怎样告慰钱伟长先生在天之灵？

这些天来,在上海大学延长校区,已有三万余人前来悼念钱伟长先生;社会上,各方人士以各种方式在表示对这位科技伟人离世的悲恸. 一位大学校长的辞世在世间引起这样大的震撼,说明钱伟长先生在人们心目中的崇高地位,说明他的精神感人至深！此刻,我想说的是,老校长已经永远地离开了我们,我们怎样告慰他老人家的在天之灵？我认为,最好的行动是传承他的伟大精神,倾情奉献,实现他的遗愿！什么是钱伟长精神？可以归纳为6个字：爱国,执着,坦荡.钱校长是彻底的爱国者,爱国主义是贯穿他漫长人生的红线. 他在人生抉择的六个关口,他都以爱国主义为准绳毫不犹豫地做了正确的选择. 无论在顺境还是在逆境,他的热爱祖国的拳拳之心从未改变. ``反右'之后的26年,他承受了各种屈辱和磨难,但报国之情矢志不渝.1980年代初,国内盛传钱伟长已移居国外,钱先生一笑置之,他说：``我从来没这么想过,我要是有这个想法,1946年就不会回来. 我是中国人,决不会离开哺育我成长的伟大的祖国.我的岗位在这里！'有人问起这些年他对所遭受的不公正待遇的想法,他说：``祖国是我们的母亲,哪有母亲不爱自己的子女的？你能说母亲错打你几下屁股,你就记恨了吗？天下没这个事情. 我们对祖国对人民的责任感就应当是永恒的. '从中可以看出他热爱祖国的赤子之心！所以,我们要慰籍老人家的在天之灵,首先要像钱先生那样,成为彻头彻尾彻里彻外的爱国者.     

A multi-functional fluorescent sensor for Zn2+ and HSO4− based on a new diarylethene derivative

A new photochromic diarylethene derivative with a hydralazine unit was designed and synthesized. It was not only acted as a Zn²⁺ sensor with the fluorescent color change from dark blue to bright orange, but also acted as a fluorescent sensor for HSO₄^? with the fluorescent color change from dark blue to bright blue. Furthermore, the derivative also exhibits multi-addressable switching properties by the stimulations of lights and chemical reagents. Based on these characteristics, two combinational logic circuits were constructed with the emission intensity as the output signals, and the UV/vis lights, chemical species as the input signals.     

Block copolymer assisted topochemical polymerization: A facile and efficient route to robust polymeric nanoporous membranes decorated with versatile amino acids

Based on block copolymer assisted topochemical polymerization,a new strategy for facilely producing robust nanoporous membranes with controlled incorporation of functional groups onto nanopores is developed.As exemplified by preparing nanoporous polypyrrole decorated with amino acids,this strategy exhibits a high degree of freedom for tailoring the surface functionality in the created pores.     

Single atom accelerates ammonia photosynthesis

Atomically dispersed metal has gained much attention because of the new opportunities they offer in catalysis. However, it is still crucial to understand the mechanism of single-atom catalysis at molecular level for expanding them to other more difficult catalytic reactions, such as ammonia synthesis from nitrogen. In fact, developing ammonia synthesis under ambient conditions to overcome the high energy consumption in well-established Haber-Bosch process has fascinated scientists for many years.Herein, we demonstrate that single Cu atom yields facile valence-electron isolation from the conjugated π electron cloud of p-CN. Electron spin resonance measurements reveal that these isolated valence electrons can be easily excited to generate free electrons under photo-illumination, thus inducing high efficient photo-induced ammonia synthesis under ambient conditions.The NH_3 producing rate of copper modified carbon nitride(Cu-CN) reached 186 μmol g~(-1) h~(-1) under visible light irradiation with the quantum efficiency achieved 1.01% at 420 nm monochromatic light. This finding surely offers a model to open up a new vista for the ammonia synthesis at gentle conditions. The introduction of single atom to isolate the valence electron also represents a new paradigm for many other photocatalytic reactions, since the most photoinduced processes have been successfully exploited sharing the same origin.     

A Facile and Efficient Method for the One-Pot Synthesis of Per-O-acetylated Thioglycosides from Unprotected Sugars

An efficient, convenient protocol for the preparation of per-O-acetylated p-tolylthio glycosides is described. Treatment of various unprotected sugars, including 2-deoxy-2-amino sugars, sialic acid, lactose, and maltose, with acetic anhydride using SnCl₄ as a catalyst, and subsequently with p-tolylthiol, furnished the corresponding thioglycosides in 71%–90% yield under solvent-free conditions.     

可生物降解的聚乳酸弹性体的性能研究

对制备的聚乳酸（聚醚）酯型聚氨酯弹性体进行了动态力学、力学性能和降解性能的测试．结果表明，弹性体的强度和弹性都较好，它们受交联度、ＰＥＧ含量和ＰＥＧ分子量的影响．该弹性体的降解速度较快．降解过程中存在自催化效应，而且是从表面开始由表及里逐渐降解的．但材料降解过程中也会出现内部降解较快的现象．动物实验表明，该弹性体是一种能满足尿道支撑管要求的有实际应用价值的材料．     

A new fluorescence probe based on diarylethene with a benzothiazine unit for selective detection of Cd2+

A novel photochromic diarylethene derivative containing a benzothiazine unit has been synthesized. Its photochromism and fluorescent selectivity to metal ions were studied in detail in methanol solution. Under the stimulation of Cd²⁺ ions, the derivative showed a significant fluorescence enhancement and obvious red shift, accompanied by the fluorescent color changed from dark purple to bright blue. The 1: 1 stoichiometry between the derivative and Cd²⁺ was verified by titration experiments and high resolution mass spectrometry. In addition, a molecular logic circuit was designed with the emission intensity at 476?nm as output and the stimuli of Cd²⁺/EDTA and UV/vis as inputs.     

A General,Concise Strategy that Enables Collective Total Syntheses of over 50 Protoberberine and Five Aporhoeadane Alkaloids within Four to Eight Steps

A concise, catalytic, and general strategy that allowed efficient total syntheses of 22 natural 13‐methylprotoberberines within four steps for each molecule is reported. This synthesis represents the most efficient and shortest route to date, featuring three catalytic processes: CuI‐catalyzed redox‐A³ reaction, Pd‐catalyzed reductive carbocyclization, and PtO₂‐catalyzed hydrogenation. Importantly, this new strategy to the tetracyclic framework has also been applied to the collective concise syntheses of >30 natural protoberberines (without 13‐methyl group) and five aporhoeadane alkaloids.     

Structure Evolution and Associated Catalytic Properties of PtSn Bimetallic Nanoparticles

Bimetallic nanoparticles (NPs) often show new catalytic properties that are different from those of the parent metals. Carefully exploring the structures of bimetallic NPs is a prerequisite for understanding the structure‐associated properties. Herein, binary Pt?Sn NPs with tunable composition are prepared in a controllable manner. X‐ray characterizations reveal that their structures evolve from SnO_2?x‐patched PtSn alloys to SnO_2?x‐patched Pt clusters when more tin is incorporated. An obvious composition‐dependent catalytic performance is observed for the hydrogenation of α,β‐unsaturated aldehydes: the selectivity to unsaturated alcohol increases substantially at high tin content, whereas the reaction rate follows a volcano shape. Furthermore, Pt sites are responsible for hydrogen dissociation, whereas oxygen vacancy (O_vac) sites, provided by SnO_2?x, drastically enhance the adsorption of carbonyl group.     

Selective response of dopamine in the presence of ascorbic acid on L-cysteine self-assembled gold electrode

A L-cysteine (L-Cys) self-assembled modified gold electrode was used to detect dopamine (DA) by chronoamperometric method (CE) in the presence of ascorbic acid (AA). The defective limit is 2.0 x 10(-8) mol L(-1) (S/N=3). The proposed method was applied to detect DA in the samples with satisfied result.