全文获取类型
收费全文 | 4610篇 |
免费 | 779篇 |
国内免费 | 296篇 |
专业分类
化学 | 1078篇 |
晶体学 | 17篇 |
力学 | 491篇 |
综合类 | 72篇 |
数学 | 829篇 |
物理学 | 1277篇 |
无线电 | 1921篇 |
出版年
2024年 | 6篇 |
2023年 | 32篇 |
2022年 | 105篇 |
2021年 | 146篇 |
2020年 | 136篇 |
2019年 | 123篇 |
2018年 | 136篇 |
2017年 | 213篇 |
2016年 | 227篇 |
2015年 | 282篇 |
2014年 | 277篇 |
2013年 | 310篇 |
2012年 | 283篇 |
2011年 | 295篇 |
2010年 | 203篇 |
2009年 | 202篇 |
2008年 | 264篇 |
2007年 | 260篇 |
2006年 | 250篇 |
2005年 | 209篇 |
2004年 | 179篇 |
2003年 | 212篇 |
2002年 | 220篇 |
2001年 | 193篇 |
2000年 | 157篇 |
1999年 | 169篇 |
1998年 | 105篇 |
1997年 | 108篇 |
1996年 | 74篇 |
1995年 | 56篇 |
1994年 | 48篇 |
1993年 | 29篇 |
1992年 | 36篇 |
1991年 | 25篇 |
1990年 | 19篇 |
1989年 | 16篇 |
1988年 | 13篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有5685条查询结果,搜索用时 867 毫秒
1.
Yujie Gao Zhiye Qiu Lei Liu Mengmeng Li Bingjie Xu Dan Yu Dongming Qi Jindan Wu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2191-2212
Refractory wounds have always been an important issue to healthcare systems, whose healing process is always delayed by multiple factors, including bacterial infections, chronic inflammation, and excessive exudates, etc. Employing multifunctional wound dressings is recognized as an effective strategy to deal with refractory wounds, which has yielded promising outcomes in recent years. Among these advanced wound dressings, fibrous dressings have gained growing attention due to their unique merits. Such wound dressings have demonstrated great potential in delivering theranostic agents, such as antibacterial agents, anti-inflammatory drugs, growth factors, and diagnostic probes, etc., for the purposes of accelerating wound healing. This paper reviews the development of multifunctional fibrous dressings and their applications in treating refractory wounds. The construction approaches of novel fibrous dressing with capabilities of antibacterial, anti-inflammation, exudate management and diagnosis were also introduced. Furthermore, the existing problems and challenges are also discussed briefly. 相似文献
2.
为了提升高校实验数据处理水平,高校实验室的相关建设工作已经步入正轨,但层出不穷的信息安全问题也向高校实验室计算机网络维护工作提出了新的挑战。文章从现阶段高校实验室计算机网络的相关建设工作出发,简要论述引发网络故障的具体原因,并对其诊断技术进行探讨。 相似文献
3.
One of the major challenges in wireless body area networks (WBANs) is sensor fault detection. This paper reports a method for the precise identification of faulty sensors, which should help users identify true medical conditions and reduce the rate of false alarms, thereby improving the quality of services offered by WBANs. The proposed sensor fault detection (SFD) algorithm is based on Pearson correlation coefficients and simple statistical methods. The proposed method identifies strongly correlated parameters using Pearson correlation coefficients, and the proposed SFD algorithm detects faulty sensors. We validated the proposed SFD algorithm using two datasets from the Multiparameter Intelligent Monitoring in Intensive Care database and compared the results to those of existing methods. The time complexity of the proposed algorithm was also compared to that of existing methods. The proposed algorithm achieved high detection rates and low false alarm rates with accuracies of 97.23% and 93.99% for Dataset 1 and Dataset 2, respectively. 相似文献
4.
Junyu Chen Yuze Li Yuming Jiang Liucheng Mao Mi Lai Lixia Jiang Huihui Liu Zongxiu Nie 《Advanced functional materials》2021,31(52):2106743
Cancer remains an intractable medical problem. Rapid diagnosis and identification of cancer are critical to differentiate it from nonmalignant diseases. High-throughput biofluid metabolic analysis has potential for cancer diagnosis. Nevertheless, the present metabolite analysis method does not meet the demand for high-throughput screening of diseases. Herein, a high-throughput, cost-effective, and noninvasive urine metabolic profiling method based on TiO2/MXene-assisted laser desorption/ionization mass spectrometry (LDI-MS) is presented for the efficient screening of bladder cancer (BC) and nonmalignant urinary disease. Combined with machine learning, TiO2/MXene-assisted LDI-MS enables high diagnostic accuracy (96.8%) for the classification of patient groups (including 47 BC and 46 ureteral calculus (UC) patients) from healthy controls (113 cases). In addition, BC patients can also be identified from noncancerous UC individuals with an accuracy of 88.3% in the independent test cohort. Furthermore, metabolite variations between BC and UC individuals are investigated based on relative quantification, and related pathways are also discussed. These results suggest that this method, based on urine metabolic patterns, provides a potential tool for rapidly distinguishing urinary diseases and it may pave the way for precision medicine. 相似文献
5.
多传感器目标的模糊识别 总被引:5,自引:0,他引:5
根据模糊理论,采用信息融合技术和模糊识别技术,讨论了在多类传感器网内进行多目标模糊识别的一般原理和方法。 相似文献
6.
本文定义了二阶微分方程的弱 Carathéodory解 ,在不涉及紧型条件的情形下 ,直接用迭代法证明了 Banach空间二阶非线性常微分方程两点边值问题存在唯一解 ,并给出逼近解迭代序列的误差估计 ,对周期边值问题得到类似的结果 相似文献
7.
8.
介绍了天线近场测量的基本原理和HD-1型平面近场测试系统,并对近场测量在实际天线测试中的应用情况、发展方向和应用前景等作了简单的描述。 相似文献
9.
10.
蓝牙技术是一种短距离无线通信技术,具有低成本、低功耗、灵活、快速、抗干扰能力强等特点,目的是取代终端的连接电缆.为提高部队的作战效能,采用蓝牙技术和计算机测量与控制技术,研制了机载火控故障诊断系统;该系统在实际应用中取得了良好效果,并具有诊断结果准确、自动化程度高、工作稳定可靠、操作简便、易于转移和维护等优点,为技术人员进行机载火控系统的性能检测与故障诊断提供了便利. 相似文献