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51.
为了解决县域三次产业标杆不属于同一组织(市县)的问题,基于县域三次产业投入产出数据,使用超效DEA-Malmquist和面板数据模型,建立了将县域三次产业优势和谐地统一到一体的虚拟标杆.应用虚拟标杆理论实证分析了海南省县域三次产业,并以万宁市作为虚拟标杆的实施者,给出了万宁市三次产业资源配置的优化决策.结果表明,构建县域三次产业虚拟标杆对提高标杆实施者的三次产业效率具有显著的作用.  相似文献   
52.
Scutellariae Radix (SR), the dried root of Scutellaria baicalensis Georgia, is a famous Chinese materia medica that has been widely employed. Raw Scutellariae Radix (RSR), steamed Scutellariae Radix (SSR), and wine Scutellariae Radix (WSR) are adopted for use in clinical practice. Because of their easily confused appearance, they are always misused. Aiming at this problem, an ultra performance liquid chromatography coupled with photodiode array detector (UPLC-PDA) method was established to survey misuse of the RSR and the processed SR (SSR and WSR) in the market by employing baicalin (BC), wogonoside (WS), baicalein (BN), and wogonin (WN) as quality indicators. Fortunately, β-glucuronidase, which mediates conversion from flavone glycoside to aglycone, was identified in the RSR samples by the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The significant production of BN and WN was witnessed in the RSR samples, which did not occur in the SSR and WSR samples in virtue of the inactivated β-glucuronidase. Besides, the different capacities of β-glucuronidase were evaluated in the tested samples. In general, we provided the first evidence to scientifically identify RSR from SSR and WSR.  相似文献   
53.
During a mass casualty incident (MCI), to which one of several area hospitals should each victim be sent? These decisions depend on resource availability (both transport and care) and the survival probabilities of patients. This paper focuses on the critical time period immediately following the onset of an MCI and is concerned with how to effectively evacuate victims to the different area hospitals in order to provide the greatest good to the greatest number of patients while not overwhelming any single hospital. This resource-constrained triage problem is formulated as a mixed-integer program, which we call the Severity-Adjusted Victim Evacuation (SAVE) model. It is compared with a model in the extant literature and also against several current policies commonly used by the so-called incident commander. The experiments indicate that the SAVE model provides a marked improvement over the commonly used ad-hoc policies and an existing model. Two possible implementation strategies are discussed along with managerial conclusions.  相似文献   
54.
Effectiveness involves more than simple efficiency, which is limited to the production process assessment of peer operational units. Effectiveness incorporates variables that are both controllable (i.e. efficiency) and non-controllable (i.e. perceived quality) by the operational units. It is a fundamental driver for the success of either a for-profit or a non-for-profit unit in a competitive environment that is customer/citizen- and goal-oriented. Additionally, with respect to the short-run production constraints, i.e. the resources available and controllable by the operational units, and the legal status, we go beyond the traditional effectiveness assessment techniques by developing a Modified or “rational” Quality-driven-Efficiency-adjusted Data Envelopment Analysis (MQE-DEA) model. This particular model provides in the short run a feasible effectiveness attainment path for every disqualified unit in order to meet high-perceived quality and high-efficiency standards. By applying the MQE-DEA model a new production equilibrium is determined, which is different from the equilibrium suggested by the mainstream microeconomic theory, in that it takes into account not only the need for operational efficiency but also the customer-driven market dynamics.  相似文献   
55.
在线社交网络中谣言的传播与抑制   总被引:6,自引:0,他引:6       下载免费PDF全文
顾亦然  夏玲玲 《物理学报》2012,61(23):544-550
根据真实在线社交网络中谣言的传播特点以及有疾病潜伏期的传染病模型,提出一个新的基于在线社交网络的谣言传播SEIR模型.首先建立基于SEIR模型的动力学演化方程组,然后给出一个高效的抑制谣言传播的免疫策略——重要熟人免疫策略.最后在真实在线社交网络Facebook的用户数据集上,结合SEIR模型与动力学演化方程组以及包含重要熟人免疫策略在内的多种免疫策略,对免疫前后谣言传播的演化过程进行计算机仿真.仿真结果表明SEIR模型符合真实在线社交网络的传播特性,且重要熟人免疫策略是解决在线社交网路中谣言抑制问题的最佳方案.  相似文献   
56.
Motivated by an underground mining operation at Kiruna, Sweden, we formulate a mixed integer program to schedule iron ore production over multiple time periods. Our optimization model determines an operationally feasible ore extraction sequence that minimizes deviations from planned production quantities. The number of binary decision variables in our model is large enough that directly solving the full, detailed problem for a three year time horizon requires hours, or even days. We therefore design a heuristic based on solving a smaller, more tractable, model in which we aggregate time periods, and then solving the original model using information gained from the aggregated model. We compute a bound on the worst case performance of this heuristic and demonstrate empirically that this procedure produces good quality solutions while substantially reducing computation time for problem instances from the Kiruna mine.  相似文献   
57.
一种辨识投入产出模型中主系数的方法   总被引:1,自引:0,他引:1  
目前在投入产出模型中四种常用辨识主系数的方法都是针对国民经济主系统而言,而随着我国经济的发展,一些具有相同经济特征的部门组成的国民经济子系统正在国民经济中的地位日趋显著,辨识国民经济子系统的主系数也就显得尤为重要.本文依据直接消耗系数的剔除将会使子系统蕴含受影响对象的信息量遭受损失,没有被剔除的系数集应蕴含受影响对象最少的信息量,以此达到剔除主系数损失最大的思想提出了损失量法,用以辨识国民经济子系统的主系数,并对2002年中国投入产出表的农业系统作了实证分析.同时将损失量法扩展到辨识国民经济主系统的主系数方面,并和信息量法作了比较,证明了损失量法能够比信息量法以更少的主系数达到相同的阈值,即在相同的阈值下损失量法选出的主系数个数比信息量法少.  相似文献   
58.
中国非金融行业上市公司现金流风险研究   总被引:2,自引:0,他引:2  
本文研究了我国非金融行业上市公司经营净现金流的风险状况,建立了风险现金流(Cash-Flow-at-Risk)的POT模型,在可比公司估计的分析框架下,度量并分析经营净现金流风险。实证结果表明:第一、房地产业和综合类风险现金流级别相对最高,而采掘业、交通运输仓储业、电力煤气及水的生产与供应业的风险现金流相对最低;第二、除房地产业和综合类业外,其他行业ST公司风险现金流值均比同行业正常公司值要高;第三、受金融危机的影响,与2006、2007年同期相比,2008年经营净现金流为负值公司数目及超出风险现金流值的公司数目均明显增加。  相似文献   
59.
研究“割圆术”思想在高等数学教学中的教学设计,讨论基于“割圆术”思想在教学中设置疑问与思考的方法,并将“割圆术”作为重要极限的应用,推导出“割圆术”中的圆面积公式.  相似文献   
60.
为了研究金融支持如何影响战略性新兴产业创新主体培育的问题,在剖析金融支持主体间双螺旋耦合机理基础上,构建了战略性新兴产业金融支持两阶段演化博弈模型,运用动态系统的相平面理论求取两阶段ESS近似解析解,并借助MATLAB实现两阶段演化博弈模型的数值仿真,分析不同参数赋值对两阶段ESS演进的影响。研究发现:(1)存在机会主义(补贴创新利润率T1<创新外活动利润率T2)和非机会主义行为(k>T2)两种对立占优情境;(2)机会主义行为(或非机会主义)占优情境下,金融支持主体的期望社会效用越小(或越大)、适度减小(或增加)补贴金额,越有利于提升战略性新兴产业创新主体接受补贴的积极性;(3)战略性新兴产业创新主体的自有资金R对其积极性影响不大,而补贴资金利率a越稳定越有利于提高其积极性。基于上述结论,本文最后构建了战略性新兴产业金融支持两阶段ESS演进实现框架,并探究其“累积式”、“悖论式”、“累积—悖论式”递进功能路径,为政府制定提升创新主体培育金融支持效率的相关政策提供了理论支持。  相似文献   
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