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161.
Geert Dhaene Erik Schokkaert Carine Van de Voorde 《Journal of multivariate analysis》2003,86(2):242-253
Given two linear regression models y1=X1β1+u1 and y2=X2β2+u2 where the response vectors y1 and y2 are unobservable but the sum y=y1+y2 is observable, we study the problem of decomposing y into components
and
, intended to be close to y1 and y2, respectively. We develop a theory of best affine unbiased decomposition in this setting. A necessary and sufficient condition for the existence of an affine unbiased decomposition is given. Under this condition, we establish the existence and uniqueness of the best affine unbiased decomposition and provide an expression for it. 相似文献
162.
Decomposition reactions of liquids and solids can be observed by the heat development using microcalorimetric methods. By determination of the released heat flow for heating up a sample, it is possible to get details to answer safety relevant questions.For reactions nth order the overall activation energy and the accompanying frequency factor can be determined, provided that the heat release is determined by the rate of a single reaction step. Researches have been carried out whether these parameters are useable for safety technical specifications.Autocatalytic affected decomposition reactions are connected with special problems. This affects the experimental examination or interpretation of results, and also the precise identification of beginning decomposition reactions in technical reactors. The application of microcalorimetric measurements on decomposition reactions is described and associated problems are pointed out.The conclusions from thermoanalysis data alone are not sufficient in the final consequence for safety technical assessments. 相似文献
163.
164.
The thermal decomposition of anhydrous (orthorhombic) copper(II) formate was studied by programmed rising-temperature methods (TG, DTG, DTA and DSC) to about 250 °C in flowing gas atmospheres of nitrogen (inert), hydrogen (reducing) and air (oxidizing). The degradation reaction, anion breakdown, proceeded to completion in two distinct, but partially overlapping, rate processes and apparent Arrhenius parameters, calculated by the Ozawa nonisothermal kinetic method, agreed satisfactorily with the literature results. It was concluded that the two consecutive processes, contributing to the overall reaction, involved stepwise cation reduction: Cu2+→Cu+→Cu0, with copper(I) formate as intermediate. This mechanism is similar to that proposed in previous studies of the decompositions of copper(II) oxalate, malonate, maleate, fumarate, mellitate and squarate. For all of these reactants, the Cu+ salt has been identified as an intermediate, exhibiting a (slightly) lower relative reactivity than the corresponding Cu2+ salt. For copper(II) formate the response curves in the three different gaseous atmospheres were generally similar, showing that neither oxidizing nor reducing conditions caused a marked change in reactivity. The temperature of reaction initiation in H2 was slightly diminished and the temperature of the second stage of reaction in O2 was raised appreciably. It is believed that electron transfer contributed to the control of reactivity and that the gases present appreciably influence the rates of the contributory reactions occurring. 相似文献
165.
使用原位热红外光谱技术对FOX-7热分解全过程的气相和凝聚相产物进行了原位在线检测,通过非等温热红外动力学处理技术,获得了热分解过程中各特征官能团的断裂分解活化能(kJ·mol-1)如下:C-N键:181.66,-NO2键:235.77,N-H键:170.65.提出了FOX-7可能的两步热分解机理:第一阶段是分子共轭键、分子间(内)氢键的断裂、硝基和亚硝基重排"脱硝"释放出NO,第二阶段是残余碎片分解释放出HCN和NH3,结合TG-DSC-IR联用技术提出了FOX-7热分解的局部化学特性. 相似文献
166.
A new rapid decomposition and dissolution method with a mixture of sodium di-hydrogen orthophosphate and di-sodium hydrogen orthophosphate as a novel flux is described. The minerals are fused with (1:1) mixture of the above salts (flux) and the melt is dissolved in distilled water. The solution is diluted to desired volume depending on the instrumental technique used for determination. ICP-OES is used for the determination of Al, Ca, Mg, Cr, V, Si, Fe and Ti without interference from titanium, iron and sodium phosphate (introduced as flux). All the elements except Si and V are also determined by AAS. The use of nitrous oxide–acetylene flame eliminates the depression due to titanium in the measurement of Mg, Mn, Cr and Fe in air–acetylene flame. Synthetic mixture conforming to ilmenite and rutile composition are analyzed by ICP-OES and AAS to check the validity of the method. The results are in good agreement. The proposed method has been applied to natural samples and the results are evaluated against the established decomposition method using potassium bisulphate. Both ICP-OES and AAS yielded comparable results. The R.S.D. of the proposed method in case of ICP-OES varies from 0.5 to 2%, whereas for AAS it varies from 1.5 to 3% for different elements (n = 5). The novelty of the proposed sample decomposition lies in its simplicity, ease and speed of fusion with minimal skills besides being eco-friendly unlike the reported tedious complicated decomposition procedures involving variety of fluxes and lot of hazardous chemicals. 相似文献
167.
A graph H is called a supersubdivison of a graph G if H is obtained from G by replacing every edge uv of G by a complete bipartite graph K2,m (m may vary for each edge) by identifying u and v with the two vertices in K2,m that form one of the two partite sets. We denote the set of all such supersubdivision graphs by SS(G). Then, we prove the following results.
- 1. Each non-trivial connected graph G and each supersubdivision graph HSS(G) admits an α-valuation. Consequently, due to the results of Rosa (in: Theory of Graphs, International Symposium, Rome, July 1966, Gordon and Breach, New York, Dunod, Paris, 1967, p. 349) and El-Zanati and Vanden Eynden (J. Combin. Designs 4 (1996) 51), it follows that complete graphs K2cq+1 and complete bipartite graphs Kmq,nq can be decomposed into edge disjoined copies of HSS(G), for all positive integers m,n and c, where q=|E(H)|.
- 2. Each connected graph G and each supersubdivision graph in SS(G) is strongly n-elegant, where n=|V(G)| and felicitous.
- 3. Each supersubdivision graph in EASS(G), the set of all even arbitrary supersubdivision graphs of any graph G, is cordial.
168.
The existence of graph designs for the two nonisomorphic graphs on five vertices and eight edges is determined in the case of index one, with three possible exceptions in total. It is established that for the unique graph with vertex sequence (3, 3, 3, 3, 4), a graph design of order n exists exactly when and n≠16, with the possible exception of n=48. For the unique graph with vertex sequence (2,3,3,4,4), a graph design of order n exists exactly when , with the possible exceptions of n∈{32,48}. 相似文献
169.
Cu/Zn、Cu/Zn/Ni催化剂甲醇部分氧化制氢 总被引:1,自引:0,他引:1
研究了甲醇在Cu/Zn及Cu/Zn/Ni催化剂上部分氧化热耦合裂解制氢的反应,系 统地考察了不同O2/CH3OH比及反应温度下催化剂性能.当O2/CH3OH=0.2时,催化剂的性能最 佳.在同样条件下, Cu/Zn催化剂对CO的选择性较Cu/Zn/Ni催化剂低,更具优势. Cu/Zn催化 剂用于甲醇部分氧化反应时,甲醇转化率在150 h寿命实验中基本保持在90%左右. XRD谱图 表明Cu/Zn合金的生成是导致Cu/Zn系催化剂在甲醇裂解反应中快速失活的主要原因,而在部 分氧化反应中, O2的存在可抑制Cu/Zn合金的生成,使Cu/Zn催化剂表现出高度的稳定性. 相似文献
170.
Quantification of ultrasonic intensity based on the decomposition reaction of porphyrin 总被引:3,自引:0,他引:3
Hiroyasu Nomura Shinobu Koda Keiji Yasuda Yoshihiro Kojima 《Ultrasonics sonochemistry》1996,3(3):1007-S156
A simple method is proposed for quantification of the effective ultrasonic intensity in the reaction vessel based on the decomposition reaction of 5,10,15,20-tetrakis(4-sulfotophenyl) porphyrin (H2TPPS4−). The change of concentration of porphyrin in solution irradiated by the ultrasound wave depends on the irradiation time and the output power of ultrasound generator. The decomposition ratio of porphyrin is defined as the ratio of the concentration of porphyrin after ultrasonic irradiation to that before ultrasonic irradiation. A linear relationship between the decomposition ratio of porphyrin and the concentration Fe3+ in the Fricke solution under sonication was obtained. The decomposition ratio was related to the absorption dose in radiation chemistry. 相似文献