Lunar surface chemistry: a new imaging technique

Detailed chemical maps of the lunar surface have been constructed by applying a new weighted-filter imaging technique to Apollo 15 and Apollo 16 x-ray fluorescence data. The data quality improvement is amply demonstrated by (i) modes in the frequency distribution, representing highland and mare soil suites, which are not evident before data filtering and (ii) numerous examples of chemical variations which are correlated with small-scale (about 15 kilometer) lunar topographic features.     

The role of surface chemistry in filter feeding by zooplankton

Surface chemistry of both particles and animals is important in filter feeding at low Reynolds number. Daphnia magna, fed mixtures of three sizes of polystyrene particles, retained particles that were smaller than the mesh size of the animals (1.0 micrometer) at greater efficiencies than predicted by a sieving model. Retention efficiency of the smallest particles (0.5 micrometer) was increased when negative surface charge on the particles was neutralized, and retention was decreased when a nonionic surfactant was, added to reduce wettability.     

Cell surface coatings and membrane potentials of malignant and nonmalignant cells

A positive surface potential indicating a cell coating is common to malignant cells, lymphocytes, and normal and malignant trophoblastic cells. This characteristic was not generally found for other normal cell types tested by microelectrode penetration.     

Laser-induced chemistry for microelectronics

Laser-controlled chemical reactions are being explored for use in all phases of the processing of semiconductor devices. Laser-induced chemical processing can produce submicrometer features without the aid of photolithography. Research is also providing new information on light-excited and light-enhanced interface reactions.     

机引甘蔗多功能施肥机的设计与研制

设计了一种机引甘蔗多功能施肥机，该机既可用于宿根蔗的松土破垄施肥作业，也可用于甘蔗种植的开种植沟施肥，甘蔗苗期的培土施肥等项作业。该机与36.8-58.8kW的轮式拖拉机配套。田间试验测得该机开沟施肥生产率为0.80hm^2/h，破垄施肥生产率为0.77hm^2/h，是人工作业的20倍以上。     

多功能造林的思考与探讨

根据森林资源的多效益性,详细阐述了多功能林业及其营林理念的产生、发展过程,提出了多功能造林技术概念,并论述了多功能造林与分类经营、混交造林的关系以及多功能造林的一些实践运用例子,同时分析了营造多功能林存在的一些问题及解决办法。     

Instrumental requirements for global atmospheric chemistry

The field of atmospheric chemistry is data-limited, primarily because of the challenge of measuring the key chemical constituents in the global environment. Several recent advances, however, in rugged, portable, remotesensing, ground-based instrumentation and accurate, fast-response airborne instrumentation have provided powerful tools for the understanding of stratospheric ozone, particularly in polar regions. Current discoveries of the role of heterogeneous chemical processes point to the need for better techniques for characterization of stratospheric aerosols. In the troposphere, advances in in situ, sensitive methods for detecting reactive nitrogen compounds have demonstrated the role that these compounds have in controlling global oxidation processes, but better measurements of the reservoir species by which the long-ranged transport of pollutant-reactive nitrogen compounds is thought to occur are urgently needed. The role of hydrocarbons, particularly those of natural origin, in ozone formation in rural areas has focused attention on the requirement for better speciation of these ubiquitous compounds. Lastly, rigorous instrument intercomparison experiments have provided unbiased estimates of measurement capabilities.     

The 1979 nobel prize for chemistry

The 1979 Nobel Prize for Chemistry has been awarded jointly to Georg Wittig of the University of Heidelberg and Herbert C. Brown of Purdue University for their separate work in organic synthesis. Wittig's major achievement was the development of a highly specific method for the synthesis of olefins. Brown found major new routes to add substituents to olefins selectively. Both employed elements that had found little previous use in organic synthesis, and both prospered by following up on unexpected observations.     

New mechanisms for chemistry at surfaces

It is becoming increasingly apparent that chemistry at surfaces, whether it be heterogeneous catalysis, semiconductors etching, or chemical vapor deposition, is controlled by much more than the nature and structure of the surface. Recent experiments that principally make use of molecular beam techniques have revealed that the energy at which an incident molecule collides with a surface can be the key factor in determining its reactivity with or on the surface. In addition, the collision energy of an incident particle has proven essential to the finding of new mechanisms for reaction or desorption of molecules at surfaces, collision-induced activation and collision-induced desorption. These phenomena are often responsible for the different surface chemistry observed under conditions of high reactant pressure, such as those present during a heterogeneous catalytic reaction, and of low pressure of reactants (< 10(-4) torr), such as those present in an ultrahigh vacuum surface science experiment. This knowledge of the microscopic origins of the effect of pressure on the chemistry at surfaces has allowed the development of a scheme to bypass the high-pressure requirement. Reactions that are normally observed only at high reactant pressures, and which are the ones most often of practical importance, can now be carried out in low-pressure, ultrahigh vacuum environments.     

Thermal barrier coatings for gas-turbine engine applications

Hundreds of different types of coatings are used to protect a variety of structural engineering materials from corrosion, wear, and erosion, and to provide lubrication and thermal insulation. Of all these, thermal barrier coatings (TBCs) have the most complex structure and must operate in the most demanding high-temperature environment of aircraft and industrial gas-turbine engines. TBCs, which comprise metal and ceramic multilayers, insulate turbine and combustor engine components from the hot gas stream, and improve the durability and energy efficiency of these engines. Improvements in TBCs will require a better understanding of the complex changes in their structure and properties that occur under operating conditions that lead to their failure. The structure, properties, and failure mechanisms of TBCs are herein reviewed, together with a discussion of current limitations and future opportunities.     

Set of multifunctional uralets tilling-sowing units

Information is given about original Russian high-productivity universal tilling-sowing units.     

Professionalization of agriculture and distributed innovation for multifunctional landscapes and territorial development

Professionalization of farmers and rural entrepreneurs is identified as a potential resource to advance transition to multifunctional landscapes and territorial development. Drawing on interactive conceptions of knowledge creation and technical change, I argue that collective structures that support pooling of experiential knowledge can complement public and private sector engagement in innovation systems. Through exercise of leadership in advancing integration of farming into regional development and in integrating ecological and social concerns into agriculture, farmers can forge a professional identity and broker a new social contract entitling them to renewal of their political and economic status.