试论实验与理论的共生关系——从“中性流”的发现过程谈起

试论实验与理论的共生关系——从“中性流”的发现过程谈起崔绪治浦根祥一、问题的由来１９６７～１９７３年期间，高能物理共同体内存在着两种相互竞争的理论，一是费因曼和盖尔曼建构的Ｖ－Ａ理论，二是温伯格和萨拉姆提出的Ｗ－Ｓ理论。这两个理论在其对Ｋ°介子弱衰变...

科学社会学视野中的科学理论之争

本文试图评介以布鲁诺·拉图尔为代表的当代科学社会学家关于“科学争论”的形成及解决过程的论述。拉图尔认为，科学理论之争的产生并非如后经验主义哲学家描述的那样产生于科学发展的特定时期，其解决的标准也不为科学共同体听普遍认同，而主要取决于争论双方相抗衡的政治实力、各自的辩护技巧及实验室资源。这为我们理解科学理论之争开拓出一个新的视野。

弥天大谎 “中国原子弹间谍案”始末

美国新闻界引爆了一颗"原子弹"3月4日,美国鼎鼎有名的《纽约时报》独家报道编辑莱利韦尔德放出风声说,他准备引爆一颗轰动美国新闻界的"原子弹"! 正当美国新闻界的同行们伸长脖子准备看莱利韦尔德第二天引爆的"原子弹"的时候,3月5日《纽约时报》头版却平淡得如同白开水。遭到同行们百般奚落的莱利韦尔德不得不透出一点儿口风说:"是联邦调查局让我们把‘原子弹’延后引爆的。"美国的新闻界更是炸开了锅:在《纽约时报》历史上,除了当年肯尼迪总统恳请报纸不要提前发布古巴雇佣军进攻猪湾的新闻获得成功外,还没有哪条消息因为美国政府的干涉而延迟发出的哩!那么,这条天大的新闻是什么呢?

Coupled Reaction/Distillation Process for Hydrolysis of Methyl Acetate

A process composed of a fixed-bed and a distillation column with a side withdraw, mainly methanol, is developed to hydrolyze methyl acetate (MA) as a typical byproduct in polyvinyl alcohol (PVA) and pure terephthalic acid (PTA) factory. The process is simulated by employing the equilibrium stage model RadFrac and plug flow model Rplug in Aspen Plus. Experiments are also carried out in a lab-scale to evaluate the process. The results show that at the molar ratio of water to methyl acetate about 4.0-5.0 in the feed stream and the volume ratio of distillate to feed MA above a critical value, the side product contains more than 80% (by mass) (MeOH) and less than 2% (by mass) MA, while the bottom contains more than 46% (by mass) acetic acid (HAc) and less than 0.5% (by mass) methanol with almost complete conversion of MA. Compared with the old catalytic distillation process we proposed before, this process can cut down 47.6% energy consumption and a distillation column.

Effects of Formulation Parameters and Process Variables on the Properties of Granules Obtained by Reactive Granulation

In this work, granulation between dodecyl-benzenesulfonic acid and sodium carbonate was investigated in a laboratory-scale high shear mixer. The effects offormulation parameters and process variables, including primary carbonate size, binder content, impeller speed, and operating temperature, were correlated to the properties ofthe product granules. Design ofexperiment and analysis ofvariance were combined to analyze the experimentaldata, and results showed that larger granule sizes with fewer fine particles can be obtained by employing higher binder contents and larger sodium carbonate sizes. The shear force ofthe impeller can extensively break oversized granules. The binder content exerted a contrasting effect on the flowability ofgranules formed with two kinds ofsodium carbonate, likely because ofdifferences in the liquid saturation ofthe solids. The dissolution rate determined by in-line size analysis showed that high binder contents were beneficialto dissolution performance, and the relationships between Hunter color and tested parameters were evaluated. The results ofthis work can be used as a reliable guidance for process controland optimization in powder detergent manufacturing.

Removal of Pesticides from Water Using Anaerobic-Aerobic Biological Treatment

The biodegradability of wastewater containing priority pollutant pesticideVydine or triadimenol（C14H18CLN3O2） in different bio-reactor configurations was investigated.Two laboratory scale biological reactors were employed：one reactor under aerobic condition and the other under anaerobic condition.The aerobic reactor was operated at an ambient temperature（22±2） °C,while the anaerobic reactor was run in the lower mesophilic range（30±2） °C.The effect of pesticide concentration,hydraulic retention time（HRT） ,and co-substrate on the treatment process was explored,using glucose as a supplemental carbon substrate.More than 96%pesticide was removed after an acclimation period of approximately 172 d（aerobic） and 230 d（anaerobic） .The aerobic reactor achieved complete Vydine utilization at feed concentrations up to 25 mg·L^-1 .On the other hand,the anaerobic reactor was able to degrade 25 mg·L^-1 of Vydine.Moreover,glucose was consumed first throughout the experiment in a sequential utilization pattern.The combination of anaerobic and aerobic biological processes yielded higher biomass concentration and lower retention time than individual units.The biomass in the combined reactors was first acclimated with the corresponding pesticide.Then,the target pesticide,at a concentration of 25 mg·L^-1,was sequentially treated in a semi batch mode in the reactors.HRT studies showed that 24 h HRT of aerobic and 12 h HRT of anaerobic were the optimum combination for the treatment of simulated wastewater containing Vydine,which produced Vydine effluent at concentration below 0.1 mg·L^-1 .The optimum ratio of substrate（Vydine） to co-substrate（glucose） was 1︰100.

A Few Questions that Should be Clarified in the Polymerase Chain Reaction

The polymerase chain reaction is one of the most useful technical ad- vance and inventions in modern molecular biology. Developed in 1983 by Kary Mullis, PCR is now a common and indispensable technique used in medical and bi- ology research labs for a variety of applications. A large number of articles relat- ed to PCR are available on the internet and other places. People know well about the basic principle and are very familiar with the procedures of the PCR. But, some details were neglected on the numbers of the target sequence and other DNA strands number after 30 to 35 cycles of the PCR. In most papers, the number of newly synthesized DNA strands including target DNA and non target DNA is am- biguous and even wrong. In this paper, highlights were given to the theoretical number of target DNA number in details and the exact number of the target DNA number can be concluded by analysis.

Reactive Adsorption of Thiophene Using a NiZnO-Based Adsorbent

The thiophene removal ability of the synthesized NiZnO-based adsorbent was tested in a lab-scale fixed-bed system. The X-ray diffractometer (XRD) and the temperature-programmed reduction (H2-TPR) instrument were used to characterize the samples. The XRD and TPR results showed that there existed stronger synergetic effect between ZnO and NiO to form well-dispersed adsorbent particles when the Zn/Ni molar ratio in adsorbent was 0.4, and that the optimum temperature for reduction of the NiZnO-based adsorbent was approximately in the range of 350℃—400℃. In addition, the effects of reaction temperature, and reaction pressure on the reactive adsorption desulfurization tests were studied.

Reactive Adsorption of Thiophene on ZnNi/Diatomite-Pseudo-Boehmite Adsorbents

The thiophene removal ability of the synthesized ZnNi/diatomite-pseudo-boehmite adsorbent was tested in a lab- scale fixed-bed reaction system. X-ray diffractograms （XRD） were used to characterize the adsorbent samples. The effects of Zn/Ni molar ratio, various model fuels and regeneration patterns on the RADS tests were studied. The adsorption mecha- nism was investigated by XRD and MS analyses. The results indicted that thiophene in the model fuel was first decomposed on the surface Ni of the adsorbent to form Ni3S2 while the hydrocarbon portion of the molecule was released back into the process stream, followed by reduction of Ni3S2 to form H2S in the presence of H2, and then HzS is stored in the adsorbent accompanied by the conversion of ZnO into ZnS.

Lipid enhancement in microalgae by temporal phase separation:Use of indigenous sources of nutrients

Microalgae have been recommended as superior candidate for fuel production because of their advantages of higher photosynthetic efficiency, biomass & lipid productivity, and faster growth rate as compared to other energy crops. To meet up all these criteria, we have developed a continuous outdoor micro-algal raceway pond reactor(RPR) and a lab scale indoor tubular photo bioreactor(PBR) for biofuel production. An attempt to utilise indigenous sources of nutrients to improve the economics also revealed that micro-algal culturing can also be used as a mode of nutrient removal and water treatment. The photosynthetic rate and lipid production were enhanced by arresting daytime cell division and promoting night-time cell division. A 50% lipid improvement was observed for the particular algal consortia. Microscopic studies revealed that temporal phase separation could be achieved by adjusting nutrient distribution pattern. To monitor temporal phase separation, it is required to know DNA multiplication model. Quantification of g DNA in RPR confirmed that cell division happens during the night which positively affects the photosynthetic efficiency and lipid productivity of microalgae.

Investigation on detection of Haemophilus ducreyi by Polymerase Chain Reaction

Objective:To investigate the application of polymerase chain reaction (PCR) detection of Haemophilus ducreyi in clinical diagnosis of chancroid. Methods: Nucleotide sequences of 16srRNA gene specific for H. dureyi were used to develop primer sets for amplification of two strains. The amplified products were tested via PCR and sequenced by electrophoresis in a 1.5% gel.These products were compared with those of heterogeneous species or related bacteria to test the specificity of the PCR assay. PCR amplification with different concentrations of H.ducreyi was performed to test its sensitivity. Results: PCR amplification of two strains of H. ducreyi produced a single band of expected 438bp length. The sequence was identified with genomic DNA. None of the other 19 reference species amplified under the same conditions gave this result. The highest sensitivity of PCR assay in the present test was 10ng/L. Conclusions: PCR assay for detection of H. ducreyi is a rapid, specific, and sensitive detection method. If laboratory conditions are strictly controlled, PCR assay is a potentially useful laboratory test for H. ducreyi infection diagnosis.

Simulation of hydrocarbons pyrolysis in a fast-mixing reactor

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals(ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of hightemperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature(up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas(LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases(LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

A Study of Acetylene Production by Methane Flaming in a Partial Oxidation Reactor

The partial oxidation of hydrocarbons is an important technical route to produce acetylene for chemical industry.The partial oxidation reactor is the key to high acetylene yields.This work is an experimental and numerical study on the use of a methane flame to produce acetylene.A lab scale partial oxidation reactor was used to produce ultra fuel-rich premixed jet flames.The axial temperature and species concentration profiles were measured for different equivalence ratios and preheating temperatures,and these were compared to numerical results from Computational Fluid Dynamics(CFD)simulations that used the Reynolds Averaged Navier-Stokes Probability Density Function(RANS-PDF)approach coupled with detailed chemical mechanisms.The Leeds 1.5,GRI 3.0 and San Diego mechanisms were used to investigate the effect of the detailed chemical mechanisms.The effects of equivalence ratio and preheating temperature on acetylene production were experimentally and numerically studied.The experimental validations indicated that the present numerical simulation provided reliable prediction on the partial oxidation of methane.Using this simulation method the optimal equivalence ratio for acetylene production was determined to be 3.6.Increasing preheating temperature improved acetylene production and shortened greatly the ignition delay time.So the increase of preheating temperature had to be limited to avoid uncontrolled ignition in the mixing chamber and the pyrolysis of methane in the preheater.

Removal of elemental mercury by modified bamboo carbon

The mercury removal performance of modified bamboo charcoal （BC） was investigated with a bench-scale fixedbed reactor, A simple impregnation method was used to modify the BC with ZnCI2 and FeCI3 separately. BET and XPS were used to determine the pore structure and surface chemistry of the sorbents. The role of Fe3 ＋ in the removal of elemental mercury by modified sorbents was discussed. The experimental results suggest that the modified BCs have excellent adsorption potential for elemental mercury at a relatively higher temperature, 140 ℃. The BET surface area and average pore size of modified sorbents do not show noticeable priority compared to unmodified BC, XPS spectra indicate that Fe atoms mainly exist in the form of Fe3 ＋ for the FeC1j-impregnated BC. Better performance of FeCl3-impregnated BC at different temperatures （20, 140 and 180 ℃） suggests the enhancement of non-chloride functional groups （Fe3 ＋）. Inhibition effect of SOx and NO for Hg removal by BC samples is present in the study.

Saline Stress Response of Plantlets of Common Wheat （Triticum aestivum） and Its Wild Congeners

The aim of this work was to study the reactions of wheat （T. aestivum L.） and its wild congeners under salt stress. Physiological mechanisms that underlie traits for salt tolerance plantlets have been used to test some wheat species and to identify sources of salty tolerance. Stress conditions were founded by means of exposure of the plantlets in NaCI water solution, 1.68% that demonstrably differentiates the samples by growth parameters. Under laboratory conditions the ability of seedlings to bear a significant shortage of water, their ability to accumulate biomass, changing the parameters of linear growth processes and changes in water content in leaves and roots of seedlings under stress was determined. Interest is also the rate of growth of root fibrils in saline conditions. These experiments allowed to provide a comprehensive diagnosis of studied forms of wheat and make an initial opinion on their salt tolerance. Different features of abiotic stress responses of some wheat species at the early stages of development were shown that testifies necessi~ of great number of approaches at selection of genetic material for improvement of modern wheat eultivars. This work is the first phase of research for practical breeding.

Cascaded Simultaneous Nitrification and Denitrification Process for Nitrogen and Phosphorus Reduction from RO Reject Wastewater： A Bench-Scale Study

The use of the reverse osmosis （RO） process, for refining secondary or tertiary effluent from plants treating domestic wastewater, is rapidly increasing. However, the disposal of the RO reject water poses a problem due to the presence of very high concentrations of salts, metals, and nutrients in it. This paper contains results of a bench-scale study aimed at reducing nutrients from RO-discarded streams utilizing a sequential bioreactors system, under partial aerobic and anoxic conditions. The tests were performed on synthetic wastewater resembling RO-reject water of an operating treatment plant, with glucose, methanol or acetate added to the water as sources of carbon. Study results indicate that the RO process removed about 50-60% of the total nitrogen and 50% of the phosphate; it reduced chemical oxygen demand （COD） by 79 to 82%, and affected no change in the metal concentrations. A clear cut removal preference for any one of the external carbon sources was not observed, although a slight advantage of glucose and methanol was recorded. The process maintained about 20% of the rector volume in the anoxic environment.

Performance Evaluation of Bioethanol Production through Continuous Fermentation with a Settling Unit

This paper analyses a model for the production of bioethanol that has been calibrated against laboratory data by previous researchers. The authors investigate the improvement in productivity that can be obtained when a centrifuge is used to recycle cells that would otherwise leave the reactor system in the efficient stream. The authors compare the performance of a double reactor cascade, possible employing a settling unit, against that of a single reactor. For the former case, this paper considers the reactor configuration in which the settling unit recycles from the effluent stream of a reactor back in the influent of the same reactor.

Hydrolytic Enzyme Inhibitors and Necrotic Reactions in Potato Leaves Reduce Reproductive Success of Colorado Potato Beetle

In field and laboratory conditions the reproductive potential （survival at different stages of development） of the Colorado potato beetle has been measured, the dependence of the parameters of insects fertility on varietal features of the feed has been investigated, the food activity of the representatives of insects from four areas of the Southern Urals has been measured, the intensity and time of hypersensitivity reactions on potato leaves has been defined. In laboratory experiments, the level of activity of hydrolytic enzymes in insects and the level of activity of these enzymes inhibitors in the leaves of three potato varieties differing in their resistance to the Colorado potato beetle have been determined. The results show that the insects-representatives of different samples have different food activity in relation to different potato varieties. High mortality rates were revealed at feeding with leaves of potato of the Bashkir variety characterized by a high level of hydrolases inhibitors and relatively rapid development of necrotic reactions after the appearance of eggs laying on the leaves. We suppose that the neerogenetic barrier appearing in the form of necrosis is the major cause of the fetal mortality of insects. The level of the content of inhibitors inactivating larvae digestive enzymes affects the survival of insects at postembryonic stages. The speed of the necrosis emergence, the level of activity of digestive enzymes inhibitors in potato can be considered as criteria for the selection of breeding material for resistance to the Colorado potato beetle.

Nontuberculous Mycobacteria Infections in Katavi Rukwa Ecosystems

A study on nontuberculous mycobacteria （NTM） was carried out in wildlife-livestock interface of Katavi Rukwa ecosystem （KRE）. 328 livestock tissues and 178 wild animals were cultured, wild animals were sampled opportunistically during professional hunting and game cropping operations in the KRE protected areas. The objective of the study was to generate data on epidemiology of NTM in the wildlife-livestock interface of the KRE. Methods used to identify the NTM were： culture and isolation, polymerase chain reaction, protein heat shock 65 kilodalton （hsp65） and sequencing. Mycobacteria were detected on 25.9% and 11.9% of livestock and wildlife tissue cultures, respectively. The most NTM isolated were M. kansasii （30%）, M. gastri （30%）, M. fortuitum （1%）, M. intracellulare （4%）, M. indicuspranii （4%）, M. nonchromogenicum （6%） and M. lentiflavum （6%）. Other NTM in smaller percentages were M. hibernae, M. engbaekii, M. septicum, M. arupense and 34.. godii. Due to rise of NTM infection in both human and animals, it is recommended that awareness and laboratory facilities be improved to curb the underreporting especially in TB-endemic countries. For species specific identification, a network of national and regional laboratories is promoted.