• 대한화학회지
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• 제26권1호
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• pp.18-23
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• 1982

Trigonal bipyramid 구조를 갖는 착물의 쌍극자모멘트를 계산하는 새로운 방법을 발전시켰다. 근사분자궤도 함수법 및 원자가 결합법을 사용하여 몇개의 trigonal bipyramid 구조를 갖는 착물의 쌍극자모멘트를 계산하였으며 근사분자궤도 함수로 계산한 값이 실험치에 보다 가까운 값을 주었다. 이 쌍극자모멘트 계산방법을 trigonal bipyramid 구조를 갖는 착물의 기하학적인 구조를 예측하는 데 도움이 된다.

• 대한수학회보
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• 제46권5호
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• pp.917-930
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• 2009

We find all distinct representatives of isomorphism classes of genus-3 pointed trigonal curves and compute the number of isomorphism classes of a special class of genus-3 pointed trigonal curves including that of Picard curves over a finite field F of characteristic 2.

• Bulletin of the Korean Chemical Society
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• 제3권3호
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• pp.104-109
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• 1982

A method to calculate the magnetic moments for $d^1$ and $d^2$ complexes in a strong crystal field of trigonal symmetry has been developed in this work choosing the trigonal axis (Ⅲ) as the quantization axis. The calculated magnetic moments using this method for $d^1$ and $d^2$ complexes in a strong trigonal ligand field fall in the range of the experimental values. The dipolar shifts for $d^1$ and $d^2$ complexes in a strong trigonal ligand field are also calculated using the calculated magnetic susceptibility components. The calculated values of the dipolar shifts also fall in the reasonable range.

• 한국환경농학회지
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• 제32권2호
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• pp.148-154
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• 2013

본 연구는 CVX 바이러스저항성 삼각주 재배가 토양 미생물에 미치는 영향과 수평적 유전자 이동성을 확인하기 위해 수행되었다. 생육시기별 토양 세균과 방선균 군집밀도는 형질전환 삼각주 재배 토양의 미생물 군집밀도와 비형질전환 삼각주 군집밀도가 유사하여 토양 미생물에 미치는 영향은 유사할 것으로 추정되었다. 토양 미생물의 우점종은 Proteobacteria, Uncultured archaeon와 Uncultured bacterium으로 나타났으며, 형질전환 삼각주 재배 토양의 우점종과 비율은 거의 일정하게 유지되었다. 근권 토양 DNA의 DGGE 분석을 통해 형질전환 삼각주와 비형질전환 삼각주 토양 미생물 군집의 profile 변화는 나타나지 않았다. 형질전환 삼각주와 비형질전환 삼각주 재배 토양의 화학성은 차이가 없었다. 형질전환 삼각주에 도입된 유전자로 토양 DNA에 대한 PCR 분석결과, 도입 유전자의 잔존성이 길지 않아 수평적 유전자 이동 가능성은 희박할 것으로 추정되었다.

• 한국세라믹학회지
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• 제40권6호
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• pp.513-518
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• 2003

La/sub 2/3-x/Li/sub 3x/□/sub 1/3-2x/TiO₃ compounds with x=0.13 and 0.12 were prepared by slow cooling (x=0.13) and rapid quenching (x=0.12) into the liquid nitrogen after sintering at 1350℃ for 6 h. Their crystal structure has been determined by Rietveld refinement of both the powder neutron and X-ray diffraction data. From neutron diffraction data, we found that the main phase was not tetragonal (P4/mmm), but trigonal (R3cH). The refinement of neutron diffraction for the slow cooled samples were in a good agreement with a new model; a mixture of trigonal (R3cH, 45.7 wt％), tetragonal (p4/mmm, 37.0 wt％), and Li/sub 0.57/Ti/sub 0.86/O₂(pbnm, 17.2 wt%), but the quenched sample was found not to contain tetragonal (p4/mmm). X-ray diffraction data couldn't be well fitted because of the Poor scattering factor of lithium ions and the similar reflection patterns among trigonal (R3cH), tetragonal (p4/mmm), and cubic (Pm3m). We also knew that one transport bottlenecks is destroyed by one La vacancy in the case of trigonal (R3cH).

• Coupled systems mechanics
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• 제5권4호
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• pp.329-340
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• 2016

The trigonal shape memory alloys (SMAs) have a great potential to be utilized as the applications with special purposes, such as actuators with high operation frequency. Most studies on the trigonal microstructures typically focus on the well-known classic herringbone pattern, but many other patterns are also possible, such as non-classic herringbone, toothbrush and checkerboard patterns. In the current work, a systematic procedure is developed to find all possible laminate twin microstructures by using geometrically linear compatibility theory. The procedure is verified by SEM images with the information of crystallographic axes of unitcells obtained by EBSD, showing good agreement. Many interesting trigonal R-phase patterns are found in the specimen. Then, their incompatibility are analyzed with nonlinear compatibility theory. The relationship between such incompatibility and the likelihood of occurrence of the microstructures is revealed. The current procedure is rapid, computationally efficient and sufficiently general to allow further extension to other crystal systems and materials.

• International Journal of Korean Welding Society
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• 제4권1호
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• pp.53-60
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• 2004

Adhesive-bonded joints are widely used in the industry. Recently, applications of adhesive bonding joints have been increased extensively in automobile and aircraft industry. The strength of adhesive joints is influenced by the surface roughness, adhesive shape, stress distribution, and etc. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, as the fundamental research of adhesive bonding joints, the effects of adhesive shape and loading speed on bonding strength properties and durability of aluminum to polycarbonate single-lap joints were studied. To evaluate the effect of adhesive shape, several modified shapes were used, and loading speeds were varied from 0.05 to 5mm/min. As a result, the load distribution showed a brittle fracture tendency. The trigonal edged single lap and bevelled lap joints showed the higher strength than the plain single lap, trigonal single lap, joggle lap and double lap joints in same adhesive area. The fractures of trigonal single lap and trigonal edged single lap joints that had the higher strength level were shown as the mixture type of the cohesive and interfacial-failure, mostly joggle lap joints that had the lower strength level were shown as the adhesive-failure.

• 대한기계학회논문집A
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• 제28권6호
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• pp.783-790
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• 2004

Adhesive-bonded joints are widely used in the industry. Recently, applications of adhesive bonding joints have been increased extensively in automobile and aircraft industry. The strength of adhesive joints is influenced by the surface roughness, adhesive shape, stress distribution, and etc. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, as the fundamental research of adhesive bonding joints, the effects of adhesive shape and loading speed on bonding strength properties and durability of aluminum to polycarbonate single-lap joints were studied. To evaluate the effect of adhesive shape, several modified shapes were used, and loading speeds were varied from 0.05 to 5 mm/min. As a result, the load-displacement distribution was shown a brittle fracture tendency. The trigonal edged single lap and bevelled lap joints showed the higher strength than the plain single lap, trigonal single lap, joggle lap and double lap joints in same adhesive area. The fractures of trigonal single lap and trigonal edged single lap joints that had the higher strength level were shown as the mixture type of the cohesive and interfacial-failure, mostly joggle lap joints that had the lower strength level were shown as the adhesive-failure.

• Bulletin of the Korean Chemical Society
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• 제5권1호
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• pp.3-16
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• 1984

The effect of solvent on the dipole moments for (chloromethyl) stannanes has been investigated by applying EHT calculation for the isomers of trigonal bipyramidal Sn(Ⅳ)$Cl_4X$ and $Cl_n$Sn(Ⅳ) $(CH_2Cl)_{4-n}$, octahedral Sn(Ⅳ)$Cl_42X$ and $Cl_nSn$(Ⅳ)$(CH_2Cl)_{4-n}$ 2X type complexes in dioxane and ethylacetate solutions (X: dioxane or ethylacetate). For Sn(Ⅳ)$Cl_4$ in dioxane solution, the calculated dipole moment for the trigonal bipyramidal Sn(Ⅳ)$Cl_4X$ type complex [isomer (b)] is closer to the experimental dipole moment than octahedral Sn(Ⅳ)$Cl_4X$2X type complexes. This calculated dipole moment suggests that Sn(Ⅳ)$Cl_4X$ may have the trigonal bipyramidal structure in dioxane solution. However, the calculated dipole moment for octahedral $Cl_3$Sn(Ⅳ) ($CH_2$Cl)2X type complex [Isomer (d)], ClSn(Ⅳ)(CH2Cl)32X type complex [Isomer(k)] and Cl2Sn(Ⅳ)(CH2Cl)22X type complex [Isomer(h)] are closer to the experimental dipole moments than other isomers for octahedral complexes and trigonal bipyramidal complexes. Such theoretical results indicate that $Cl_3Sn$(Ⅳ )($CH_2Cl$), ClSn(Ⅳ)$(CH_2Cl)_3$ and $Cl2Sn$(Ⅳ)$(CH_2Cl)_2$ complexes may have octahedral structures, Isomer(d), (k) and (h) in ethylacetate solution, respectively.

• Journal of Korean Neurosurgical Society
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• 제50권6호
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• pp.538-541
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• 2011

Objective : We evaluated a modified trans-middle temporal gyrus (MTG) approach with good postoperative visual preservation for patients with trigonal tumors. Methods : Three patients with a trigonal tumor were treated via the modified trans-MTG approach guided by a neuro-navigator. Modified trans-MTG approach involve the incision at the MTG within 5 mm to the superior temporal sulcus. This approach makes a proper trajectory to the trigone but also reduces the retraction injury of MTG as little as possible to prevent postoperative visual field defect. Preoperative and postoperative visual field examination using perimetry was performed to evaluate the visual field. Results : Three patients underwent surgery for lymphoma in the right trigone, meningioma in the left trigone, and focal enhancing nodule in the right paratrigonal area, respectively. In case of lymphoma, preoperative examination showed a left homonymous hemianopsia : one week later after surgery, a visual field examination was performed and revealed improvement of the visual field defect. In case of the meningioma, the preoperative examination showed no visual field defect : one month later, the visual field had no defect. In case of the enhancing nodule, preoperative visual field testing revealed a partial left homonymous hemianopsia. Visual examination within one month after surgery showed no visual field defect. All three patients treated with the modified trans-MTG approach showed no visual deterioration after surgery. Conclusion : The modified trans-MTG approach provides a safe and useful technique for trigonal tumors without postoperative visual field deterioration and affords adequate exposure of the trigonal tumor with a short trajectory.