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101.
The vomeronasal organ (VNO) that preferentially detects species‐specific substances is diverse among animal species, and its morphological properties seem to reflect the ecological features of animals. This histological study of two female reticulated giraffes (Giraffa camelopardalis reticulata) found that the VNO is developed in giraffes. The lateral and medial regions of the vomeronasal lumen were covered with sensory and nonsensory epithelia, respectively. The vomeronasal glands were positive for periodic acid‐Schiff and alcian blue (pH 2.5) stains. The VNO comprises several large veins like others in the order Cetartiodactyla, suggesting that these veins function in a pumping mechanism in this order. In addition, numerous thin‐walled vessels located immediately beneath the epithelia covering the lumen entirely surrounded the vomeronasal lumen. This sponge‐like structure might function as a specific secondary pump in giraffes.  相似文献   
102.
103.
Intracellular free zinc ([Zn2+]i) is mobilized in neuronal and non-neuronal cells under physiological and/or pathophysiological conditions; therefore, [Zn2+]i is a component of cellular signal transduction in biological systems. Although several transporters and ion channels that carry Zn2+ have been identified, proteins that are involved in Zn2+ supply into cells and their expression are poorly understood, particularly under inflammatory conditions. Here, we show that the expression of Zn2+ transporters ZIP8 and ZIP14 is increased via the activation of hypoxia-induced factor 1α (HIF-1α) in inflammation, leading to [Zn2+]i accumulation, which intrinsically activates transient receptor potential ankyrin 1 (TRPA1) channel and elevates basal [Zn2+]i. In human fibroblast-like synoviocytes (FLSs), treatment with inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and interleukin-1α (IL-1α), evoked TRPA1-dependent intrinsic Ca2+ oscillations. Assays with fluorescent Zn2+ indicators revealed that the basal [Zn2+]i concentration was significantly higher in TRPA1-expressing HEK cells and inflammatory FLSs. Moreover, TRPA1 activation induced an elevation of [Zn2+]i level in the presence of 1 μM Zn2+ in inflammatory FLSs. Among the 17 out of 24 known Zn2+ transporters, FLSs that were treated with TNF-α and IL-1α exhibited a higher expression of ZIP8 and ZIP14. Their expression levels were augmented by transfection with an active component of nuclear factor-κB P65 and HIF-1α expression vectors, and they could be abolished by pretreatment with the HIF-1α inhibitor echinomycin (Echi). The functional expression of ZIP8 and ZIP14 in HEK cells significantly increased the basal [Zn2+]i level. Taken together, Zn2+ carrier proteins, TRPA1, ZIP8, and ZIP14, induced under HIF-1α mediated inflammation can synergistically change [Zn2+]i in inflammatory FLSs.  相似文献   
104.
针对脂润滑汽车轮毂轴承单元一旦进水可能导致轴承产生异常磨损、锈蚀或提前失效的问题,经过分析与试验,提出通过改变润滑脂添加剂来维持较厚的油膜厚度,并形成坚硬的氧化膜,以避免滚动体与滚道间金属的直接接触、防止滚道面锈蚀及氢元素渗入,达到延长轴承寿命的效果。  相似文献   
105.
Novel, anionic surface-active monomers, sodium di(10-undecenyl)sulphosuccinate (DUSS) and sodium n-undecyl 10-undecenylsulphosuccinate (MUSS) were prepared. The monomers were soluble in both water and apolar organic solvents on heating. DUSS and MUSS in water exhibited Kraft points at about 39°C and 48°C, respectively. The critical micelle concentrations for aqueous solutions of DUSS and MUSS at 50°C were determined to be 2.4 × 10−5 and 1.2 × 10−5 mol l−1, respectively. Polymerization of the monomers in darkness and under u.v. irradiation at 50°C were studied using three different solvents, namely water, n-hexane and dioxane, giving aqueous micelles (or vesicles), reversed micelles and isotropic solution, respectively. Only traces of polymers were formed for the polymerizations in darkness, while the polymerizations under u.v. irradiation gave polymers, except for the polymerization of MUSS in dioxane. The solvents used for the polymerization were observed to exert an effect on the solubility of the polymers of DUSS and only the polymer obtained from the polymerization in water was soluble in solvents such as water and N,N-dimethylformamide. Thus, the monomer aggregation, especially for the aqueous system, was found to affect the structure of the resulting polymers.  相似文献   
106.
To investigate the combustion characteristics of palm methyl ester (PME) as an alternative fuel for gas turbines, combustion experiments at atmospheric pressure using high-temperature air (673 K) were performed. Chemical equilibrium calculations and investigations of fuel atomizing characteristics using a laser diffraction spray analyzer (LDSA) were also conducted. The results show that combustion characteristics of PME are similar to those of diesel fuel. Furthermore, it is indicated that NOx emissions can be reduced by using PME instead of diesel fuel for gas turbines.  相似文献   
107.
108.
Ozonated water was used for inactivation of Fusarium oxysporum conidia in sterilized water and inorganic soil-less nutrient medium at different treatment temperatures. F. oxysporum conidia were effectively inactivated in both water and nutrient media and the inactivation curves were almost same at 15°C, 25°C and 30°C. Approximate 4-log orders of F. oxysporum conidia were killed when the ozonated water with initial ozone concentration of 1.0 ppm had been used. The surviving curves, however, were characterized by a tailing-off effect, and the effect was related to the residual ozone concentration in the ozone treated suspensions.  相似文献   
109.
We investigated an easy way to prepare industrially a conductive paint made with polyaniline (PANI)/dodecylbenzenesulfonic acid (DBSA) dispersion and poly(methyl methacrylate) (PMMA) in organic media. First, water‐dispersible PANI doped with DBSA was chemically synthesized with aniline sulfate using ammonium persulfate in water, and the resulting PANI/DBSA was readily extracted from the reaction medium with a mixture of toluene and methyl ethyl ketone (MEK) (toluene:MEK = 1:1 (v/v)), which is useful for industrial applications. The obtained PANI/DBSA organic dispersion was mixed with PMMA organic solution to give the corresponding PANI/DBSA conductive paint containing PMMA. A film prepared with the resulting PANI/DBSA conductive paint was found to possess relatively good conductivity and low surface resistivity for a conductive paint utilized for an electrostatic discharge even at low PANI/DBSA content in the PANI/DBSA–PMMA composite film (the conductivity and the surface resistivity were 9.48 × 10?4 S cm?1 and 3.14 × 106 Ω cm?2, respectively, when the feed ratio of PANI/DBSA:PMMA was 1:39 (w/w)). Furthermore, it was found that the conductivity of the film composed of PANI/DBSA–PMMA composite can be readily and widely controlled by the PANI/DBSA content of the composite or by the amount of DBSA used during the PANI/DBSA synthesis. The highest conductivity of PANI/DBSA–PMMA composite film (7.84 × 10?1 S cm?1) was obtained when the feed ratio of PANI/DBSA:PMMA was 1:4 (w/w). Copyright © 2007 Society of Chemical Industry  相似文献   
110.
利用神经学统计图像分析软件NEUROSTAT分析健康志愿者和逼尿肌过度活动患者的SPECT图像,探讨膀胱贮尿的大脑控制区及其控制机理。15例健康志愿者(Ⅰ组)和25例下尿道尿储存功能障碍患者接受了SPECT扫描。25例中19例患者为逼尿肌过度活动症(Ⅱ组),6例患者逼尿肌功能正常(Ⅲ组)。所有受检者均在排空膀胱的静息状态和控尿状态接受SPECT扫描。控尿状态的图像用第二次扫描后的图像减去第一次的图像获得。用NEUROSTAT对比分析3组受检者在静息状态下的脑血流(rCBF)情况及各组受检者控尿状态与静息状态rCBF的差异,进行多重对照校正。静息状态下Ⅱ组与Ⅲ组相比脑血流差异无统计学意义(P〉0.05)。Ⅰ组和Ⅲ组控尿状态与静息状态相比,两侧额下回和右侧颞中回rCBF明显增高,其中右侧额下回在Z-值和病灶范围方面均最为明显(多重对照校正P〈0.05,工组对应Z-值〉4.476,Ⅲ组对应二值〉4.414)。Ⅱ组控尿状态与静息状态相比,仅左侧颞中回和额中回rCBF明显增高(多重对照校正P〈0.05,Ⅱ组对应Z-值〉4.35)。3组结果中,没有任何病灶脑血流降低达统计学标准。本研究结果表明两侧额下回和右侧颞中回与膀胱贮尿功能的大脑控制有关,特别是右侧额下回在膀胱贮尿的大脑控制中起重要作用,抑制控尿期逼尿肌的收缩。  相似文献   
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