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排序方式: 共有347条查询结果,搜索用时 31 毫秒
31.
针对现有瓜科嫁接机砧木生长点去除不干净,以及生长点去除过程中砧木苗易损伤的缺点,该文以葫芦苗为试验对象,通过瓜科蔬菜砧木苗生长点去除理论运动轨迹分析和对生长点去除机构的动力学分析,设计开发了一种应用于瓜科蔬菜嫁接的生长点去除机构,该机构利用模仿人工方法通过手指去除生长点的原理,采用曲柄连杆机构外加柔性手指,实现生长点的去除。试验结果表明,砧木苗在13~17 d培育期间内,所设计的机构能较好地去除砧木苗生长点,去除成功率达90%以上,伤苗率小于5%,所研发的瓜科蔬菜嫁接砧木生长点去除机构是可行的。该研究可为解决蔬菜嫁接砧木苗生长点去除困难提供参考。  相似文献   
32.
In order to get experimental data on apple rootstock with iron-efficient genotypes capable of improving scion resistance to iron deficiency, this experiment was conducted on the physiological and molecular characteristics of Fuji/ Chistock 1 (F/C) under different iron conditions and compared it to Fuji/ M. Baccata (F/B). F/C was less sensitive to iron deficiency than F/B. F/B showed chlorosis after 25 days under iron-deficient conditions, but F/C showed no phenotypic changes, even after 40 days. The shoot and leaf area growth of F/C were respectively 5cm and 1000 mm2 higher than those of F/B, regardless of the iron-deficient or iron-efficient conditions. The young leaf chlorophyll and active iron of F/C were 5 SPAD and 5 mg kg?1 higher than those of F/B, either in iron-deficient or iron-efficient conditions. The expression of YSL5 and CS1 showed the same pattern. The enhancement expression of iron transport genes may be one explanation for these findings.  相似文献   
33.
Summary The results obtained by four methods for detecting PLRV in potato tubers grown in Israel were compared with the results obtained by aphid transmission to test plants. The correlation coefficients for potatoes lifted in July (seed for autumn) and September (seed for spring) were: Igel-Lange test, 0.18 and 0.25; datura grafting with tuber sprouts, 0.71 and 0.63; aphid transmission from sprouts to test plants, 0.89 and 0.81; and visual assessment in the Florida test (for spring seed), Up-to-Date 0.58, Blanka 0.67 and Désirée 0.33. The Igel-Lange test proved unreliable; datura grafting is time consuming and PLRV symptoms were similar to reactions ofDatura stramonium to wounding and to stress. The results of the Florida test were somewhat variable and were obtained too late. The sprout test was deemed the most suitable as it is accurate and the results can be obtained within two months. Contribution No 156-E, 1979 series, Volcani Center.  相似文献   
34.
Reasons for performing study: The nerve‐muscle pedicle graft technique is a treatment for recurrent laryngeal neuropathy (RLN), but the optimal placement of the pedicles within the cricoarytenoideus dorsalis (CAD) muscle is unknown. Hypothesis: The magnitude and direction of force placed on the muscular process of the left arytenoid cartilage affects the magnitude of laryngeal abduction. Methods: Five larynges were harvested from cadavers. Using increments of 0.98 N, a dead‐weight force generator applied a force of 0–14.7 N for 1 min each to the left muscular process at 0, 10, 20, 30, 40, 50, 60 and 70° angles. The rima glottis was photographed digitally 1 min after each force had been applied. Distances between biomarkers (Lines 1–4) and right to left angle quotient (RLQ) were used to assess the degree of left arytenoid abduction. Results: Increasing force from 0–14.7 N progressively and significantly increased the length of all lines and RLQ, indicating abduction. Furthermore, there was a significant interaction between force and angles. Applying forces of 7.84 N or greater (Lines 2–4 and RLQ) or 11.76 N or greater (Line 1) at angles 0, 10, 20 and 30° resulted in significantly greater abduction than applying the same forces at 40, 50, 60 and 70°. Angles of 0–30° correspond with the direction of pull exerted by the lateral compartment of the CAD muscle. Conclusion: In RLN, nerve‐muscle pedicle grafts should be placed preferentially in the lateral rather than in the medial compartment of the CAD muscle. Potential relevance: The information presented can be used to assist surgeons in the planning and application of the nerve‐muscle pedicle graft procedure.  相似文献   
35.
Vertebral body osteomyelitis in the cervical spine secondary to Rhodococcus equi has been treated both medically and surgically. This Case Report describes a 4‐month‐old foal exhibiting severe neurological signs from R. equi vertebral body osteomyelitis. Rapid, significant resolvement of neurological signs was noted in this case with surgical debridement and use of synthetic bone filler. The outcome suggests that aggressive surgical therapy in conjunction with synthetic allograft may be indicated in treatment of cervical vertebral body osteomyelitis.  相似文献   
36.
Amniotic membrane transplantation (AMT) is an effective clinical therapy for reconstruction of the ocular surface in human and veterinary patients. Amnion is avascular and strong, contains antiangiogenic and antiinflammatory properties and growth factors, and has properties that prevent or decrease fibrosis in healing tissue. Indications for its use are steadily growing and include grafting to replace diseased, missing or excised tissue, patching to support diseased tissue during the healing process and as a substrate for the expansion of epithelial cells for transplantation to the cornea. AMT through a combination of mechanical and biologic factors can preserve the integrity of the globe, optimize the visual outcome, and minimize scarring in severely diseased corneas.  相似文献   
37.
嫁接两年生茶树新梢主要生化成分的变化   总被引:1,自引:1,他引:1  
吴姗  骆耀平 《茶叶》2001,27(3):22-26
研究了两年生嫁接茶树浙农113/鸠坑,龙井43/鸠坑,水仙/鸠坑及相应接穗,砧木品种新梢的主要生化成分,嫁接茶树浙农113/鸠坑,龙井/鸠坑氨基酸含量的升高,多酚含量的减少使其较对应接穗品种的酚氨比降低,而水仙/鸠坑的酚氨比升高,咖啡碱含量因嫁接组合的不同而呈不同的变化趋势,与嫁接一年生时的结果作比较,未表现出一致的规律,表明嫁接初时对茶树产生的影响有一个“时效”问题,嫁接后两年,嫁接茶树体的茶多酚,咖啡碱,氨基酸等主要滋味成分的含量受砧木影响较大。  相似文献   
38.
杜鹃红山茶(Camellia azalea)为山茶科山茶属常绿灌木或小乔木,是中国特有珍稀濒危物种,在园林与观赏园艺方面具有广阔的应用前景,兼具有极高的科研价值。国内外关于杜鹃红山茶嫁接繁殖的研究主要集中在木质化砧木嫁接方面,而芽苗砧嫁接技术及芽苗砧嫁接亲和性生理的研究鲜有报道。为了从生理层面揭示杜鹃红山茶接穗与不同油茶芽苗砧的亲和性差异,本研究以广西栽培面积广泛的高州油茶、广宁红花油茶、岑溪软枝油茶、普通油茶为芽苗砧,以杜鹃红山茶当年生半木质化枝条为接穗进行芽苗砧嫁接,于嫁接后90 d,考察不同芽苗砧处理对杜鹃红山茶接穗死亡率、嫁接苗叶片中初生代谢产物含量、抗氧化生理指标以及光合色素含量的影响。结果表明:(1)不同芽苗砧木对杜鹃红山茶接穗的死亡率有显著影响,采用高州油茶作为芽苗砧,杜鹃红山茶嫁接死亡率最低,为18.5%;(2)不同芽苗砧木对杜鹃红山茶接穗叶片中可溶性蛋白含量及淀粉含量有显著影响,采用高州油茶砧木,嫁接苗叶片中可溶性糖、可溶性蛋白及淀粉含量均处于最高水平;(3)不同芽苗砧木对杜鹃红山茶嫁接苗叶片中脯氨酸含量及过氧化物酶(POD)活性有显著影响,采用高州油茶作为芽苗砧,嫁接苗叶片中脯氨酸和丙二醛(MDA)含量最低,超氧化物歧化酶(SOD)和POD活性最高;(4)不同芽苗砧木对杜鹃红山茶嫁接苗叶片中总叶绿素、叶绿素a及叶绿素b含量有显著影响,采用高州油茶作为芽苗砧的杜鹃红山茶嫁接苗叶片中总叶绿素、叶绿素a及叶绿素b含量均最高。研究认为,杜鹃红山茶接穗与高州油茶芽苗砧具有较好的亲和性,其嫁接苗抗性优于其他芽苗砧处理,叶片生长状况较好,具有较强的光合能力。  相似文献   
39.
本研究以环己烷为连续相,Span 80/Tween 80为分散剂,采用氧化还原引发体系,通过反相悬浮聚合技术,合成疏水缔合阳离子淀粉接枝共聚物。研究了反应温度,引发剂用量,反应时间对接枝性能的影响及溶解性能。并用IR、X衍射对共聚物进行了表征。结果表明:采用氧化还原引发剂可使聚合反应低温快速进行,在m(St)∶m(AM)∶m(DMDACC)∶m(OA)为4∶7.4∶1.5∶0.6时,引发剂用量3.1 mmol/L,30℃反应3 h,单体转化率92.6%,接枝率53.8%,粘均相对分子质量(MV)3.26×106。  相似文献   
40.
用湿法改性方法将硅烷偶联剂接枝在纳米SiO2表面上,并分析了pH值、反应时间、反应温度及硅烷偶联剂的加入量对接枝效果的影响,继而讨论了接枝后的纳米SiO2在原位乳液聚合过程中的分散稳定性.结果表明,较佳的改性工艺条件为:pH值为3~4,反应温度为80℃,反应时间为120 min,硅烷偶联剂的加入量为纳米SiO2重量的10%左右.接枝了硅烷偶联剂的纳米SiO2,能够使乳化剂聚集在其表面上,形成“胶束”区域,从而提高了在乳液聚合体系中的分散性和稳定性.  相似文献   
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