全文获取类型
收费全文 | 2012篇 |
免费 | 21篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 2034篇 |
出版年
2023年 | 6篇 |
2022年 | 29篇 |
2021年 | 40篇 |
2020年 | 14篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 25篇 |
2015年 | 18篇 |
2014年 | 41篇 |
2013年 | 63篇 |
2012年 | 66篇 |
2011年 | 99篇 |
2010年 | 67篇 |
2009年 | 86篇 |
2008年 | 91篇 |
2007年 | 95篇 |
2006年 | 73篇 |
2005年 | 60篇 |
2004年 | 48篇 |
2003年 | 63篇 |
2002年 | 41篇 |
2001年 | 40篇 |
2000年 | 53篇 |
1999年 | 48篇 |
1998年 | 186篇 |
1997年 | 113篇 |
1996年 | 73篇 |
1995年 | 60篇 |
1994年 | 46篇 |
1993年 | 47篇 |
1992年 | 28篇 |
1991年 | 15篇 |
1990年 | 17篇 |
1989年 | 21篇 |
1988年 | 17篇 |
1987年 | 10篇 |
1986年 | 21篇 |
1985年 | 24篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 21篇 |
1981年 | 17篇 |
1980年 | 17篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1976年 | 20篇 |
1975年 | 7篇 |
1974年 | 7篇 |
排序方式: 共有2034条查询结果,搜索用时 15 毫秒
51.
Gab-Soo Do Yasuyuki Sagara Mizuho Tabata Ken-ichi Kudoh Toshiro Higuchi 《International Journal of Refrigeration》2004,27(2):184-190
A novel technique has been developed for measuring the three-dimensional (3-D) structure and distribution of ice crystals formed in frozen beef by using a micro-slicer image processing system (MSIPS). The system has functions to reconstruct the 3-D image based on the image data of exposed cross-sections obtained by multi-slicing of a frozen sample with the minimum thickness of 1 μm and to display the internal structure as well as an arbitrary cross-section of the sample choosing observation angles. The size and distribution of ice crystals can be determined from the 2-D quantitative information, such as the periphery and area of the crystals. The effects of freezing conditions on the morphology and distribution of the ice crystals were demonstrated quantitatively from the observations of raw beef stained by fluorescent indicator. For the samples frozen at −15 °C, the network structure of ice crystals were observed mainly at intercellular space, having approximately 100 μm in cross-sectional size, while that prepared at −120 °C showed the spherical crystals of 10–20 μm in diameter within the cells. The 3-D image of the sample demonstrated that the growth of ice columns was restricted by the intrinsic structure of muscle fibers. The proposed method provided a new tool to investigate the effects of freezing conditions on the size, morphology and distribution of ice crystals. 相似文献
52.
Katsumasa Tsurushima Masanobu Tsubaki Tomoya Takeda Takuya Matsuda Akihiro Kimura Honoka Takefuji Akane Okada Chiaki Sakamoto Toshihiko Ishizaka Shozo Nishida 《International journal of molecular sciences》2022,23(15)
Triple-negative breast cancer (TNBC) has the poorest prognosis of all breast cancer subtypes. Recently, the activation of NF-κB, which is involved in the growth and survival of malignant tumors, has been demonstrated in TNBC, suggesting that NF-κB may serve as a new therapeutic target. In the present study, we examined whether dimethyl fumarate (DMF), an NF-κB inhibitor, induces apoptosis in TNBC cells and enhances the apoptosis-inducing effect of paclitaxel and adriamycin. Cell survival was analyzed by the trypan blue assay and apoptosis assay. Protein detection was examined by immunoblotting. The activation of NF-κB p65 was correlated with poor prognosis in patients with TNBC. DMF induced apoptosis in MDA-MB-231 and BT-549 cells at concentrations that were non-cytotoxic to the normal mammary cell line MCF-10A. Furthermore, DMF inhibited NF-κB nuclear translocation and Survivin, XIAP, Bcl-xL, and Bcl-2 expression in MDA-MB-231 and BT-549 cells. Moreover, DMF enhanced the apoptosis-inducing effect of paclitaxel and adriamycin in MDA-MB-231 cells. These findings suggest that DMF may be an effective therapeutic agent for the treatment of TNBC, in which NF-κB is constitutively active. DMF may also be useful as an adjuvant therapy to conventional anticancer drugs. 相似文献
53.
54.
Shin Takasawa Ryogo Shobatake Yoshinori Takeda Tomoko Uchiyama Akiyo Yamauchi Mai Makino Sumiyo Sakuramoto-Tsuchida Keito Asai Hiroyo Ota Asako Itaya-Hironaka 《International journal of molecular sciences》2022,23(11)
Sleep apnea syndrome (SAS), characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia (IH)), is a risk factor for hypertension and insulin resistance. We report a correlation between IH and insulin resistance/diabetes. However, the reason why hypertension is induced by IH is elusive. Here, we investigated the effect of IH on the expression of catecholamine-metabolizing enzymes using an in vitro IH system. Human and mouse neuroblastoma cells (NB-1 and Neuro-2a) were exposed to IH or normoxia for 24 h. Real-time RT-PCR revealed that IH significantly increased the mRNA levels of dopamine β-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) in both NB-1 and Neuro-2a. Western blot showed that the expression of DBH and PNMT in the NB-1 cells was significantly increased by IH. Reporter assays revealed that promoter activities of DBH and PNMT were not increased by IH. The miR-375 level of IH-treated cells was significantly decreased relative to that of normoxia-treated cells. The IH-induced up-regulation of DBH and PNMT was abolished by the introduction of the miR-375 mimic, but not by the control RNA. These results indicate that IH stress increases levels of DBH and PNMT via the inhibition of miR-375-mediated mRNA degradation, potentially playing a role in the emergence of hypertension in SAS patients. 相似文献
55.
Voltage Control of Static Var Compensator for a Remote System Interconnected by Long‐Distance AC Cables 下载免费PDF全文
Yuji Tamura Shinji Takasaki Yasuyuki Miyazaki Hideo Takeda Shoichi Irokawa Kikuo Takagi Naoto Nagaoka 《Electrical Engineering in Japan》2014,186(3):19-30
The voltage variation in a remote system is large when the system is connected by long‐distance AC cables due to the cable capacitance. In Japan, the longest 54‐km 66‐kV AC submarine cable interconnection between the Kyushu mainland and Goto Islands was commissioned in 2005. It was requested to mitigate the voltage variation caused by switching off and on one circuit of the two circuits in the AC cables when a fault occurs. Since the conventional voltage control methods such as transformer tap changer or shunt capacitor and reactor banks are not sufficient because of their slow response time, a static var compensator (SVC) was installed on the Goto Islands. In such an application, an SVC control method should be developed so as not to override the existing voltage control systems. This paper describes the SVC control method developed for the Goto Islands AC interconnection project, which can be applied to similar situations. The effectiveness of the control method was verified by the results of effective value simulation and of field testing, which was implemented before the SVC was commissioned in 2007. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(3): 19–30, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22337 相似文献
56.
Yasuyuki Tada 《Electrical Engineering in Japan》2014,187(1):16-23
This paper proposes a new estimation method to determine arbitrary circuit parameters for the harmonic analysis of a distribution network. Harmonic analysis is important in maintaining electric power quality. An interesting phenomenon, a temporary cut‐down of the harmonic voltage level at dawn, even if demand is slightly increasing at this time, is often observed in actual power systems. This paper proposes to utilize observations of this phenomenon to estimate circuit parameters. In addition, it is claimed that a detailed equivalent circuit is preferable to a conventional simplified equivalent circuit for explaining the phenomenon. This paper also discusses the usefulness of the Harmonic Characteristics Curve, which is proposed in this paper as a new concept, at the secondary winding of the distribution transformer, and the correlation of PQ, the monitored values of the active and reactive power at the secondary winding of distribution transformer. This correlation should determine the equivalent fundamental frequency admittance of the shunt capacitors installed for distribution lines. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(1): 16–23, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22451 相似文献
57.
With recent advances in information and telecommunications technologies, a large range of digital content is distributed over the Internet. Whereas diverse licenses are provided to protect the content legally and have the advantage of offering authors many choices, the obstruction of smooth content distribution may occur if the relationships between licenses are not revealed because of differences between the restrictions imposed by each license. To activate digital content distribution, license interoperability must be revealed. In this paper, we propose a framework for formally examining license interoperability by using many-sorted first-order logic. We formalize five actual licenses and examine their interoperability to prove the effectiveness of our proposed framework. The results show that the framework reveals the relationships between licenses. 相似文献
58.
Chunjiang Fu Yasuyuki Suzuki Ken Kiyono Pietro Morasso Taishin Nomura 《Journal of the Royal Society Interface》2014,11(101)
Stability of human gait is the ability to maintain upright posture during walking against external perturbations. It is a complex process determined by a number of cross-related factors, including gait trajectory, joint impedance and neural control strategies. Here, we consider a control strategy that can achieve stable steady-state periodic gait while maintaining joint flexibility with the lowest possible joint impedance. To this end, we carried out a simulation study of a heel-toe footed biped model with hip, knee and ankle joints and a heavy head-arms-trunk element, working in the sagittal plane. For simplicity, the model assumes a periodic desired joint angle trajectory and joint torques generated by a set of feed-forward and proportional-derivative feedback controllers, whereby the joint impedance is parametrized by the feedback gains. We could show that a desired steady-state gait accompanied by the desired joint angle trajectory can be established as a stable limit cycle (LC) for the feedback controller with an appropriate set of large feedback gains. Moreover, as the feedback gains are decreased for lowering the joint stiffness, stability of the LC is lost only in a few dimensions, while leaving the remaining large number of dimensions quite stable: this means that the LC becomes saddle-type, with a low-dimensional unstable manifold and a high-dimensional stable manifold. Remarkably, the unstable manifold remains of low dimensionality even when the feedback gains are decreased far below the instability point. We then developed an intermittent neural feedback controller that is activated only for short periods of time at an optimal phase of each gait stride. We characterized the robustness of this design by showing that it can better stabilize the unstable LC with small feedback gains, leading to a flexible gait, and in particular we demonstrated that such an intermittent controller performs better if it drives the state point to the stable manifold, rather than directly to the LC. The proposed intermittent control strategy might have a high affinity for the inverted pendulum analogy of biped gait, providing a dynamic view of how the step-to-step transition from one pendular stance to the next can be achieved stably in a robust manner by a well-timed neural intervention that exploits the stable modes embedded in the unstable dynamics. 相似文献
59.
Texture,sensory and swallowing characteristics of high-pressure-heat-treated pork meat gel as a dysphagia diet 总被引:2,自引:0,他引:2
To develop a soft meat product for a dysphagia diet, high-pressure technology was applied. Pressure-heat-treated ground pork meat (PH) was prepared from ground pork mixed with water (ground meat: water, 1:0.5 or 1:1) and salt (1.5%). PH-gels were made from these meat homogenates by treatment at 400 MPa for 20 min, followed by heat treatment. Heat-treated pork meat homogenates (H) were also prepared. The hardness and adhesiveness of the 1:1PH-gel was lower than those of the 1:1H-gel. The PH-gel scored higher in sensory evaluations of elasticity, smoothness and ease of swallowing. Scanning electron micrographs indicated that the superior textural property of the 1:1PH-gel was caused by a network of myosin filaments. Videofluoroscopic examination of swallowing revealed that the 1:1PH-gel was easy to swallow and left little residue in the oropharynx. These results proved the utility of pressurization in creating a dysphagia meat diet. 相似文献
60.
Muhammad Javed Iqbal Rafaqat Ali KhanShigeru Takeda Shigemi MizukamiTerunobu Miyazaki 《Journal of Alloys and Compounds》2011,509(28):7618-7624
The static and dynamic magnetic properties of W-type hexaferrites are tuned to meet the requirements of wide band frequencies for attenuation of electromagnetic interference and microwave absorptions purposes. For this purpose, the W-type hexaferrite of entirely new composition of BaCoZnFe16−2yAlyCeyO27 (y = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) has been synthesized by the chemical co-precipitation. The material is characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The complex permittivity (?r = ?′ − j?″) and permeability (μr = μ′ − jμ″) spectra are determined using Vector Network Analyzer (VNA) in a range from 0.5 GHz to 10 GHz. During this study, it is noticeable that the Al3+ and Ce3+ ions have considerable effect on the shape of the nanoparticles. Samples having Al-Ce contents y = 0.2 and y = 0.4 showed large values for magnetization (70.5 emu/g) and remanent magnetization (32.9 emu/g). In addition, more than 99% absorption (>−20 dB) is noted for this sample composition. Based on these results it is concluded that the microwave absorption characteristics of these compounds can be tuned for the required frequency by varying the thickness of the absorber. Due to this reason, potential employment of the synthesized nanoparticles for absorption of electromagnetic radiations at wide frequency band of 0.5-10 GHz has been proposed. 相似文献