全文获取类型
收费全文 | 123篇 |
免费 | 4篇 |
国内免费 | 2篇 |
专业分类
化学工业 | 19篇 |
金属工艺 | 1篇 |
机械仪表 | 6篇 |
建筑科学 | 1篇 |
能源动力 | 10篇 |
轻工业 | 8篇 |
无线电 | 19篇 |
一般工业技术 | 33篇 |
原子能技术 | 5篇 |
自动化技术 | 27篇 |
出版年
2024年 | 5篇 |
2023年 | 6篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 3篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有129条查询结果,搜索用时 15 毫秒
91.
A new approach to the modelling of aircraft wings, based on the combination of hybrid quadric (parabolic and circular) cylinders, has been presented for electromagnetic applications. Closed-form expressions have been obtained for ray parameters required in the high-frequency mutual coupling computation of antenna pairs located arbitrarily on an aircraft wing 相似文献
92.
Aamer Saeed Syeda Abida Ejaz Aqsa Khalid Pervaiz Ali Channar Mubashir Aziz Qamar Abbas Tanveer A. Wani Nawaf A. Alsaif Mohammed M. Alanazi Abdullah M. Al-Hossaini Nojood Altwaijry Seema Zargar Muawya Elhadi Tuncer Hkelek 《International journal of molecular sciences》2022,23(21)
The acetophenone-based 3,4-dihydropyrimidine-2(1H)-thione was synthesized by the reaction of 4-methylpent-3-en-2-one (1), 4-acetyl aniline (2) and potassium thiocyanate. The spectroscopic analysis including: FTIR, 1H-NMR, and single crystal analysis proved the structure of synthesized compound (4), with the six-membered nonplanar ring in envelope conformation. In crystal structure, the intermolecular N–H ⋯ S and C–H ⋯ O hydrogen bonds link the molecule in a two-dimensional manner which is parallel to (010) the plane enclosing R22 (8) and R22 (10) ring motifs. After that, the Hirshfeld surfaces and their related two-dimensional fingerprint plots were used for thorough investigation of intermolecular interactions. According to Hirshfeld surface analysis, the most substantial contributions to the crystal packing are from H ⋯ H (59.5%), H ⋯ S/S ⋯ H (16.1%), and H ⋯ C/C ⋯ H (13.1%) interactions. The electronic properties and stability of the compound were investigated through density functional theory (DFT) studies using B3LYP functional and 6-31G* as a basis set. The compound 4 displayed the high chemical reactivity with chemical softness of 2.48. In comparison to the already reported known tyrosinase inhibitor, the newly synthesized derivatives exhibited almost seven-fold better inhibition of tyrosinase (IC50 = 1.97 μM), which was further supported by molecular docking studies. The compound 4 inside the active pocket of ribonucleotide reductase (RNR) exhibited a binding energy of −19.68 kJ/mol, and with mammalian deoxy ribonucleic acid (DNA) it acts as an effective DNA groove binder with a binding energy of −21.32 kJ/mol. The results suggested further exploration of this compound at molecular level to synthesize more potential leads for the treatment of cancer. 相似文献
93.
Kousain Kousar Tahir Ahmad Maisa S. Abduh Balquees Kanwal Syeda Saba Shah Faiza Naseer Sadia Anjum 《International journal of molecular sciences》2022,23(22)
miRNAs are 20–22 long nucleotide non-coding ribonucleic acid molecules critical to the modulation of molecular pathways. Immune evasion and the establishment of a suitable tumor microenvironment are two major contributors that support tumor invasion and metastasis. Tumorigenic miRNAs support these two hallmarks by desensitizing important tumor-sensitive regulatory cells such as dendritic cells, M1 macrophages, and T helper cells towards tumors while supporting infiltration and proliferation of immune cells like Treg cells, tumor-associated M2 macrophages that promote self-tolerance and chronic inflammation. miRNAs have a significant role in enhancing the efficacies of immunotherapy treatments like checkpoint blockade therapy, adoptive T cell therapy, and oncolytic virotherapy in cancer. A clear understanding of the role of miRNA can help scientists to formulate better-targeted treatment modalities. miRNA therapeutics have emerged as diverse class of nucleic acid-based molecules that can suppress oncogenic miRNAs and promote the expression of tumor suppressor miRNAs. 相似文献
94.
Md. Ariful Islam Ho Jin Choi Raju Dash Syeda Ridita Sharif Diyah Fatimah Oktaviani Dae-Hyun Seog Il Soo Moon 《International journal of molecular sciences》2021,22(1)
Recently, we showed that N-acetylglucosamine kinase (NAGK), an enzyme of amino sugar metabolism, interacts with dynein light chain roadblock type 1 (DYNLRB1) and promotes the functions of dynein motor. Here, we report that NAGK interacts with nuclear distribution protein C (NudC) and lissencephaly 1 (Lis1) in the dynein complex. Yeast two-hybrid assays, pull-down assays, immunocytochemistry, and proximity ligation assays revealed NAGK–NudC–Lis1–dynein complexes around nuclei, at the leading poles of migrating HEK293T cells, and at the tips of migratory processes of cultured rat neuroblast cells. The exogenous expression of red fluorescent protein (RFP)-tagged NAGK accelerated HEK293T cell migration during in vitro wound-healing assays and of neurons during in vitro neurosphere migration and in utero electroporation assays, whereas NAGK knockdown by short hairpin RNA (shRNA) delayed migration. Finally, a small NAGK peptide derived from the NudC interacting domain in in silico molecular docking analysis retarded the migrations of HEK293T and SH-SY5Y cells. These data indicate a functional interaction between NAGK and dynein–NudC–Lis1 complex at the nuclear envelope is required for the regulation of cell migration. 相似文献
95.
Aneela Anwar Samina Akbar Mohsin Kazmi Ayesha Sadiqa Syeda Rubina Gilani 《Ceramics International》2018,44(17):21170-21175
In the present investigation, a novel strategy of continuous microwave assisted flow synthesis (CMFS) has been adopted in comparison to traditional synthesis procedures (sol-gel and chemical precipitation method) for the quick production of TiO2 nanoparticles with very fine particle properties. The X-ray powder diffraction analysis (XRPD) and transmission electron microscopy (TEM) were two techniques used for analysing the properties related to structure and particle morphology of the resultant samples. It was observed that the particles formed by using continuous flow route were less agglomerated, and particle size (~ 6?nm) was smaller in comparison with others obtained using sol-gel (~ 9?nm) and chemical precipitation method (~ 15?nm). X-ray diffraction impressions established the generation of Anatase phase with preferential [101] dimension. Zeta potential computations were taken to inspect the colloidal stability of nanoparticles. Antimicrobial nature of TiO2 nano-samples was analyzed by using various bacterial and fungal strains. The nanostructured TiO2 particles confirmed outstanding uniformity with respect to chemical and structure. This new ceramic substance with strong antimicrobial activity promised magnificent potential in bone tissue engineering. 相似文献
96.
Syeda Tasneem Fathima N. B. Naduvinamani B. N. Hanumagowda J. Santhosh Kumar 《摩擦学汇刊》2013,56(4):660-667
We make an effort to analyze the behavior of squeeze film characteristics of different finite plates with couple stress fluid in the presence of a transverse magnetic field. On the basis of the Stokes couple stress fluid model and hydromagnetic flow model, a modified Reynold's equation is derived, which is solved by using appropriate boundary conditions to obtain squeeze film pressure, load-carrying capacity, and squeeze film time. The graphical representation of the results suggests that the different bearing systems register an enhanced performance with couple stresses compared to that of a bearing system working with a conventional lubricant in the presence of a transverse magnetic field. It is observed that the effect of applied magnetic field on the squeeze film lubrication between different finite plates with conducting couple stress fluids is to increase the load-carrying capacity significantly and to delay the time of approach compared to the corresponding nonconducting Newtonian case. It is seen that for all of the finite plates of different shapes, the circular shape gives the maximum load and time. 相似文献
97.
Syeda Humaira Tasnim Roydon Andrew Fraser 《International Communications in Heat and Mass Transfer》2010
The hydro- and thermodynamic processes near and within two-dimensional stack plates are simulated by numerical solution of the unsteady compressible Navier–Stokes, continuity, energy equations, and the equation of state (for air as the working fluid). The stack is assumed to consist of flat plates of equal thickness. The second order mean velocity field is computed in the neighborhood of the stack plates. In the stack plate extremities the vortical mean flow is observed which is due to the abrupt change of a slip condition to a no-slip velocity boundary condition. The temperature of the stack is governed by the energy equation; therefore the entire problem is treated as a conjugate heat transfer problem. The temperature fields in the neighborhood of the solid stack plate are also observed. From the location of the heat exchangers in Fig. 1(a), it is obvious that knowledge of the flow and thermal fields at the edges of the stack plates is the key for the development of a systematic design methodology for heat exchangers in thermoacoustic devices. 相似文献
98.
Multimedia Tools and Applications - The meanings of passing information from one side to other side by a conventional way is been changed because of internet and communication technology. The... 相似文献
99.
Syeda M. Bakht Manuel Gomez-Florit Tara Lamers Rui L. Reis Rui M. A. Domingues Manuela E. Gomes 《Advanced functional materials》2021,31(46):2104245
The creation of microphysiological systems like tissue and organ-on-chip for in vitro modeling of human physiology and diseases is gathering increasing interest. However, the platforms used to build these systems have limitations concerning implementation, automation, and cost-effectiveness. Moreover, their typical plastic-based housing materials are poor recreations of native tissue extracellular matrix (ECM) and barriers. Here, the controlled self-assembly of plant-derived cellulose nanocrystals (CNC) is combined with the concept of 3D bioprinting in suspension baths for the direct biofabrication of microphysiological systems embedded within an ECM mimetic fibrillar support material. The developed support CNC fluid gel allows exceptionally high-resolution bioprinting of 3D constructs with arbitrary geometries and low restrictions of bioink choice. The further induction of CNC self-assembly with biocompatible calcium ions results in a transparent biomimetic nanoscaled fibrillar matrix that allows hosting different compartmentalized cell types and perfusable channels, has tailored permeability for biomacromolecules diffusion and cellular crosstalk, and holds structural stability to support long-term in vitro cell maturation. In summary, this xeno-free nanoscale CNC fibrillar matrix allows the biofabrication of hierarchical living constructs, opening new opportunities not only for developing physiologically relevant 3D in vitro models but also for a wide range of applications in regenerative medicine. 相似文献
100.
Syeda Shegufta Ameer Mohammad Bakhtiar Hossain Ralph Knll 《International journal of molecular sciences》2020,21(23)
Epigenetics refers to changes in phenotypes without changes in genotypes. These changes take place in a number of ways, including via genomic DNA methylation, DNA interacting proteins, and microRNAs. The epigenome is the second dimension of the genome and it contains key information that is specific to every type of cell. Epigenetics is essential for many fundamental processes in biology, but its importance in the development and progression of heart failure, which is one of the major causes of morbidity and mortality worldwide, remains unclear. Our understanding of the underlying molecular mechanisms is incomplete. While epigenetics is one of the most innovative research areas in modern biology and medicine, compounds that directly target the epigenome, such as epidrugs, have not been well translated into therapies. This paper focuses on epigenetics in terms of genomic DNA methylation, such as 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) modifications. These appear to be more dynamic than previously anticipated and may underlie a wide variety of conditions, including heart failure. We also outline possible new strategies for the development of novel therapies. 相似文献