Growth kinetics of interfacial intermetallic compounds formed in SnPbInBiSb high entropy alloy soldered joints on Cu substrates

The growth behavior of the complex intermetallic compounds(IMCs)formed at the interface of Cu/SnPbInBiSb high entropy alloy solder joints was explored.The growth inhibition mechanism of the IMCs at the Cu/SnPbInBiSb solid−liquid reaction interface was revealed.The results showed that the growth rate of the complex IMCs obviously decreased at the Cu/SnPbInBiSb solid−liquid reaction interface.The maximum average thickness of IMCs only reached up to 1.66μm after reflowing at 200℃for 10 min.The mechanism for the slow growth of the complex IMCs was analyzed into three aspects.Firstly,the high entropy of the liquid SnPbInBiSb alloy reduced the growth rate of the complex IMCs.Secondly,the distorted lattice of complex IMCs restrained the diffusion of Cu atoms.Lastly,the higher activation energy(40.9 kJ/mol)of Cu/SnPbInBiSb solid−liquid interfacial reaction essentially impeded the growth of the complex IMCs.

曹张地道战的前前后后

忻州市忻府区是著名的革命老区,无论在抗日战争还是在解放战争中,都对中国革命的胜利做出了重要的贡献。如著名的忻口战役、蒲阁寨围困战、晋北战役等等。前不久我们走进忻府区曹张地道战遗址,重温那段历史,回望那段峥嵘的岁月。

Nine compounds from the root bark of Lycium chinense and their anti-inflammatory activities

Two new compounds, named lyciumlignan D(1) and lyciumphenyl propanoid A(2), along with seven known compounds, were isolated from the root bark of Lycium chinense. Their structures were elucidated using spectroscopic data(UV, IR, HR-ESI-MS, 1D and 2D NMR, CD), as well as by comparison with those of the literature. Compounds 3–9 were isolated from this genus for the first time. In the in vitro assay, compounds 3, 6, and 7 exhibited stronger anti-inflammatory effects than the positive control curcumin at a concentration of 10 μmol/L.

Elevated high sensitive C-reactive protein and apelin levels after percutaneous coronary intervention and drug-eluting stent implantation

Objective:Percutaneous coronary intervention(PCI) triggers an acute inflammatory response,while sirolimus is known to have anti-inflammatory properties;the inflammatory system response to PCI after sirolimus-eluting stent placement remains unclear.The purpose of this study is to determine the changes in high sensitive C-reactive protein(hs-CRP) and apelin after PCI procedure and drug-eluting stent implantation in patients with and without reduced left ventricular systolic function.Methods:Forty-eight consecutive patients undergoing PCI at the Beijing Anzhen Hospital between July and September 2006 were recruited.Sirolimus-eluting stents were employed in all patients.Blood samples were drawn immediately before and 24 h after the procedure.Plasma hs-CRP and apelin levels were determined by enzyme immunoassay.Results:Paired t-test revealed a significant increase in both hs-CRP and apelin post-procedure(P=0.006 and P<0.0001,respectively).Patients with reduced left ventricular ejection fraction(LVEF) had significantly lower baseline apelin levels compared to those with normal ventricular function [(46.8±10.8) vs.(72.0±8.4) pg/ml,P<0.001].However,apelin increased to a level similar to the level of those with normal left ventricular systolic function 24 h after the PCI procedure [(86.7±11.6) vs.(85.1±6.1) pg/ml,P=0.72].Conclusions:hs-CRP and apelin levels increased after PCI and sirolimus-eluting stent implantation.Patients with impaired left ventricular systolic function had significantly lower baseline apelin levels,which increased significantly after PCI.

Metallurgical microstructure control in metal-silicon reactions

A comprehensive review on interfacial reactions to form silicides between metal and Si nanowire or wafer is given.Formation of silicide contacts on Si wafers or Si nanowires is a building block needed in making current-based Si devices.Thus,the microstructure control of silicide formation on the basis of kinetics of nucleation and growth has relevant applications in microelectronic technology.Repeating events of homogeneous nucleation of epitaxial silicides of Ni and Co on Si in atomic layer reaction is presented.The chemical effort on intrinsic diffusivities in diffusion-controlled layer-typed intermetallic compound growth of Ni2Si is analyzed.

乡间逆流伪宗教

经过四十年的沉寂,中国民间的宗法势力正在日益发展和抬头。所谓‘伪宗教’,不过是民间宗法势力发展中的一种形式。问题的复杂在于:宗法关系是中国长期历史发展中的一种社会关系形态,它不可能简单地靠法律或者靠发动社会革命来解决;另一方面,宗法关系中反现代化的一面(比如‘伪宗教’)又在恶化着社会秩序,在当前必须予以制约。在法律不便干预的情况下,舆论也算是一种教化的方式吧。