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研究工业运输活动释放出的重金属元素对周边荒漠草原植被群落特征和土壤性状的关系,为工业活动影响下的荒漠草原植被恢复和重建提供科学依据。以宁夏盐池县高沙窝工业集中区邻近的荒漠草原为研究对象,结合前期土壤和降尘的重金属含量,根据内梅罗污染指数划分了五个污染梯度(梯度Ⅰ、梯度Ⅱ、梯度Ⅲ、梯度Ⅳ和梯度Ⅴ),采用野外调查和室内分析的方法,对比分析了不同污染梯度下的植被群落特征与土壤性状的关系。结果显示:在前三个污染梯度下物种组成相对较多,禾本科(Gramineae)、藜科(Chenopodiaceae)、豆科(Leguminosae)和菊科(Compositae)为优势科。其中,牛枝子(Lespedeza potaninii)和短花针茅(Stipa breviflora)的重要值分别为59.41和44.26,是研究区工业生产和交通运输影响下的主要物种。随着污染梯度的升高,植物群落均匀度指数显著下降(P<0.05),工业交通运输活动造成研究区荒漠草原植被组成单一,群落结构不稳定。表层土壤养分受重金属影响波动较大,土壤全氮和有机质是影响物种多样性指数的主要土壤因子,随着污染梯度的升高显著降低(P... 相似文献
453.
【背景】金黄色葡萄球菌是常见的人畜共患条件致病菌,随着多耐药菌株分离率的增长,研发与抗生素作用模式不同的抗菌剂迫在眉睫。【目的】分离高效且特异性强的金黄色葡萄球菌噬菌体,对其进行功能注释,并对其编码的裂解酶进行功能验证。【方法】通过对噬菌体全基因组序列进行分析找到裂解酶基因,利用原核表达系统对其编码的2个裂解酶蛋白进行克隆,用SDS-PAGE与蛋白免疫印迹法(Western blotting)鉴定目的蛋白是否表达,并采用单斑法验证其裂解活性。【结果】本研究的噬菌体为一株新的金黄色葡萄球菌噬菌体,命名为vB_Sau_P68,该基因组全长为139 409 bp,GC含量为31.0%,编码220个开放阅读框(open reading frame,ORF),透射电镜观察具有正二十面体头部和收缩性尾部,形态学分类属于肌尾噬菌体。该噬菌体编码2个裂解酶基因,分别具有CHAP催化结构域与SH3_5结合结构域,SDS-PAGE与Western blotting表明Lys161能够表达且有裂解活性,Lys163则无法外源表达。对Lys161序列进行分析,该裂解酶无信号肽,无跨膜区域,以无规则卷曲为主。【... 相似文献
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The present study was conducted primarily to determine the occurrence of polypharmacy in patients with schizophrenia on risperidone. The secondary aim was to ascertain the incidence of inappropriate prescribing with anticholinergics. A retrospective review of the medical records of all patients who were being followed up at the out-patient clinic of a tertiary-care hospital in Malaysia was conducted. Only patients who were being prescribed risperidone between 1 June 2008 and 31 December 2008 were included in the study. Demographic data such as patient’s age, gender and race were obtained from the patient’s medical records. In total, 113 patients met the selection criteria. Polypharmacy was found to occur in 34 patients (30.09%), with the majority (76.47%) being on two antipsychotics. In total, 27 patients (34.18%) on monotherapy with risperidone were prescribed an anticholinergic on scheduled dosing, while 19 patients (24.05%) were prescribed it on an as-needed basis. Of the patients on polypharmacy, 26 (76.47%) were on scheduled dosing of anticholinergics, while three (8.82%) were taking the medication on an as-needed basis. Polypharmacy should be avoided, and the use of anticholinergics should be closely reviewed. By adopting more efficient prescribing practices, costs can be reduced and financial resources can instead be channelled towards more beneficial areas for the patients. 相似文献
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Of the weeds that were found in banana production areas, only Asystasia gangetica was parasitised by Radopholus similis; Helicotylenchus multicinctus and Hoplolaimus pararobustus were able to parasitise all weed species. Field trials were carried out in Cote d'Ivoire to assess the potential for using nematode-free micro-propagated banana plants following cultural and chemical methods for nematode control. Banana (Musa acuminata) cv. Poyo was examined for nematodes after weed fallow, flooding and chemical treatment. Before replanting bananas, nematode assays showed that: i) all nematode species declined but were not eliminated after a 1,3-dichloropropene soil treatment; ii) H. multicinctus, H. pararobustus and Cephalenchus emarginatus were still present after either a 2-year weed fallow (dominated by Chromolaena odorata or Asystasia gangetica) or a 10-week flooding; iii) R. similis did not persist after fallowing or flooding. All nematode species were found in plots treated with 1,3-dichloropropene and that had been planted with bullheads, suckers or nematode-free micropropagated plants. After both fallow and flooding, R. similis was reintroduced on infested planting materials (bullheads and suckers) even when they were pre-treated with a nematicide. When fallow and flooded plots were planted with nematode-free materials (vitro-plants), R. similis did not appear in the roots for two vegetative cycles. The other species, still present in the soil, invaded the roots and increased slowly in numbers. These results were confirmed in commercial banana plantations. 相似文献
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目的 通过对比对照组和太极拳运动组,评价太极拳运动在早中期帕金森病患者康复作用。方法 45例帕金森病患者随机分为:对照组(n=15),不接受干预;太极拳1组(n=15)采用24式简化太极拳练习,40 min/次,3次/周;太极拳2组(n=15)采用24式简化太极拳练习,60 min/次,3次/周。在基线、12周、24周运动后采用患者跌倒功效量表(FES)、起立-行走计时测试(TUGT)、Berg平衡量表评分(BBS)、统一帕金森病评定量表(UPDRS) Ⅲ评分、汉密尔顿焦虑抑郁量表评分(HAMD、HAMA)、匹兹堡睡眠质量指数评分(PSQI)进行评估。结果 太极拳1组,24周对比基线在TUGT、BBS评分的改善上有统计学意义(P<0.05)。太极拳2组,24周对比基线在TUGT、 BBS评分的改善上有统计学意义(P<0.05),24周对比12周在TUGT的改善上有统计学意义(P<0.05)。结论 太极拳运动可以改善早中期帕金森病患者的平衡障碍,可降低跌倒风险。 相似文献
460.