully applied to a tissue distribution study of CBN and CBT after intravenous administration of CBN to rats. The results of this study indicated that CBN could be detected in all of the selected tissues after i.v. administration. CBN was distributed to rat tissues rapidly and could be metabolized to CBT in most detected tissues. Of the detected tissues, heart had the highest uptake of CBN, which suggested that heart might be one of the main target tissues of CBN. Concentrations of CBT were obviously higher in the digestive system than in other assayed tissues. The information provided by this research is very useful for gaining knowledge of the capacities of CBN and CBT to access different tissues. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
89.
Increasing applications and markets for essential oils could bring new opportunities for cost-effective and sustainable management of unused forestry biomass; however, better knowledge of the production and application of such essential oils is necessary. The objective of this work is to contribute to greater knowledge of the essential oil production on a pilot scale from foliage biomass of wild shrubs and tree residues produced in some forestry enhancement operations and to study their antioxidant capacity (ORAC—oxygen radical absorbance capacity). Fresh biomass (twigs) of seven species (E. globulus, E. nitens, P. pinaster, P. sylvestris, R. officinalis, C. ladanifer, and J. communis) was manually collected in Spain in two different periods and was ground at 30 mm and distilled in a 30 L stainless steel still with saturated steam. The essential oil components were identified by GC–MS and quantified by GC–FID, and their antioxidant activity was determined with the ORAC method. Promising results on essential oil yield were obtained with E. globulus, E. nitens, R. officinalis, and J. communis. All essential oils studied exhibited antioxidant capacity by the ORAC assay, particularly that from C. ladanifer. Moreover, oxygenated sesquiterpenes contents, one of the minor components of oils, were significantly correlated with ORAC values.  相似文献   
90.
A novel and rapid microwave extraction and ultra high performance liquid chromatography coupled with a triple quadrupole‐linear ion trap mass spectrometry method was developed and validated for the determination of 21 bioflavonoids in Siegesbeckia pubescens Makino. The optimal conditions for the extraction of flavonoids from Siegesbeckia pubescens Makino involved the use of methanol as the extraction solvent, a microwave temperature of 70°C, an extraction time of 11 min, and a solvent‐to‐solid ratio of 40 mL/g. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column(100 × 2.1 mm, 1.7 μm) with a gradient mobile phase (A: 0.3% v/v aqueous formic acid and B: acetonitrile) at a flow rate of 0.25 mL/min. All calibration curves showed good linearity (r > 0.999) within the test ranges. The method developed was validated with acceptable sensitivity, intra‐ and interday precision, reproducibility, and extraction recoveries. The validated method was successfully applied to determine the contents of 21 bioflavonoids in Siegesbeckia pubescens Makino from different sources.  相似文献   
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