全文获取类型
收费全文 | 2466篇 |
免费 | 143篇 |
国内免费 | 3篇 |
出版年
2023年 | 30篇 |
2022年 | 75篇 |
2021年 | 126篇 |
2020年 | 49篇 |
2019年 | 57篇 |
2018年 | 78篇 |
2017年 | 45篇 |
2016年 | 76篇 |
2015年 | 102篇 |
2014年 | 128篇 |
2013年 | 178篇 |
2012年 | 178篇 |
2011年 | 158篇 |
2010年 | 93篇 |
2009年 | 68篇 |
2008年 | 88篇 |
2007年 | 117篇 |
2006年 | 80篇 |
2005年 | 97篇 |
2004年 | 102篇 |
2003年 | 73篇 |
2002年 | 68篇 |
2001年 | 37篇 |
2000年 | 51篇 |
1999年 | 35篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 19篇 |
1994年 | 18篇 |
1993年 | 17篇 |
1992年 | 32篇 |
1991年 | 18篇 |
1990年 | 18篇 |
1989年 | 28篇 |
1988年 | 16篇 |
1987年 | 18篇 |
1986年 | 14篇 |
1985年 | 11篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 18篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1975年 | 12篇 |
1973年 | 12篇 |
1972年 | 10篇 |
1971年 | 16篇 |
1970年 | 12篇 |
排序方式: 共有2612条查询结果,搜索用时 15 毫秒
61.
Caroline Ward Lindsay C. Stringer Eleanor Warren‐Thomas Fahmuddin Agus Keith Hamer Nathalie Pettorelli Bambang Hariyadi Jenny Hodgson Winda D. Kartika Jennifer Lucey Colin McClean Neneng L. Nurida Asmadi Saad Jane K. Hill 《Restoration Ecology》2020,28(4):817-827
Ecological restoration is considered to play an important role in mitigating climate change, protecting biodiversity, and preventing environmental degradation. Yet, there are often multiple perspectives on what outcomes restoration should be aiming to achieve, and how we should get to that point. In this study we interview a range of policymakers, academics, and non‐governmental organization (NGO) representatives to explore the range of perspectives on the restoration of Indonesia's tropical peatlands—key global ecosystems that have undergone large‐scale degradation. Thematic analysis suggests that participants agreed about the importance of restoration, but had differing opinions on how effective restoration activities to date have been and what a restored peatland landscape should look like. These results exemplify how ecological restoration can mean different things to different people, but also highlight important areas of consensus for moving forward with peatland restoration strategies. 相似文献
62.
Muhammad Tariq-Khan Tariq Mukhtar Anjum Munir Johannes Hallmann Holger Heuer 《Journal of Phytopathology》2020,168(6):322-336
The present study documents the root-knot nematodes (RKN) fauna of the Poonch division in Azad Jammu and Kashmir infecting vegetables. An overall prevalence of 40% of RKN was recorded. Of the four districts investigated, maximum prevalence was recorded in district Poonch with 59%, followed by Sudhnuti with 58%. The lowest prevalence of RKN was found in districts Bagh (29%) and Haveli (33%). Out of 15 vegetables investigated, RKN was found on five crops. The highest prevalence of 37.8% was recorded on okra, followed by 31.3% on cucumber and 17.5% on tomato. RKN was less prevalent on eggplant (8.3%) and beans (7.7%). Three RKN species, that is Meloidogyne incognita, Meloidogyne javanica and Meloidogyne arenaria, were found infecting the hosts. M. javanica was found to be the most prevalent followed by M. incognita and M. arenaria. This trend was found in all the districts. Overall prevalence of M. javanica as sole population was 9% and that of M. incognita was 2%. Meloidogyne arenaria was not found in any of the fields as sole population. The prevalence of M. incognita with M. javanica or M. arenaria as mixed populations was 8% and 5%, respectively, and that of M. javanica with M. arenaria was 4%. Similarly, all the three species prevailed as mixed populations in 12% of the fields in the division. The severity of RKN infections, measured as galling index, was found to be variable within each infected field (GI 2–9). Identification of RKN species was based on the morphology of perineal patterns and confirmed by molecular SCAR and CO1 makers based identification. In conclusion, RKN were distributed in the Poonch division and M. javanica was predominant. Cucumber, okra, tomato and eggplant were severely attacked by these nematodes warranting the adoption of stringent control strategies for their management. 相似文献
63.
Muhammad Shahid Muhammad Tariq Javed Kashif Tanwir Muhammad Sohail Akram Syeda Khola Tazeen Muhammad Hamzah Saleem Sajid Masood Sadia Mujtaba Hassan Javed Chaudhary 《Physiology and Molecular Biology of Plants》2020,26(12):2417
Cadmium (Cd) is highly toxic metal for plant metabolic processes even in low concentration due to its longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of a Cd-tolerant phytobeneficial bacterial strain Bacillus sp. SDA-4, isolated, characterized and identified from Chakera wastewater reservoir, Faisalabad, Pakistan, together with spinach (as a test plant) under different Cd regimes. Spinach plants were grown with and without Bacillus sp. SDA-4 inoculation in pots filled with 0, 5 or 10 mg kg−1 CdCl2-spiked soil. Without Bacillus sp. SDA-4 inoculation, spinach plants exhibited reduction in biomass accumulation, antioxidative enzymes and nutrient retention. However, plants inoculated with Bacillus sp. SDA-4 revealed significantly augmented growth, biomass accumulation and efficiency of antioxidative machinery with concomitant reduction in proline and MDA contents under Cd stress. Furthermore, application of Bacillus sp. SDA-4 assisted the Cd-stressed plants to sustain optimal levels of essential nutrients (N, P, K, Ca and Mg). It was inferred that the characterized Cd-tolerant PGPR strain, Bacillus sp. SDA-4 has a potential to reduce Cd uptake and lipid peroxidation which in turn maintained the optimum balance of nutrients and augmented the growth of Cd-stressed spinach. Analysis of bioconcentration factor (BCF) and translocation factor (TF) revealed that Bacillus sp. SDA-4 inoculation with spinach sequestered Cd in rhizospheric zone. Research outcomes are important for understanding morpho-physio-biochemical attributes of spinach-Bacillus sp. SDA-4 synergy which might provide efficient strategies to decrease Cd retention in edible plants and/or bioremediation of Cd polluted soil colloids. 相似文献
64.
Bikram Pandey Janak R. Khatiwada Lin Zhang Kaiwen Pan Mohammed A. Dakhil Qinli Xiong Ram Kailash P. Yadav Mohan Siwakoti Akash Tariq Olusanya Abiodun Olatunji Meta Francis Justine Xiaogang Wu Xiaoming Sun Ziyan Liao Zebene Tadesse Negesse 《Ecology and evolution》2020,10(17):9474-9485
Studying the pattern of species richness is crucial in understanding the diversity and distribution of organisms in the earth. Climate and human influences are the major driving factors that directly influence the large‐scale distributions of plant species, including gymnosperms. Understanding how gymnosperms respond to climate, topography, and human‐induced changes is useful in predicting the impacts of global change. Here, we attempt to evaluate how climatic and human‐induced processes could affect the spatial richness patterns of gymnosperms in China. Initially, we divided a map of the country into grid cells of 50 × 50 km2 spatial resolution and plotted the geographical coordinate distribution occurrence of 236 native gymnosperm taxa. The gymnosperm taxa were separated into three response variables: (a) all species, (b) endemic species, and (c) nonendemic species, based on their distribution. The species richness patterns of these response variables to four predictor sets were also evaluated: (a) energy–water, (b) climatic seasonality, (c) habitat heterogeneity, and (d) human influences. We performed generalized linear models (GLMs) and variation partitioning analyses to determine the effect of predictors on spatial richness patterns. The results showed that the distribution pattern of species richness was highest in the southwestern mountainous area and Taiwan in China. We found a significant relationship between the predictor variable set and species richness pattern. Further, our findings provide evidence that climatic seasonality is the most important factor in explaining distinct fractions of variations in the species richness patterns of all studied response variables. Moreover, it was found that energy–water was the best predictor set to determine the richness pattern of all species and endemic species, while habitat heterogeneity has a better influence on nonendemic species. Therefore, we conclude that with the current climate fluctuations as a result of climate change and increasing human activities, gymnosperms might face a high risk of extinction. 相似文献
65.
66.
67.
Khan Muhammad Tahir Zeb Muhammad Tariq Ahsan Hina Ahmed Abrar Ali Arif Akhtar Khalid Malik Shaukat Iqbal Cui Zhilei Ali Sajid Khan Anwar Sheed Ahmad Manzoor Wei Dong-Qing Irfan Muhammad 《Archives of microbiology》2021,203(1):59-66
Archives of Microbiology - Severe acute respiratory syndrome virus 2 (SARS-CoV-2) belongs to the single-stranded positive-sense RNA family. The virus contains a large genome that encodes four... 相似文献
68.
Ali Meissam Saleem Uzma Anwar Fareeha Imran Muhammad Nadeem Humaira Ahmad Bashir Ali Tahir Atta-ur-rehman Ismail Tariq 《Neurochemical research》2021,46(4):905-920
Neurochemical Research - Alzheimer's disease (AD) is age-dependent neurological disorder with progressive loss of cognition and memory. This multifactorial disease is characterized by... 相似文献
69.
Siddiqui Maqsood A. Farshori Nida N. Al-Oqail Mai M. Pant Aditya B. Al-Khedhairy Abdulaziz A. 《Neurochemical research》2021,46(2):171-182
Neurochemical Research - The antioxidant, anti-inflammatory, and anticancer activities of Withania somnifera (WS) are known for a long time. This study was aimed to examine whether WS also... 相似文献
70.