全文获取类型
收费全文 | 777篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 180篇 |
金属工艺 | 28篇 |
机械仪表 | 22篇 |
建筑科学 | 33篇 |
矿业工程 | 1篇 |
能源动力 | 19篇 |
轻工业 | 83篇 |
水利工程 | 11篇 |
石油天然气 | 6篇 |
无线电 | 68篇 |
一般工业技术 | 108篇 |
冶金工业 | 113篇 |
原子能技术 | 15篇 |
自动化技术 | 109篇 |
出版年
2024年 | 3篇 |
2023年 | 5篇 |
2022年 | 15篇 |
2021年 | 21篇 |
2020年 | 20篇 |
2019年 | 23篇 |
2018年 | 19篇 |
2017年 | 24篇 |
2016年 | 32篇 |
2015年 | 18篇 |
2014年 | 29篇 |
2013年 | 66篇 |
2012年 | 49篇 |
2011年 | 48篇 |
2010年 | 19篇 |
2009年 | 35篇 |
2008年 | 33篇 |
2007年 | 42篇 |
2006年 | 22篇 |
2005年 | 19篇 |
2004年 | 21篇 |
2003年 | 29篇 |
2002年 | 20篇 |
2001年 | 15篇 |
2000年 | 15篇 |
1999年 | 13篇 |
1998年 | 31篇 |
1997年 | 25篇 |
1996年 | 17篇 |
1995年 | 12篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1968年 | 1篇 |
排序方式: 共有805条查询结果,搜索用时 0 毫秒
741.
Material characterization for the prediction of ductile fracture occurrence: An inverse approach 总被引:2,自引:0,他引:2
The most advanced approach to the prediction of ductile fracture occurrence in metal forming processes is represented by a damage mechanics formulation. Such an approach requires a suitable evaluation of the parameters which appear in the yield condition for the damaging material and in the model which governs the evolution of microvoids (nucleation, growth and coalescence), which allow to calibrate the model with respect to the actual state and properties of the material.
In the paper this aim is pursued employing an inverse identification approach based on an optimization technique which permits to adjust the material variables so that the numerical response matches the experimental one. In particular the load vs. displacement curve during a tensile test has been used to optimise the comparison between the numerical and the experimental results and to develop a full damage characterisation of the material. 相似文献
742.
V Silingardi M Federico L Cavanna P Avanzini PG Gobbi M Lombardo M Carotenuto A Frassoldati C Pieresca D Vallisa 《Canadian Metallurgical Quarterly》1995,17(3-4):313-320
A randomized trial was designed in order to compare the efficacy and feasibility of ProMECE-CytaBOM (P-C) and MACOP-B (M-B) in patients with advanced, aggressive non Hodgkin's lymphoma (NHL). P-C and M-B were chosen due to their association with a very high complete remission rate when compared to other published protocols. The study was conducted on 210 patients with intermediate or high-grade NHL in stage I bulky, or stages II-IV, randomized to receive either 6 courses of P-C delivered every 28 days (106 patients), or 12 weeks of M-B chemotherapy (104 patients). In both regimens doxorubicin was replaced by a 20% higher dose of epidoxorubicin (i.e. 30 mg/m2 of the analog). At the end of induction therapy patients could receive additional radiotherapy to residual masses or to sites of previous bulky disease. The two groups of patients were compared for response rates, number and severity of therapy related side effects, overall survival, disease-free survival, and time to treatment failure. Sixty-five patients (62%) treated with P-C and 69 patients (67%) treated with M-B achieved a complete remission, with no significant differences between the two treatment arms (P = 0.13). The overall objective response rate (complete + partial remission) was 74% for patients treated with P-C, and 81% for patients treated with M-B, respectively. The 4-year relapse-free survival rate was 59% for P-C and 69% for M-B, respectively (P = 0.11).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
743.
Occipital neuralgia, a painful condition thought to be caused by nerve entrapment, has been described in the general population. Athletes, particularly those who participate in collision sports, such as football, may be predisposed to this condition. An illustrative case is presented along with discussion of the differential diagnosis and treatment of this type of headache. 相似文献
744.
M Federico V Clò M Brugiatelli M Carotenuto PG Gobbi D Vallisa M Lombardo P Avanzini N Di Renzo D Dini L Baldini V Silingardi 《Canadian Metallurgical Quarterly》1998,83(9):800-811
BACKGROUND AND OBJECTIVE: To compare the efficacy of ProME(Epidoxorubicin)CE-CytaBOM (PE-C) and ProMI(Idarubicin)CE-CytaBOM (PI-C) in the treatment of adult patients with aggressive non Hodgkin's lymphoma in a multicenter randomized controlled trial performed by 18 centers of the Italian Lymphoma Study Group (GISL). DESIGN AND METHODS: One hundred and twenty-eight and 122 patients were randomly assigned to receive either 6 courses of PE-C or PI-C, respectively. Some patients achieving complete remission with induction therapy participated in another randomized study comparing no further therapy versus maintenance therapy consisting of four blocks of two drugs. RESULTS: The rate of CRs was 62% and 64% for patients treated with PE-C and PI-C, respectively (p = 0.51). The 5-year relapse-free survival was 60% for PE-C and 53% for PI-C (p = 0.29). The estimated relapse-free disease survival rates at 4 years were 75% for patients in the consolidation group and 57% for those in the observation group (p = 0.11). Patients alive in first complete remission 4 years after study entry were estimated to be 39% in the PE-C arm and 38% in the PI-C arm (p = 0.90). The 3-year and 5-year estimated survival rates were 61% and 55% for the PE-C group and 56% and 47% for the PI-C group (p = 0.26). Fatal toxicities occurred in 7 patients (2.9%) with active disease and in 4 patients (1.7%) in complete remission. Stage (p = 0.04), bulky disease (p = 0.02), serum LDH (p = 0.0006), serum albumin (p = 0.0051), hemoglobin (p = 0.0011), performance status (p = 0.0001), International prognostic index (p < 0.0001) and the index proposed by the French group G.E.L.A. (p < 0.0001) were of prognostic value. In a multivariate analysis (Cox regression model) alternatively IPI alone or G.E.L.A. index plus performance status emerged as independent prognostic factors. INTERPRETATION AND CONCLUSIONS: The present study indicates that epirubicin and idarubicin in a combined chemotherapy regimen, have similar activities. The toxic profile also indicates the safety of both anthracyclines at the dosages employed, suggesting their possible dose escalation in a combined chemotherapy setting. PE-C and PI-C were both effective and feasible regimens in an outpatient setting, with acceptable cardiovascular toxicity. The trend toward a better outcome in patients undergoing consolidation therapy after the achievement of a complete remission, warrants further investigation. 相似文献
745.
Secure remote access from office to home 总被引:1,自引:0,他引:1
When accessing IP-ready appliances at home from a remote site, security is a major concern. We address the seemingly common scenario of accessing IP-ready appliances behind a home firewall from a remote PC within a corporate intranet. The scenario reveals the complex nature of secure remote access. Various IP tunneling technologies can provide secure remote access without sacrificing the ubiquitous accessibility of the Internet; however, the problem of multiple authentication processes is evident in the framework. Digital certificate technology can simplify the authentication process required to establish multiple IP tunnels. However, IP tunneling technologies do not scale well, and become infeasible if the number of firewalls to traverse increases. Scalability and end-to-end security requirements call for the deployment of authenticated firewall traversal methods that use minimal or no IP tunnels. This article describes a meet-in-the-middle network model as a simple and practical method 相似文献
746.
S Puleo G Trombatore R Lombardo L Greco M Rodolico A Di Cataldo 《Canadian Metallurgical Quarterly》1998,18(8):479-481
Many surgical procedures have been proposed in the treatment of varicocele; however, the rate of recurrence and of postoperative complications, together with important correlation of this disease with male sterility, has played an important role in determining the success of microsurgery. In the present brief review, the indications for microsurgery and microsurgical dissection and/or anastomosis are described in comparison to traditional surgery. 相似文献
747.
Polystyrene powder was compacted in a cylindrical die at constant compaction speed. Compaction was found to be influenced by test temperature, compaction speed and void fraction of the powder bed. The stress reduction behavior of an axial stress σ1 and a radial stress σ2 was observed at constant void fraction after compaction. The stress reduction thus obtained was interpretable by adopting an octahedral normal stress σoct and an octahedral shear stress τoct which were converted from σ1 and σ2. This behavior was attributable to the deformation of polystyrene around contact points and to a sliding mechanism between particles. It was ascertained that the relation between a shear stress τ and a normal stress σ obtained on compaction differed from that obtained in shear by a mechanism involving movement between polystyrene particles. 相似文献
748.
749.
750.
The selective oxidation of methane has been studied both in the presence and absence of solids (inert or catalysts) with and without NO added, at 1 bar of total pressure. NO enhances the yield to formaldehyde, while the solids favor its decomposition. These results, together with abundant literature data, show a maximum for formaldehyde yield of about 4.0%. 相似文献