全文获取类型
收费全文 | 1271篇 |
免费 | 23篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 47篇 |
综合类 | 3篇 |
化学工业 | 366篇 |
金属工艺 | 93篇 |
机械仪表 | 43篇 |
建筑科学 | 30篇 |
能源动力 | 73篇 |
轻工业 | 59篇 |
石油天然气 | 2篇 |
无线电 | 56篇 |
一般工业技术 | 237篇 |
冶金工业 | 113篇 |
原子能技术 | 59篇 |
自动化技术 | 118篇 |
出版年
2022年 | 6篇 |
2021年 | 22篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 25篇 |
2017年 | 17篇 |
2016年 | 30篇 |
2015年 | 6篇 |
2014年 | 28篇 |
2013年 | 78篇 |
2012年 | 55篇 |
2011年 | 70篇 |
2010年 | 80篇 |
2009年 | 65篇 |
2008年 | 59篇 |
2007年 | 51篇 |
2006年 | 63篇 |
2005年 | 38篇 |
2004年 | 41篇 |
2003年 | 39篇 |
2002年 | 41篇 |
2001年 | 37篇 |
2000年 | 20篇 |
1999年 | 27篇 |
1998年 | 52篇 |
1997年 | 31篇 |
1996年 | 29篇 |
1995年 | 27篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 12篇 |
1991年 | 16篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 14篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 16篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 4篇 |
1975年 | 7篇 |
1973年 | 4篇 |
1970年 | 3篇 |
排序方式: 共有1299条查询结果,搜索用时 31 毫秒
991.
Triaxial Crystalline Orientation of MgTi2O5 Achieved Using a Strong Magnetic Field and Geometric Effect
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tohru S. Suzuki Yoshikazu Suzuki Tetsuo Uchikoshi Yoshio Sakka 《Journal of the American Ceramic Society》2016,99(6):1852-1854
Tailoring the crystallographic orientation in ceramics is very useful for improving their properties. We reported that the colloidal processing in a strong magnetic field was able to control the crystallographic orientation even in diamagnetic ceramics. In this process, a strong magnetic field is applied to the particles in a stable suspension. The orientation of the crystal depends on the axis having easy magnetization and one‐dimensional orientation can be controlled. In this study, our concept is that control of multiaxial crystalline orientation in ceramics by using both anisometric particles and a magnetic field. The control of the triaxial orientation was achieved by tape casting of rod‐like MgTi2O5 particle in a magnetic field. The b‐axis was aligned by the magnetic field, and the a‐axis was aligned by the geometric effect and shear stress during tape casting. 相似文献
992.
Onocerin Biosynthesis Requires Two Highly Dedicated Triterpene Cyclases in a Fern Lycopodium clavatum
下载免费PDF全文
![点击此处可从《Chembiochem : a European journal of chemical biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Takeshi Araki Yusuke Saga Momo Marugami Dr. Junnosuke Otaka Dr. Hiroshi Araya Prof. Dr. Kazuki Saito Dr. Mami Yamazaki Dr. Hideyuki Suzuki Dr. Tetsuo Kushiro 《Chembiochem : a European journal of chemical biology》2016,17(4):288-290
Onocerin is known for its unusual structure among triterpenoids, with a symmetrical structure that is formed by cyclizations at the both termini of dioxidosqualene. The nature of the enzyme catalyzing these unusual cyclizations has remained elusive for decades. Here, we report the cloning of genes responsible for these reactions; they exhibited unprecedented substrate specificities among oxidosqualene cyclase family members. Two genes, LCC and LCD, were identified from the fern Lycopodium clavatum. Expression in yeast revealed that both were required to produce α‐onocerin. LCC, the first dioxidosqualene cyclase, catalyzed the production of a novel intermediate pre‐α‐onocerin from only dioxidosqualene as a substrate; LCD catalyzed the second half of the cyclization, exclusively from pre‐α‐onocerin. These results demonstrated that these two most unusual oxidosqualene cyclases were involved in onocerin biosynthesis. 相似文献
993.
Cover Picture: Unexpected Photo‐instability of 2,6‐Sulfonamide‐Substituted BODIPYs and Its Application to Caged GABA (ChemBioChem 13/2016)
下载免费PDF全文
![点击此处可从《Chembiochem : a European journal of chemical biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
994.
Morley’s theorem states that for any triangle, the intersections of its adjacent angle trisectors form an equilateral triangle. The construction of Morley’s triangle by the straightedge and compass method is impossible because of the well-known impossibility result for angle trisection. However, by origami, the construction of an angle trisector is possible, and hence that of Morley’s triangle. In this paper we present a computational origami construction of Morley’s triangle and an automated correctness proof of the generalized Morley’s theorem.During the computational origami construction, geometrical constraints in symbolic representation are generated and accumulated. Those constraints are then transformed into algebraic forms, i.e. a set of polynomials, which in turn are used to prove the correctness of the construction. The automated proof is based on the Gröbner bases method. The timings of the experiments of the Gröbner bases computations for our proofs are given. They vary greatly depending on the origami construction methods, the algorithms for the Gröbner bases computation, and variable orderings. 相似文献
995.
This paper describes a decision model for an autonomous agent that provides an inhabitant with comfort based on information
network technologies that connect home electric appliances with household equipment. The inhabitant enjoys the benefit of
comfort, while he pays the cost for keeping that comfort. The autonomous agent should decide and control household equipment
considering that cost from the inhabitant’s viewpoint. Thus, we utilized a representation scheme called an “influence diagram”
that enabled us to model the decision-making process of the agent from the inhabitant’s point of view. First, decision modeling
using the influence diagram is presented via an example. The presented model consists of three information-processing modules:
a module for estimating the situation of an inhabitant based on information from home networks, a module for evaluating comfort
of the inhabitant, and a module for making decisions that maximize the utility of the inhabitant from both the viewpoints
of comfort and the cost paid for that comfort. Next, an experiment for verifying whether the presented model is effective
or not, and its results are described. Finally, our model of the agent is discussed in relation to social intelligence design
by investigating the interactive processes between the agent and the inhabitant. 相似文献
996.
Yoshihito Hara Tetsuo Kikuchi Hideki Kitagawa Junichi Morinaga Hiroyuki Ohgami Hajime Imai Tohru Daitoh Takuya Matsuo 《Journal of the Society for Information Display》2018,26(3):169-177
We succeeded in G8 factory for mass production of Indium–Gallium–Zink–Oxide thin‐film transistor (IGZO‐TFT) for the first time in the world. The initial TFT process was an etching stop‐type TFT, but now, we are mass producing channel etching‐type TFTs. And, its application range is smartphones, tablets, PCs, monitors, TV, and so on. In particular, because of recent demands for high‐resolution and narrow frame, our IGZO display has been advanced in technology development with gate driver in panel. In this paper, we report development combining low resistance technology and the latest IGZO‐TFT (IGZO5) for large‐screen 8K display. 相似文献
997.
We formalize paper fold (origami) by graph rewriting. Origami construction is abstractly described by a rewriting system (O,?), where O is the set of abstract origamis and ? is a binary relation on O, that models fold . An abstract origami is a structure (Π,∽,?), where Π is a set of faces constituting an origami, and ∽ and ? are binary relations on Π, each representing adjacency and superposition relations between the faces. 相似文献
998.
Dexterous manipulation is an important function for working robots. Manipulator tasks such as assembly and disassembly can generally be divided into several motion primitives. We call such motion primitives “skills,” and explain how most manipulator tasks can be composed of sequences of these skills. We are currently planning to construct a maintenance robot for household electrical appliances. We considered establishing a hierarchy of the manipulation tasks of this robot since the maintenance of such appliances has become more complex than ever before. In addition, as errors seem likely to increase in complex tasks, it is important to implement an effective error recovery technology. This article presents our proposal for a new type of error recovery that uses the concepts of task stratification and error classification. 相似文献
999.
Tetsuo Sato Hideyuki Abe Sumio Kawano Goro Ueno Kiyoji Suzuki Mutsuo Iwamoto 《Journal of the American Oil Chemists' Society》1994,71(10):1049-1055
The feasibility of near infrared (NIR) spectroscopy was examined for analyzing quality criteria or deterioration induces of
soybeans, such as the nitrogen solubility index (NSI), acid value, digestibility and percentage germination, as well as the
contents of their major constituents (moisture, oil and total nitrogen). Because all the criteria are closely related to yield
and quality of the final product, their rapid analysis is required for process control in the oil milling plant. NIR diffuse-reflectace
spectra were measured on ground samples in an InfraAlyzer 500 (Bran+Luebbe Co., Norderstedt, Germany). As for the major constituents,
the standard errors of prediction (SEP) were 0.34% (moisture), 0.24% (oil) and 0.067% (total nitrogen). There results show
the ability of NIR for analyzing these parameters, as many researchers reported previously. As for the other quality criteria,
the SEP values were 2.40 (NSI), 5.58 (digestibility), 0.29 (acid value) and 15.27 (germinatio percentage). Further, NIR analysis
for some of these criteria of the extracted residue and defatted soybeans was also examined, and almost the same level of
SEP values was obtained. Although it is still necessary to improve the accuracy, we concluded that the NIR method has the
feasibility to measure quality criteria for the purpose of process control in the plant in place of the time-consuming chemical
analysis that are conventionally used.
Part of this study was presented at 84th AOCS Annual Meeting & Expo, April 27, 1993, Anaheim, California. 相似文献
1000.
Yongfu Lian Takatsugu Wakahara Takeshi Akasaka Said Kazaoui Tetsuo Shimizu 《Carbon》2005,43(13):2750-2759
Optical absorption and resonant Raman spectra are proven to be convenient and effective to monitor the centrifugal fractionation and to evaluate the quality of soluble single-walled carbon nanotubes (SWNTs) achieved by inorganic oxidation and organic functionalization. Through a systemic study of a series of centrifuged solutions, we confirmed that heavily functionalized amorphous carbon was fractionated into the early centrifuged solutions, whereas lightly functionalized graphite fragments as well as polyhedral carbon and metal catalysts particles were fractionated into the late centrifuged solutions and centrifuged residue, and then highly pure and well dispersed SWNTs were collected from the middle centrifuged solutions. It is proposed that the purity, dispersibility, and aggregation state of SWNTs can be qualitatively estimated by the relative intensity of their absorption features, the fine structure and slope of their absorption curves. The Raman features of centrifuged SWNTs are found systematically up-shifted except the disorder-induced D band in comparison with those of as-prepared material, indicating that the SWNTs in centrifuged solutions are individual or in thin bundles. Two new features were identified at 1428 and 941 cm−1 in the Raman spectrum of thermally annealed centrifuged SWNTs, which were assigned to achiral nanotubes and combined mode, respectively. 相似文献