全文获取类型
收费全文 | 2235篇 |
免费 | 70篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 462篇 |
金属工艺 | 42篇 |
机械仪表 | 28篇 |
建筑科学 | 113篇 |
矿业工程 | 4篇 |
能源动力 | 30篇 |
轻工业 | 227篇 |
水利工程 | 18篇 |
石油天然气 | 3篇 |
无线电 | 141篇 |
一般工业技术 | 347篇 |
冶金工业 | 470篇 |
原子能技术 | 24篇 |
自动化技术 | 381篇 |
出版年
2023年 | 27篇 |
2022年 | 28篇 |
2021年 | 43篇 |
2020年 | 38篇 |
2019年 | 37篇 |
2018年 | 67篇 |
2017年 | 56篇 |
2016年 | 59篇 |
2015年 | 42篇 |
2014年 | 55篇 |
2013年 | 125篇 |
2012年 | 100篇 |
2011年 | 137篇 |
2010年 | 113篇 |
2009年 | 82篇 |
2008年 | 109篇 |
2007年 | 98篇 |
2006年 | 76篇 |
2005年 | 87篇 |
2004年 | 74篇 |
2003年 | 61篇 |
2002年 | 57篇 |
2001年 | 40篇 |
2000年 | 32篇 |
1999年 | 30篇 |
1998年 | 70篇 |
1997年 | 47篇 |
1996年 | 45篇 |
1995年 | 28篇 |
1994年 | 39篇 |
1993年 | 35篇 |
1992年 | 31篇 |
1991年 | 23篇 |
1990年 | 26篇 |
1989年 | 25篇 |
1988年 | 19篇 |
1987年 | 21篇 |
1986年 | 14篇 |
1985年 | 18篇 |
1984年 | 20篇 |
1983年 | 17篇 |
1982年 | 24篇 |
1981年 | 18篇 |
1980年 | 13篇 |
1979年 | 25篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1973年 | 6篇 |
排序方式: 共有2308条查询结果,搜索用时 0 毫秒
991.
This article explores the use of the unique flora from Western Australia. These wildflower essences are collected from across the state and are made into flower essences. These essences are made in a form similar to homoeopathy. The essences can be given internally, or applied to the external body and acupressure points. Angela and Craig Balinski have used the Western Australian flower essences in their complementary therapy practice where patients are treated for stress and pain management. This programme is currently being utilized at nine of Perth's hospitals. The Western Australian flower essences and their specific application techniques are compatible within the hospital environment because they are safe, produce consistent results, and take little time to apply to the patient. One of the other outstanding features of these essences is that they can be used without any interference to medical procedures. The Western Australian flower essences and the techniques for their use are unique and have, over the last two years, been presented at all of the major nursing conferences in Australia. At present, across Australia there are over 16 hospitals which are currently offering these treatments to their patients. 相似文献
992.
E Bonnefoy S Filley G Kirkorian J Guidollet R Roriz J Robin P Touboul 《Canadian Metallurgical Quarterly》1998,114(2):482-486
The anatomy of the labiomandibular fold was evaluated in a series of 12 fresh hemifacial cadaver dissections. The techniques of methylene blue dye injection, histologic evaluation, and gross dissection all confirm that the labiomandibular fold has distinct anatomic boundaries. The superior boundary is formed by the cutaneous insertion of the depressor anguli oris muscle at the labiomandibular crease. The inferior boundary is determined by the mandibular ligament, which has been previously described. The cutaneous insertion of the depressor muscle and the mandibular ligament act as relative points of fixation. The dynamic forces of both aging and facial animation act about these two points to create the typical appearance of the labiomandibular fold. This anatomy is consistent with that seen in other areas of the face such as the nasolabial and nasojugal folds, where the dermal insertion of muscle and/or fascia defines an anatomically distinct region. Clinically, this anatomy may suggest that a subcutaneous plane of dissection during the face lift procedure may allow manipulation and reduction of the fat that was noted lateral to the dermal insertion of the depressor anguli muscle. Subcutaneous dissection also avoids lateral pull on the platysma muscle, which may tend to accentuate and distort the labiomandibular crease due to its intimate association with the overlying depressor muscle. 相似文献
993.
OBJECTIVE: To describe a case of acute abdomen arising from an underlying urological condition. METHODS/RESULTS: Herein we describe a patient with acute abdomen arising from a pyonephrotic kidney with fistulization to the peritoneal cavity. The clinical manifestations disappeared following nephrectomy by the anterior approach and drainage of the intraperitoneal cavity. CONCLUSION: Although infrequent, it should be taken into account that peritoneal abscess and/or pyonephrosis can cause acute abdomen when they fistulize to the peritoneal cavity. 相似文献
994.
JE Max DA Robin SD Lindgren WL Smith Y Sato PJ Mattheis JA Stierwalt CS Castillo 《Canadian Metallurgical Quarterly》1997,36(9):1278-1285
OBJECTIVE: To extend findings regarding predictive factors of psychiatric outcome from the first to the second year after traumatic brain injury (TBI) in children and adolescents. METHOD: Subjects were children aged 6 to 14 years at the time they were hospitalized after TBI. The study used a prospective follow-up design. Assessments of preinjury psychiatric, behavioral, adaptive functioning, family functioning and family psychiatric history status were conducted. Severity of injury was assessed by standard clinical scales and neuroimaging was analyzed. The outcome measure was the presence of a psychiatric disorder, not present before the injury ("novel"), during the second year after TBI. RESULTS: Fifty subjects enrolled, and the analyses focused on 42 subjects followed at 24 months. Severity of injury, preinjury family function, and preinjury lifetime psychiatric history predicted the development of a "novel" psychiatric disorder present in the second year. CONCLUSION: These data suggest that there are children, identifiable through clinical assessment, at increased risk for "novel" psychiatric disorders in the second year after TBI. 相似文献
995.
Fletcher Jack M.; Taylor H. Gerry; Morris Robin; Satz Paul 《Canadian Metallurgical Quarterly》1982,18(1):124
Administered to 678 White kindergarten boys 4 finger recognition tasks (FRTs) and a battery of other tests, including the Embedded Figures Test, the Peabody Picture Vocabulary Test, and the Wechsler Preschool and Primary Scale of Intelligence, as part of a 6-yr longitudinal project. In their 3rd yr in school, the 80 Ss having the most significant difficulties in learning to read were identified and compared with 80 Ss who had acquired adequate reading skills. These 2 groups received the same FRTs in both their 3rd and 6th school years. FRTs (a) were differentially associated with other developmental variables in kindergarten, (b) were mastered at different ages, (c) demonstrated differential age-dependent relationships with reading status, and (d) were not related to neurological indices of brain integrity. Findings show that FRTs do not provide unitary measures of brain integrity in learning-disabled boys and do not have specific relationships with reading achievement. The significance of FRTs for reading achievement accrued primarily from their sensitivity to other developmental processes underlying reading acquisition. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
T Weissland P Pelayo J Vanvelcenaher G Marais JM Lavoie H Robin 《Canadian Metallurgical Quarterly》1997,76(5):428-433
The aims of the present study were: first, to assess the interindividual variations of a spontaneously chosen crank rate (SCCR) in relation to the power developed during an incremental upper body exercise on an arm ergometer set at a constant power regime, and second, to compare heart rate (HR) responses, expired minute ventilation (V[E]) and oxygen consumption (VO2) when the pedal rates were chosen spontaneously (T[SCCR]) or set at +/- 10% of the freely chosen rates (T[+10%] and T[-10%], respectively). The mean pedal rate values were linearly related (P < 0.01) with the power developed during arm cranking (r = 0.96), although large variations of pedalling rate strategies were observed between subjects. Maximal power (MP) and time to exhaustion values were significantly higher (P < 0.05) during T(SCCR) than during T(+10%) and T(-10%). Peak VO2 values were significantly higher (P < 0.05) in T(+10%) than in T(SCCR) and T(-10%). The increase in HR, V(E), and VO2 mean values, in relation to the increase in the power developed, was significantly higher (P < 0.05) when the pedal rate was set at plus 10% of the SCCR (T[+/-10%]) than in the two other conditions. The findings of the present study suggest that the use of an electromagnetically braked ergometer, which automatically adjusts the resistance component to maintain a constant work rate, should be used in order to achieve the highest MP values during an incremental upper body exercise. A 10% increase of the SCCR should be used in order to provide the highest peak VO2 value. 相似文献
997.
Rutter Michael; Pickles Andrew; Murray Robin; Eaves Lindon 《Canadian Metallurgical Quarterly》2001,127(3):291
There have been strong critiques of the notion that environmental influences can have an important effect on psychological functioning. The substance of these criticisms is considered in order to infer the methodological challenges that have to be met. Concepts of cause and of the testing of causal effects are discussed with a particular focus on the need to consider sample selection and the value (and limitations) of longitudinal data. The designs that may be used to test hypotheses on specific environmental risk mechanisms for psychopathology are discussed in relation to a range of adoption strategies, twin designs, various types of "natural experiments," migration designs, the study of secular change, and intervention designs. In each case, consideration is given to the need for samples that "pull-apart" variables that ordinarily go together, specific hypotheses on possible causal processes, and the specification and testing of key assumptions. It is concluded that environmental risk hypotheses can be (and have been) put to the test but that it is usually necessary to use a combination of research strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
T Hoang-Xuan H Robin M Heller F Caux C Prost 《Canadian Metallurgical Quarterly》1997,104(9):1414-1420
OBJECTIVE: To describe for the first time the direct immunoelectron microscopic pattern of immune deposits on the conjunctival basement membrane in epidermolysis bullosa acquisita (EBA). DESIGN: Case reports. PARTICIPANTS: Two patients. INTERVENTION: Epidermolysis bullosa acquisita associated with cicatrizing conjunctivitis. MAIN OUTCOME MEASURES: Direct immunofluorescence and direct immunoelectron microscopy without freezing on conjunctival and skin biopsy specimens, indirect immunofluorescence, Western immunoblot analysis. RESULTS: Results of direct immunoelectron microscopic examination of the conjunctiva showed the presence of immune deposits in the anchoring fibril zone, just beneath the lamina densa, in both patients. This finding was the same as the direct immunoelectron microscopic pattern shown in the skin of these patients, which is known to be very specific for EBA. Direct immunofluorescence was positive in the conjunctiva of only one patient. Indirect immunofluorescence and Western immunoblot analysis failed to detect circulating autoantibodies. CONCLUSIONS: Direct immunoelectron microscopy on the conjunctiva is a useful diagnostic tool to differentiate EBA from other related autoimmune mucocutaneous blistering diseases. 相似文献
999.
Martina Cihova Patrik Schmutz Robin Schublin Jrg F. Lffler 《Advanced materials (Deerfield Beach, Fla.)》2019,31(42)
Biodegradable magnesium alloys generally contain intermetallic phases on the micro‐ or nanoscale, which can initiate and control local corrosion processes via microgalvanic coupling. However, the experimental difficulties in characterizing active degradation on the nanoscale have so far limited the understanding of how these materials degrade in complex physiological environments. Here a quasi‐in situ experiment based on transmission electron microscopy (TEM) is designed, which enables the initial corrosion attack at nanometric particles to be accessed within the first seconds of immersion. Combined with high‐resolution ex situ cross‐sectional TEM analysis of a well‐developed corrosion‐product layer, mechanistic insights into Mg‐alloys' degradation on the nanoscale are provided over a large range of immersion times. Applying this methodology to lean Mg–Zn?Ca alloys and following in detail the dissolution of their nanometric Zn‐ and Ca‐rich particles the in statu nascendi observation of intermetallic‐particle dealloying is documented for magnesium alloys, where electrochemically active Ca and Mg preferentially dissolve and electropositive Zn enriches, inducing the particles' gradual ennoblement. Based on electrochemical theory, here, the concept of cathodic‐polarization‐induced dealloying, which controls the dynamic microstructural changes, is presented. The general prerequisites for this new dealloying mechanism to occur in multicomponent alloys and its distinction to other dealloying modes are also discussed. 相似文献
1000.
Konorov SO Schulze HG Atkins CG Piret JM Aparicio SA Turner RF Blades MW 《Analytical chemistry》2011,83(16):6254-6258
We present a method to perform absolute quantification of glycogen in human embryonic stem cells (hESCs) in situ based on the use of Raman microspectroscopy. The proposed quantification method was validated by comparison to a commonly used commercial glycogen assay kit. With Raman microspectroscopy, we could obtain the glycogen content of hESCs faster and apparently more accurately than with the kit. In addition, glycogen distributions across a colony could be obtained. Raman spectroscopy can provide reliable estimates of the in situ glycogen content in hESCs, and this approach should also be extensible to their other biochemical constituents as well as to other cell types. 相似文献