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1.
Breast and prostate cancers are frequently treated with chemotherapy. Several novel chemicals are being reported for this purpose, particularly synthetic and natural benzophenones. This work reports the synthesis of substituted 2-hydroxybenzophenones through 1,4-conjugate addition/intramolecular cycloaddition/dehydration of nitromethane on key intermediate chromones. Structures were extensively studied by means of 2D NMR spectroscopy and single-crystal XRD. Their cytotoxicity was evaluated in vitro in two breast cancer cell lines (MDA-MB-231 and T47-D) and one prostate cancer cell line (PC3). The most potent compound exhibited good cytotoxic effects against the three cancer cell lines (IC50 values ranging from 12.09 to 26.49 μm ) and induced cell-cycle retardation only on prostate cancer cells, which suggested that it might exert cell-type-specific effects.  相似文献   
2.
The purpose of this paper is to establish a coupled coincidence point for a pair of commuting mappings in partially ordered complete metric spaces. We also present a result on the existence and uniqueness of coupled common fixed points. An example is given to support the usability of our results.  相似文献   
3.
This paper describes the development of an empirical model which may be used for predicting the G*/sin δ for neat and crumb rubber modified (CRM) binders. The model was developed using 36 unique CRM binder combinations, crumb rubber concentrations were varied at 5% intervals between 5% and 20%. The effects of crumb rubber particle size on model accuracy were also studied, ultimately a model was produced with the capability of predicting G*/sin δ values over a range of temperatures and crumb rubber concentrations. By definition, the upper limit of the performance grade is dependent on the G*/sin δ value; therefore, the relationship was also considered in terms of high end failure temperature.The rubber coefficient for G*/sin δ (Rcg) was identified as an important parameter in the estimation of G*/sin δ in addition to the CRM. This term is a quantitative representation of the increase typically witnessed in G*/sin δ values with the addition of CRM. Ambient ground CRM exhibited higher Rcg values than cryogenically ground particles. Additionally, 95% confidence intervals were generated for the predictive model, thus providing a range of accuracy for the model. The resulting confidence intervals were approximately ±1300 Pa, these confidence intervals were seen to capture 92.6% of the 462 data points used. Findings from this research suggest that the differences between cryogenic and ambient CRM binder are accurately described using the Rcg, furthermore binder properties may be predicted using an empirical equation.  相似文献   
4.
提出了在面内剪应力与正应力联合作用下膜单元破坏模式识别、设计和强度计算的简化方法。该SMCS(合成应力简化模型)的非迭代方法以修正受压理论(MCFT)的简化结果为基础。除了钢筋的作用大于"平衡"钢筋用量而被忽略,以及最大剪应力不超过断裂强度以外,这种简化使得方程与塑性理论方程相类似,断裂强度从普通和高强混凝土(100兆帕)膜试验数据中得到。以平面内剪应力和正应力为条件,对84个钢筋混凝土膜试验结果进行对比,试验剪切力强度与计算结果的比值平均为1·03,变异系数为11.3%。对于原始的修正受压理论,对应的值分别为0.99和11.1%。所提出方法的结果与ACI规范、简化的修正受压理论以及塑性理论也进行了比较,得到了满意的结果。49个试件中有45个破坏模式可以用所提出的合成应力简化模型准确计算,通过设计和承载力计算案例,对简化模型进行了验证。  相似文献   
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Metabolic acidosis is frequently present, poorly controlled, and associated with adverse effects among hemodialysis patients. Potential determinants of metabolic acidosis include endogenous acid production, administration of alkali, neutralization of acid by buffers, dilution of serum bicarbonate by interdialytic fluid gain, and loss of bicarbonate in stool. Understanding the relative importance of these determinants may help guide efforts to manage metabolic acidosis. We used chart abstraction, patient interviews, and laboratory testing to assess variables related to acid production (protein breakdown), alkali administration (dialysis dose, missed treatments, dialysate bicarbonate concentration, oral bicarbonate supplements), acid buffering (phosphorus binders), dilution of bicarbonate (interdialytic weight gain), and loss of bicarbonate in stool (diarrhea) for 190 randomly selected patients from 44 hemodialysis facilities. We used multivariate analyses to determine which potential determinants were independently associated with predialysis serum bicarbonate levels. Of all patients, 30% had metabolic acidosis (serum bicarbonate level <22 mEq/L). On multivariate analysis, metabolic acidosis was more likely with increased protein nitrogen appearance (odds ratio [OR] 1.60 per 0.2 g/kg/day, p=0.001) and less likely with increased Kt/V (OR 0.61 per 0.20 increase in Kt/V, p<0.001) and with increased calcium carbonate use (OR 0.38 per 2 g/day, p=0.003). Key determinants of metabolic acidosis among hemodialysis patients are protein breakdown, dialysis dose, and specific phosphorus binders. Further work is needed to develop interventions to address these determinants.  相似文献   
7.
Gold nanorods (GNRs) have promising applications in drug delivery and cancer treatment and are generally administered via direct injection into the circulation. Thus it is necessary to evaluate their potential adverse effects on blood vessels. Herein, GNRs with various surface modifications are used to evaluate the toxicity and cellular uptake of GNRs into vascular endothelial and smooth muscle cells of isolated rat aortic rings. Surfactant-capped GNRs are synthesized and either coated with polyelectrolyte (PE) to prepare PE-GNRs, or modified with thiolated polyethylene glycol (PEG) to prepare PEG-GNRs. Using toxicity assays, small-vessel myography, fluorescence microscopy, and electron microscopy, it is shown that therapeutic concentrations of PE-GNRs but not PEG-GNRs are toxic to the vascular endothelium, which leads to an impaired relaxation function of aortic rings. However, no toxicity to smooth muscles is observed. Moreover, electron microscopy analysis confirms the cellular uptake of PE-GNRs but not PEG-GNRs into the endothelium of exposed aortic rings. The difference in toxicity and cellular uptake of PE-GNRs versus PEG-GNRs is explained and linked to free surfactant molecules and protein adsorption, respectively. The results indicate that toxicity and cellular uptake in the vascular endothelium in blood vessels are potential adverse effects of systemically administered GNR solutions, which can be prevented by appropriate surface functionalization.  相似文献   
8.
Asphalt binder viscosity is of great importance during the production process of hot mix asphalt mixture as typically asphalt plants will store binders between 149 °C and 177 °C. SHRP guidelines state that asphalt binder viscosity must not exceed 3 Pa s. Therefore, given the documented increases in asphalt viscosity when modified with crumb rubber modifier (CRM) it is necessary to produce asphalt binder that fulfills the SHRP criteria while not exceeding plant mixing and storing requirements. This paper reports the results of an investigation of the importance of CRM properties on viscosity of CRM binder. Two binder sources were modified at four concentration levels using four different crumb rubber sources; the viscosities of the produced binders were evaluated by AASHTO T 316. Crumb rubber properties were evaluated by elemental analysis using a scanning electron microscope (SEM) and by determination of glass transition temperature (Tg) using a differential scanning calorimeter (DSC). In general, results indicate that processing procedure and tire type plays an important role in the determination of CRM binder viscosity.  相似文献   
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Participatory optimization scenario process was developed for water resources management of the Zarqa River Basin in Jordan. The basin was selected to represent a case study of semi-arid area in the Mediterranean because of its entire range of prototypical water management problems. The nature of the institutional framework, the severity of the water related problems and concentration of population in the basin have required the need for stakeholders’ involvement in the optimization process. The paper demonstrates a Water Resources Model (WRM) consisting of integrated cascade of modules, embedded in a framework of a participatory approach in water resources optimization. The system includes baseline scenario, identification of constrains and instruments, the optimization scenario and analysis of results. In a participatory approach, stakeholders identified the optimization criteria (constraints) and the management interventions (instruments). Constraints were set to securing high supply/demand ratio of 0.98 and improving reliability of supply to 75 %, while specific eight instruments were suggested and manipulated by the model to achieve the above criteria. The results of the WRM optimization scenario showed that the specified constraints were met so that the supply/demand ratio increased from 0.90 to 0.996 and the reliability of supply improved from 58 % to 84 %. The benefit/cost ratio, water shortfall, and the economic efficiency had responded effectively. The model proved its efficiency in using the full featured basin characteristics towards baseline and optimization scenarios with the support of stakeholders in simulating the basin behavior over time using the model parameters.  相似文献   
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