全文获取类型
收费全文 | 926篇 |
免费 | 0篇 |
专业分类
综合类 | 1篇 |
化学工业 | 2篇 |
建筑科学 | 1篇 |
轻工业 | 1篇 |
冶金工业 | 921篇 |
出版年
2022年 | 1篇 |
2016年 | 1篇 |
2013年 | 1篇 |
1999年 | 26篇 |
1998年 | 266篇 |
1997年 | 144篇 |
1996年 | 105篇 |
1995年 | 65篇 |
1994年 | 50篇 |
1993年 | 53篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 44篇 |
1976年 | 78篇 |
1975年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1962年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有926条查询结果,搜索用时 0 毫秒
11.
Striated muscle fibers (or cells) were observed in three of the six swine pineal glands. The muscle fibers occurred in clusters of several fibers about the parenchymal blood vessels. They were in general poorly developed, lacked regular cross striations and were not readily recognized histologically. The muscle fibers were, however, easily identified on electron microscopy because of the myofilaments they contain. In most of the muscle fibers, the myofilaments were arranged in ill-defined, disorderly bundles and rarely formed well-defined myofibrils and sarcomeres. The sarcotubular system was also poorly developed and triads were sparse and randomly scattered. Leptomeres were observed in several muscle fibers. The source of the muscle fibers in the pineal glands is not well understood and, whatever the source may be, the muscle fibers seem to remain poorly developed in the pineal glands. 相似文献
12.
EG Il'inskaia AK Pankov IuS Sidorenko VM Birbraer IuN Bordiushkov 《Canadian Metallurgical Quarterly》1976,22(10):38-44
In the gynecological department of Rostov Oncological Institute endolymphatic polychemotherapy with a preliminary determination of tumor sensitivity to chemotherapy was employed in 54 patients with cervical cancer, 3 of them in stage III and IV having contraindications to radiotherapy. A combination of chemical substances and the dosage of single administration were as follows: thio-TEPA--100--150 mg + methotrexate 75--100 mg; thio-TEPA--100--150 mg + 5-fluoruracil--1000 mg; cyclophosphane--2000 mg + methotrexate--75--100 mg; cyclophosphane--1600 mg + methotrexate--75--100 mg + 5-fluoruracil--750 mg. Lymphoinfusion was made in the lower extremity, and after 7--10 days it was repeated in the second one. Visual disappearance of the tumor was noted in 17 patients, lessening of the tumor size by two-thirds--in 16, a 1/2 decrease--in 20. Among 23 patients in stage III after the treatment parametrial infiltrations disappeared entirely in 11 cases and only in pelvic walls--in 12. In 40 cases an extensive extirpation of the uterus with adnexa was performed. In all cases degenerative changes in tumor tissues were observed, whereas in 7 cases no tumor cells were found. 相似文献
13.
Anterograde and retrograde tracing experiments have been used to demonstrate the origin and terminal distribution of commissural fibers in the first somatosensory cortex (SI) of the rat. The commissural fibers originate from pyramidal cells of all layers, but predominantly from layers III and V. The fibers terminate in a series of approximately vertical bands. In each of these there are concentrations of terminals extending from the inner portion of the molecular layer to the deep portion of layer III as well as in the superficial part of layer V, and in layer VI. Discrete vertical bands of cortex are reciprocally connected across the midline to give both the origin and terminal regions of the projection a patchy or "columnar" appearance. The commissural fibers arise from and terminate in areas of the cortex that lie between and alongside the aggregations of granule cells that distinguish SI of the rat. No commissural fibers terminate within the aggregations of layer IV cells themselves but the more superficial terminal ramifications may come to overlie these aggregations. A heterotopic projection to the contralateral second somatosensory cortex has been observed and is similar in form to the homotopic projection to SI. Many commissural fibers have crossed the midline in the corpus callosum by the day of birth but lie in the underlying white matter and do not enter the cortical plate until at least the third postnatal day. During the first postnatal week these fibers grow somewhat diffusely into the maturing cortex and their topographic and laminar pattern of distribution attains its adult characteristics by the end of the first week. Commissural axons, thus, arise from immature cells but the maturation of cell form seems to precede the ingrowth of these axons and the acquisition of commissural synapses. 相似文献
14.
The use of photodynamic dye and light inactivation for the treatment of genital herpes simplex virus infections has been associated with the risk of potential oncogenesis. Sixteen patients treated with neutral red and fluorescent light for documented herpetic infections were studied at intervals ranging from 9 to 52 months following treatment. Four patients treated with other modalities were included in the study. Biopsies of the treated areas were obtained, and 3925 tissue sections were examined. Mild atypical epithelial changes were focally present in most specimens regardless of therapy. Histologically identifiable premalignant change could not be demonstrated. 相似文献
15.
Cardioacceleration produced by operant conditioning was associated with elevation of plasma renin activity. This study suggests that emotional stimuli, which produce cardioacceleration, may also cause increased renin secretion, thus providing a mechanism by which factors operating through the mind and sodium intake could summate in the production of hypertension. 相似文献
16.
Affinity chromatography of human plasma and platelet factor XIII on organomercurial agarose 总被引:1,自引:0,他引:1
J Mcdonagh WG Waggoner EG Hamilton B Hindenbach RP Mcdonagh 《Canadian Metallurgical Quarterly》1976,446(2):345-357
A method for affinity chromatography of plasma and platelet factor XIII has been developed, based on known structural characteristics of these molecules. Plasma factor XIII is composed of a and b subunits which are held together by noncovalent interactions; platelet factor XIII has only a subunits. a subunit contains free sulfhydryl groups, while in b subunit all the cystines form disulfide bonds. The affinity gel is an organomercurial agarose with p-chloromercuribenzoate as the reactive group. Both the zymogen and activated forms of a subunit reversibly bind to the ligand by forming covalent mercaptide bonds and are eluted by reducing agents. b subunit does not bind to the affinity gel and is held to it only through interaction with a subunit. Affinity chromatography can be used to purify plasma and platelet factor XIII and to study interactions of the subunits. Experiments on the affinity chromatography of purified plasma factor XIII in several stages of activation agree with earlier observations that activation is a two-step procedure in which b subunit is not quantitatively released from the complex until the final stage of activation by Ca2+. 相似文献
17.
18.
19.
20.
We have determined the free cortisol concentration in serum using either the Amicon MPS-1 ultrafiltration-centrifugation method (I) or equilibrium dialysis (II). If procedure I was used we found that [1,2,6,7-3H]-, and [4-14C]cortisol had a lower affinity than unlabelled cortisol for corticosteroid binding globulin (CBG). The binding affinity (Ka) to three separate CBG-containing samples was 8-18 times lower for [1,2,6,7-3H]cortisol and 30-90 times lower for [4-14C]cortisol, when compared with that of unlabelled cortisol. This difference in affinity to CBG was not observed if method II was used for the free cortisol determinations. The observed isotope effect in method I is not caused by unspecific binding to material such as the Amicon MPS-1 chamber or to impurities in the tracer. We suggest that the centrifugation step during ultrafiltration changed the conformation of CBG, thereby reducing its affinity for labelled cortisol. It is concluded that incorrect results will be obtained if radiolabelled is cortisol used for determining the free cortisol content of plasma with the Amicon MPS-1 device. 相似文献