基于CEEMDAN-BO-BiGRU的矿井涌水量预测研究

为提高矿井涌水量预测的准确度,基于涌水量数据的不稳定性及随机性,提出一种自适应噪声完备集合经验模态分解(complete ensemble empirical mode decomposition with adaptive noise,CEEMDAN)、贝叶斯优化(Bayesian optimization,BO)与双向门控循环单元(bi-directional gated recurrent unit,BiGRU)相结合的矿井涌水量预测模型CEEMDAN-BO-BiGRU。所提模型通过CEEMDAN将涌水量数据分解为多个较平稳的固有模态分量(intrinsic mode function,IMF)和残差分量(residual components,Res),过滤数据噪声,提取数据不同时间尺度波动特征,降低预测误差。利用贝叶斯优化对BiGRU模型多个超参数进行迭代寻优,进一步提高模型的预测精度。之后对各分量进行超前1~3步预测,最终将各分量预测结果加和得到涌水量多步预测结果。以小庄煤矿矿井涌水量数据进行试验,并将CEEMDAN-BO-BiGRU预测结果与其他多种预测模型结果进行对比分析。结果表明:采用CEEMDAN-BO-BiGRU组合网络模型对矿井涌水量预测结果更准确,该方法对涌水量的短时预测提供了一种新思路。

冶金机理与贝叶斯优化XGBoost融合的VD炉精炼终点钢液温度预测

在炼钢生产过程中,真空脱气精炼(VD)炉是生产高品质钢的重要设备之一,其精炼终点温度对钢液质量、生产效率和连铸顺行具有重要影响。为了实现对VD炉精炼终点钢液温度的精准控制,本文采用冶金机理和贝叶斯优化极端梯度提升(metallurgical mechanism–Bayesian optimization–extreme gradient boosting,MM–BO–XGBoost)相结合的方法建立钢液温度预测模型。首先,基于VD炉冶金机理解析,确定影响精炼终点钢液温度的主要因素;其次,使用3σ原则对实际生产数据进行预处理,剔除异常值,并采用皮尔逊相关性分析剔除对钢液温度影响较小的因素,从而确定模型的输入变量;再次,将冶金机理与XGBoost模型进行融合,对输入变量的初始特征重要性进行部分放大;最后,针对XGBoost模型的超参数寻优问题,采用贝叶斯优化(BO)对其进行超参数寻优,由此构建了MM–BO–XGBoost模型。在模型仿真过程中,对本文模型同时使用网格搜索和随机搜索进行超参数寻优,旨在对比和验证BO寻优的效果;此外,使用本文提供的数据对已有的冶金机理模型、多元线性回归模型和反向传播神经网络模型进行仿真,并与MM–BO–XGBoost模型进行性能对比。结果表明:本文提出的MM–BO–XGBoost模型的超参数优化效果最好;本文模型的预测VD炉终点钢液温度在±10℃和±15℃误差范围内的命中率分别为87.81%和96.42%,均高于其他对比模型,综合性能最优。本文构建的VD炉钢液精炼终点温度预测模型,对实现钢液温度精准控制、降低生产成本和提高VD炉精炼效率具有重要的现实意义。

并列双方柱绕流的Lattice Boltzmann模拟分析

采用Lattice Boltzmann方法对并列双方柱绕流问题进行数值模拟。对方柱间距比s/D=0.2、0.3、0.4、0.5、1.0、1.4、1.5、1.6、1.8、2.0、2.5共11种情况下的流场分别进行计算,给出了对应的流线图、方柱的升力图及阻力图,同时计算了方柱各边中点的压力,给出了压力与间距比的变化曲线,并对各个流线图、升力图、阻力图及压力图进行了分析讨论。结果表明:当s/D≤1.5时,流动呈偏流型,形成周期漩涡;当s/D>1.5时,流动呈对称型,形成对称漩涡;s/D=1.5为流动从偏流型向对称型转换的临界间距比。该结果对工程中建筑物位置的安排及其安全系数的提高有一定的参考价值。

BO分子α带系A^2Π-X^2Σ^+及β带系B^2Σ^+-X^2Σ^+Franck-Condon因子的计算

在双原子分子核运动的波动方程中，计入分子的振转相互作用项，得出的波函数除与振动量子数有关外，还与转动量子数有关。用该波函数编程计算了ＢＯ分子α带系Ａ２Π－Ｘ２Σ＋及β带系Ｂ２Σ＋－Ｘ２Σ＋的Ｆｒａｎｃｋ－Ｃｏｎｄｏｎ因子。计算中转动量子数的取值由Ｊ＝０取至Ｊ＝２００，结果适用于低温、高温和强激波条件。

Differential diagnosis in inflammatory bowel disease colitis:State of the art and future perspectives

Distinction between Crohn's disease of the colonrectum and ulcerative colitis or inflammatory bowel disease(IBD) type unclassified can be of pivotal importance for a tailored clinical management,as each entity often involves specific therapeutic strategies and prognosis.Nonetheless,no gold standard is available and the uncertainty of diagnosis may frequently lead to misclassification or repeated examinations.Hence,we have performed a literature search to address the problem of differential diagnosis in IBD colitis,revised current and emerging diagnostic tools and refined disease classification strategies.Nowadays,the differential diagnosis is an untangled issue,and the proper diagnosis cannot be reached in up to 10% of patients presenting with IBD colitis.This topic is receiving emerging attention,as medical therapies,surgical approaches and leading prognostic outcomes require more and more disease-specific strategies in IBD patients.The optimization of standard diagnostic approaches based on clinical features,biomarkers,radiology,endoscopy and histopathology appears to provide only marginal benefits.Conversely,emerging diagnostic techniques in the field of gastrointestinal endoscopy,molecular pathology,genetics,epigenetics,metabolomics and proteomics have already shown promising results.Novel advanced endoscopic imaging techniques and biomarkers can shed new light for the differential diagnosis of IBD,better reflecting diverse disease behaviors based on specific pathogenic pathways.

YBaNa(BO_3)_2晶体的助熔剂法生长与表征

采用助熔剂自发成核法,探索了生长YBaNa(BO3)2晶体的不同助熔剂体系,从中选出2Na2CO3-4H3BO3-BaCO3做助熔剂,生长了YBaNa(BO3)2晶体。采用X射线衍射(XRD),红外吸收光谱和透过光谱,差热失重分析对生长的晶体进行了表征。结果表明,晶体属于六方晶系,空间群为R3,晶胞参数为a=0.53382(2)nm,c=3.58303(19)nm。BO3-3基团存在于晶体结构中,晶体的紫外截止波长在208 nm左右,晶体在800℃时有明显的相变点。

Structure and Properties of a New Rare-earth Borate LiSrY_2(BO_3)_3

The structure of LiSrY2（BO3）3 has been solved by single-crystal X-ray diffraction analysis at 298 and 113 K on different diffractometers.It crystallizes in trigonal with space group P-3m1（No.164）.The cell parameters at room temperature are as follows：a = 10.3345（9）,c = 6.4049（11） ,V = 592.41（13） 3,Z = 3,Mr = 448.81,F（000） = 618,μ = 21.327 mm-1 and Dc = 3.774 g/cm3.The crystal structure consists of gear-like [BY6O33] groups which are linked together by corner-sharing to form a two-dimensional layer parallel to the ab plane.These layers are connected one after another by sharing oxygen atoms with B（2） atoms along the c direction to construct a three-dimensional framework.Li and Sr atoms just occupy the cavities formed by oxygen atoms.In addition,the vibrational spectroscopy of LiSrY2（BO3）3 and photoluminescence properties of the Eu3＋ doped LiSrY2（BO3）3 were also studied.

Morphology, Growth Process and Symmetry of {0001} Face on Yb:YAl_3(BO_3)_4 Crystal

The {0001} face develops on the habit of self-frequency doubling laser crystal Yb: YAI3(B03)4 (YbYAB) only under high growth rate condition, and its morphology is rough. To study the growth mechanism of {0001} face, we have observed the growth morphology on {0001} polishing section by atomic force microscopy (AFM). A series of AFM images captured in different growth durations on the {0001} polishing section reflect the crystal growth process. It is shown that the growth morphology on the {0001} polishing section was rough with many hillocks at the first growth stage, and it can become smooth finally, although the growth morphology on the {0001} face developed naturally on YbYAB crystal habit is always rough. On the smooth {0001} surface formed at the last growth stage, there are some triangular pits. This fact is different from that of hillocks in most crystal growth morphologies. AFM can easily distinguish the pits or hillocks on the surface, but differential interfere contrast microscopy (DIC) can not do. The orientation of the triangular pits is just the opposite to the triangular {0001} faces. The chemical etching pattern is also composed of this kind of triangular pits. These growth morphology and etching pattern of the {0001} faces show 3m symmetry, but the point group of YbYAB crystal is 32. The symmetric contradiction between morphology and point group does not exist for quartz, although which has the same point group as YbYAB. From quartz {0001} surface morphology we can distinguish the right form or left form of the crystal, but from YbYAB {0001} surface morphology we can not do. The reason for the symmetric contradiction between YbYAB {0001} surface morphology and its point group is not known yet.

Ultra-broadband near-infrared NOPAs based on the nonlinear crystals Bi BO and YCOB

We evaluate and demonstrate ultra-broadband near-infrared noncollinear optical parametric amplification in two nonlinear crystals,bismuth borate(Bi BO)and yttrium calcium oxyborate(YCOB),which are not commonly used for this application.The spectral bandwidth is of the microjoule level;the amplified signal is≥200 nm,capable of supporting sub-10 fs pulses.These results,supported by numerical simulations,show that these crystals have a great potential as nonlinear media in both low-energy,few-cycle systems and high peak power amplifiers for terawatt to petawatt systems based on noncollinear optical parametric chirped pulse amplification(NOPCPA)or a hybrid.

The low-temperature sintering and microwave dielectric properties of (Zn_(0.7)Mg_(0.3))TiO_3 ceramics with H_3BO_3

The effects of the addition of H3BO3 on the microstructure, phase formation, and microwave dielectric properties of （Zn0.TMg0.3）TiO3 ceramics sintered at temperatures ranging from 890 ℃ to 950 ℃ are investigated. H3BO3 as a sintering agent can effectively lower the sintering temperature of ZMT ceramics below 950 ℃due to the liquid-phase effect. The microwave dielectric properties are found to strongly correlate with the amount of H3BO3. With the increase in H3BO3 content, the dielectric constant （er） monotonically increases, but the quality factor （Q x f） reaches a maximum at 1 wt% H3BO3, and the apparent density of ZMT ceramics with H3BO3〉 1 wt% gradually decreases. At 950 ℃, the ZMT ceramics with 1% H3BO3 exhibit excellent microwave dielectric properties： er = 19.8, and Q x f -- 43800 GHz （8.94 GHz）.

Growth and Characteristic of YbAl_3(BO_3)_4 Crystal

YbAl3(BO3)4 crystal of good optical quality was grown by the flux method. The structure of YbAl3(BO3)4 crystal was determined by single-crystal X-ray diffraction. The experiment shows that YbAl3(BO3)4 belongs to the double bo-rates with a trigonal structure. The space group is R32 and its unit cell constants were measured to be a = 0.92965 nm, c=0.72129 nm, V = 0.53673 nm3, Z=3. The transmittance spectra were measured. The cut-off of YbAl3(BO3)4 crystal is 216 nm, and there are two absorption peaks located at 940 and 975 nm from 190 nm to 2600 nm. The thermal properties of YbAl3(BO3)4 crystal were studied for the first time. The average thermal expansion coefficients were determined to be 2×10-6/℃, 9.5×10-6/℃along a- and c- direction. The specific heat of YbAl3(BO3)4 crystal was measured to be 0.6695 J·(g·℃) -1 at room temperature . All results indicate that the YbAl3(BO3)4 crystal is an excellent stoichioimet-ric laser material.

The concentration quenching and crystallographic sites of Eu^(2+) in Ca_2BO_3Cl

A yellow phosphor, Ca2BO3CI：Eu2＋, is prepared by the high-temperature solid-state method. Under the condition of excitation sources ranging from ultraviolet to visible light, efficient yellow emission can be observed. The emission spectrum shows an asymmetrical single intensive band centred at 573 nm, which corresponds to the 4f65dl→4f7 transition of Eu2＋. Eu2＋ ions occupy two types of Ca2＋ sites in the Ca2BO3C1 lattice and form two corresponding emission centres, respectively, which lead to the asymmetrical emission of Eu2＋ in Ca2BO3C1. The emission intensity of Eu2＋ in Ca2BO3C1 is influenced by the Eu2＋ doping concentration. Concentration quenching is discovered, and its mechanism is verified to be a dipole-dipole interaction. The value of the critical transfer distance is calculated to be 2.166 nm, which is in good agreement with the 2.120 nm value derived from the experimental data.

Growth and Spectroscopic Properties of Nd^(3+):Sr_3Gd_2(BO_3)_4 Crystal

This paper reports the growth, X-ray diffraction and spectroscopy of Nd3＋：Sr3Gd2（BO3）4 crystal. A Nd3＋：Sr3Gd2（BO3）4 crystal with dimensions of φ20 × 45 mm3 has been grown by the Czochralski method. Nd3＋：Sr3Gd2（BO3）4 crystal belongs to the orthorhombic system, space group Pnma （D2h） with a = 0.7401, b = 1.604 and c = 0.8755 nm. The absorption and emission spectra of Nd3＋：Sr3Gd2（BO3）4 were investigated. The absorption cross section oa is 3.11 × 10^-20cm2 at 808 nm. The absorption transition at 808 nm has an FWHM of 14 nm. The luminescence lifetime τf is 51.7 μs. The emission cross section oc at 1064 nm wavelength is 1.09 × 10^-19 cm2.

Wnt7b can replace Ihh to induce hypertrophic cartilage vascularization but not osteoblast differentiation during endochondral bone development

Indian hedgehog （Ihh） is an essential signal that regulates endochondral bone development. We have previously shown that Wnt7b promotes osteoblast differentiation during mouse embryogenesis, and that its expression in the perichondrium is dependent on Ihh signaling. To test the hypothesis that Wnt7b may mediate some aspects of Ihh function during endochondral bone development, we activated Wnt7b expression from the R26-Wnt7b allele with Col2-Cre in the Ihh-/- mouse. Artificial expression of Wnt7b rescued vascularization of the hypertrophic cartilage in the Ihh-/- mouse, but failed to restore orthotopic osteoblast differentiation in the perichondrium. Similarly, Wnt7b did not recover Ihh-dependent perichondral bone formation in the Ihh-/-; Gli3-/- embryo. Interestingly, Wnt7b induced bone formation at the diaphyseal region of long bones in the absence of Ihh, possibly due to increased vascularization in the area. Thus, Ihh-dependent expression of Wnt7b in the perichondrium may contribute to vascularization of the hypertrophic cartilage during endochondral bone development.

The Analysis of “Feng Qiao Ye Bo” on the Basis of Nida's Translation Theory

"Feng Qiao Ye Bo" has been translated into many different English versions,a systematic translation analysis using Nida's two types of equivalence-formal equivalence and dynamic equivalence-has not been undertaken.This thesis thus aims at translating " Feng Qiao Ye Bo" by using two important translation theories of Nida and trys to search for their differences.

INSERTION OF PTC-GENERATED DICHLOROCARBENE INTO C-B BO ND.A FACILE SYNTHESIS OF KETONES FROM ALKENES VIA ORGANOBORATES

The insertion of dichlorocarbene generated from chloroform by Phase Transfer Catalysis(PTC)into carbon-boron bond of dialkylborate anions 3,obtained by method A and B,resulted in the formation of the inter- mediates 5,which were oxidized with alkaline hydrogen peroxide to give the corresponding dialkylketones in 36-77.9% yields.

Phonon Sideband Spectra Analysis for Eu^(3+)-Doped XF_n-H_3BO_3

The glasses of 59 5H 3BO 3 40XF n 0 5Eu 2O 3 (X=Ca, Mg, Y, Pb, n =2 or 3) were prepared. The measurement of phonon sideband was performed. The higher energy range of phonon sideband spectra was fitted by Gaussian function, and the electron phonon coupling constant was calculated. The decreasing order of electron phonon coupling constant is from CaF 2, YF 3, MgF 2 to PbF 2, and the phonon sideband spectra are coincide with Raman scattering spectra.

Enhancement of green emission by the codoping A^+ (A= Li, Na, K) in Ca_2BO_3Cl:Tb^(3+) phosphor

Tb3＋-doped Ca2BO3C1 compounds with different charge compensation approaches are synthesized by a hightemperature solid-state reaction method, and the luminescent properties and Commission Internationale de l＇Eclairage （CIE） chromaticity coordinates are systematically characterized. Ca2BO3Cl：Tb3＋ can produce green emission under 376 nm radiation excitation. With codoped A＋ （A = Li, Na, K） as charge compensators, the relative emission intensities of Ca2BO3Cl：Tb3＋ are enhanced by about 1.61, 1.97, and 1.81 times compared with those of the direct charge balance, which is considered to be due to the effect of the difference in ion radius on the crystal field. The CIE chromaticity coordinates of Ca2BO3CI：Tb3＋, A＋ （A = Li, Na, K） are （0.335, 0.584）, （0.335, 0.585）, and （0.335, 0.585）, corresponding to the hues of green. Therefore, A＋ （A = Li, Na, K） may be the optimal charge compensator for Ca2BO3Cl：Tb3＋.

Luminescence characteristics of Ca_4YO(BO_3)_3 doped with Bi^(3+),Dy^(3+) and Pr^(3+) ions

The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were measured using a spectrofluorometer.For Ca4YO(BO3)3:Bi3+,the excitation spectrum showed the bands at about 228,309,and 370 nm which correspond to the 1S0→1P1 transition and the 1S0→3P1 transition of Bi3+ ions.The emission band at 390 nm corresponded to the 3P1→1S0 transition of Bi3+ ions.For Ca4YO(...