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81.
气相色谱-质谱法测定猪肝中氯丙嗪残留量 总被引:5,自引:0,他引:5
猪肝中残留的氯丙嗪在碱性条件下经乙酸乙酯提取后,40℃水浴中旋转蒸发至近干,经乙腈溶解,正己烷脱脂,C18柱净化,以气相色谱-质谱选择86、233、272、318 4个碎片离子进行定性定量分析。氯丙嗪在10~200μg/L呈线性关系(R2为0.9998),3种不同添加浓度1.0、5.0和10μg/kg下氯丙嗪平均回收率分别为80.2%、90.7%、90.6%,相对标准偏差分别为8.6%、8.5%、5.9%,检出限(S/N=3)为1μg/kg,方法适用于猪肝等动物组织中氯丙嗪的测定。 相似文献
82.
采用十四种稀土(La、Ce、Pr、Nd、Sm、Eu、Gd、Dy、Ho、Er、Tm、Yb、Lu、Y)环烷酸盐-三异丁基铝络合催化体系,在室温下均能使苯乙炔(PA)于混合溶剂中直接成膜聚合。成膜聚合的最佳条件大致相同;[Ln(naph)_3]=3×10~(-5)mol/ml,[M]=3×10~(-4)mol/ml,Al/Ln:7,V_h/V_t=1。不同稀土元素显示的催化活性次序为Gd>Lu>Nd~Ce>Ho>Sm>Dy~Eu>Er>Pr>>La>Y~Tm>Yb。苯乙炔在含苯溶剂中反应活性较高,在卤代烃中反应活性很低。混合溶剂比单组分溶剂更有利于成膜聚合并有高的催化活性和高的分子量。各种稀土聚苯乙炔膜的结构和性能基本相同。稀土聚苯乙炔为片层结晶,具有较高的结晶性。 相似文献
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84.
Kaolinite is a kind of clay mineral which often causes large deformations in soft-rock tunnel engineering and thus causes safety issues.To deal with these engineering safety issues,the physical/chemical properties of the kaolinite should be studied from basic viewpoints.By using the density-functional theory,in this paper,the atomic and the electronic structures of the kaolinite are studied within the local-density approximation(LDA).It is found that the kaolinite has a large indirect band gap with the conduction band minimum(CBM) and the valence band maximum(VBM) being at the Γ and the B points,respectively.The chemical bonding between the cation and the oxygen anion in kaolinite is mainly ionic,accompanied by a minor covalent component.It is pointed that the VBM and the CBM of kaolinite consist of oxygen 2p and cation s states,respectively.The bond lengths between different cations and anions,as well as of the different OH groups,are also compared. 相似文献
85.
为了明确团聚现象及表面性质对ZnS纳米材料发光性质的影响,采用SiO2对ZnS材料进行了表面修饰,并对ZnS及ZnS/SiO2复合材料的光学性质进行对比研究.采用吸收光谱分析了包覆前后光吸收性质的差异,发现SiO2包覆后ZnS纳米材料的带边由333 nm红移至360 nm.为了研究ZnS纳米材料与ZnS/SiO2纳米复合材料的光发射性质,分别对含纳米材料的水溶液样品及粉末样品的发光光谱进行了采集.对比研究的结果表明,SiO2包覆后ZnS纳米材料在蓝紫光区的发光得到了明显增强.以氙灯作为激发光源所获得荧光光谱显示ZnS/SiO2粉末样品发光的积分强度增大为原来的17.5倍,但相同条件下针对溶液样品的测试结果显示其发光强度只增大了1.1倍,这种增强可用SiO2的存在抑制了ZnS纳米粒子间的团聚来解释,且这一推断由325 nm紫外激光激发下获得的光致发光数据进行了验证. 相似文献
86.
Pump-induced carrier envelope offset frequency dynamics and stabilization of an Yb-doped fiber frequency comb 下载免费PDF全文
In this paper, we demonstrate a carrier envelope phase-stabilized Yb-doped fiber frequency comb seeding by a nonlinear-polarization-evolution(NPE) mode-locked laser at a repetition rate of 60 MHz with a pulse duration of 191 fs.The pump-induced carrier envelope offset frequency( f0) nonlinear tuning is discussed and further explained by the spectrum shift of the laser pulse. Through the environmental noise suppression, the drift of the free-running f0 is reduced down to less than 3 MHz within an hour. By feedback control on the pump power with a self-made phase-lock loop(PLL)electronics the carrier envelope offset frequency is well phase-locked with a frequency jitter of 85 m Hz within an hour. 相似文献
87.
88.
以聚乙烯醇(PVA)为分散剂,过氧化苯甲酰(BPO)为引发剂,采用水相悬浮聚合法合成了聚甲基丙烯酸十二酯(PLMA),将其与聚氨酯(PU)共混、造粒、熔融纺丝制得PLMA/PU共混纤维.通过傅里叶变换红外光谱仪(FTIR)、扫描电子显微镜(SEM)、单纤维强力仪及光学接触角测量仪等分析了纤维的结构与性能,同时研究了纤维对有机液体的吸附性能及循环使用性能等.研究结果表明,纤维具有良好的疏水亲油性,吸附后,纤维形态明显胀大;纤维对油性低分子有机物具有良好的吸附性能,其中对甲苯、三氯乙烯、柴油、煤油和含有原油(质量分数为10%)的甲苯溶液最大吸附率分别为4.86,8.1,2.42,2.04和3 g/g,吸附油品后的纤维经脱附可多次循环使用;PLMA对纤维吸附有机液体起决定作用,而PU的存在对纤维吸油时保持形态和纺丝成形起到重要作用. 相似文献
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90.
Kaolinite is a kind of clay mineral which often causes large deformations in soft-rock tunnel engineering and thus causes safety issues. To deal with these engineering safety issues, the physical/chemical properties of the kaolinite should be studied from basic viewpoints. By using the density-functional theory, in this paper, the atomic and the electronic structures of the kaolinite are studied within the local-density approximation (LDA). It is found that the kaolinite has a large indirect band gap with the conduction band minimum (CBM) and the valence band maximum (VBM) being at the Γ and the B points, respectively. The chemical bonding between the cation and the oxygen anion in kaolinite is mainly ionic, accompanied by a minor covalent component. It is pointed that the VBM and the CBM of kaolinite consist of oxygen 2p and cation s states, respectively. The bond lengths between different cations and anions, as well as of the different OH groups, are also compared. 相似文献