全文获取类型
收费全文 | 225篇 |
免费 | 7篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 31篇 |
机械仪表 | 2篇 |
建筑科学 | 15篇 |
轻工业 | 15篇 |
水利工程 | 3篇 |
无线电 | 18篇 |
一般工业技术 | 21篇 |
冶金工业 | 84篇 |
自动化技术 | 41篇 |
出版年
2023年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 6篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 13篇 |
2009年 | 10篇 |
2008年 | 11篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 27篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 7篇 |
1982年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有232条查询结果,搜索用时 15 毫秒
1.
2.
James Charles Tomas Pfister Mark Everingham Andrew Zisserman 《International Journal of Computer Vision》2014,110(1):70-90
We present a fully automatic arm and hand tracker that detects joint positions over continuous sign language video sequences of more than an hour in length. To achieve this, we make contributions in four areas: (i) we show that the overlaid signer can be separated from the background TV broadcast using co-segmentation over all frames with a layered model; (ii) we show that joint positions (shoulders, elbows, wrists) can be predicted per-frame using a random forest regressor given only this segmentation and a colour model; (iii) we show that the random forest can be trained from an existing semi-automatic, but computationally expensive, tracker; and, (iv) introduce an evaluator to assess whether the predicted joint positions are correct for each frame. The method is applied to 20 signing footage videos with changing background, challenging imaging conditions, and for different signers. Our framework outperforms the state-of-the-art long term tracker by Buehler et al. (International Journal of Computer Vision 95:180–197, 2011), does not require the manual annotation of that work, and, after automatic initialisation, performs tracking in real-time. We also achieve superior joint localisation results to those obtained using the pose estimation method of Yang and Ramanan (Proceedings of the IEEE conference on computer vision and pattern recognition, 2011). 相似文献
3.
44 patients with 47 recurrent inguinal hernias entered a prospective study. All patients were operatively managed by a standardized technique using a polypropylene (Prolene) mesh inserted through a pre-peritoneal approach. Operating in the pre-peritoneal space avoids dissection of the scared cord and the "inlay" prosthetic mesh safely creates a new "fascia transversalis" with a low rate of recurrences. All patients were personally controlled every 6 months with a follow-up time of 12 to 60 months (mean 20.2 months). The low postoperative morbidity included only one seroma, no infection and no testicular complications. We observed one recurrence occurring 6 months after surgery (2%). The described operative technique using an inlay patch is recommended as the therapy of choice in all recurrent groin hernias. 相似文献
4.
Tall larkspur (Delphinium spp.) is a palatable but toxic poisonous plant in the western United States. The toxins in tall larkspur are diterpenoid alkaloids. We examined the influences of food flavor and postingestive consequences on consumption of a 33% larkspur pellet during 30-min feeding periods for five days using esophageally fistulated cattle that were sham-fed larkspur pellets. Consumption by the sham-fed group was compared to a control group fed alfalfa pellets, and a larkspur group fed only larkspur pellets. Sham-fed cattle did not decrease (P > 0.1) feed consumption compared to controls, indicating no significant difference in food flavor. The larkspur group decreased (P < 0.05) feed consumption by 41% relative to controls and by 31% relative to sham-fed animals (P = 0.08). This reduction in feed consumption indicates the adverse postingestive consequences of tall larkspur ingestion, as the larkspur group apparently developed a conditioned taste aversion to the larkspur pellet. Even though these animals were averted to the pellets, they showed none of the classical signs of intoxication from ingestion of tall larkspur.This research was supported in part by the Utah Agricultural Experiment Station, Utah State University, Logan, Utah 84322. Approved as journal article No. 3846. 相似文献
5.
Zwicker M. Vetro A. Sehoon Yea Matusik W. Pfister H. Durand F. 《Signal Processing Magazine, IEEE》2007,24(6):88-96
Multiview three-dimensional (3-D) displays offer viewing of high-resolution stereoscopic images from arbitrary positions without glasses. This article surveyed different approaches to develop signal processing algorithms for these displays. Such displays consist of view-dependent pixels that reveal a different color according to the viewing angle. Therefore, the left and right eye of an observer sees slightly different images on the screen. This leads to the perception of 3-D depth and parallax effects when the observer moves. Although the basic optical principles of multiview auto-stereoscopy have been known for over a century, only recently displays with increased resolution, or systems based on multiple projectors, have made this approach practical. 相似文献
6.
Novel CMOS Schmitt trigger with controllable hysteresis 总被引:3,自引:0,他引:3
A novel CMOS Schmitt trigger with controllable hysteresis based on the standard CMOS circuit with three transistor pairs is proposed. With the addition of only one transistor pair a Schmitt trigger with two selectable hysteresis characteristics can be achieved. Simulation results are compared with theory and a possible application is presented.<> 相似文献
7.
Andreas Miller Eva Lassek Julia Pfister Richard Klinger Werner Höbel Holger Knapp Franziska Gaßmann Uwe Wollein Nicholas Schramek 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2016,11(2):127-135
In the European Union, carminic acid and its ammonium, calcium, potassium or sodium salts and its aluminium lakes are approved as food additive E120. In beverages obtained from the German market 4-aminocarminic acid (“acid-stable carmine”) was detected by HPLC–PDA and LC–MS/MS. Isolation of the colorant from a liquid dye preparation used for the production of a beverage sample and subsequent NMR analysis confirmed the presence of 4-aminocarminic acid. Synthesis of 15N-4-aminocarminic acid clearly demonstrated that “acid-stable carmine” is not the ammonium salt of carminic acid, which is approved as food additive in the European Union. In fact, nitrogen in “acid-stable carmine” is covalently bound. The molecular structure of carminic acid is chemically modified and 4-aminocarminic acid does not comply with the specifications laid down for E120 in Commission Regulation (EU) No 231/2012. 4-Aminocarminic acid was also detected in the red-colored glaze of a raspberry cake and in the liquid dye preparation used for coloring this glaze. 相似文献
8.
Cook D Shi L Gardner DR Pfister JA Grum D Welch KD Ralphs MH 《Journal of chemical ecology》2012,38(2):195-203
Locoweeds are defined as Astragalus and Oxytropis species that cause intoxication due to the alkaloid swainsonine. Swainsonine concentrations in Oxytropis sericea were influenced by location, plant part, and the developmental stage of the plant. Concentrations followed similar trends
at each location, generally increasing over the growing season in above-ground parts until the plant reaches maturity with
no change in concentration in the crowns. At the onset of senescence, swainsonine decreased in floral parts to less than half
of the peak concentration. Similar to swainsonine concentrations, endophyte amounts were influenced by location, plant part,
and the developmental stage of the plant. Likewise, endophyte amounts generally increased over the growing season in above
ground parts and remained static in the crowns at all four locations. Swainsonine in Oxytropis sericea was positively associated with the endophyte Undifilum, which is responsible for swainsonine biosynthesis. 相似文献
9.
Summary: The powder blend of poly(acrylic acid) (PAA) with zinc oxide or zinc oxide/magnesium oxide was applied successfully to produce zinc polycarboxylate during the 3D dispensing of an aqueous ink by means of 3D printers (Z402? from ZCorporation and Deskmodeler? from bmt Company). The layer‐by‐layer inkjet printing afforded zinc ionomer 3D objects with excellent water resistance, no inherent color formation and high mechanical and dimensional stabilities. In contrast to the 3D printing of conventional powders such as starch/cellulose/dextrose blends, poly(vinyl alcohol) (PVA) or plaster, no postprinting treatments were required. Excellent dimensional accuracy of the models, as evidenced by very small deviation of the dimensions from those of the corresponding CAD data, was achieved. The mechanical properties improved with increasing PAA content, ink amount (saturation value), decreasing particle size of the sintered zinc oxide ceramic. At high PAA content >7 wt.‐%, post‐treatment with aqueous zinc acetate solution improved the mechanical properties. The setting time of the zinc cements shows no significant effect on the mechanical properties, but on the water resistance of the models. The porosity of the 3D objects, measured by means of X‐ray microtomography (μ‐CT), had profound impact on the variations of the mechanical properties of the 3D objects prepared by 3D printing processes.
10.
A Functional Explanation for Patterns of Norditerpenoid Alkaloid Levels in Tall Larkspur (Delphinium barbeyi) 总被引:1,自引:0,他引:1
Concentrations of norditerpenoid alkaloids vary among larkspur (Delphinium) species, locations, and years, but environmental stresses seem to have little effect on alkaloid levels. There is a need for a functional hypothesis of alkaloid synthesis and metabolism to explain the observed trends in concentration and to predict the toxicity of larkspur populations. This study was replicated at two locations over two years in the mountains of central Utah. Ten tall larkspur (D. barbeyi) plants were marked at each location, and a single stalk was harvested from each plant at weekly intervals throughout the growing season. Concentrations of toxic and total alkaloids were measured by Fourier-transformed infrared spectroscopy (FTIR), and alkaloid pools were calculated by multiplying the alkaloid concentration by the dry weight of the plant to determine the amount of alkaloids in the stalk. Alkaloid pools in the stalks increased for the first three weeks, leveled off, and then declined to low levels as the plants began to senesce. Concentrations of alkaloids declined through the season, as the alkaloids were diluted in the increasing biomass as the plants grew. These patterns will be used to predict potential toxicity of larkspur populations. 相似文献