Recent Industrial Applications of Lignin: A Sustainable Alternative to Nonrenewable Materials

Lignin represents a vastly under-utilized natural polymer co-generated during papermaking and biomass fractionation. Different types of lignin exist, and these differ with regard to isolation protocol and plant resource (i.e., wood type or agricultural harvesting residue). The incorporation of lignin into polymeric systems has been demonstrated, and this depends on solubility and reactivity characteristics. Several industrial utilization examples are presented for sulfur-free, water-insoluble lignins. These include materials for automotive brakes, wood panel products, biodispersants, polyurethane foams, and epoxy resins for printed circuit boards.     

生物学模型与海洋学模型的耦合

海洋生态系统的动力问题,如可观测的化学-生物量的时空变化是由于生物和物理过程决定的.预报海洋系统的未来发展需要有一个理论框架.如模型,而这个模型是根据对相关的各个不同过程的研究和了解而发展的.从理论上描述海洋系统的自然方法似乎是把化学生物模型与环境模型结合在一起.但是,环境模型相对比较先进,而化学-生物过程的定量理论描述比较落后.本文讨论了一些关于发展相容理论的方法和问题,指出了海洋生物学模型和海洋学模型耦合的潜在盖处.     

Problems of modern cosmology: how dominant is the vacuum?

It would be hard to find a cosmologist today who does not believe that the vast bulk of the Universe (95% or more) is hidden from our eyes. We review the evidence for this remarkable consensus, and for the latest proposal, that the mysterious dark matter consists of as many as four separate ingredients: baryons, massive neutrinos, new "exotic" dark matter particles, and vacuum energy, also known as the cosmological constant (L\Lambda ). Of these, only baryons fit within standard theoretical physics; the others, if their existence is confirmed, will mean rewriting textbooks. Fresh experimental evidence has recently appeared for and against all four components, so that the subject is in a state of turmoil and excitement. The past 3 years in particular have seen the fourth (vacuum) component come into new prominence, largely at the expense of the third (exotic dark matter). We conclude our review by exploring the possibility that the energy density of the vacuum is in fact so dominant as to leave little room for significant amounts of exotic dark matter.