http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
박상언,홍명선 한국화학공학회 1985 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.23 No.5
2차 부틸 알코올의 탈수소 반응에 의한 메틸에틸케톤 제조시 사용되는 산화아연 촉매는 수소처리에 의해 촉매의 반응성이 증가될뿐 아니라 탈수반응이 감소되어 촉매의 선택성이 향상되었다. 또한 촉매의 수명도 수소처리 하지 않은 촉매에 비해 상당히 연장되었다. 그러나 과도한 수소처리는 아연성분의 무리(cluster) 현상을 야기시켜 아연결정체(Zinc crystallite)를 생성시킴으로써 산화아연 촉매의 탈수소 반응에 대한 활성을 감소시켰다. In manufacturing methyl ethyl ketone by dehydrogenation of secondary-butyl alcohol, the hydrogen treatment of zinc oxide enhances the catalytic activity and the selectivity with decreasing dehydration reaction. Also, the catalyst lifetime of hydrogen treated zinc oxide is much longer than that of nonhydrogen-treated zinc oxide. But, excessive hydrogen treatment of zinc oxide catalyst leads to the cluster phenomenon to form zinc crystallite which results in deactivation of dehydrogenation reaction.
박상언,Sujandi 한국물리학회 2008 Current Applied Physics Vol.8 No.6
Among the various green keys, catalysis, especially using heterogeneous catalysts, has been powerfully applied to achieve greener chemical processes. Here are presented nanoporous materials which have mesoporosity with the functional groups on the inner pore walls. The materials were synthesized via a rather greener process, such as microwave synthesis, and over these nanocatalysts some of the green chemical reactions were carried out with high activities and selectivities. Cobalt species has been successfully functionalized and stabilized as a Co(III) complex onto SBA-15 support and proven to be an active catalyst in alkylaromatic oxidation with molecular oxygen, styrene epoxidation with tert-butyl hydroperoxide (TBHP), and allylic oxidation of cycloolefins with H2O2. Short-channeled amino-functionalized SBA-15 catalyst with hexagonal plate morphology was synthesized directly by using microwave synthesis from the co-condensation of aminopropyl triethoxysilane (APTES) and sodium metasilicate under a strong acidic condition. The catalyst showed high catalytic activity in liquid-phase Knoevenagel condensation reactions, due to easy diffusion and mass transfer of substrates into the short mesopore channel. The HO3S–SBA-15 was prepared by grafting of mercaptopropyl trimethoxysilane onto the calcined mesoporous silica surface and subsequently oxidized with H2O2. The resulting catalyst was applied as a Bronsted solid-acid catalyst for the esterification of oleic acid with methanol.
박상언 한국광학회 2000 한국광학회지 Vol.11 No.4
세슘오븐에서 방출되는 열원자빔에 대해 횡방향 냉각을 실시하여 원자빔을 집속하였다. 이를 위해 원자빔의 진행방향에 수직으로, 서로 반대방향으로 진행하는 $\sigma^+$와 $\sigma^-$의 원편광 레이저를 비추었다. 그 결과, 원자의 횡방향 속도 성분에 해당하는 온도를 430 mK에서 약 60 uK으로 냉각시킬 수 있었다. 그리고 서로 반대 방향에서 진행하는 냉각용 레이저광의 세기가 다를 경우와 원자빔에 자장을 가하는 경우에 원자빔의 공간적 분포가 달라지는 것을 관찰하였고, 도플러 냉각이론에 이용하여 정성적으로 설명하였다. Thermal cesium atomic beam was collimated by transversely cooling of atoms, for which circularly polarized ($\sigma^+$ and $\sigma^-$ polarized) laser light was illuminated to the atomic beam from two perpendicular directions. As a result, the temperature corresponding to the transverse velocity component could be decreased from 430 mK to 60 11K. In addition, the spatial atomic distribution was observed according to the power difference of the two laser beams and the magnetic field applied, and the result was qualitatively coincided with the calculation result by the Doppler cooling theory. heory.
Warm Sitz Bath: Are There Benefits after Transurethral Resection of the Prostate?
박상언,이승환,정연구,박경기,마상열,홍성준,정병하 대한비뇨의학회 2010 Investigative and Clinical Urology Vol.51 No.11
Purpose: We aimed to evaluate the efficacy of warm water sitz baths in patients who have undergone transurethral resection of the prostate (TURP) owing to lower urinary tract symptoms secondary to benign prostatic hyperplasia. Materials and Methods: We reviewed the records of 1,783 patients who had undergone TURP between 2001 and 2009. In the warm water sitz bath group, patients were instructed to sit in a tub containing lukewarm water at 40-45oC for 10 minutes each time. Patients were advised to perform the procedure for at least 5 days immediately after the removal of a Foley urethral catheter. The differences in post-TURP complications between the warm water sitz bath group and the no sitz bath group were compared. Results: After TURP, 359 of the 1,561 patients performed a warm water sitz bath. Complications after TURP, such as hemorrhage, urinary tract infection, urethral stricture, and acute urinary retention were found in 19 (5.3%) and 75 (6.2%) patients in the sitz bath and no sitz bath groups, respectively (p=0.09). There was a significant difference in postoperative complications such as urethral stricture between the warm sitz bath group and the no sitz bath group (p=0.04). The group that did not undergo warm water sitz bath treatment showed a 1.13-fold increased risk of rehospitalization within 1 month after TURP due to postoperative complications compared with the warm water sitz bath group (odds ratio [OR]=1.134; 95% confidence interval [CI], 1.022 to 1.193; p=0.06). Conclusions: Warm water sitz bath treatment reduced postoperative complications such as urethral stricture. These results suggest that large-scale prospective studies are needed to establish an ideal method and optimal duration of sitz baths.
CO2 를 이용한 에틸벤젠 탈수소반응에 미치는 지르코니아 촉매의 구조적 영향
박상언,장종산,박진남,노점임 한국공업화학회 1999 응용화학 Vol.3 No.1
It is already reported by our group that zirconia has good catalytic activity in the dehydrogenation of ethylbenzene with carbon dioxide as oxidant. Tetragonal and monoclinic zirconia are prepared by precipitation method. Tetragonal zirconia showed better ethylbenzene conversion and styrene selectivity than monoclinic zirconia. This can be ascribed by the difference of the amount of defects on zirconia surface and the difference of the surface basicity. Therefore, tetragonal zirconia is more efficient in this catalysis and there is more possibility of improvement in the modification of tetragonal zirconia.