探寻均值不等式与2011年高考数学湖北卷21题之间的关系

2011年高考数学湖北卷21题(1)已知函数f(x)=lnx-x+1,x∈(0,+∞),求函数f(x)的最大值;(2)设ak,bk(k=1,2,…,n)均为正数,证明:①若a1b1+a2b2+…+anbn≤b1+b2+…+bn,则a1b1a2b1…anb1≤1;     

50 MW速调管用分数比脉冲调制器

研制了一套S波段50 MW速调管用分数比脉冲调制器,具有脉冲变压器变比1∶300、初级电源电压1.25 kV、输出峰值功率113 MW等特点。分数比脉冲调制器属于加法器式固态调制器的类型,其原理为分开铁心使其磁场感应叠加,再高变比脉冲变压器升压。利用1∶60的高变比升压脉冲变压器技术,实现了初级单元电路为较低工作电压、各组件模块化、放电单元接地等优点,同时实现了脉冲变压器初级低漏感值、次级绕组低分布电容值、放电单元及传输回路低电感值。工程样机测试结果为输出脉冲电压大于312 kV、脉冲电流大于360 A、脉冲前后沿小于1.4 μs的高功率全固态脉冲调制器,为国内工业辐照加速器、自由电子激光加速器等需要高稳定射频功率源的应用提供一种解决方案。分数比脉冲调制器具有输出脉冲宽度可较大范围调节,可以适应负载阻抗的较大范围变化,无线性调制器中使用的氢闸流管的寿命限制,较低工作电压的高运行可靠性等优点。     

12C6+束辐照引起的实验猪皮肤急性损伤反应的研究

探讨了正常皮肤对重离子辐照急性损伤反应的耐受性, 为重离子治癌临床应用提供安全性检测的实验依据。实验前10 min, 实验猪肌肉注射复方氯胺酮1.2 mg/kg进行麻醉, 然后在兰州重离子研究装置（HIRFL）辐照终端利用12C6+束照射, 辐照剂量分别为0, 12, 21和27 Gy, 辐照分3次完成, 剂量率约为1.2 Gy/min, Bragg峰区照射, 辐照后每隔7 d对照射野拍照并活检取样, 做HE组织病理学观察。不同剂量12C6+离子束辐照实验猪皮肤后, 皮肤外观反应随辐照剂量增大而加快, 表现为肿胀和色素沉积等; 皮肤组织结构的变化明显, 上皮细胞排列紊乱、 萎缩、 空泡变性; 基本恢复正常所需时间也越长, 且都存在明显的剂量效应关系。结果表明, 辐照剂量范围为0—27 Gy时, 重离子对正常皮肤的辐照是安全的。The tolerance of the normal skin to the acute radiation injury reaction induced by heavy ion beams has been studied experimentally. The experimental pigs were injected with 1.2 mg/kg ketamine in 10 min before irradiation and were irradiated with 0, 12 , 21 and 27 Gy 12C6+ ion at a dose rate of 1.2 Gy/min at the Heavy Ion Research Facility in Lanzhou（HIRFL）. The total radiation dose was finished by 3 times at Bragg Peak Region of Heavy Ion Beams.The radiation fields of skin were taken photo and performed biopsy. The contaneous tissues of radiation fields were stained by HE and examined histopatholo gical changes every seven days after irradiation. The results indicated that the cutaneous appearance reaction became more faster with radiation dosage rising and presented with swollen, melanin forming and so on after irradiated by the carbon ions at different dosage. The Pathological examination showed noticeable changes in histological and structural of experimental pigs skin, such as atrophy, vacuolation, denaturation and arranged irregularly in epithelial cells. Furthermore, the time for return to normality became longer with the increasing of radiation dosage. All indexes demonstrated correlation between the does and effects. It is concluded that the irradiation of heavy ion beams to normal skin is security when the radiation dose range is about 0—27 Gy.     

苹果酸基脂肪共聚酯反应性共混制备超韧聚乳酸共混物

通过反应性共混使聚乳酸(PLA)与增韧剂原位生成接枝共聚物,可增强界面相互作用,有效提高不相容共混物的韧性.本研究将聚(癸二酸/苹果酸-co-丁二醇/丙二醇)酯(PBSePM)在六亚甲基二异氰酸酯(HDI)作用下与PLA反应性共混制备了PLA/PBSePM共混物.重点研究了HDI对PLA/PBSePM共混物的力学性能、...     

矢车菊甙-辣根过氧化物酶-过氧化氢新体系及其在酶联免疫传感分析中的应用

以一种天然色素矢车菊素-3-葡萄糖苷（Cyanidin-3-glucose,CAG）为辣根过氧化物酶（HRP）底物建立了矢车菊甙-辣根过氧化物酶-过氧化氢新体系.CAG在540nm处有一个吸收峰（AP1）,在HRP催化下被H2O2氧化,AP1降低;同时,其氧化产物在482nm处产生一个新吸收峰（AP2）,并且反应体系中两峰值的比值R（AP2/AP1）与HRP量在一定浓度范围内呈线性相关.根据此原理,以猪口蹄疫病毒蛋白（food and mouth disease virus antigen,FMDVAg）为分析模型,建立了检测猪口蹄疫病毒的酶联免疫传感分析新方法.该方法利用伴刀豆蛋白（Conconvalina,ConA）对糖蛋白的识别特性固定HRP-猪口蹄疫病毒抗体连接物（HRP-FMDVAb）,由ConA介导和磁性分离实现了免疫反应特异性组分和非特异成分,以及反应免疫磁性珠与没反应免疫磁性珠的分离.运用制备的传感体系测定猪口蹄疫病毒的线性范围为1.5×10^-8～2.7×10^-6g/mL,抗原检出限为3.1×10^-9g/mL,相对标准偏差为3.7%（n=11）.底物CAG及其产物的水溶性好,对人体无毒副作用,在临床上可代替传统HRP底物进行免疫检测.     

Ab initio study on the electronic states and laser cooling of AlCl and AlBr

We investigate whether AlCl and AlBr are promising candidates for laser cooling. We report new ab initio calculations on the ground state X~1Σ~+ and two low-lying states(A~1Π and a~3Π) of AlCl and AlBr. The calculated spectroscopic constants show good agreement with available theoretical and experimental results. We also obtain the permanent dipole moments(PDMs) curve at multi-reference configuration interaction(MRCI) level of theory. The transition properties of A~1Π and a~3Π states are predicted, including the transition dipole moments(TDMs), Franck–Condon factors(FCFs), radiative times and radiative width. The calculated radiative lifetimes are of the order of a nanosecond, implying that they are sufficiently short for rapid laser cooling. Both AlCl and AlBr have highly diagonally distributed FCFs which are crucial requirement for molecular laser cooling. The results demonstrate the feasibility of laser cooling AlCl and AlBr, and we propose laser cooling schemes for AlCl and AlBr.     

Hybrid density functional study on lattice vibration,thermodynamic properties,and chemical bonding of plutonium monocarbide

Hybrid density functional theory is employed to systematically investigate the structural,magnetic,vibrational,thermodynamic properties of plutonium monocarbide(Pu C and Pu C_(0.75)).For comparison,the results obtained by DFT,DFT + U are also given.For Pu C and Pu C_(0.75),Fock-0.25 hybrid functional gives the best lattice constants and predicts the correct ground states of antiferromagnetic(AFM) structure.The calculated phonon spectra suggest that Pu C and Pu C_(0.75) are dynamically stable.Values of the Helmholtz free energy ?F,internal energy ?E,entropy S,and constant-volume specific heat C_v of Pu C and Pu C_(0.75) are given.The results are in good agreement with available experimental or theoretical data.As for the chemical bonding nature,the difference charge densities,the partial densities of states and the Bader charge analysis suggest that the Pu–C bonds of Pu C and Pu C_(0.75) have a mixture of covalent character and ionic character.The effect of carbon vacancy on the chemical bonding is also discussed in detail.We expect that our study can provide some useful reference for further experimental research on the phonon density of states,thermodynamic properties of the plutonium monocarbide.     

STABILIZED FINITE ELEMENT METHODS FOR THE REISSNER-MINDLIN PLATE

A new stabilized finite element method which is different from Hughes and Franco's (1988) is presented for the Reissner-Mindlin plate model. The least square mesh-dependent residual form of the shear constitute equation is added to the Partial Projection scheme to enhance the stability. Using piecewise polynomials of order k≥1 for the rotations, of order k+1 for the displacement and of order k-1 for the shear, the kth order error-estimates are obtained. Besides, our computing scheme can be also applied to some lower order elements. All error-estimates are obtained independent of the plate thickness, and the stability parameter is an arbitrary positive constant.     

爆炸法修复变形石油套管的研究

针对油田生产中大量石油套管发生变形的现状，提出用爆炸胀形法来修复变形的石油套管，建立了该方法的理论计算模型，推导了炸药量的计算公式，并用工程实例验证了公式的正确性。     

2009年北京高考数学理科第20题的思考

一、试题略解 第一小题非常简单，只要能够抓住性质P，那么解起来是非常容易的，基本上所有考生都能得到此处的分；而第二问除了求首项就是求的这个数列的前竹项和，而这个数列并非我们平常熟知的特殊数列，所以就得从它所具有的性质出发了，关键就在于它的运算封闭性，