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31.
32.
农牧交错带土壤营养元素分布及其改善途径——以内蒙古自治区多伦县为例 总被引:1,自引:0,他引:1
对农牧交错带内蒙古自治区多伦县61个表层土样测定分析表明,有32.0%的土样有机质含量<1g/kg,40%的土样有机质分量为1~3g/kg,属中等水平,仅有28%的土样有机质含量为3g/kg。大量元素中32.7%的土壤缺N,58.9%缺P,19.5%的土壤缺K;微量元素中100.0%的土壤缺Mo,88.7%的土壤缺Zn,52.7%的土壤缺B,24.3%的土壤缺Mn等。并进行综合评价,指出不同地型各类土壤合理施肥、退耕增产及其沙化治理、改善生态环境的对策。 相似文献
33.
Investigation of sulfonamide, tetracycline, and quinolone antibiotics in vegetable farmland soil in the Pearl River Delta area, southern China 总被引:2,自引:0,他引:2
Li YW Wu XL Mo CH Tai YP Huang XP Xiang L 《Journal of agricultural and food chemistry》2011,59(13):7268-7276
Thirteen antibiotics in soil from vegetable farmlands of the Pearl River Delta, southern China, were investigated. At least three antibiotics were detected in each sample. Six antibiotics including four quinolones, tetracycline, and sulfamethoxazole were detected in >94% of the samples. The total contents of three tetracyclines, eight sulfonamides, and four quinolones were not detected-242.6, 33.3-321.4, and 27.8-1537.4 μg/kg, respectively. The highest antibiotic concentrations were observed mainly in vegetable farmlands affiliated with livestock farms. Chlortetracycline, sulfameter, and quinolones in some samples exceed the ecotoxic effect trigger value (100 μg/kg) set by the Steering Committee of Veterinary International Committee on Harmonization. The composition and concentration of antibiotics in soil were correlated with vegetable species. This study has revealed an alarming condition of antibiotics in vegetable farmland soil. Further investigation including environmental fate, plant uptake, and human exposure to antibiotics by plant-derived food should be conducted. 相似文献
34.
Rabab Saba Badenhorst Pieter Chen Yi-Ping Phoebe Daetwyler Hans D. 《Precision Agriculture》2021,22(1):124-153
Precision Agriculture - Due to the increase in the use of precision agriculture, field trials have increased in size to allow for genomic selection tool development by linking quantitative... 相似文献
35.
Nobuko Saigusa Sheng-Gong Li Hyojung Kwon Kentaro Takagi Lei-Ming Zhang Reiko Ide Masahito Ueyama Jun Asanuma Young-Jean Choi Jung Hwa Chun Shi-Jie Han Takashi Hirano Ryuichi Hirata Minseok Kang Tomomichi Kato Joon Kim Ying-Nian Li Takahisa Maeda Akira Miyata Yasuko Mizoguchi Shohei Murayama Yuichiro Nakai Takeshi Ohta Taku M. Saitoh Hui-Ming Wang Gui-Rui Yu Yi-Ping Zhang Feng-Hua Zhao 《Journal of Forest Research》2013,18(1):41-48
The datasets of net ecosystem CO2 exchange (NEE) were acquired from 21 forests, 3 grasslands, and 3 croplands in the eastern part of Asia based on the eddy covariance measurements of the international joint program, CarboEastAsia. The program was conducted by three networks in Asia, ChinaFLUX, JapanFlux, and KoFlux, to quantify, synthesize, and understand the carbon budget of the eastern part of Asia. An intercomparison was conducted for NEE estimated by three gap-filling procedures adopted by ChinaFLUX, JapanFlux, and KoFlux to test the range of uncertainty in the estimation of NEE. The overall comparison indicated good agreement among the procedures in the seasonal patterns of NEE, although a bias was observed in dormant seasons depending on the different criteria of data screening. Based on the gap-filled datasets, the magnitude and seasonality of the carbon budget were compared among various biome types, phenology, and stress conditions throughout Asia. The annual values of gross primary production and ecosystem respiration were almost proportional to the annual air temperature. Forest management, including clear-cutting, plantation, and artificial drainage, was significant and obviously affected the annual carbon uptake within the forests. Agricultural management resulted in notable seasonal patterns in the crop sites. The dataset obtained from a variety of biome types would be an essential source of knowledge for ecosystem science as well as a valuable validation dataset for modeling and remote sensing to upscale the carbon budget estimations in Asia. 相似文献
36.
细胞悬浮系的中短期保存广泛需要。本文应用中花15细胞悬浮系,比较了AA、N6、MS三种固体培养基对水稻细胞悬浮系的繁殖保存效果,结果表明,AA固体培养基保存效果最好。细胞系可以在AA0培养基上4个月、在AA0.5培养基上6个月(中间45 d左右继代一次)连续保存后仍然保持其可重悬性。通过比较AA固体培养基繁殖保存、冷冻保存、连续悬浮培养3种保存方法,表明AA固体培养基繁殖保存细胞系2~9个月内,既可保持细胞的可悬浮性,又对细胞系的POD、SOD活性和植株再生率影响较小,是一种理想的细胞悬浮系中短期保存方法。 相似文献
37.
从Phytozome数据库中获得包括大豆在内的12种植物的谷氨酰胺合成酶(glutamine synthetase, GS)氨基酸序列,利用MEGA5.10软件进行多序列比对、构建进化树。进化分析表明,植物GS可以分成胞质型(GS1)和质体型(GS2)两大类,GS1可进一步分成分5个亚类,包括双子叶植物为主的I、II和III亚类、低等植物类(IV)和单子叶植物类(V)。这5亚类中,第II类是豆科植物特有的一类,大豆的4个GS1 (GmGS1β1/2和GmGS1γ1/2)属于该亚类;利用qPCR在大豆盛花期分析GS1基因的组织表达特异性,结果表明不同类型GmGS1基因在表达部位和表达丰度上存在较大差异,而同一类基因之间具有相似的表达规律;4个豆科植物特有的GS1基因在大豆根瘤中都有较高的表达量,其中位于大豆第18染色体上的GmGS1β2基因表达丰度最高;利用原核表达系统体外表达GmGS1β2蛋白,诱导出分子量大小与理论预测值一致的目标蛋白,酶活性分析表明GmGS1β2可以与底物发生催化反应,具有谷氨酰胺合成酶活性,推测该基因在大豆根瘤氮素同化代谢中具有重要作用。 相似文献
38.
小偃54和京411及其杂交后代稳定优选株系光合特性的动态变化 总被引:3,自引:0,他引:3
以上海种植的小偃54和京411及其杂交后代稳定优选株系6号、7号和10号为材料,通过测定抽穗期剑叶的毫秒延迟发光(ms-DLE)和不同生育期倒数第1片功能叶的光合速率(Pn)、叶绿素含量(Chl)、比叶重(SLW)、Fv/Fm、ATP含量和P700还原初始速率来分析其光合特性的动态变化,为小麦育种选择中改善光合性能提供理论依据和技术途径。结果表明,小麦杂交优选后代6号株系的形态农艺性状近于小偃54,7号株系近于京411,10号株系的变异较大。不同基因型小麦及其杂交优选后代的光合特性与生育时期和衡量指标密切相关,Pn为分蘖期>抽穗期>灌浆期>拔节期,叶绿素含量为灌浆期>抽穗期>分蘖期>拔节期,ATP含量为灌浆期>拔节期>分蘖期>抽穗期,P700还原初始速率为灌浆期>抽穗期>拔节期>分蘖期,各生育期间的Fv/Fm无明显差异。小麦光合特性的超亲优势随生育时期而异,杂交优选后代10号株系的Pn和Chl在灌浆期有超亲优势,ATP含量在抽穗期有超亲优势,SLW和P700还原初始速率介于两亲本间。杂交优选后代株系10号聚合了Pn、Chl和ATP含量的超亲优势,其光合特性优于两亲本,而6号劣于两亲本,7号介于两亲本之间。 相似文献
39.
Yan-Ju Liu Yi-Ping Tong Yong-Guan Zhu Hui Ding F. Andrew Smith 《Journal of plant nutrition》2013,36(7):1207-1217
The objective of this study was to investigate the possibility of predicting the concentrations of total nitrogen (N), nitrate-nitrogen, and ascorbic acid in spinach (Spinacia oleracea) leaves using the pocket chlorophyll meter SPAD-502 (Minolta, Japan) in a pot experiment in a greenhouse. Spinach plants were grown in plastic pots filled with 0.5 kg of brown soil per pot with urea as N fertilizer at 0, 30, 60, 120, and 240 mg N/kg soil. SPAD readings of the two uppermost fully expanded leaves were recorded 18, 25, and 32 d after sowing and at harvesting (34 d). Dry-matter biomass and total N concentrations in leaves and roots, and NO3-N, and ascorbic acid concentrations in leaves, were measured after harvesting. SPAD readings showed continuous reduction with increasing growth period irrespective of N applications. SPAD readings at harvest were significantly correlated with total N, leaf dry weight (DW), and NO3-N concentration. However, this correlation did not exist between SPAD readings and ascorbic acid concentrations in leaves. The above results suggest that it is possible to apply SPAD readings to estimate NO3-N concentrations in spinach plants, and that they may be applied for field assessments in decision-making and operational nutrient-management programs for the plant. Furthermore, the SPAD method may also be useful for ascertaining the harvest time. The results suggest that treatment with 120 mg N/kg significantly improved both leaf yields and leaf quality (i.e., leaf nitrate-N concentration and ascorbic acid). Too little and too much N fertilizer was not good for yield or spinach quality. 相似文献
40.
降解地膜的热解特性及热动力学研究 总被引:1,自引:0,他引:1
Developing degradable films is an important means for resolving the problem of film pollution; however, in recent years, there have been only few studies related to the thermal analysis of degradable plastic films. This research detailed the composition and pyrolysis of one kind of ordinary and three kinds of degradable plastic films using the differential thermal analysis (DTA) technique. The results showed that degradable films and ordinary film had similar DTA curves, which reflected their similar compositions; however, small differences were measured, which were due to the added constituents of the degradable films. The pyrolysis reaction orders of each film were about 0.93. The pyrolysis activation energies and pre-exponential factors followed the order of ordinary film 〉 photodegradable film 〉 photodegradable calcium carbonate film 〉 biodegradable film. The results of this research laid the foundation for new theories for harnessing soil pollution caused by plastic films. 相似文献