Niedermayrite, Cu4Cd(SO4)2(OH)6 · 4H2O, a new mineral from the Lavrion Mining District, Greece

Summary Niedermayrite, Cu₄Cd(SO₄)₂(OH)₆ · 4H₂O, is a new mineral discovered in 1995 in the Km3-area of the Lavrion mining district, Greece. It forms tiny euhedral plates, commonly intergrown as green crusts up to several cm² in size on a matrix consisting of a brecciated marble with sphalerite, chalcopyrite, galena, greenockite, hawleyite and pyrite. Associated secondary minerals are gypsum, malachite, chalcanthite, brochantite, hemimorphite, hydrozincite, aurichalcite, one unknown Cd-sulfate, monteponite and otavite. Niedermayrite is non-fluorescent and has a bluish-green colour with vitreous lustre, the streak is white. The crystals are brittle with perfect cleavage parallel {010}. Optics: biaxial (–) with n(calc.), n, and n =1.609, 1.642(2), and 1.661(2), respectively; orientation n//b. The calculated density is 3.292 gcm^–3. The most prominent form is {010}. Analysis by electron microprobe gives CdO 16.5, CuO 45.7, SO₃ 21.6, H₂O 16.2 wt.% (calc. to 100% sum) and the empirical formula Cu_4.29Cd_0.96S_2.01O_11.28 · 6.71 H₂O (based on 18 oxygens p.f.u.). By TGA an H₂O content of 18.9 wt.% was obtained. The ideal formula (confirmed by the crystal structure refinement) is Cu₄Cd(SO₄)₂(OH)₆ · 4H₂O with a theoretical H₂O content of 17.2 wt.%. The strongest lines in the X-ray powder diffraction pattern (Gandolfi camera, visually estimated I, refined lattice parameters a = 5.535(2), b = 21.947(9), c = 6.085(2) Å, = 91.98(3)°) are: (d_obs[Å]/I_obs/hkl) (11.02/90/0 2 0), (5.874/20/0 1 1), (5.496/100/0 4 0), (5.322/25/0 2 1), (4.079/50/0 4 1), (3.660/20/0 6 0), (3. 437/30/1 5 0), (3.243/40/1 4 1), (2.470/30/2 4 0), (2.425/20/1 4 –2), (2.205/20/2 6 0) and (1.897/20/1 8 2). The mineral is monoclinic, P2₁/m, Z = 2, a = 5.543(1) Å, b = 21.995(4) Å, c = 6.079(1) Å, = 92.04(3)°, V = 740.7(2) ų. The crystal structure was determined by single crystal X-ray methods and was refined to R1= 0.026, wR2 = 0.056. The structure of niedermayrite is characterized by ² [Cu₄(OH)₆O₂]^2– sheets of edgesharing Cu coordination octahedra parallel to (010) with attached SO₄ tetrahedra, and intercalated CdO₂(H₂O)₄ octahedra with a system of hydrogen bonds. Close relationships to the crystal structures of christelite and campigliaite exist. The new mineral is named for Dr. Gerhard Niedermayr, Naturhistorisches Museum Wien, Austria.

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Niedermayrit, Cu₄Cd(SO₄)₂(OH)₆ · 4H₂O, ein neues Mineral aus dem Bergbaugebiet Lavrion, Griechenland

Zusammenfassung Niedermayrit, Cu₄Cd(SO₄)₂(OH)₆ · 4H₂O, ist ein neues Mineral, das 1995 im Km3-Bereich des Bergbaugebietes Lavrion, Griechenland, gefunden wurde. Es bildet winzige gut ausgebildete Plättchen, häufig miteinander verwachsen in grünen Krusten bis zu mehreren cm² Größe. Die Matrix besteht aus brecciösem Marmor mit Sphalerit, Chalcopyrit, Galenit, Greenockit, Hawleyit und Pyrit. Sekundäre Begleitminerale sind Gips, Malachit, Chalcanthit, Brochantit, Hemimorphit, Hydrozincit, Aurichalcit, ein unbekanntes Cd-Sulfat, Monteponit und Otavit. Niedermayrit fluoresziert nicht, besitzt blaugrüne Farbe mit Glasglanz, der Strich ist weiß. Die Kristalle sind spröd mit perfekter Spaltbarkeit parallel {010}. Optik: biaxial (–) mit n(ber.), n, und n=1.609, 1.642(2), und 1.661(2); Orientierung n//b. Die berechnete Dichte beträgt 3.292 gcm^–3. Die auffallendste Flächenform ist {010}. Die chemische Analyse mittels Mikrosonde ergibt CdO 16.5, CuO 45.7, SO₃ 21.6, H₂O 16.2wt.% (ber. auf 100% Summe) und die empirische Formel Cu_4.29Cd_0.96S_2.01O_11.28 · 6.71 H₂O (basierend auf 18 Sauerstoffatomen pro Formeleinheit). Aus der TGA wurde ein H₂O Gehalt von 18.9 Gew.% erhalten. Die Idealformel (bestätigt durch die Kristallstrukturverfeinerung) ist Cu₄Cd(SO₄)₂(OH)₆ · 4H₂O bei einem theoretischen H₂O-Gehalt von 17.2 Gew.%. Die stärksten Linien im Pulverdiffraktogramm (Gandolfi Kamera, visuell geschätzte I, verfeinerte Gitterkonstanten a = 5.535(2), b = 21.947(9), c = 6.085(2) Å, = 91.98(3)°) sind: (d_obs[Å]/I_obs/hkl) (11.02/90/0 2 0), (5.874/20/0 1 1), (5.496/100/0 4 0), (5.322/25/0 2 1), (4.079/50/0 4 1), (3.660/20/0 6 0), (3.437/30/1 5 0), (3.243/40/1 4 1), (2.470/30/2 4 0), (2.425/20/1 4 –2), (2.205/20/2 6 0) und (1.897/20/1 8 2). Das Mineral ist monoklin, P2₁/m, Z = 2, a = 5.543(1) Å, b = 21.995(4) Å, c = 6.079(1) Å, = 92.04(3)°, V = 740.7(2) ų Die Kristallstruktur wurde mittels Einkristallröntgenmethoden bestimmt und zu R1 = 0.026, wR2 = 0.056 verfeinert. Die Struktur von Niedermayrit ist durch ² [Cu₄(OH)₆O₂]^2– Schichten von kantenverknüpften Cu-Koordinationsoktaedern parallel (010) gekennzeichnet mit damit verbundenen SO₄ Tetraedern und dazwischen befindlichen CdO₂(H₂O)₄ Oktaedem mit einem Wasserstoffbrückensystem. Es bestehen enge Beziehungen mit den Kristallstrukturen von Christelit und Campigliait. Das neue Mineral ist nach Dr. Gerhard Niedermayr, Naturhistorisches Museum Wien, Österreich, benannt.

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With 7 Figures     

2维,2.5维,3维和4维的差别

２维、２．５维、３维和４维的差别Ａ．ＫｅｉｔｈＴｕｒｎｅｒ于海英译孔玲君校译稿收到日期１９９７０５２３据说开创地理学科的地质学家曾是一位化学家。鉴于此，许多地质学家可以共享化学家分析地质样品中的化学成分，同时他们又对样品的空间位置保持浓厚的兴趣。因为...     

Lahnsteinite, Zn4(SO4)(OH)6 · 3H2O, a new mineral from the Friedrichssegen Mine, Germany

A new mineral, lahnsteinite, has been found in the dump of the Friedrichssegen Mine, Bad Ems district, Rhineland-Palatinate (Rheinland-Pfalz), Germany. Lahnsteinite, occurring as colorless tabular crystals in the cavities of goethite, is associated with pyromorphite, hydrozincite, quartz, and native copper. The Mohs’ hardness is 1.5; the cleavage is perfect parallel to (001). D _calc = 2.995 g/cm³, D _meas = 2.98(2) g/cm³. The IR spectrum is given. The new mineral is optically biaxial, negative, α = 1.568(2), β = 1.612(2), γ = 1.613(2), 2V _meas = 18(3)°, 2V _calc = 17°. The chemical composition (wt %, electron microprobe data; H₂O was determined by gas chromatography of ignition products) is as follows: 3.87 FeO, 1.68 CuO, 57.85 ZnO, 15.83 SO₃, 22.3 H₂O, total is 101.53. The empirical formula is (Zn_3.3Fe_0.27Cu_0.11)_Σ3.91(S_0.98O₄)(OH)₅ · 3H_2.10O. The crystal structure has been studied on a single crystal. Lahnsteinite is triclinic, space group P1, a = 8.3125(6), b = 14.545(1), c = 18.504(2) Å, α = 89.71(1), β = 90.05(1), γ = 90.13(1)°, V = 2237.2(3) ų, Z = 8. The strong reflections in the X-ray powder diffraction pattern [d, Å (I, %)] are: 9.30 (100), 4.175 (18), 3.476 (19), 3.290 (19), 2.723 (57), 2.624 (36), 2.503 (35), 1.574 (23). The mineral has been named after its type locality near the town of Lahnstein. The type specimen of lahnsteinite is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, registration number 4252/1.     

Vigrishinite, Zn2Ti4 − x Si4O14(OH,H2O,□)8, a new mineral from the Lovozero alkaline complex, Kola Peninsula, Russia

A new mineral vigrishinite, epistolite-group member and first layer titanosilicate with species-defining Zn, was found at Mt. Malyi Punkaruaiv, in the Lovozero alkaline complex, Kola Peninsula, Russia. It occurs in a hydrothermally altered peralkaline pegmatite and is associated with microcline, ussingite, aegirine, analcime, gmelinite-Na, and chabazite-Ca. Vigrishinite forms rectangular or irregularly shaped lamellae up to 0.05 × 2 × 3 cm flattened on [001]. They are typically slightly split and show blocky character. The mineral is translucent to transparent and pale pink, yellowish-pinkish or colorless. The luster is vitreous. The Mohs’ hardness is 2.5–3. Vigrishinite is brittle. Cleavage is {001} perfect. D _meas = 3.03(2), D _calc = 2.97 g/cm³. The mineral is optically biaxial (?), α = 1.755(5), β = 1.82(1), γ = 1.835(8), 2V _meas = 45(10)°, 2V _calc = 50°. IR spectrum is given. The chemical composition (wt %; average of 9 point analyses, H₂O is determined by modified Penfield method) is as follows: 0.98 Na₂O, 0.30 K₂O, 0.56 CaO, 0.05 SrO, 0.44 BaO, 0.36 MgO, 2.09 MnO, 14.39 ZnO, 2.00 Fe₂O₃, 0.36 Al₂O₃, 32.29 SiO₂, 29.14 TiO₂, 2.08 ZrO₂, 7.34 Nb₂O₅, 0.46 F, 9.1 H₂O, ?0.19 O=F₂, total is 101.75. The empirical formula calculated on the basis of Si + Al = 4 is: H_7.42(Zn_1.30Na_0.23Mn_0.22Ca_0.07Mg_0.07K_0.05Ba_0.02)_Σ1.96(Ti_2.68Nb_0.41Fe _0.18 ³⁺ Zr_0.12)_Σ3.39(Si_3.95Al_0.05)_{Σ4 20.31}F_0.18. The simplified formula is: Zn₂Ti_4?x Si₄O₁₄(OH,H₂O,□)₈ (x < 1). Vigrishinite is triclinic, space group P $\bar 1$ , a = 8.743(9), b = 8.698(9), c = 11.581(11)Å, α = 91.54(8)°, β = 98.29(8)°, γ = 105.65(8)°, V = 837.2(1.5) ų, Z = 2. The strongest reflections in the X-ray powder pattern (d, Å, ?I[hkl]) are: 11.7-67[001], 8.27-50[100], 6.94-43[0 $\bar 1$ 1, $\bar 1$ 10], 5.73–54[1 $\bar 1$ 1, 002], 4.17-65[020, $\bar 1$ $\bar 1$ 2, 200], and 2.861-100[3 $\bar 1$ 0, 2 $\bar 2$ 2, 004, 1 $\bar 3$ 1]. The crystal structure model was obtained on a single crystal, R = 0.171. Vigrishinite and murmanite are close in the structure of the TiSiO motif, but strongly differ from each other in part of large cations and H-bearing groups. Vigrishinite is named in honor of Viktor G. Grishin (b. 1953), a Russian amateur mineralogist and mineral collector, to pay tribute to his contribution to the mineralogy of the Lovozero Complex. The type specimen is deposited in the Fersman Mineralogical Museum of Russian Academy of Sciences, Moscow.     

AbstractsofEarthScience—JournalofChinaUniversityofGeosciences(ChineseVersion,Volume23,Numbers4-6,1998)

Ｎｏ．４Ｂａｓｉｃｔｅｃｈｎｏｌｏｇｙａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｇｅｏｇｒａｐｈｉｃｉｎｆｏｒｍａｔｉｏｎｓｙｓｔｅｍ．ＷｕＸｉｎｃａｉ．（４）：３２９－３３３．Ｔｈｉｓｐａｐｅｒａｎａｌｙｚｅｓｔｈｅｂａｓｉｃｃｏｎｃｅｐｔａｎｄｒｅｓｅａｒ...     

Sergeysmirnovite,MgZn2(PO4)2 · 4H2O,a New Mineral from the Kester Deposit (Sakha-Yakutia,Russia)

Doklady Earth Sciences - Sergeysmirnovite, MgZn2(PO4)2 ·&nbsp;4H2O, is a new mineral from the oxidation zone of the Kester mineral deposit, Sakha-Yakutia, Russia. This mineral forms...     

Study of cloudburst and flash floods around Leh, India, during August 4–6, 2010

Leh and surrounding region of the Ladakh mountain range in the trans-Himalaya experienced multiple cloudbursts and associated flash floods during August 4–6, 2010. However, 12.8 mm/day rainfall recorded at the nearest meteorological station at Leh did not corroborate with the flood severity. For better understanding of this event, hydrological analysis and atmospheric modeling are carried out in tandem. Two small catchments (<3 km²) were studied along the stream continuum to assess the flood characteristics to identify the cloudburst impact zones. Peak flood discharges were estimated close to the head wall region and at the catchment outlet of the Leh town and the Sabu eastern tributary catchments. Storm runoff depth is estimated by developing a triangular hydrograph by using the known time base of the flood hydrograph. This triangular hydrographs have been transformed further into storm hydrographs to gain a better understanding of the storm duration by using the dimensionless hydrograph method at selected cross sections. Storm duration is estimated by using the relationship between time to peak and time of concentration of the catchment. The peak flood estimates ranged from 122(±35 %) m³/s for Leh town catchment (2.393 km²), 545(±35 %) m³/s for Sabu eastern tributary catchment (2.831 km²) to 1,070(±35 %) m³/sec for Sabu catchment (64.95 km²). To assess the atmospheric processes associated with this event, a triple nest simulation (27, 9 and 3 km) is performed using Advanced Research Weather Research and Forecasting (WRF) modeling system. The simulation does show the evolution of the event from August 4 to 6, 2010. Observation constraints, orographic responses, etc. make such analysis complex at such scale. Independent estimate by the atmospheric process model and the hydrological method shows the storm depth of 70 mm and 91.8(±35 %) mm, respectively, in catchment scale. Hydrological evaluation further refined the spatial and temporal extents of the cloudbursts in the respective catchments with an estimated storm depth of 209(±35 %) mm in 11.9 min and 320(±35 %) in 8.8 min occurring in an area of 0.842–1.601 km², respectively. This study shows that the insight developed on the cloudburst phenomena by the atmospheric and the hydrological modeling is hugely constrained by the spatial and temporal scales of data used for the analysis. Apart from this, study also highlighted the regular occurrence of cloudburst events over this region in the recent past. Most of such events go unreported due to lack of monitoring mechanisms in the region and weaken our ability to understand these events in complete perspective.     

Kobyashevite, Cu5(SO4)2(OH)6·4H2O, a new devilline-group mineral from the Vishnevye Mountains, South Urals, Russia

A new mineral kobyashevite, Cu₅(SO₄)₂(OH)₆·4H₂O (IMA 2011–066), was found at the Kapital’naya mine, Vishnevye Mountains, South Urals, Russia. It is a supergene mineral that occurs in cavities of a calcite-quartz vein with pyrite and chalcopyrite. Kobyashevite forms elongated crystals up to 0.2 mm typically curved or split and combined into thin crusts up to 1?×?2 mm. Kobyashevite is bluish-green to turquoise-coloured. Lustre is vitreous. Mohs hardness is 2½. Cleavage is {010} distinct. D(calc.) is 3.16 g/cm³. Kobyashevite is optically biaxial (?), α 1.602(4), β 1.666(5), γ 1.679(5), 2 V(meas.) 50(10)°. The chemical composition (wt%, electron-microprobe data) is: CuO 57.72, ZnO 0.09, FeO 0.28, SO₃ 23.52, H₂O(calc.) 18.39, total 100.00. The empirical formula, calculated based on 18 O, is: Cu_4.96Fe_0.03Zn_0.01S_2.01O_8.04(OH)_5.96·4H₂O. Kobyashevite is triclinic, $ P\overline{\,1 } $ , a 6.0731(6), b 11.0597(13), c 5.5094(6)?Å, α 102.883(9)°, β 92.348(8)°, γ 92.597(9)°, V 359.87(7)?ų, Z?=?1. Strong reflections of the X-ray powder pattern [d,Å-I(hkl)] are: 10.84–100(010); 5.399–40(020); 5.178–12(110); 3.590–16(030); 2.691–16(20–1, 040, 002), 2.653–12(04–1, 02–2), 2.583–12(2–11, 201, 2–1–1), 2.425–12(03–2, 211, 131). The crystal structure (single-crystal X-ray data, R?=?0.0399) сontains [Cu₄(SO₄)₂(OH)₆] corrugated layers linked via isolated [CuO₂(H₂O)₄] octahedra; the structural formula is CuCu₄(SO₄)₂(OH)₆·4H₂O. Kobyashevite is a devilline-group member. It is named in memory of the Russian mineralogist Yuriy Stepanovich Kobyashev (1935–2009), a specialist on mineralogy of the Urals.     

Editorial board page for “International Geology Review”, Volume 24, Number 4

Abstract

This is a scanned image of the original Editorial Board page(s) for this issue     

Editorial board page for “International Geology Review”, Volume 23, Number 4

Abstract

This is a scanned image of the original Editorial Board page(s) for this issue     

Molluscan fauna from the Miocene sediments of Kachchh,Gujarat, India — Part 4, Indarca,a new anadaroid genus

An interesting bivalve fossil obtained from the Claystone Member of the Chhasra Formation (Burdigalian), Kachchh District, India was found conspecific with Anadara gourae Dey (Arcidae, Anadarinae) from the Quilon Beds (Burdigalian), Kerala. However, this form is feebly inequivalve and has dissimilar ornamentation on the two valves, a trapezoidal form and its maximum height is at the posterior. Also, there is a small but distinct median sulcus on the exterior of the umbonal region. These characteristics do not agree with definition of the genus Anadara. Hence it is described here under a new genus, Indarca. Subgenus Cunearca Dall of genus Scapharca Gray (Arcidae, Anadarinae), also shows dissimilar ornamentation on the two valves, but differs from Indarca in having an inflated form, left valve slightly larger and absence of a sulcus on the umbonal region. Indarca resembles Bentharca Verrill and Bush (Arcidae, Anadarinae) in certain respects, but differs from it in not having a markedly reduced anterior. Occurrence of Indarca gourae strengthens the faunal affinity between the Chhasra Formation of Kachchh and the Quilon Beds of Kerala.     

Synthetic MgGa2O4-Mg2GeO4 spinel solid solution and β-Mg3Ga2GeO8: chemistry, crystal structures, cation ordering, and comparison to Mg2GeO4 olivine

 Structural parameters and cation ordering are determined for four compositions in the synthetic MgGa₂O₄-Mg₂GeO₄ spinel solid solution (0, 8, 15 and 23 mol% Mg₂GeO₄; 1400 °C, 1 bar) and for spinelloid β-Mg₃Ga₂GeO₈ (1350 °C, 1 bar), by Rietveld refinement of room-temperature neutron diffraction data. Sample chemistry is determined by XRF and EPMA. Addition of Mg₂GeO₄ causes the cation distribution of the MgGa₂O₄ component to change from a disordered inverse distribution in end member MgGa₂O₄, ^[4]Ga = x = 0.88(3), through the random distribution, toward a normal cation distribution, x = 0.37(3), at 23 mol% Mg₂GeO₄. An increase in a_o with increasing Mg₂GeO₄ component is correlated with an increase in the amount of Mg on the tetrahedral site, through substitution of 2 Ga³⁺⇄ Mg²⁺+Ge⁴⁺. The spinel exhibits high configurational entropy, reaching 20.2 J mol⁻¹ (four oxygen basis) near the compositional upper limit of the solid solution. This stabilizes the spinel in spite of positive enthalpy of disordering over the solid solution, where ΔH _D  = αx + βx ², α = 22(3), β = −21(3) kJ mol⁻¹. This model for the cation distribution across the join suggests that the empirically determined limit of the spinel solid solution is correlated with the limit of tetrahedral ordering of Mg, after which local charge-balanced substitution is no longer maintained. Spinelloid β-Mg₃Ga₂GeO₈ has cation distribution ^M1[Mg_0.50(2)Ga_0.50(2)] ^M2[Mg_0.96(2)Ga_0.04(2)] ^M3[Mg_0.77(2) Ga_0.23(2)]₂ (Ge_0.5Ga_0.5)₂O₈ (tetrahedral site occupancies are assumed). Octahedral site size is correlated to Mg distribution, where site volume, site distortion, and Mg content follow the relation M1<M3<M2. The disordered cation distribution provides local electrical neutrality in the structure, and stabilization through increased configurational entropy (27.6 J mol⁻¹; eight oxygen basis). Comparison of the crystal structures of Mg_{1+ N} Ga_{2−2 N} Ge _N O₄ spinel, β-Mg₃Ga₂GeO₈, and Mg₂GeO₄ olivine reveals β-Mg₃Ga₂GeO₈ to be a true structural intermediate. Phase transitions across the pseudobinary are necessary to accommodate an increasing divergence of cation size and valence, with addition of Mg₂GeO₄ component. Octahedral volume increases while tetrahedral volume decreases from spinel to β-Mg₃Ga₂GeO₈ to olivine, with addition of Mg and Ge, respectively. Furthermore, M-M distances increase regularly across the join, suggesting that changes in topology reduce cation-cation repulsion. Received: 9 November 1998 / Revised, accepted: 3 August 1999     

Thermodynamic properties of tooeleite,Fe63+(As3+O3)4(SO4)(OH)4·4H2O

Tooeleite, nominally Fe₆³⁺(As³⁺O₃)₄(SO₄)(OH)₄·4H₂O, is a relatively uncommon mineral of some acid-mine drainage systems. Yet, if it does occur, it does so in large quantities, indicating that some specific conditions favor the formation of this mineral in the system Fe-As-S-O-H. In this contribution, we report the thermodynamic properties of synthetic tooeleite. The sample was characterized by powder X-ray diffraction, scanning electron microscopy, extended X-ray absorption fine-structure spectroscopy, and Mössbauer spectroscopy. These methods confirmed that the sample is pure, devoid of amorphous impurities of iron oxides, and that the oxidation state of arsenic is 3+. Using acid-solution calorimetry, the enthalpy of formation of this mineral from the elements at the standard conditions was determined as −6196.6 ± 8.6 kJ mol⁻¹. The entropy of tooeleite, calculated from low-temperature heat capacity data measured by relaxation calorimetry, is 899.0 ± 10.8 J mol⁻¹ K⁻¹. The calculated standard Gibbs free energy of formation is −5396.3 ± 9.3 kJ mol⁻¹. The log K_sp value, calculated for the reaction Fe₆(AsO₃)₄(SO₄)(OH)₄·4H₂O + 16H⁺ = 6Fe³⁺ + 4H₃AsO₃ + SO₄²⁻ + 8H₂O, is −17.25 ± 1.80. Tooeleite has stability field only at very high activities of aqueous sulfate and arsenate. As such, it does not appear to be a good candidate for arsenic immobilization at polluted sites. An inspection of speciation diagrams shows that the predominance field of Fe³⁺ and As³⁺ overlap only at strongly basic conditions. The formation of tooeleite, therefore, requires strictly selective oxidation of Fe²⁺ to Fe³⁺ and, at the same time, firm conservation of the trivalent oxidation state of arsenic. Such conditions can be realized only by biological systems (microorganisms) which can selectively oxidize one redox-active element but leave the other ones untouched. Hence, tooeleite is the first example of an “obligatory” biomineral under the conditions prevailing at or near the Earth's surface because its formation under these conditions necessitates the action of microorganisms.     

Photoluminescence of zircon (ZrSiO4) doped with REE3+ (REE = Pr, Sm, Eu, Gd, Dy, Ho, Er)

The photoluminescence properties of synthetic zircon, ZrSiO₄, doped with REE³⁺ (REE = Pr, Sm, Eu, Gd, Dy, Ho, Er) were investigated using combined excitation and emission spectroscopy. All samples showed luminescence characteristics of intra-ion energy transitions, similar to other lanthanide-doped materials. However, the relative intensities were dependent on the energy of excitation and the presence of charge-transfer bands were inferred from excitation spectra. From the data, we conclude that the lanthanides in zircon occur in more than one type of coordination. Energy transfer between different lanthanides was observed in some co-doped samples and emissions that were unassigned in previous studies have been assigned to specific lanthanides based on excitation spectroscopy.     

稻田CH4排放和土壤,大气条件的关系

在杭州地区利用静态箱法对稻田CH_4排放进行连续观测,结果证明CH_4排放率有较大的日变化和季节变化,CH_4排放率的日变化较复杂,除了和温度变化一致的峰型外,还有夜间峰、双峰型、多峰等。CH_4排放率的季节波动较大,在分蘖期和长穗前期分别有一较大峰值,早稻和晚稻的变化规律略有不同。稻田CH_4排放规律可用稻田中有机物含量的变化和空气、土壤温度的变化等作一定性解释。 早稻和晚稻的CH_4排放总量有较大的差别,平均来看,早稻的排放量为0.46g·m~(-2)·d~(-1),晚稻为0.80g·m~(-2)·d~(-1)。稻田CH_4排放也有较大的年际变化,1988年全年CH_4排放量为0.23g·m~(-2)·d~(-1),1989年为0.95g·m~(-2)·d~(-1),施肥对CH_4排放有一定的影响,施有机肥的稻田CH_4排放量最高,施化肥的稻田次之,不施肥的稻田CH_4排放量最低。     

气相色谱法测定岩石矿物中CO2,SO2,H2O^＋,H2O^—,CH4

选择Ｃｈｒｏｍｓｏｒｂ１０４作固定相，解决了Ｈ２Ｏ对测ＳＯ２的干扰，也避免了酸分解法测ＣＯ２的干扰，可一次实现四种成份连测，具有快速，灵敏（万分之几至十万分之几）用样量少等特点，很适宜批量样品的分析。