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41.
The genetic determinants of hair texture in humans are largely unknown. Several human syndromes exist in which woolly hair comprises a part of the phenotype; however, simple autosomal recessive inheritance of isolated woolly hair has only rarely been reported. To identify a gene involved in controlling hair texture, we performed genetic linkage analysis in six families of Pakistani origin with autosomal recessive woolly hair (ARWH; OMIM 278150). All six families showed linkage to chromosome 13q14.2-14.3 (Z = 17.97). In all cases, we discovered pathogenic mutations in P2RY5, which encodes a G protein-coupled receptor and is a nested gene residing within intron 17 of the retinoblastoma 1 (RB1) gene. P2RY5 is expressed in both Henle's and Huxley's layers of the inner root sheath of the hair follicle. Our findings indicate that disruption of P2RY5 underlies ARWH and, more broadly, uncover a new gene involved in determining hair texture in humans.  相似文献   
42.
It has been observed in laboratory experiments that when nonlinear dispersive waves are forced periodically from one end of undisturbed stretch of the medium of propagation, the signal eventually becomes temporally periodic at each spatial point. The observation has been confirmed mathematically in the context of the damped Korteweg-de Vries (KdV) equation and the damped Benjamin-Bona-Mahony (BBM) equation. In this paper we intend to show the same results hold for the pure KdV equation (without the damping terms) posed on a finite domain. Consideration is given to the initial-boundary-value problem {ut+ux+uux+uxxx=0, u(x,0)=φ(x), 0〈x〈1, t〉0,u(0,t)=h(t), u(1,t) = 0, ux(1,t) = 0, t〉0.It is shown that if the boundary forcing h is periodic with small ampitude, then the small amplitude solution u of (*) becomes eventually time-periodic. Viewing (*) (without the initial condition) as an infinite-dimensional dynamical system in the Hilbert space L^2(0, 1), we also demonstrate that for a given periodic boundary forcing with small amplitude, the system (*) admits a (locally) unique limit cycle, or forced oscillation, which is locally exponentially stable. A list of open problems are included for the interested readers to conduct further investigations.  相似文献   
43.
采用带限制算子的傅立叶拟谱方法近似求解了Burgers方程,分别证明了它的(Burgers方程)一般化的稳定性和收敛性,并获得了数值结果.  相似文献   
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The wide compatibility gene, S 5 n , can overcome embryo sac sterility between indica and japonica subspecies of rice. Therefore, it is very important to characterize the features of the S 5 n sequence to reveal the origin and evolution of S 5 n . In this paper, 26 cultivated rice haplotypes and 22 wild rice accessions harboring S 5 n were used to sequence S 5 n . The results showed that 15 genotypes among the 48 materials were fully consistent with control cultivar 02428 (CK). The other 33 accessions had different degrees of variation in the S 5 n sequence. Variations in the coding region mainly occurred in the second exon and eight materials showed a 10-bp deletion at 1710?C1719 bp, including wild (O. nivara) and cultivated rice, such as IRW501 and Yuetai B. S 5 n sequences were not biased and evolved neutrally. The 48 materials could be divided into 4 categories using a phylogenetic tree of the amino acid sequences. Most of the wild rice clustered together, and the cultivated rice clustered into another group. Eight cultivated rice and O. nivara (wild rice) clustered in another group, which were found to lack 10 consecutive bases in exon 2. Eight rice varieties with high numbers of differences in their S 5 n coding regions were crossed with testers (typically indica and japonica) to produced test cross F1 populations. The F1s were examined for their ability to overcome indica-japonica hybrid sterility. The result showed that the embryo sac fertility of S 5 n -containing hybrids increased significantly compared with control hybrids, but there were no differences among the materials with divergent sequences, indirectly proving that S 5 n is a non-functional gene.  相似文献   
46.
Chaotic behavior and detailed parameter analysis of stretch-twist-fold (STF) flow are investigated. STF flow is associated with fluid particle motion which naturally arises in the dynamo theory. It proposes a mechanism, by which a celestial bodies, such as earth and sun, can maintain and amplify the magnetic field continuously. Parameter analysis is performed using linearization theory for different choices of parameters. The existence of Heteroclinic trajectory of Sil’nikov type is proved using an undetermined coefficient method. It connects two non trivial equilibrium points. As a consequence, the Sil’nikov criterion guarantees that STF flow has Smale horseshoes chaos.  相似文献   
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为了探索微塑料和全氟辛烷磺酸类物质(PFOS)在海洋生物体内的复合污染毒性机制, 以翡翠贻贝为研究对象, 在聚苯乙烯微塑料(0.2 μm) 4.55×108个/L以及PFOS浓度为10, 100和1000 μg/L的条件下, 研究PFOS或微塑料单独暴露以及二者复合暴露对翡翠贻贝滤食率、活性氧水平(ROS)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、谷胱甘肽巯基转移酶(GST)活性和谷胱甘肽还原酶(GR)活性的影响。结果表明, 与溶剂对照组相比, 暴露于微塑料和PFOS后翡翠贻贝的滤食率均没有显著变化。在翡翠贻贝的鳃、内脏团和性腺中, 微塑料或PFOS的胁迫都会引起酶响应的显著变化。与PFOS单独暴露组相比, 微塑料和 1000 μg/L PFOS共同暴露时, ROS水平在鳃和性腺中显著提升, 在内脏团中显著下降; MDA含量在鳃和内脏团中显著提升, 在性腺中显著下降; GST和GR活性在鳃中显著下降, 在性腺中显著提高。研究结果说明微塑料会改变翡翠贻贝对PFOS的氧化应激响应。  相似文献   
49.
Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma.  相似文献   
50.
In this paper,we consider the power optimization problem in Orthogonal Frequency Division Multiplexing(OFDM)-based relay-enhanced device-to-device(D2D) communication.In a single cell transmission scenario,dualhop communication is assumed in which each D2D user re-uses the spectrum of just one Cellular User(CU).In this work,we formulate a joint optimization scheme under a Decode-and-Forward(DF) relaying protocol to maximize the sum throughput of D2D and cellular networks via power allocation over different sub-carriers.The problem is thus transformed into a standard convex optimization,subject to individual power constraints at different transmitting nodes.We exploit the duality theory to decompose the problem into several sub-problems and use Karush–Kuhn–Tucker(KKT) conditions to solve each sub-problem.We provide simulation results to validate the performance of our proposed scheme.  相似文献   
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