康德区分开了理由与原因吗

后期维特根斯坦所做出的最为独特的哲学贡献是将理由与原因严格地区别开来。正是基于这个区分,他对遵守规则现象及语言现象的本性做出了独特的说明。此区分不仅在维特根斯坦后期哲学中居于核心的位置,而且也在当代哲学特别是道德哲学和行动哲学的讨论中占有着一个非常重要的位置。维特根斯坦是哲学史上第一个明确地做出这种区别的哲学家。不过,这个断言与一些哲学史家的观点相背。著名康德专家艾利森声称,康德在其著名的理知因致性学说或自由学说中就已经做出了−至少应该做出了−维特根斯坦意义上的理由与原因之分。这种解读是错误的。     

高三物理高考专题复习教学模式讨论——基于一个教学实验的启示

通过针对高三专题复习的教学实验,分析当前主流教学模式存在的问题,并提出了对教学模式改革的看法.     

Multiple fire interactions: A further investigation by burning rate data of square fire arrays

This paper presents the first effort to explore the spatial distributions of the burning rates in group fires consisting of a large number of fire points, by analyzing burn-out time data from experimental square fire arrays ranging from 3 × 3 to 15 × 15. A new concept termed fire layer is introduced and defined to characterize the spatial locations of fire points by which the complex spatial variations of burning rates, under different conditions, are analyzed and physically interpreted. Analysis shows that the fire layer burning rates vary from outer to inner in definite nonlinear modes. This indicates that the two fire interaction effects, heat feedback enhancement and air supply restriction, involve distinct spatial fluctuations in fire arrays. The spatial fluctuations of the two interaction effects are significantly affected by the two major parameters, fire spacing and fire array size. Definite spatial regions and parameter ranges for the spatial fluctuations and high competitions of the two interaction effects are clearly distinguished. It is demonstrated that the average burning rates of all fire layers involve consistent variations versus fire spacing or fire array size, especially with high comparability to the entire fire array. It is found that by varying fire spacing, the average burning rates for all fire layers vary linearly versus the fire area ratio, within the same ranges as the entire fire array, while there exist different fluctuation modes of fire layer burning rates with respect to fire array size. Furthermore, analysis shows that the burning rates of all fire layers will be significantly affected by fire merging when it occurs. Finally, a new approach is presented to simulate fire propagation among discrete fuel sources, by which the positive effect of the surrounding new fire points on the burning rates of the original ones is definitely indicated.     

Design of Sensitive Biocompatible Quantum‐Dots Embedded in Mesoporous Silica Microspheres for the Quantitative Immunoassay of Human Immunodeficiency Virus‐1 Antibodies

A novel sandwich‐type electrochemiluminescence (ECL) immunosensor was developed to enable the sensitive detection of HIV‐1 antibodies. This system incorporated mesoporous silica (mSiO₂) complexed with quantum dots (QDs) and nano‐gold particles, which were assembled to enhance signal detection. Magnetic beads were used by immobilizing the secondary anti‐IgG antibody. This was first employed to capture HIV‐1 antibody (Ab) to form a Fe₃O₄/anti‐IgG/Ab complex. A high loading and signal‐enhanced nanocomposite (hereafter referred to as Au‐mSiO₂‐CdTe) was used as a HIV‐1 antigen label. The Au‐mSiO₂‐CdTe nanocomposite was conjugated with the Fe₃O₄/anti‐IgG/Ab complex to form an immunocomplex (hereafter referred to as Fe₃O₄/anti‐IgG/Ab/HIV‐1/CdTe‐mSiO₂‐Au). This complex could be further separated by an external magnetic field to produce ECL signals. Due to the large specific surface area and pore volume of mSiO₂, the loading of the CdTe QDs was markedly increased. Thus, the loaded QDs released a powerful chemiluminescent signal with a concordantly increased sensitivity of the immunosensor. The immunosensor was highly sensitive, and displayed a linear range of responses for HIV‐1 antibody across a dilution range of 1 : 1500 through 1 : 50 with the detection limit of 1 : 4500. The immunoassay can be a promising candidate in early diagnosis of HIV infection.     

Unraveling the reactivity of a cationic iminoborane: avenues to unusual boron cations

A cationic terminal iminoborane [Mes*N B ← IPr₂Me₂][AlBr₄] (3⁺[AlBr₄]⁻) (Mes* = 2,4,6-tri-tert-butylphenyl and IPr₂Me₂ = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) has been synthesized and characterized. The employment of an aryl group and N-heterocyclic carbene (NHC) ligand enables 3⁺[AlBr₄]⁻ to exhibit both B-centered Lewis acidity and BN multiple bond reactivities, thus allowing for the construction of tri-coordinate boron cations 5⁺–12⁺. More importantly, initial reactions involving coordination, addition, and [2 + 3] cycloadditions have been observed for the cationic iminoborane, demonstrating the potential to build numerous organoboron species via several synthetic routes.

An NHC-stabilized aryliminoboryl cation exhibits both boron-centered Lewis acidity and multiple bond reactivity and could be utilized as an effective synthon for unusual cationic boron species.     

壳聚糖衍生物的制备及其吸附性能

壳聚糖衍生物的制备及其吸附性能曲荣君，马千里，郑秀丽，孙言志（烟台师范学院化学系烟台２６４０２５）关键词壳聚精衍生物，制备，吸附壳聚糖（ＣＴＳ）是重金瞩离子的吸附剂￣［１，２］，由于壳聚精分子中的－ＮＨ＿２在ｐＨ较低的水溶液易形成而使ＣＴＳ溶于水，造...     

Synthesis of a Monophosphoryl Derivative of Escherichia coli Lipid A and Its Efficient Coupling to a Tumor‐Associated Carbohydrate Antigen

Monophosphoryl lipid A is a safe and potent immunostimulant and vaccine adjuvant, which is potentially useful for the development of effective carbohydrate‐based conjugate vaccines. This paper presents a convergent and efficient synthesis of a monophosphoryl derivative of E. coli lipid A that has an alkyne functionality at the reducing end, which is suitable for coupling with various molecules. The coupling of this derivative to an N‐modified analogue of tumor‐associated antigen GM3 through click chemistry is also presented.     

Simple Peptide‐Tuned Self‐Assembly of Photosensitizers towards Anticancer Photodynamic Therapy

Peptide‐tuned self‐assembly of functional components offers a strategy towards improved properties and unique functions of materials, but the requirement of many different functions and a lack of understanding of complex structures present a high barrier for applications. Herein, we report a photosensitive drug delivery system for photodynamic therapy (PDT) by a simple dipeptide‐ or amphiphilic amino‐acid‐tuned self‐assembly of photosensitizers (PSs). The assembled nanodrugs exhibit multiple favorable therapeutic features, including tunable size, high loading efficiency, and on‐demand drug release responding to pH, surfactant, and enzyme stimuli, as well as preferable cellular uptake and biodistribution. These features result in greatly enhanced PDT efficacy in vitro and in vivo, leading to almost complete tumor eradication in mice receiving a single drug dose and a single exposure to light.     

Virtually epimerization-free synthesis of peptide-alpha-thioesters

Under slightly basic or neutral reaction conditions peptide-alpha-thioesters are photochemically synthesized from peptide-alpha-nitroindoline precursors, either in solution, or by direct photorelease from a solid support.     

Low molecular weight organogelators derived from threefold symmetric tricarbamates

A group of new low molecular weight organogelators based on threefold symmetric tricarbamate were synthesized and characterized. The tricarbamates with long alkyl chains were able to gelate a wide range of polar and nonpolar organic solvents such as acetonitrile and cyclohexane, generally at concentrations lower than 20 g/L. The best organogel formation was obtained using a threefold symmetric tricarbamate in n-dodecane, in which a sufficiently transparent gel was formed at the critical gelation concentration 1 g/L. Intermolecular hydrogen bonding by the tricarbamate in a nonpolar solvent benzene-d₆ was indicated by ¹H NMR spectra. Its maximum UV absorption was 11 nm higher in chloroform than in n-dodecane, and this red shift indicated increased conjugation between the benzene core and the carbamate substituents, which confirmed a change in its conformation from nonpolar to polar solvent. The self-assembling behavior of the tricarbamate in dilute solutions was investigated by TEM. Fiber-like networks were observed in a large range of solution concentrations.