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1.
为了提高温室环境测控系统中传感器数据的准确性,针对温室环境参数变化的时间相关性和空间相似性特点,提出了一种基于主成分分析(Principal component analysis,PCA)的故障检测与基于时空信息比较的温室环境监测系统的传感器故障识别方法。首先利用基于PCA的传感器故障检测方法,通过监控统计量T2和SPE的变化实现传感器系统故障检测;再针对检测出故障的传感器节点,对该时刻传感器节点采用基于时空特性的节点信息比较实现不同传感器的故障识别。分别对比基于时间尺度、空间尺度、时空尺度的节点信息比较方法对传感器故障识别的影响进行了分析与试验验证,验证结果表明:基于PCA的传感器故障检测方法能够有效地实现对传感器系统故障的初步检测,提出的基于时空信息比较的传感器故障识别方法,融合考虑时间尺度和空间尺度的节点信息,能够有效地实现传感器具体故障定位;所建立的传感器故障识别方法检测正确率CDR为98.37%、平均虚警率FAR为1.72%,较传统的传感器故障识别方法检测正确率CDR提高了22.067个百分点,而平均虚警率FAR则降低了15.762个百分点,能够有效地保证故障诊断效率、提高故障诊断精度、降低虚警率,具有可靠性和准确性。  相似文献   
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为了更好地指导藤材的合理利用,缓解日益紧张的木材供需矛盾,采用显微图像分析方法,对3组黎藤试样2m处藤节间与节部的纤维形态特征进行了观察与统计,并进行对比与分析。结果显示,黎藤节间与节部纤维的长度、宽度、长宽比、腔径、双壁厚分别为981.779和921.271μm、7.786和8.719μm、130.822和113.021、3.716和3.669μm、4.070和5.051μm。由藤芯到藤皮节间处纤维长度和长宽比均呈现先增后降的趋势,节部处纤维长度和长宽比、节间纤维宽度均呈现逐渐下降的趋势;节间、节部处纤维腔径及节部宽度均呈现先降后增的趋势;节间处双壁厚呈现逐渐下降的趋势,节部处双壁厚呈逐渐增加的趋势。经F检验,在0.05水平上节间与节部处纤维宽度和双壁厚存在极显著差异。平均纤维微纤丝角为42.71°,变化区间在39.38°~46.03°;平均纤维素结晶度为46.96%,变化区间在44.10%~49.82%,且藤皮处结晶度大于藤芯处。  相似文献   
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Several sentinel lymph node (SLN) mapping techniques, to detect nodal metastasis in canine tumours have been investigated in the last 10 years in veterinary oncology. The purpose of this prospective study was to describe a reliable, quick, and inexpensive technique for SLN mapping in canine patients affected by cutaneous and subcutaneous mast cell tumours (MCT). Eighty dogs were enrolled in this study for a total of 138 cytologically diagnosed MCTs. Sentinel lymph node mapping was performed by injecting iomeprole peritumorally followed by serial radiographs at 1, 3, 6 and 9-min post injection. A total of 168 SLNs were detected, 90% at first radiograph, 1 min after the peritumoral iomeprole injection, while in the rest of the cases SLN was identified at 3 min. Sentinel lymph nodes detected by the preoperative radiographic indirect lymphography with iomeprole (PRILI) differed from regional lymph nodes in 57% of cases. The PRILI technique detected simultaneously multiple SLNs in the 26% of cases and multiple lymph centers in the 31% of MCTs. To allow the surgical identification of the SLNs, a peritumoral injection of methylene blue was performed at the time of surgery. This study reports a widely available technique for SLN mapping using digital radiographs in combination with a water-soluble medium, representing a cost-effective alternative to other SLN mapping procedures. Based on our results, this technique can be effective for SLNs mapping in dogs with MCTs but further comparative studies are needed to assess its reliability and efficacy in different tumours.  相似文献   
5.
It is known that the regional lymph node (RLN) may not correspond to the sentinel lymph node (SLN) (the first lymph node draining the tumour), and many diagnostic techniques have recently been aimed at its detection. Although lymphoscintigraphy is the gold standard in both human and veterinary medicine for SLN mapping, it is relatively unavailable in veterinary medicine due to costs and difficult management of the radiotracer. This prospective study evaluated, as a first aim, the feasibility and sensitivity of the computed tomography lymphography (CTL) in detecting the SLN in 62 mast cell tumours (MCTs). The second aim was to evaluate the accuracy of the CTL in identifying the most representative lymph node of the patient's lymphatic status; the histological status of the SNL was compared with that of the RLN, to see in how many cases the patient's stage would have changed according to the RLN. When the RLN turned out to be also the SLN it was decided to excise, as a control LN, the one localised in the neighbourhood of the MCT (neighbouring lymph node; NLN). The detection rate was 90%, with failure of SLN identification in six cases. In 18 (32%) of 56 MCTs with a diagnostic CTL, the SLN did not correspond to the RLN. Forty-five MCTs were surgically removed, together with their corresponding SLN and RLN/NLN. Since the clinical stage of the patient would have changed in only 7% of cases, CTL is a reliable method of detecting the SLN and, for staging purposes, there is no need to remove other LNs.  相似文献   
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Commercial cultivation of Bt cotton produced higher boll load which led to stiff inter-original competition for photosynthates, resulting in early cessation of growth (premature senescence) due to more availability of sink and less sources. To overcome this problem, field experiment was conducted during 2011 and 2012 using five treatments of plant growth manipulation viz. no fruiting branch removal (F1), removal of first fruiting branch (F2), removal of first and second fruiting branch (F3), removal of all squares from first fruiting branch (F4), removal of all squares from first and second fruiting branches (F5), and three potassium (K) application rates viz. 50 kg ha?1 (K1), 100 kg ha?1 (K2), and 150 kg ha?1 (K3). More nodes above white flower were recorded in F5, followed by F3, while minimum were recorded in F1. Among potassium levels, maximum nodes above white flower were recorded in K3 followed by K2 and K1 during both years of study. Plant height recorded at physiological cutout stage or at maturity stage showed that plants gained more height with removal of all squares from first tosecond fruiting branches with higher potassium dose. Leaf K increased with increasing applied potassium and also with square/branch removal. So early removal of squares/fruiting branches along with higher potassium dose helped in delaying canopy senescence in Bt cotton.  相似文献   
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目的 探讨磁共振常规及弥散加权成像在宫颈癌淋巴结转移诊断中的敏感性、特异性.方法 113例ⅠB1至ⅡB期宫颈癌患者行术前MRI常规及弥散加权成像检查、根治性子宫切除术加盆腔或盆腔及腹主动脉旁淋巴结清扫术.结果 94例(83.2%)经术后病理学检查证实无淋巴结转移,19例(16.8%)有淋巴结转移.MRI常规及弥散加权成...  相似文献   
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