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571.
AIn 2005, the classical intersection bodies and Lp intersection bodies were extended. Afterwards, the concept of general Lp intersection bodies and the generalized intersection bodies was introduced. In this paper, we define the generalized bodies with parameter. Besides, we establish the extremal values for volume, Brunn-Minkowski type inequality for radial combination and Lp harmonic Blaschke combination of this notion.  相似文献   
572.
In this paper, we consider the three dimensional compressible viscous magnetohydrodynamic equations(MHD) with the external potential force. We first derive the corresponding non-constant stationary solutions. Next, we show global wellposedness of the initial value problem for the three dimensional compressible viscous magnetohydrodynamic equations, provided that the initial data is close to the stationary solution. Finally, based on the elaborate energy estimates for the nonlinear system and L~p-L~q decay estimates of the linearized equation, we show the optimal convergence rates of the solution in L~q-norm with 2≤q≤6 and its first derivative in L~2-norm when the initial perturbation is bounded in L~p-norm with 1≤p6/5.  相似文献   
573.
Green coverage has pronounced influences on urban heat island (UHI) effect, while the impacts of seasonal variation and Land-Use/Land-Cover (LULC) types on this effect has not been implemented. This paper investigated the spatio-seasonal characteristics of urban thermal environment and the vegetation-soil mixed area, and then explored the effects of vegetation status on UHI intensity from the perspectives of seasons and regions in Xi’an using four Landsat 8 images. UHI intensity index was implemented to extract UHI intensity based on thermal infrared imagery, and difference vegetation index (DVI) was used to represent vegetation-soil mixed area. Results indicated that DVI has impacts on UHI intensity, and their relations vary with season and region. In the whole Xi’an, if UHI intensity is smaller than -0.1, DVI increases with the increase of UHI intensity; whereas for UHI intensity is greater than -0.1, DVI decreases with increases of the UHI intensity from early spring to autumn. The highest correlation level was discovered in the autumn map (R2=0.713). Results of correlation analysis further displayed that DVI positively correlated with UHI intensity at impervious surface, and that the main urban area possessed the best correlation with R2=0.564 5.  相似文献   
574.
A time-domain electromagnetic transmitter (TDET) with great power and large current was designed by using a closed-loop phase shifting control strategy. A clamping voltage source circuit was applied in this system to improve the falling edge of emission current and shorten the turn-off time. The simulated results showed that this TDET exhibited the advantages including a large current, strong capability for rapid turn-off, stably output voltage, preferably dynamic performance, a widely adjustable range in transmitting voltage, accurate measurement precision.  相似文献   
575.
In order to improve the efficiency of the fingerprint core location algorithm, a fingerprint core location method using sliding window on the basis of core location algorithm with the complex filter was proposed. The local region of the fingerprint image was extracted by a fixed-size window sliding in the region of the fingerprint image, and the selected local region by window as the calculation object is used to detect the core. The experiment results show that the method cannot only effectively detect fingerprint core, but also improve the efficiency of the detection algorithm comparing with the global fingerprint core location detection algorithm.  相似文献   
576.
This paper describes a simple method of generating concentration gradients with linear and parabolic profiles by using a Christmas tree-shaped microfluidic network.The microfluidic gradient generator consists of two parts:a Christmas tree-shaped network for gradient generation and a broad microchannel for detection.A two-dimensional model was built to analyze the flow field and the mass transfer in the microfluidic network.The simulating results show that a series of linear and parabolic gradient profiles were generated via adjusting relative flow rate ratios of the two source solutions(R_L~2≥0.995 and _PR~2≥0.999),which could match well with the experimental results(R_L~2≥0.987 and _PR~2≥0.996).The proposed method is promising for the generation of linear and parabolic concentration gradient profiles,with the potential in chemical and biological applications such as combinatorial chemistry synthesis,stem cell differentiation or cytotoxicity assays.  相似文献   
577.
In this paper, we show that when Minkowski measure of asymmetry of convex body K of constant width is bigger than α (n-1), K has at least n+1 critical chords, where \(\alpha (n) = \frac{{n + \sqrt {2n(n + 1)} }}{{n + 2}}\).  相似文献   
578.
The Wiener index of a connected graph (molecule graph) G is the sum of the distances between all pairs of vertices of G. In this paper, simple exact formula are established for the expected value of Wiener index in random cyclooctane chain. Moreover, we obtain the average value of the Wiener indices with respect to the set of all cyclooctane chains with n octagons.  相似文献   
579.
目的探讨联合检测血清胱抑素C(CYSC)、β_2微球蛋白(β_2-MG)和尿转铁蛋白(TRF)对原发性肾小球肾炎患者的早期诊断价值.方法选择原发性肾小球肾炎患者50例为观察组,选择体检中心健康体检者50例作对照组,比较两组3种检验指标的结果并进行分析.结果观察组血清中CYS C,β_2-MG和TRF水平高于健康对照组,差异具有统计学意义(P0.05).观察组根据临床病理分型的Ⅱ,Ⅲ,Ⅳ型患者血清中CYSC,β_2-MG,TRF水平浓度均高于Ⅰ型,血清水平呈递增性升高.结论通过联合检测CYSC,β_2-MG,TRF有助于原发性肾小球肾炎的早期诊断,并且能够准确、灵敏地反映肾小球功能损伤程度.  相似文献   
580.
目的比较张力带和髌骨爪置入治疗单纯横行骨折和粉碎性骨折患者疗效,为临床两种手术方法的选择提供依据.方法对接受治疗的38例髌骨骨折患者进行回顾性分析,其中20例患者采用张力带疗法,18例患者采用髌骨爪疗法,比较不同疗法患者手术时间、术中出血量、并发症发生率、骨折愈合时间、膝关节功能恢复情况.结果张力带固定组患者术中出血量(305.2±36.5)m L,显著高于髌骨爪固定组患者(283.4±24.8)m L(P0.05),张力带固定组粉碎性骨折患者平均手术时间(54.1±9.1)min,显著长于髌骨爪固定组粉碎性骨折患者(52.9±2.8)min(P0.05).两组患者骨折愈合时间无显著性差异(11.9±1.9,12.4±1.8)周,膝关节功能评价平均分髌骨爪固定组患者(78.7±9.3)分,显著优于张力带固定组患者(84.7±9.2)分(P0.05).结论对于一般髌骨横行骨折患者,可采用张力带固定方式,而对于年龄较大、身体素质较差、粉碎性骨折患者,推荐采用髌骨爪固定方式,以减少术后并发症发生,促进膝关节功能恢复.  相似文献   
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