全文获取类型
收费全文 | 2982篇 |
免费 | 144篇 |
国内免费 | 21篇 |
专业分类
电工技术 | 46篇 |
综合类 | 18篇 |
化学工业 | 888篇 |
金属工艺 | 59篇 |
机械仪表 | 58篇 |
建筑科学 | 91篇 |
矿业工程 | 9篇 |
能源动力 | 88篇 |
轻工业 | 388篇 |
水利工程 | 30篇 |
石油天然气 | 25篇 |
武器工业 | 2篇 |
无线电 | 255篇 |
一般工业技术 | 362篇 |
冶金工业 | 482篇 |
原子能技术 | 14篇 |
自动化技术 | 332篇 |
出版年
2024年 | 4篇 |
2023年 | 19篇 |
2022年 | 140篇 |
2021年 | 148篇 |
2020年 | 74篇 |
2019年 | 56篇 |
2018年 | 88篇 |
2017年 | 78篇 |
2016年 | 73篇 |
2015年 | 76篇 |
2014年 | 95篇 |
2013年 | 171篇 |
2012年 | 123篇 |
2011年 | 161篇 |
2010年 | 123篇 |
2009年 | 138篇 |
2008年 | 134篇 |
2007年 | 138篇 |
2006年 | 104篇 |
2005年 | 77篇 |
2004年 | 73篇 |
2003年 | 96篇 |
2002年 | 83篇 |
2001年 | 53篇 |
2000年 | 41篇 |
1999年 | 34篇 |
1998年 | 169篇 |
1997年 | 103篇 |
1996年 | 99篇 |
1995年 | 59篇 |
1994年 | 44篇 |
1993年 | 49篇 |
1992年 | 17篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 15篇 |
1986年 | 14篇 |
1985年 | 14篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 12篇 |
1976年 | 22篇 |
1971年 | 7篇 |
排序方式: 共有3147条查询结果,搜索用时 0 毫秒
71.
Silvio Borrelli Ida Matarazzo Eugenio Lembo Laura Peccarino Claudia Annoiato Maria Rosaria Scognamiglio Andrea Foderini Chiara Ruotolo Aldo Franculli Federica Capozzi Pavlo Yavorskiy Fatme Merheb Michele Provenzano Gaetano La Manna Luca De Nicola Roberto Minutolo Carlo Garofalo 《International journal of molecular sciences》2022,23(12)
Increasing potassium intake ameliorates blood pressure (BP) and cardiovascular (CV) prognoses in the general population; therefore the World Health Organization recommends a high-potassium diet (90–120 mEq/day). Hyperkalaemia is a rare condition in healthy individuals due to the ability of the kidneys to effectively excrete dietary potassium load in urine, while an increase in serum K+ is prevalent in patients with chronic kidney disease (CKD). Hyperkalaemia prevalence increases in more advanced CKD stages, and is associated with a poor prognosis. This scenario generates controversy on the correct nutritional approach to hyperkalaemia in CKD patients, considering the unproven link between potassium intake and serum K+ levels. Another concern is that drug-induced hyperkalaemia leads to the down-titration or withdrawal of renin-angiotensin system inhibitors (RASI) and mineralocorticoids receptors antagonists (MRA) in patients with CKD, depriving these patients of central therapeutic interventions aimed at delaying CKD progression and decreasing CV mortality. The new K+-binder drugs (Patiromer and Sodium-Zirconium Cyclosilicate) have proven to be adequate and safe therapeutic options to control serum K+ in CKD patients, enabling RASI and MRA therapy, and possibly, a more liberal intake of fruit and vegetables. 相似文献
72.
73.
Michela Pecoraro Stefania Marzocco Silvia Franceschelli Ada Popolo 《International journal of molecular sciences》2022,23(12)
Human epidermal growth factor receptor-2 (HER2) is overexpressed in up to 30% of breast cancer cases, causing a more aggressive tumour growth and poor prognosis. Trastuzumab, the humanized antibody targeted to HER2, increased the life expectancy of patients, but severe cardiotoxicity emerged as a long-term adverse effect. Clinical evidence highlights that Trastuzumab-induced cardiotoxicity drastically increases in association with Doxorubicin; however, the exact mechanisms involved remain incompletely understood. In order to analyse the molecular mechanisms involved and the possible adaptative responses to Trastuzumab and Doxorubicin treatment, in this study, H9c2 cardiomyoblasts were used. Results showed that Trastuzumab and Doxorubicin sequential administration in cardiomyoblast increased cytosolic and mitochondrial ROS production, intracellular calcium dysregulation, mitochondrial membrane depolarization, and the consequent apoptosis, induced by both Trastuzumab and Doxorubicin alone. Furthermore, in these conditions, we observed increased levels of Connexin43 phosphorylated on Ser368 (pCx43). Since phosphorylation on Ser368 decreases gap junction intracellular communication, thus reducing the spread of death signals to adjacent cells, we hypothesized that the increase in pCx43 could be an adaptative response implemented by cells to defend neighbouring cells by Trastuzumab and Doxorubicin sequential administration. However, the other side of the coin is the resulting conduction abnormalities. 相似文献
74.
Christos Masaoutis Kostas Palamaris Stefania Kokkali Georgia Levidou Stamatios Theocharis 《International journal of molecular sciences》2022,23(14)
Thymic Epithelial Tumors (TETs) represent a rare tumor family, originating from the epithelial component of the thymus gland. Clinicopathologically, they are segregated into six major subtypes, associated with distinct histological features and clinical outcomes. Their emergence and evolution are accompanied by the generation of a complex tumor microenvironment (TME), dominated by phenotypically and functionally divergent immune cellular subsets, in different maturation states and in analogies that vary significantly among different subtypes. These heterogenous leukocyte populations exert either immune-permissive and tumor-suppressive functions or vice versa, and the dynamic equilibrium established among them either dictates the tumor immune milieu towards an immune-tolerance state or enables the development of a productive spontaneous tumoricidal response. The immunologically “hot” microenvironment, defining a significant proportion of TETs, makes them a promising candidate for the implementation of immune checkpoint inhibitors (ICIs). A number of phase I and II clinical trials have already demonstrated significant, type-specific clinical efficacy of PD-L1 inhibitors, even though substantial limitations in their utilization derive from their immune-mediated adverse effects. Moreover, the completed clinical studies involved relatively restricted patient samples and an expansion in the enrolled cohorts is required, so that more trustworthy conclusions regarding the benefit from ICIs in TETs can be extracted. 相似文献
75.
Agnese Filippello Stefania Di Mauro Alessandra Scamporrino Sebastiano Alfio Torrisi Gian Marco Leggio Antonino Di Pino Roberto Scicali Maurizio Di Marco Roberta Malaguarnera Francesco Purrello Salvatore Piro 《International journal of molecular sciences》2022,23(14)
Intestinal cell dysfunctions involved in obesity and associated diabetes could be correlated with impaired intestinal cell development. To date, the molecular mechanisms underlying these dysfunctions have been poorly investigated because of the lack of a good model for studying obesity. The main aim of this study was to investigate the effects of lipotoxicity on intestinal cell differentiation in small intestinal organoid platforms, which are used to analyze the regulation of cell differentiation. Mouse intestinal organoids were grown in the presence/absence of high palmitate concentrations (0.5 mM) for 48 h to simulate lipotoxicity. Palmitate treatment altered the expression of markers involved in the differentiation of enterocytes and goblet cells in the early (Hes1) and late (Muc2) phases of their development, respectively, and it modified enterocytes and goblet cell numbers. Furthermore, the expression of enteroendocrine cell progenitors (Ngn3) and I cells (CCK) markers was also impaired, as well as CCK-positive cell numbers and CCK secretion. Our data indicate, for the first time, that lipotoxicity simultaneously influences the differentiation of specific intestinal cell types in the gut: enterocytes, goblet cells and CCK cells. Through this study, we identified novel targets associated with molecular mechanisms affected by lipotoxicity that could be important for obesity and diabetes therapy. 相似文献
76.
Argyris C. Hadjimichael Alexandros Pergaris Angelos Kaspiris Athanasios F. Foukas Stefania Kokkali Gerasimos Tsourouflis Stamatios Theocharis 《International journal of molecular sciences》2022,23(9)
Musculoskeletal sarcomas represent rare heterogenous malignancies of mesenchymal origin that can be divided in two distinct subtypes, bone and soft tissue sarcomas. Current treatment options combine the surgical excision of local tumors and multidrug chemotherapy to prevent metastatic widespread disease. Due to the grim prognosis that usually accompanies such tumors, researchers have attempted to shed light on the molecular pathways implicated in their pathogenesis in order to develop novel, innovative, personalized therapeutic strategies. Erythropoietin-producing human hepatocellular receptors (EPHs) are tyrosine-kinase transmembrane receptors that, along with their ligands, ephrins, participate in both tumor-suppressive or tumor-promoting signaling pathways in bone and soft tissue sarcomas. The EPH/ephrin axis orchestrates cancerous processes such as cell–cell and cell–substrate adhesion and enhances the remodeling of the intracellular cytoskeleton to stimulate the motility and invasiveness of sarcoma cells. The purpose of our study was to review published PubMed literature to extract results from in vitro, in vivo and clinical trials indicative of the role of EPH/ephrin signaling in bone and soft tissue sarcomas. Based on these reports, significant interactions between the EPH/ephrin signaling pathway and a plethora of normal and abnormal cascades contribute to molecular mechanisms enhancing malignancy during sarcoma progression. In addition, EPHs and ephrins are prospective candidates for diagnostic, monitoring and therapeutic purposes in the clinical setting against bone and soft tissue sarcomas. 相似文献
77.
78.
M. De La Sen 《控制论与系统》2013,44(8):835-840
The asymptotic stability of time-delayed systems subject to multiple bounded point delays has received important attention in past years (see, for instance, Bourles, H. 1994. International Journal of Control , 59(2): 529-541; De la Sen, M. 2000. Electronics Letters , 36(4): 373-374; Xu, B. 2000. Journal of Mathematical Analysis and Applications , 282: 484-494). It is basically proved that the local f -stability in the delays (i.e., all the eigenvalues have prefixed strictly negative real parts located in Re s h - f < 0) may be tested for a set of admissible delays including possible zero delays either through a set of Lyapunov matrix inequalities or, equivalently, by checking that an identical number of matrices related to the delayed dynamics are all stability matrices. The result may be easily extended to check the k -asymptotic stability, independent of the delays; that is, for all the delays having any values, the eigenvalues are stable and located in Re s h k M 0 - (De la Sen, 2000; Xu, 2000). This number is 2 r for a set of r distinct point delays and includes all possible cases of alternate signs for summations for all the matrices of delayed dynamics (Xu, 2000). 相似文献
79.
流动人口是一支较为活跃的社会群体,随着社会主义市场经济的迅速发展,流动人口的数量逐年增多,人口的频繁流动,给社会治安、计划生育、城市管理带来许多新情况、新问题、抓好流动人口综合治理与服务工作逐步成为一项重要工作内容. 相似文献
80.
D. Schmoranzer M. La Mantia G. Sheshin I. Gritsenko A. Zadorozhko M. Rotter L. Skrbek 《Journal of Low Temperature Physics》2011,163(5-6):317-344
We report on experimental investigations of acoustic emission by quartz tuning forks resonating at frequencies 32 kHz, 38 kHz, 77 kHz and 100 kHz immersed in cold gaseous 4He and its normal and superfluid liquid phases. Frequency dependence of the observed low-drive-linewidth at 350 mK together with the temperature and pressure dependences (1.3 K < T < 4.2 K, 0 < p < 25 bar) of the observed damping of the high frequency (77 and 100 kHz) resonators measured in normal liquid 4He and its superfluid phase provide strong and direct evidence of the importance of sound emission by these tuning forks. Three analytical models of acoustic emission by vibrating tuning forks are developed and compared with the experimental results. We also discuss the importance of sound emission for experiments with the commonly used 32 kHz tuning forks as well as other oscillating structures??spheres, wires, grids and various micromachined sensors. We compare the relative importance of dissipative losses due to laminar viscous/ballistic drag and acoustic emission in liquid and superfluid 4He. 相似文献