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201.
木荷凋落物分解及对土壤作用规律的研究 总被引:18,自引:0,他引:18
在福建省永春碧卿林场开展的木荷凋落物分解及土壤淋溶试验表明 :木荷人工林凋落物量和养分积累量下坡 >中坡 >上坡 ,养分积累量Ca >N >K >Mg >Fe >P >Zn >Cu ;凋落物分解的失重率Ws与时间t之间存在Ws =34 45 2Lnt -3 0 741(R =0 98)的对数关系 ;木荷凋落物可通过增加土壤有机质 ,提高土壤和下渗液的盐基量 ,提高土壤pH值 ,降低土壤水解性总酸度等途径来缓解土壤的酸化作用 相似文献
202.
杨粮间作林内土温及水分因子的变化 总被引:4,自引:0,他引:4
根据江苏省泗阳县境内南方杨树杨粮间作林内土温及水分因子4a定位观测资料,系统地分析了杨粮间作林中土温及水分因子的变化规律。间作地年均温度低于对照,且温度变化缓慢;各原土壤含水量均低于对照,减少了对间作物的水分供应,但林粮间作可降低风速,减少蒸发,提高相对湿度。 相似文献
203.
杉木根际与非根际土壤酶活性比较 总被引:19,自引:2,他引:19
杉木根际与非根际土壤酶活性比较陈f竣(中国林业科学研究院林业研究所北京100091)李传涵(华中农业大学土化系武汉430070)关键词杉木,根际土壤,土壤酶,杉木中毒由于林木生长的影响,使得林木根际土壤pH值、养分含量、微生物数目、生化活性等性质发生... 相似文献
204.
For two Scots pine (Pinus sylvestris) ecosystems in S Germany with different atmospheric N deposition (Pfaffenwinkel, intermediate N deposition; Pustert, large N deposition), the supply with phosphorus (P) has been monitored for unfertilized and fertilized plots over more than four decades by foliar analysis (1964–2007). Additionally, topsoil concentrations and stocks of total P and plant-available P (citric-acid-extractable phosphate) were quantified in 10-year intervals (1982/1984, 1994, 2004). At both sites, fertilization experiments, including the variants control, NPKMgCa + lime, PKMgCa + lime + introduction of lupine, corresponding to an addition of 75 and 90 kg ha−1 P in Pustert and Pfaffenwinkel, respectively had been established in 1964. Our study revealed different trends of the P nutritional status for the pines at the two sites during the recent four decades: At Pustert, elevated atmospheric N deposition together with small topsoil P pools resulted in significant deterioration of Scots pine P nutrition and in an increasingly unbalanced N/P nutrition. At Pfaffenwinkel a trend of improved P nutrition from 1964 to 1991 was replaced by an opposite trend in the most recent 15 years. For our study sites, which are characterized by acidic soils with thick O layers, the forest floor stock of citric-acid-extractable phosphate showed a strong and significant correlation with the P concentration in current-year pine foliage, and thus was an appropriate variable to predict the P nutritional status of the stands. Total P stocks as well as the concentrations of total P in the forest floor or in the mineral topsoil were poorly correlated with pine foliar P concentrations and thus inappropriate predictors of P nutrition. P fertilization in the 1960s sustainably improved the P nutritional status of the stands. At Pfaffenwinkel, foliar P concentrations and topsoil stocks of citric-acid-extractable phosphate were increased at the fertilized plots relative to the control plots even 40 years after fertilization; at Pustert, foliar P concentrations were increased for about 20 years. 相似文献
205.
Assessing the effects of initial soil characteristics,machine mass and traffic intensity on forest soil compaction 总被引:1,自引:0,他引:1
An extensive field trial was set up in eight forest stands to examine the influence of soil texture (two stands on sand, four on loam to silt loam, two on clay), machine mass (light, heavy) and traffic intensity (one and five skidding cycles) (i.e. pass back and forth on the skid trail) on soil compaction after mechanized harvesting. Dry bulk density (BD), penetration resistance (PR), micro-topography and soil carbon dioxide (CO2) concentration were applied as response variables for soil compaction. Significant effects on BD were nearly absent (<7% increase) and occurred occasionally for PR (60–70% increase, up to 150% on clay soils). Especially for loam to silt loam and clay soils, this was in contrast with the expectation. The negligible compaction degrees for loam to silt loam are attributed to high initial compaction levels that prevented further compaction, as was found by general linear modelling (GLM) for both BD and PR. For clay soils the small compaction degrees can be explained by the high water contents that result in plastic deformation instead of strong compaction degrees, as was confirmed by the micro-topographical measurements. GLM also revealed a significant impact of machine mass (BD) and soil water content (BD, PR) on the compaction degree. Soil texture, traffic intensity and position in relation to the wheel tracks generally turned out to have an insignificant influence. With regard to clear interactions the influence of traffic intensity depends on the position in relation to the wheel tracks and the machine that was used (PR). 相似文献
206.
以净月潭国家森林公园兴安落叶松林为研究对象,以NH4NO3为原料模拟4个强度的氮沉降,分析土壤总有机碳(TOC)、易氧化有机碳(ROC)、溶解性有机碳(DOC)和微生物量碳(MBC)的动态变化。研究结果表明:低氮沉降量(L,50 kg N yr-1 ha-1)提高了TOC、ROC、DOC和MBC浓度,但除MBC外均未达到显著性水平;中氮沉降量(M,100 kg N yr-1 ha-1)提高了TOC和DOC浓度,降低了ROC和MBC浓度;高氮沉降量(H,150 kg N yr-1 ha-1)提高了ROC和MBC浓度,降低了TOC和DOC浓度。 相似文献
207.
以黑龙江省佳木斯市孟家岗林场的长白落叶松中龄林为研究对象,在2012年进行林隙间伐(5 m×5 m、7 m×7 m、10 m×10 m),并于2013年和2014年选择0~10 cm、10~20 cm、20~40 cm的土层进行取样,测定土壤的物理性质,其结果表明:林隙间伐能够改善长白落叶松中龄林土壤的物理性质,林隙7 m×7 m的林分,改善了土壤的松散程度,使容重减小,提高土壤毛管孔隙度,持水能力增强。 相似文献
208.
针对巴基斯坦高温干旱的自然条件及高填方高速公路边坡土壤高盐碱、贫瘠、板结等特点,通过添加有机质(甘蔗渣、河泥)、腐殖酸、脱硫石膏等改善土壤理化性质,并通过实地调查,选择适宜该地栽培的草本种类及种植方式进行边坡植草。结果表明:在土壤中加入甘蔗渣和河泥可以有效的改善土壤板结情况,最佳施用比例为50%原状土+20%甘蔗渣+30%河泥;在土壤中加入腐殖酸和脱硫石膏可有效的降低土壤pH值,降低土壤盐碱度,最佳配比为0.5kg/m^2腐殖酸+8kg/m^2脱硫石膏;在土壤中加入磷酸二铵可有效的增加土壤中氮磷含量,最佳添加量为22.5g/m^2。通过沿线物种调查,优选出高抗性本地品种狗牙根,并通过对比试验得出最佳种植方式为条植。该研究对于巴基斯坦高填方公路边坡绿化防护具有积极的现实意义及广阔的推广前景。 相似文献
209.
210.